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[PATCH 3/6] Move conversion of a "historic" to MVCC snapshot to a separate function.
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* [PATCH 3/6] Move conversion of a "historic" to MVCC snapshot to a separate function.
@ 2026-01-08 16:47  Antonin Houska <ah@cybertec.at>
  0 siblings, 0 replies; 458+ messages in thread

From: Antonin Houska @ 2026-01-08 16:47 UTC (permalink / raw)

The conversion is now handled by SnapBuildMVCCFromHistoric(). REPACK
CONCURRENTLY will also need it.
---
 src/backend/replication/logical/snapbuild.c | 57 +++++++++++++++++----
 src/backend/utils/time/snapmgr.c            |  3 +-
 src/include/replication/snapbuild.h         |  1 +
 src/include/utils/snapmgr.h                 |  1 +
 4 files changed, 50 insertions(+), 12 deletions(-)

diff --git a/src/backend/replication/logical/snapbuild.c b/src/backend/replication/logical/snapbuild.c
index 7f79621b57e..95f230f8e9b 100644
--- a/src/backend/replication/logical/snapbuild.c
+++ b/src/backend/replication/logical/snapbuild.c
@@ -440,10 +440,7 @@ Snapshot
 SnapBuildInitialSnapshot(SnapBuild *builder)
 {
 	Snapshot	snap;
-	TransactionId xid;
 	TransactionId safeXid;
-	TransactionId *newxip;
-	int			newxcnt = 0;
 
 	Assert(XactIsoLevel == XACT_REPEATABLE_READ);
 	Assert(builder->building_full_snapshot);
@@ -485,7 +482,33 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 
 	MyProc->xmin = snap->xmin;
 
-	/* allocate in transaction context */
+	/* Convert the historic snapshot to MVCC snapshot. */
+	return SnapBuildMVCCFromHistoric(snap, true);
+}
+
+/*
+ * Turn a historic MVCC snapshot into an ordinary MVCC snapshot.
+ *
+ * Unlike a regular (non-historic) MVCC snapshot, the 'xip' array of this
+ * snapshot contains not only running main transactions, but also their
+ * subtransactions. On the other hand, 'subxip' will usually be empty. This
+ * difference does not affect the result of XidInMVCCSnapshot() because it
+ * searches both in 'xip' and 'subxip'.
+ *
+ * Pass true for 'in_place' if you don't care about modifying the source
+ * snapshot. If you need a new instance, and one that was allocated as a
+ * single chunk of memory, pass false.
+ */
+Snapshot
+SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place)
+{
+	TransactionId xid;
+	TransactionId *oldxip = snapshot->xip;
+	uint32		oldxcnt = snapshot->xcnt;
+	TransactionId *newxip;
+	int			newxcnt = 0;
+	Snapshot	result;
+
 	newxip = palloc_array(TransactionId, GetMaxSnapshotXidCount());
 
 	/*
@@ -494,7 +517,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 	 * classical snapshot by marking all non-committed transactions as
 	 * in-progress. This can be expensive.
 	 */
-	for (xid = snap->xmin; NormalTransactionIdPrecedes(xid, snap->xmax);)
+	for (xid = snapshot->xmin; NormalTransactionIdPrecedes(xid, snapshot->xmax);)
 	{
 		void	   *test;
 
@@ -502,7 +525,7 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 		 * Check whether transaction committed using the decoding snapshot
 		 * meaning of ->xip.
 		 */
-		test = bsearch(&xid, snap->xip, snap->xcnt,
+		test = bsearch(&xid, snapshot->xip, snapshot->xcnt,
 					   sizeof(TransactionId), xidComparator);
 
 		if (test == NULL)
@@ -519,11 +542,25 @@ SnapBuildInitialSnapshot(SnapBuild *builder)
 	}
 
 	/* adjust remaining snapshot fields as needed */
-	snap->snapshot_type = SNAPSHOT_MVCC;
-	snap->xcnt = newxcnt;
-	snap->xip = newxip;
+	snapshot->xcnt = newxcnt;
+	snapshot->xip = newxip;
+
+	if (in_place)
+		result = snapshot;
+	else
+	{
+		result = CopySnapshot(snapshot);
+
+		/* Restore the original values so the source is intact. */
+		snapshot->xip = oldxip;
+		snapshot->xcnt = oldxcnt;
+
+		/* newxip has been copied */
+		pfree(newxip);
+	}
+	result->snapshot_type = SNAPSHOT_MVCC;
 
-	return snap;
+	return result;
 }
 
 /*
diff --git a/src/backend/utils/time/snapmgr.c b/src/backend/utils/time/snapmgr.c
index 2e6197f5f35..3af1b366adf 100644
--- a/src/backend/utils/time/snapmgr.c
+++ b/src/backend/utils/time/snapmgr.c
@@ -213,7 +213,6 @@ typedef struct ExportedSnapshot
 static List *exportedSnapshots = NIL;
 
 /* Prototypes for local functions */
-static Snapshot CopySnapshot(Snapshot snapshot);
 static void UnregisterSnapshotNoOwner(Snapshot snapshot);
 static void FreeSnapshot(Snapshot snapshot);
 static void SnapshotResetXmin(void);
@@ -604,7 +603,7 @@ SetTransactionSnapshot(Snapshot sourcesnap, VirtualTransactionId *sourcevxid,
  * The copy is palloc'd in TopTransactionContext and has initial refcounts set
  * to 0.  The returned snapshot has the copied flag set.
  */
-static Snapshot
+Snapshot
 CopySnapshot(Snapshot snapshot)
 {
 	Snapshot	newsnap;
diff --git a/src/include/replication/snapbuild.h b/src/include/replication/snapbuild.h
index ccded021433..34383dea776 100644
--- a/src/include/replication/snapbuild.h
+++ b/src/include/replication/snapbuild.h
@@ -73,6 +73,7 @@ extern void FreeSnapshotBuilder(SnapBuild *builder);
 extern void SnapBuildSnapDecRefcount(Snapshot snap);
 
 extern Snapshot SnapBuildInitialSnapshot(SnapBuild *builder);
+extern Snapshot SnapBuildMVCCFromHistoric(Snapshot snapshot, bool in_place);
 extern const char *SnapBuildExportSnapshot(SnapBuild *builder);
 extern void SnapBuildClearExportedSnapshot(void);
 extern void SnapBuildResetExportedSnapshotState(void);
diff --git a/src/include/utils/snapmgr.h b/src/include/utils/snapmgr.h
index b8c01a291a1..de824945f0b 100644
--- a/src/include/utils/snapmgr.h
+++ b/src/include/utils/snapmgr.h
@@ -63,6 +63,7 @@ extern Snapshot GetTransactionSnapshot(void);
 extern Snapshot GetLatestSnapshot(void);
 extern void SnapshotSetCommandId(CommandId curcid);
 
+extern Snapshot CopySnapshot(Snapshot snapshot);
 extern Snapshot GetCatalogSnapshot(Oid relid);
 extern Snapshot GetNonHistoricCatalogSnapshot(Oid relid);
 extern void InvalidateCatalogSnapshot(void);
-- 
2.47.3


--=-=-=
Content-Type: text/plain
Content-Disposition: attachment;
 filename=v29-0004-Add-CONCURRENTLY-option-to-REPACK-command.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
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Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index c0640e071b9..17fcd246b0c 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Xf36GNcW+0xZNily
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v2-0004-use-Buffer-instead-of-buffer-ID-for-startup-s-buf.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
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Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
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Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
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Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
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Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57  Nathan Bossart <nathan@postgresql.org>
  0 siblings, 0 replies; 458+ messages in thread

From: Nathan Bossart @ 2026-07-09 18:57 UTC (permalink / raw)

---
 src/backend/access/transam/parallel.c | 22 ++++++++--------------
 1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/src/backend/access/transam/parallel.c b/src/backend/access/transam/parallel.c
index 89e9d224eec..57f5f26bbec 100644
--- a/src/backend/access/transam/parallel.c
+++ b/src/backend/access/transam/parallel.c
@@ -37,7 +37,6 @@
 #include "storage/ipc.h"
 #include "storage/predicate.h"
 #include "storage/proc.h"
-#include "storage/spin.h"
 #include "tcop/tcopprot.h"
 #include "utils/combocid.h"
 #include "utils/guc.h"
@@ -101,11 +100,8 @@ typedef struct FixedParallelState
 	TimestampTz stmt_ts;
 	SerializableXactHandle serializable_xact_handle;
 
-	/* Mutex protects remaining fields. */
-	slock_t		mutex;
-
 	/* Maximum XactLastRecEnd of any worker. */
-	XLogRecPtr	last_xlog_end;
+	pg_atomic_uint64 last_xlog_end;
 } FixedParallelState;
 
 /*
@@ -358,8 +354,7 @@ InitializeParallelDSM(ParallelContext *pcxt)
 	fps->xact_ts = GetCurrentTransactionStartTimestamp();
 	fps->stmt_ts = GetCurrentStatementStartTimestamp();
 	fps->serializable_xact_handle = ShareSerializableXact();
-	SpinLockInit(&fps->mutex);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_init_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 	shm_toc_insert(pcxt->toc, PARALLEL_KEY_FIXED, fps);
 
 	/* We can skip the rest of this if we're not budgeting for any workers. */
@@ -532,7 +527,7 @@ ReinitializeParallelDSM(ParallelContext *pcxt)
 
 	/* Reset a few bits of fixed parallel state to a clean state. */
 	fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-	fps->last_xlog_end = InvalidXLogRecPtr;
+	pg_atomic_write_u64(&fps->last_xlog_end, InvalidXLogRecPtr);
 
 	/* Recreate error queues (if they exist). */
 	if (pcxt->nworkers > 0)
@@ -900,10 +895,12 @@ WaitForParallelWorkersToFinish(ParallelContext *pcxt)
 	if (pcxt->toc != NULL)
 	{
 		FixedParallelState *fps;
+		XLogRecPtr	last_xlog_end;
 
 		fps = shm_toc_lookup(pcxt->toc, PARALLEL_KEY_FIXED, false);
-		if (fps->last_xlog_end > XactLastRecEnd)
-			XactLastRecEnd = fps->last_xlog_end;
+		last_xlog_end = pg_atomic_read_u64(&fps->last_xlog_end);
+		if (last_xlog_end > XactLastRecEnd)
+			XactLastRecEnd = last_xlog_end;
 	}
 }
 
@@ -1596,10 +1593,7 @@ ParallelWorkerReportLastRecEnd(XLogRecPtr last_xlog_end)
 	FixedParallelState *fps = MyFixedParallelState;
 
 	Assert(fps != NULL);
-	SpinLockAcquire(&fps->mutex);
-	if (fps->last_xlog_end < last_xlog_end)
-		fps->last_xlog_end = last_xlog_end;
-	SpinLockRelease(&fps->mutex);
+	pg_atomic_monotonic_advance_u64(&fps->last_xlog_end, last_xlog_end);
 }
 
 /*
-- 
2.50.1 (Apple Git-155)


--Ot5x3ffkWEuxilWO
Content-Type: text/plain; charset=us-ascii
Content-Disposition: attachment;
	filename=v1-0004-convert-PROC_HDR-startupBufferPinWaitBufId-to-an-.patch



^ permalink  raw  reply  [nested|flat] 458+ messages in thread