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[PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS 7+ messages / 2 participants [nested] [flat]
* [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 17 +++++++---------- src/include/storage/proc.h | 7 +++---- 2 files changed, 10 insertions(+), 14 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index ca22336e35..cd58c5faf0 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -2685,17 +2685,14 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the statusFlags that affect how the + * value is interpreted by vacuum. + */ MyProc->xmin = TransactionXmin = xmin; - - /* walsender cheats by passing proc == MyProc, don't check its flags */ - if (proc != MyProc) - { - /* Flags being copied must be valid copy-able flags. */ - Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyProc->statusFlags = proc->statusFlags; - ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; - } + MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) | + (proc->statusFlags & PROC_XMIN_FLAGS); + ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; result = true; } diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 15be21c00a..2579e619eb 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -69,11 +69,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, flags that are set during parallel - * vacuum and parallel index creation are allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --zgl76stv2tlmzxb2-- ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 11 ++++++----- src/include/storage/proc.h | 7 +++---- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 6ff8d8699b..447b6e3de7 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -1916,12 +1916,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the vacuumFlags that affect how the + * value is interpreted by vacuum. + */ MyPgXact->xmin = TransactionXmin = xmin; - - /* Flags being copied must be valid copy-able flags. */ - Assert((pgxact->vacuumFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyPgXact->vacuumFlags = pgxact->vacuumFlags; + MyPgXact->vacuumFlags = (MyPgXact->vacuumFlags & ~PROC_XMIN_FLAGS) | + (pgxact->vacuumFlags & PROC_XMIN_FLAGS); result = true; } diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 9cf9684b41..7c85b5645b 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -63,11 +63,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_ANALYZE | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, a flag that is set during parallel - * vacuum is allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --gseizntho2k3boor Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename="v14-0001-Repurpose-PROC_COPYABLE_FLAGS-as-PROC_XMIN_FLAGS.patch" ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 11 ++++++----- src/include/storage/proc.h | 7 +++---- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 127be9c017..08053a7e8f 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -2686,12 +2686,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the statusFlags that affect how the + * value is interpreted by vacuum. + */ MyProc->xmin = TransactionXmin = xmin; - - /* Flags being copied must be valid copy-able flags. */ - Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyProc->statusFlags = proc->statusFlags; + MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) | + (proc->statusFlags & PROC_XMIN_FLAGS); ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; result = true; diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 11b514c9ae..1464fad9b9 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -66,11 +66,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, flags that are set during parallel - * vacuum and parallel index creation are allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --gseizntho2k3boor-- ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 17 +++++++---------- src/include/storage/proc.h | 7 +++---- 2 files changed, 10 insertions(+), 14 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index ca22336e35..cd58c5faf0 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -2685,17 +2685,14 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the statusFlags that affect how the + * value is interpreted by vacuum. + */ MyProc->xmin = TransactionXmin = xmin; - - /* walsender cheats by passing proc == MyProc, don't check its flags */ - if (proc != MyProc) - { - /* Flags being copied must be valid copy-able flags. */ - Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyProc->statusFlags = proc->statusFlags; - ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; - } + MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) | + (proc->statusFlags & PROC_XMIN_FLAGS); + ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; result = true; } diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 15be21c00a..2579e619eb 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -69,11 +69,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, flags that are set during parallel - * vacuum and parallel index creation are allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --zgl76stv2tlmzxb2-- ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 11 ++++++----- src/include/storage/proc.h | 7 +++---- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 6ff8d8699b..447b6e3de7 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -1916,12 +1916,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the vacuumFlags that affect how the + * value is interpreted by vacuum. + */ MyPgXact->xmin = TransactionXmin = xmin; - - /* Flags being copied must be valid copy-able flags. */ - Assert((pgxact->vacuumFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyPgXact->vacuumFlags = pgxact->vacuumFlags; + MyPgXact->vacuumFlags = (MyPgXact->vacuumFlags & ~PROC_XMIN_FLAGS) | + (pgxact->vacuumFlags & PROC_XMIN_FLAGS); result = true; } diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 9cf9684b41..7c85b5645b 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -63,11 +63,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_ANALYZE | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, a flag that is set during parallel - * vacuum is allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --gseizntho2k3boor Content-Type: text/x-diff; charset=utf-8 Content-Disposition: attachment; filename="v14-0001-Repurpose-PROC_COPYABLE_FLAGS-as-PROC_XMIN_FLAGS.patch" ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS @ 2022-05-14 14:51 Alvaro Herrera <alvherre@alvh.no-ip.org> 0 siblings, 0 replies; 7+ messages in thread From: Alvaro Herrera @ 2022-05-14 14:51 UTC (permalink / raw) This is a slight, convenient semantics change from what commit 0f0cfb494004 introduced that lets us simplify the coding in the one place where it is used. --- src/backend/storage/ipc/procarray.c | 11 ++++++----- src/include/storage/proc.h | 7 +++---- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/backend/storage/ipc/procarray.c b/src/backend/storage/ipc/procarray.c index 127be9c017..08053a7e8f 100644 --- a/src/backend/storage/ipc/procarray.c +++ b/src/backend/storage/ipc/procarray.c @@ -2686,12 +2686,13 @@ ProcArrayInstallRestoredXmin(TransactionId xmin, PGPROC *proc) TransactionIdIsNormal(xid) && TransactionIdPrecedesOrEquals(xid, xmin)) { - /* Install xmin */ + /* + * Install xmin and propagate the statusFlags that affect how the + * value is interpreted by vacuum. + */ MyProc->xmin = TransactionXmin = xmin; - - /* Flags being copied must be valid copy-able flags. */ - Assert((proc->statusFlags & (~PROC_COPYABLE_FLAGS)) == 0); - MyProc->statusFlags = proc->statusFlags; + MyProc->statusFlags = (MyProc->statusFlags & ~PROC_XMIN_FLAGS) | + (proc->statusFlags & PROC_XMIN_FLAGS); ProcGlobal->statusFlags[MyProc->pgxactoff] = MyProc->statusFlags; result = true; diff --git a/src/include/storage/proc.h b/src/include/storage/proc.h index 11b514c9ae..1464fad9b9 100644 --- a/src/include/storage/proc.h +++ b/src/include/storage/proc.h @@ -66,11 +66,10 @@ struct XidCache (PROC_IN_VACUUM | PROC_IN_SAFE_IC | PROC_VACUUM_FOR_WRAPAROUND) /* - * Flags that are valid to copy from another proc, the parallel leader - * process in practice. Currently, flags that are set during parallel - * vacuum and parallel index creation are allowed. + * Xmin-related flags. Make sure any flags that affect how the process' Xmin + * value is interpreted by VACUUM are included here. */ -#define PROC_COPYABLE_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) +#define PROC_XMIN_FLAGS (PROC_IN_VACUUM | PROC_IN_SAFE_IC) /* * We allow a small number of "weak" relation locks (AccessShareLock, -- 2.30.2 --gseizntho2k3boor-- ^ permalink raw reply [nested|flat] 7+ messages in thread
* [PATCH v2 3/6] Introduce multiple shmem segments for shared buffers @ 2025-02-24 19:08 Dmitrii Dolgov <9erthalion6@gmail.com> 0 siblings, 0 replies; 7+ messages in thread From: Dmitrii Dolgov @ 2025-02-24 19:08 UTC (permalink / raw) Add more shmem segments to split shared buffers into following chunks: * BUFFERS_SHMEM_SEGMENT: contains buffer blocks * BUFFER_DESCRIPTORS_SHMEM_SEGMENT: contains buffer descriptors * BUFFER_IOCV_SHMEM_SEGMENT: contains condition variables for buffers * CHECKPOINT_BUFFERS_SHMEM_SEGMENT: contains checkpoint buffer ids * STRATEGY_SHMEM_SEGMENT: contains buffer strategy status Size of the corresponding shared data directly depends on NBuffers, meaning that if we would like to change NBuffers, they have to be resized correspondingly. Placing each of them in a separate shmem segment allows to achieve that. There are some asumptions made about each of shmem segments upper size limit. The buffer blocks have the largest, while the rest claim less extra room for resize. Ideally those limits have to be deduced from the maximum allowed shared memory. --- src/backend/port/sysv_shmem.c | 19 ++++++- src/backend/storage/buffer/buf_init.c | 79 +++++++++++++++++--------- src/backend/storage/buffer/buf_table.c | 5 +- src/backend/storage/buffer/freelist.c | 4 +- src/backend/storage/ipc/ipci.c | 2 +- src/include/storage/bufmgr.h | 2 +- src/include/storage/pg_shmem.h | 24 +++++++- 7 files changed, 99 insertions(+), 36 deletions(-) diff --git a/src/backend/port/sysv_shmem.c b/src/backend/port/sysv_shmem.c index 62f01d8218a..59aa67cb135 100644 --- a/src/backend/port/sysv_shmem.c +++ b/src/backend/port/sysv_shmem.c @@ -149,8 +149,13 @@ static int next_free_segment = 0; * 7f4718400000-7f4718401000 /usr/lib64/libicudata.so.74.2 * ... */ -Size SHMEM_EXTRA_SIZE_LIMIT[1] = { - 0, /* MAIN_SHMEM_SLOT */ +Size SHMEM_EXTRA_SIZE_LIMIT[6] = { + 0, /* MAIN_SHMEM_SEGMENT */ + (Size) 1024 * 1024 * 1024 * 10, /* BUFFERS_SHMEM_SEGMENT */ + (Size) 1024 * 1024 * 1024 * 1, /* BUFFER_DESCRIPTORS_SHMEM_SEGMENT */ + (Size) 1024 * 1024 * 100, /* BUFFER_IOCV_SHMEM_SEGMENT */ + (Size) 1024 * 1024 * 100, /* CHECKPOINT_BUFFERS_SHMEM_SEGMENT */ + (Size) 1024 * 1024 * 100, /* STRATEGY_SHMEM_SEGMENT */ }; /* Remembers offset of the last mapping from the probe address */ @@ -179,6 +184,16 @@ MappingName(int shmem_segment) { case MAIN_SHMEM_SEGMENT: return "main"; + case BUFFERS_SHMEM_SEGMENT: + return "buffers"; + case BUFFER_DESCRIPTORS_SHMEM_SEGMENT: + return "descriptors"; + case BUFFER_IOCV_SHMEM_SEGMENT: + return "iocv"; + case CHECKPOINT_BUFFERS_SHMEM_SEGMENT: + return "checkpoint"; + case STRATEGY_SHMEM_SEGMENT: + return "strategy"; default: return "unknown"; } diff --git a/src/backend/storage/buffer/buf_init.c b/src/backend/storage/buffer/buf_init.c index ed1f8e03190..f5b9290a640 100644 --- a/src/backend/storage/buffer/buf_init.c +++ b/src/backend/storage/buffer/buf_init.c @@ -61,7 +61,10 @@ CkptSortItem *CkptBufferIds; * Initialize shared buffer pool * * This is called once during shared-memory initialization (either in the - * postmaster, or in a standalone backend). + * postmaster, or in a standalone backend). Size of data structures initialized + * here depends on NBuffers, and to be able to change NBuffers without a + * restart we store each structure into a separate shared memory segment, which + * could be resized on demand. */ void BufferManagerShmemInit(void) @@ -73,22 +76,22 @@ BufferManagerShmemInit(void) /* Align descriptors to a cacheline boundary. */ BufferDescriptors = (BufferDescPadded *) - ShmemInitStruct("Buffer Descriptors", + ShmemInitStructInSegment("Buffer Descriptors", NBuffers * sizeof(BufferDescPadded), - &foundDescs); + &foundDescs, BUFFER_DESCRIPTORS_SHMEM_SEGMENT); /* Align buffer pool on IO page size boundary. */ BufferBlocks = (char *) TYPEALIGN(PG_IO_ALIGN_SIZE, - ShmemInitStruct("Buffer Blocks", + ShmemInitStructInSegment("Buffer Blocks", NBuffers * (Size) BLCKSZ + PG_IO_ALIGN_SIZE, - &foundBufs)); + &foundBufs, BUFFERS_SHMEM_SEGMENT)); /* Align condition variables to cacheline boundary. */ BufferIOCVArray = (ConditionVariableMinimallyPadded *) - ShmemInitStruct("Buffer IO Condition Variables", + ShmemInitStructInSegment("Buffer IO Condition Variables", NBuffers * sizeof(ConditionVariableMinimallyPadded), - &foundIOCV); + &foundIOCV, BUFFER_IOCV_SHMEM_SEGMENT); /* * The array used to sort to-be-checkpointed buffer ids is located in @@ -98,8 +101,9 @@ BufferManagerShmemInit(void) * painful. */ CkptBufferIds = (CkptSortItem *) - ShmemInitStruct("Checkpoint BufferIds", - NBuffers * sizeof(CkptSortItem), &foundBufCkpt); + ShmemInitStructInSegment("Checkpoint BufferIds", + NBuffers * sizeof(CkptSortItem), &foundBufCkpt, + CHECKPOINT_BUFFERS_SHMEM_SEGMENT); if (foundDescs || foundBufs || foundIOCV || foundBufCkpt) { @@ -153,33 +157,54 @@ BufferManagerShmemInit(void) * BufferManagerShmemSize * * compute the size of shared memory for the buffer pool including - * data pages, buffer descriptors, hash tables, etc. + * data pages, buffer descriptors, hash tables, etc. based on the + * shared memory segment. The main segment must not allocate anything + * related to buffers, every other segment will receive part of the + * data. */ Size -BufferManagerShmemSize(void) +BufferManagerShmemSize(int shmem_segment) { Size size = 0; - /* size of buffer descriptors */ - size = add_size(size, mul_size(NBuffers, sizeof(BufferDescPadded))); - /* to allow aligning buffer descriptors */ - size = add_size(size, PG_CACHE_LINE_SIZE); + if (shmem_segment == MAIN_SHMEM_SEGMENT) + return size; - /* size of data pages, plus alignment padding */ - size = add_size(size, PG_IO_ALIGN_SIZE); - size = add_size(size, mul_size(NBuffers, BLCKSZ)); + if (shmem_segment == BUFFER_DESCRIPTORS_SHMEM_SEGMENT) + { + /* size of buffer descriptors */ + size = add_size(size, mul_size(NBuffers, sizeof(BufferDescPadded))); + /* to allow aligning buffer descriptors */ + size = add_size(size, PG_CACHE_LINE_SIZE); + } - /* size of stuff controlled by freelist.c */ - size = add_size(size, StrategyShmemSize()); + if (shmem_segment == BUFFERS_SHMEM_SEGMENT) + { + /* size of data pages, plus alignment padding */ + size = add_size(size, PG_IO_ALIGN_SIZE); + size = add_size(size, mul_size(NBuffers, BLCKSZ)); + } - /* size of I/O condition variables */ - size = add_size(size, mul_size(NBuffers, - sizeof(ConditionVariableMinimallyPadded))); - /* to allow aligning the above */ - size = add_size(size, PG_CACHE_LINE_SIZE); + if (shmem_segment == STRATEGY_SHMEM_SEGMENT) + { + /* size of stuff controlled by freelist.c */ + size = add_size(size, StrategyShmemSize()); + } - /* size of checkpoint sort array in bufmgr.c */ - size = add_size(size, mul_size(NBuffers, sizeof(CkptSortItem))); + if (shmem_segment == BUFFER_IOCV_SHMEM_SEGMENT) + { + /* size of I/O condition variables */ + size = add_size(size, mul_size(NBuffers, + sizeof(ConditionVariableMinimallyPadded))); + /* to allow aligning the above */ + size = add_size(size, PG_CACHE_LINE_SIZE); + } + + if (shmem_segment == CHECKPOINT_BUFFERS_SHMEM_SEGMENT) + { + /* size of checkpoint sort array in bufmgr.c */ + size = add_size(size, mul_size(NBuffers, sizeof(CkptSortItem))); + } return size; } diff --git a/src/backend/storage/buffer/buf_table.c b/src/backend/storage/buffer/buf_table.c index a50955d5286..ac449954dab 100644 --- a/src/backend/storage/buffer/buf_table.c +++ b/src/backend/storage/buffer/buf_table.c @@ -59,10 +59,11 @@ InitBufTable(int size) info.entrysize = sizeof(BufferLookupEnt); info.num_partitions = NUM_BUFFER_PARTITIONS; - SharedBufHash = ShmemInitHash("Shared Buffer Lookup Table", + SharedBufHash = ShmemInitHashInSegment("Shared Buffer Lookup Table", size, size, &info, - HASH_ELEM | HASH_BLOBS | HASH_PARTITION); + HASH_ELEM | HASH_BLOBS | HASH_PARTITION, + STRATEGY_SHMEM_SEGMENT); } /* diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index 336715b6c63..4919a92f2be 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -491,9 +491,9 @@ StrategyInitialize(bool init) * Get or create the shared strategy control block */ StrategyControl = (BufferStrategyControl *) - ShmemInitStruct("Buffer Strategy Status", + ShmemInitStructInSegment("Buffer Strategy Status", sizeof(BufferStrategyControl), - &found); + &found, STRATEGY_SHMEM_SEGMENT); if (!found) { diff --git a/src/backend/storage/ipc/ipci.c b/src/backend/storage/ipc/ipci.c index 4f6c707c204..68778522591 100644 --- a/src/backend/storage/ipc/ipci.c +++ b/src/backend/storage/ipc/ipci.c @@ -112,7 +112,7 @@ CalculateShmemSize(int *num_semaphores, int shmem_segment) sizeof(ShmemIndexEnt))); size = add_size(size, dsm_estimate_size()); size = add_size(size, DSMRegistryShmemSize()); - size = add_size(size, BufferManagerShmemSize()); + size = add_size(size, BufferManagerShmemSize(shmem_segment)); size = add_size(size, LockManagerShmemSize()); size = add_size(size, PredicateLockShmemSize()); size = add_size(size, ProcGlobalShmemSize()); diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h index 7c1e4316dde..bb7fe02e243 100644 --- a/src/include/storage/bufmgr.h +++ b/src/include/storage/bufmgr.h @@ -297,7 +297,7 @@ extern bool EvictUnpinnedBuffer(Buffer buf); /* in buf_init.c */ extern void BufferManagerShmemInit(void); -extern Size BufferManagerShmemSize(void); +extern Size BufferManagerShmemSize(int); /* in localbuf.c */ extern void AtProcExit_LocalBuffers(void); diff --git a/src/include/storage/pg_shmem.h b/src/include/storage/pg_shmem.h index 138078c29c5..ba0192baf95 100644 --- a/src/include/storage/pg_shmem.h +++ b/src/include/storage/pg_shmem.h @@ -52,7 +52,7 @@ typedef struct ShmemSegment } ShmemSegment; /* Number of available segments for anonymous memory mappings */ -#define ANON_MAPPINGS 1 +#define ANON_MAPPINGS 6 extern PGDLLIMPORT ShmemSegment Segments[ANON_MAPPINGS]; @@ -105,7 +105,29 @@ extern bool PGSharedMemoryIsInUse(unsigned long id1, unsigned long id2); extern void PGSharedMemoryDetach(void); extern void GetHugePageSize(Size *hugepagesize, int *mmap_flags); +/* + * To be able to dynamically resize largest parts of the data stored in shared + * memory, we split it into multiple shared memory mappings segments. Each + * segment contains only certain part of the data, which size depends on + * NBuffers. + */ + /* The main segment, contains everything except buffer blocks and related data. */ #define MAIN_SHMEM_SEGMENT 0 +/* Buffer blocks */ +#define BUFFERS_SHMEM_SEGMENT 1 + +/* Buffer descriptors */ +#define BUFFER_DESCRIPTORS_SHMEM_SEGMENT 2 + +/* Condition variables for buffers */ +#define BUFFER_IOCV_SHMEM_SEGMENT 3 + +/* Checkpoint BufferIds */ +#define CHECKPOINT_BUFFERS_SHMEM_SEGMENT 4 + +/* Buffer strategy status */ +#define STRATEGY_SHMEM_SEGMENT 5 + #endif /* PG_SHMEM_H */ -- 2.45.1 --q7xzg7duksj2kgko Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="v2-0004-Introduce-pending-flag-for-GUC-assign-hooks.patch" ^ permalink raw reply [nested|flat] 7+ messages in thread
end of thread, other threads:[~2025-02-24 19:08 UTC | newest] Thread overview: 7+ messages (download: mbox mbox.gz follow: Atom feed) -- links below jump to the message on this page -- 2022-05-14 14:51 [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2022-05-14 14:51 [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2022-05-14 14:51 [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2022-05-14 14:51 [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2022-05-14 14:51 [PATCH] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2022-05-14 14:51 [PATCH v2] Repurpose PROC_COPYABLE_FLAGS as PROC_XMIN_FLAGS Alvaro Herrera <alvherre@alvh.no-ip.org> 2025-02-24 19:08 [PATCH v2 3/6] Introduce multiple shmem segments for shared buffers Dmitrii Dolgov <9erthalion6@gmail.com>
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