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[PATCH v3 5/7] Row pattern recognition patch (docs).
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* [PATCH v3 5/7] Row pattern recognition patch (docs).
@ 2023-07-26 10:49 Tatsuo Ishii <[email protected]>
  0 siblings, 0 replies; 244+ messages in thread

From: Tatsuo Ishii @ 2023-07-26 10:49 UTC (permalink / raw)

---
 doc/src/sgml/advanced.sgml   | 52 ++++++++++++++++++++++++++++++++++
 doc/src/sgml/func.sgml       | 54 ++++++++++++++++++++++++++++++++++++
 doc/src/sgml/ref/select.sgml | 29 +++++++++++++++++--
 3 files changed, 133 insertions(+), 2 deletions(-)

diff --git a/doc/src/sgml/advanced.sgml b/doc/src/sgml/advanced.sgml
index 755c9f1485..eda3612822 100644
--- a/doc/src/sgml/advanced.sgml
+++ b/doc/src/sgml/advanced.sgml
@@ -537,6 +537,58 @@ WHERE pos &lt; 3;
     <literal>rank</literal> less than 3.
    </para>
 
+   <para>
+    Row pattern common syntax can be used with row pattern common syntax to
+    perform row pattern recognition in a query. Row pattern common syntax
+    includes two sub clauses. <literal>DEFINE</literal> defines definition
+    variables along with an expression. The expression must be a logical
+    expression, which means it must
+    return <literal>TRUE</literal>, <literal>FALSE</literal>
+    or <literal>NULL</literal>. Moreover if the expression comprises a column
+    reference, it must be the argument of <function>rpr</function>. An example
+    of <literal>DEFINE</literal> is as follows.
+
+<programlisting>
+DEFINE
+ LOWPRICE AS price &lt;= 100,
+ UP AS price &gt; PREV(price),
+ DOWN AS price &lt; PREV(price)
+</programlisting>
+
+    Note that <function>PREV</function> returns price column in the previous
+    row if it's called in a context of row pattern recognition. So in the
+    second line means the definition variable "UP" is <literal>TRUE</literal>
+    when price column in the current row is greater than the price column in
+    the previous row. Likewise, "DOWN" is <literal>TRUE</literal> when when
+    price column in the current row is lower than the price column in the
+    previous row.
+   </para>
+   <para>
+    Once <literal>DEFINE</literal> exists, <literal>PATTERN</literal> can be
+    used. <literal>PATTERN</literal> defines a sequence of rows that satisfies
+    certain conditions.  For example following <literal>PATTERN</literal>
+    defines that a row starts with the condition "LOWPRICE", then one or more
+    rows satisfy "UP" and finally one or more rows satisfy "DOWN". If a
+    sequence of rows found, rpr returns the column at the starting row.
+    Example of a <literal>SELECT</literal> using the <literal>DEFINE</literal>
+    and <literal>PATTERN</literal> clause is as follows.
+
+<programlisting>    
+SELECT company, tdate, price, max(price) OVER w FROM stock
+ WINDOW w AS (
+ PARTITION BY company
+ ROWS BETWEEN CURRENT ROW AND UNBOUNDED FOLLOWING
+ AFTER MATCH SKIP PAST LAST ROW
+ INITIAL
+ PATTERN (LOWPRICE UP+ DOWN+)
+ DEFINE
+  LOWPRICE AS price &lt;= 100,
+  UP AS price &gt; PREV(price),
+  DOWN AS price &lt; PREV(price)
+);
+</programlisting>
+   </para>
+
    <para>
     When a query involves multiple window functions, it is possible to write
     out each one with a separate <literal>OVER</literal> clause, but this is
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index dcc9d6f59d..b333d62410 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -21714,6 +21714,7 @@ SELECT count(*) FROM sometable;
         returns <literal>NULL</literal> if there is no such row.
        </para></entry>
       </row>
+
      </tbody>
     </tgroup>
    </table>
@@ -21753,6 +21754,59 @@ SELECT count(*) FROM sometable;
    Other frame specifications can be used to obtain other effects.
   </para>
 
+  <para>
+   Row pattern recognition navigation functions are listed in
+   <xref linkend="functions-rpr-navigation-table"/>.  These functions
+   can be used to describe DEFINE clause of Row pattern recognition.
+  </para>
+
+   <table id="functions-rpr-navigation-table">
+    <title>Row Pattern Navigation Functions</title>
+    <tgroup cols="1">
+     <thead>
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        Function
+       </para>
+       <para>
+        Description
+       </para></entry>
+      </row>
+     </thead>
+
+     <tbody>
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>prev</primary>
+        </indexterm>
+        <function>prev</function> ( <parameter>value</parameter> <type>anyelement</type> )
+        <returnvalue>anyelement</returnvalue>
+       </para>
+       <para>
+        Returns the column value at the previous row;
+        returns NULL if there is no previous row in the window frame.
+       </para></entry>
+      </row>
+
+      <row>
+       <entry role="func_table_entry"><para role="func_signature">
+        <indexterm>
+         <primary>next</primary>
+        </indexterm>
+        <function>next</function> ( <parameter>value</parameter> <type>anyelement</type> )
+        <returnvalue>anyelement</returnvalue>
+       </para>
+       <para>
+        Returns the column value at the next row;
+        returns NULL if there is no next row in the window frame.
+       </para></entry>
+      </row>
+
+     </tbody>
+    </tgroup>
+   </table>
+
   <note>
    <para>
     The SQL standard defines a <literal>RESPECT NULLS</literal> or
diff --git a/doc/src/sgml/ref/select.sgml b/doc/src/sgml/ref/select.sgml
index 0ee0cc7e64..16478a3950 100644
--- a/doc/src/sgml/ref/select.sgml
+++ b/doc/src/sgml/ref/select.sgml
@@ -966,8 +966,8 @@ WINDOW <replaceable class="parameter">window_name</replaceable> AS ( <replaceabl
     The <replaceable class="parameter">frame_clause</replaceable> can be one of
 
 <synopsis>
-{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
-{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ]
+{ RANGE | ROWS | GROUPS } <replaceable>frame_start</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
+{ RANGE | ROWS | GROUPS } BETWEEN <replaceable>frame_start</replaceable> AND <replaceable>frame_end</replaceable> [ <replaceable>frame_exclusion</replaceable> ] [row_pattern_common_syntax]
 </synopsis>
 
     where <replaceable>frame_start</replaceable>
@@ -1074,6 +1074,31 @@ EXCLUDE NO OTHERS
     a given peer group will be in the frame or excluded from it.
    </para>
 
+   <para>
+    The
+    optional <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+    defines the <firstterm>row pattern recognition condition</firstterm> for
+    this
+    window. <replaceable class="parameter">row_pattern_common_syntax</replaceable>
+    includes following subclauses. <literal>AFTER MATCH SKIP PAST LAST
+    ROW</literal> or <literal>AFTER MATCH SKIP TO NEXT ROW</literal> controls
+    how to proceed to next row position after a match
+    found. With <literal>AFTER MATCH SKIP PAST LAST ROW</literal> (the
+    default) next row position is next to the last row of previous match. On
+    the other hand, with <literal>AFTER MATCH SKIP TO NEXT ROW</literal> next
+    row position is always next to the last row of previous
+    match. <literal>DEFINE</literal> defines definition variables along with a
+    boolean expression. <literal>PATTERN</literal> defines a sequence of rows
+    that satisfies certain conditions using variables defined
+    in <literal>DEFINE</literal> clause.
+
+<synopsis>
+[ AFTER MATCH SKIP PAST LAST ROW | AFTER MATCH SKIP TO NEXT ROW ]
+PATTERN <replaceable class="parameter">pattern_variable_name</replaceable>[+] [, ...]
+DEFINE <replaceable class="parameter">definition_varible_name</replaceable> AS <replaceable class="parameter">expression</replaceable> [, ...]
+</synopsis>    
+   </para>
+
    <para>
     The purpose of a <literal>WINDOW</literal> clause is to specify the
     behavior of <firstterm>window functions</firstterm> appearing in the query's
-- 
2.25.1


----Next_Part(Wed_Jul_26_21_21_34_2023_317)--
Content-Type: Text/X-Patch; charset=us-ascii
Content-Transfer-Encoding: 7bit
Content-Disposition: inline;
 filename="v3-0006-Row-pattern-recognition-patch-tests.patch"



^ permalink  raw  reply  [nested|flat] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v2 3/9] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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] 244+ messages in thread

* [PATCH v1 3/8] convert FixedParallelState->last_xlog_end to an atomic
@ 2026-07-09 18:57 Nathan Bossart <[email protected]>
  0 siblings, 0 replies; 244+ 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)


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