From 122fcbf0a0e38d6ba7880b22ec093aa8bb8011e4 Mon Sep 17 00:00:00 2001 From: Andrey Borodin Date: Sat, 9 May 2020 16:42:07 +0500 Subject: [PATCH v8 4/4] Add GUCs to tune MultiXact SLRUs --- doc/src/sgml/config.sgml | 31 +++++++++++++++++++ src/backend/access/transam/multixact.c | 8 ++--- src/backend/utils/init/globals.c | 2 ++ src/backend/utils/misc/guc.c | 22 +++++++++++++ src/backend/utils/misc/postgresql.conf.sample | 8 +++++ src/include/access/multixact.h | 4 --- src/include/miscadmin.h | 2 ++ 7 files changed, 69 insertions(+), 8 deletions(-) diff --git a/doc/src/sgml/config.sgml b/doc/src/sgml/config.sgml index d9c27daa49..fab9715e83 100644 --- a/doc/src/sgml/config.sgml +++ b/doc/src/sgml/config.sgml @@ -1860,6 +1860,37 @@ include_dir 'conf.d' + + + multixact_offsets_slru_buffers (integer) + + multixact_offsets_slru_buffers configuration parameter + + + + + Specifies the amount of memory to be used for MultiXact offsets. MultiXact offsets + are used to store information about offsets of multiple row lockers (caused by SELECT FOR UPDATE and others). + It defaults to 64 kilobytes (64KB). + + + + + + multixact_members_slru_buffers (integer) + + multixact_members_slru_buffers configuration parameter + + + + + Specifies the amount of memory to be used for MultiXact members. MultiXact members + are used to store information about XIDs of multiple row lockers. Tipically multixact_members_slru_buffers + is twice more than multixact_offsets_slru_buffers. + It defaults to 128 kilobytes (128KB). + + + max_stack_depth (integer) diff --git a/src/backend/access/transam/multixact.c b/src/backend/access/transam/multixact.c index ffd35c2aea..76b4ad75bc 100644 --- a/src/backend/access/transam/multixact.c +++ b/src/backend/access/transam/multixact.c @@ -1867,8 +1867,8 @@ MultiXactShmemSize(void) mul_size(sizeof(MultiXactId) * 2, MaxOldestSlot)) size = SHARED_MULTIXACT_STATE_SIZE; - size = add_size(size, SimpleLruShmemSize(NUM_MULTIXACTOFFSET_BUFFERS, 0)); - size = add_size(size, SimpleLruShmemSize(NUM_MULTIXACTMEMBER_BUFFERS, 0)); + size = add_size(size, SimpleLruShmemSize(multixact_offsets_slru_buffers, 0)); + size = add_size(size, SimpleLruShmemSize(multixact_members_slru_buffers, 0)); return size; } @@ -1884,12 +1884,12 @@ MultiXactShmemInit(void) MultiXactMemberCtl->PagePrecedes = MultiXactMemberPagePrecedes; SimpleLruInit(MultiXactOffsetCtl, - "MultiXactOffset", NUM_MULTIXACTOFFSET_BUFFERS, 0, + "MultiXactOffset", multixact_offsets_slru_buffers, 0, MultiXactOffsetSLRULock, "pg_multixact/offsets", LWTRANCHE_MULTIXACTOFFSET_BUFFER, SYNC_HANDLER_MULTIXACT_OFFSET); SimpleLruInit(MultiXactMemberCtl, - "MultiXactMember", NUM_MULTIXACTMEMBER_BUFFERS, 0, + "MultiXactMember", multixact_members_slru_buffers, 0, MultiXactMemberSLRULock, "pg_multixact/members", LWTRANCHE_MULTIXACTMEMBER_BUFFER, SYNC_HANDLER_MULTIXACT_MEMBER); diff --git a/src/backend/utils/init/globals.c b/src/backend/utils/init/globals.c index 9ca71933dc..a5ec7bfe88 100644 --- a/src/backend/utils/init/globals.c +++ b/src/backend/utils/init/globals.c @@ -151,3 +151,5 @@ bool VacuumCostActive = false; double vacuum_cleanup_index_scale_factor; int multixact_local_cache_entries = 256; +int multixact_offsets_slru_buffers = 8; +int multixact_members_slru_buffers = 16; diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index ae2a3e1304..d86d34b4a5 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -2257,6 +2257,28 @@ static struct config_int ConfigureNamesInt[] = NULL, NULL, NULL }, + { + {"multixact_offsets_slru_buffers", PGC_POSTMASTER, RESOURCES_MEM, + gettext_noop("Sets the number of shared memory buffers used for MultiXact offsets SLRU."), + NULL, + GUC_UNIT_BLOCKS + }, + &multixact_offsets_slru_buffers, + 8, 2, INT_MAX / 2, + NULL, NULL, NULL + }, + + { + {"multixact_members_slru_buffers", PGC_POSTMASTER, RESOURCES_MEM, + gettext_noop("Sets the number of shared memory buffers used for MultiXact members SLRU."), + NULL, + GUC_UNIT_BLOCKS + }, + &multixact_members_slru_buffers, + 16, 2, INT_MAX / 2, + NULL, NULL, NULL + }, + { {"temp_buffers", PGC_USERSET, RESOURCES_MEM, gettext_noop("Sets the maximum number of temporary buffers used by each session."), diff --git a/src/backend/utils/misc/postgresql.conf.sample b/src/backend/utils/misc/postgresql.conf.sample index b7fb2ec1fe..1fb33809ee 100644 --- a/src/backend/utils/misc/postgresql.conf.sample +++ b/src/backend/utils/misc/postgresql.conf.sample @@ -189,6 +189,14 @@ # (change requires restart) #backend_flush_after = 0 # measured in pages, 0 disables +# - MultiXact Buffers - + +#multixact_offsets_slru_buffers = 8 # memory used for MultiXact offsets + # (change requires restart) +#multixact_members_slru_buffers = 16 # memory used for MultiXact members + # (change requires restart) +#multixact_local_cache_entries = 256 # number of cached MultiXact by backend + # (change requires restart) #------------------------------------------------------------------------------ # WRITE-AHEAD LOG diff --git a/src/include/access/multixact.h b/src/include/access/multixact.h index 9a30380901..630ceaea4d 100644 --- a/src/include/access/multixact.h +++ b/src/include/access/multixact.h @@ -29,10 +29,6 @@ #define MaxMultiXactOffset ((MultiXactOffset) 0xFFFFFFFF) -/* Number of SLRU buffers to use for multixact */ -#define NUM_MULTIXACTOFFSET_BUFFERS 8 -#define NUM_MULTIXACTMEMBER_BUFFERS 16 - /* * Possible multixact lock modes ("status"). The first four modes are for * tuple locks (FOR KEY SHARE, FOR SHARE, FOR NO KEY UPDATE, FOR UPDATE); the diff --git a/src/include/miscadmin.h b/src/include/miscadmin.h index 01af61c963..ef8abea84d 100644 --- a/src/include/miscadmin.h +++ b/src/include/miscadmin.h @@ -161,6 +161,8 @@ extern PGDLLIMPORT int MaxBackends; extern PGDLLIMPORT int MaxConnections; extern PGDLLIMPORT int max_worker_processes; extern PGDLLIMPORT int max_parallel_workers; +extern PGDLLIMPORT int multixact_offsets_slru_buffers; +extern PGDLLIMPORT int multixact_members_slru_buffers; extern PGDLLIMPORT int multixact_local_cache_entries; -- 2.24.3 (Apple Git-128)