From 9bfc0af26dcfc0c0061b98e170bc6fa02acaf709 Mon Sep 17 00:00:00 2001 From: Heikki Linnakangas Date: Wed, 7 Aug 2024 14:03:08 +0300 Subject: [PATCH v1 1/1] Run WAL redo functions in a temporary memory context Some resource managers already used such a temporary memory context on their own. Let's consolidate that and run all WAL redo functions in a temporary context that is reset between each record. This leaves the rm_startup and rm_cleanup hooks unused in core code, but I kept them because they might still be used by extensions, and it might come handy for builtin rmgrs again in the future too. --- doc/src/sgml/custom-rmgr.sgml | 17 +++++++++++++++++ src/backend/access/gin/ginxlog.c | 21 --------------------- src/backend/access/gist/gistxlog.c | 19 ------------------- src/backend/access/nbtree/nbtxlog.c | 21 --------------------- src/backend/access/spgist/spgxlog.c | 23 ----------------------- src/backend/access/transam/xlogrecovery.c | 12 ++++++++++++ src/include/access/ginxlog.h | 2 -- src/include/access/gistxlog.h | 2 -- src/include/access/nbtxlog.h | 2 -- src/include/access/rmgrlist.h | 8 ++++---- src/include/access/spgxlog.h | 2 -- src/include/access/xlog_internal.h | 5 +++++ 12 files changed, 38 insertions(+), 96 deletions(-) diff --git a/doc/src/sgml/custom-rmgr.sgml b/doc/src/sgml/custom-rmgr.sgml index 3032b2dc0d..bfa15e33d6 100644 --- a/doc/src/sgml/custom-rmgr.sgml +++ b/doc/src/sgml/custom-rmgr.sgml @@ -29,6 +29,11 @@ * This struct must be kept in sync with the PG_RMGR definition in * rmgr.c. * + * rm_redo is the core function that replays one WAL record. During WAL + * recovery, it is called once for every WAL record belonging to the resource + * manager. It's called in a temporary memory context that is reset between + * every record. + * * rm_identify must return a name for the record based on xl_info (without * reference to the rmid). For example, XLOG_BTREE_VACUUM would be named * "VACUUM". rm_desc can then be called to obtain additional detail for the @@ -55,6 +60,18 @@ typedef struct RmgrData + + + Prior to PostgreSQL version 18.0, + the rm_redo function was called in a long-lived memory + context, and if you needed a short-lived context you had to create one + yourself e.g. in rm_startup. Starting with version + 18.0, it's called in a temporary memory context instead, and if you need + to retain data over calls, you need to explicitly allocate them in + TopMemoryContext. + + + The src/test/modules/test_custom_rmgrs module contains a working example, which demonstrates usage of custom WAL diff --git a/src/backend/access/gin/ginxlog.c b/src/backend/access/gin/ginxlog.c index 07ba0b559e..59afd5e4b4 100644 --- a/src/backend/access/gin/ginxlog.c +++ b/src/backend/access/gin/ginxlog.c @@ -19,8 +19,6 @@ #include "access/xlogutils.h" #include "utils/memutils.h" -static MemoryContext opCtx; /* working memory for operations */ - static void ginRedoClearIncompleteSplit(XLogReaderState *record, uint8 block_id) { @@ -726,7 +724,6 @@ void gin_redo(XLogReaderState *record) { uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; - MemoryContext oldCtx; /* * GIN indexes do not require any conflict processing. NB: If we ever @@ -734,7 +731,6 @@ gin_redo(XLogReaderState *record) * killed tuples outside VACUUM, we'll need to handle that here. */ - oldCtx = MemoryContextSwitchTo(opCtx); switch (info) { case XLOG_GIN_CREATE_PTREE: @@ -767,23 +763,6 @@ gin_redo(XLogReaderState *record) default: elog(PANIC, "gin_redo: unknown op code %u", info); } - MemoryContextSwitchTo(oldCtx); - MemoryContextReset(opCtx); -} - -void -gin_xlog_startup(void) -{ - opCtx = AllocSetContextCreate(CurrentMemoryContext, - "GIN recovery temporary context", - ALLOCSET_DEFAULT_SIZES); -} - -void -gin_xlog_cleanup(void) -{ - MemoryContextDelete(opCtx); - opCtx = NULL; } /* diff --git a/src/backend/access/gist/gistxlog.c b/src/backend/access/gist/gistxlog.c index 451e8d8d98..3127cffc03 100644 --- a/src/backend/access/gist/gistxlog.c +++ b/src/backend/access/gist/gistxlog.c @@ -23,8 +23,6 @@ #include "utils/memutils.h" #include "utils/rel.h" -static MemoryContext opCtx; /* working memory for operations */ - /* * Replay the clearing of F_FOLLOW_RIGHT flag on a child page. * @@ -397,7 +395,6 @@ void gist_redo(XLogReaderState *record) { uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; - MemoryContext oldCxt; /* * GiST indexes do not require any conflict processing. NB: If we ever @@ -405,7 +402,6 @@ gist_redo(XLogReaderState *record) * tuples outside VACUUM, we'll need to handle that here. */ - oldCxt = MemoryContextSwitchTo(opCtx); switch (info) { case XLOG_GIST_PAGE_UPDATE: @@ -429,21 +425,6 @@ gist_redo(XLogReaderState *record) default: elog(PANIC, "gist_redo: unknown op code %u", info); } - - MemoryContextSwitchTo(oldCxt); - MemoryContextReset(opCtx); -} - -void -gist_xlog_startup(void) -{ - opCtx = createTempGistContext(); -} - -void -gist_xlog_cleanup(void) -{ - MemoryContextDelete(opCtx); } /* diff --git a/src/backend/access/nbtree/nbtxlog.c b/src/backend/access/nbtree/nbtxlog.c index b5b0e22447..0073e8bcdb 100644 --- a/src/backend/access/nbtree/nbtxlog.c +++ b/src/backend/access/nbtree/nbtxlog.c @@ -22,8 +22,6 @@ #include "storage/standby.h" #include "utils/memutils.h" -static MemoryContext opCtx; /* working memory for operations */ - /* * _bt_restore_page -- re-enter all the index tuples on a page * @@ -1014,9 +1012,7 @@ void btree_redo(XLogReaderState *record) { uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; - MemoryContext oldCtx; - oldCtx = MemoryContextSwitchTo(opCtx); switch (info) { case XLOG_BTREE_INSERT_LEAF: @@ -1065,23 +1061,6 @@ btree_redo(XLogReaderState *record) default: elog(PANIC, "btree_redo: unknown op code %u", info); } - MemoryContextSwitchTo(oldCtx); - MemoryContextReset(opCtx); -} - -void -btree_xlog_startup(void) -{ - opCtx = AllocSetContextCreate(CurrentMemoryContext, - "Btree recovery temporary context", - ALLOCSET_DEFAULT_SIZES); -} - -void -btree_xlog_cleanup(void) -{ - MemoryContextDelete(opCtx); - opCtx = NULL; } /* diff --git a/src/backend/access/spgist/spgxlog.c b/src/backend/access/spgist/spgxlog.c index 4e31d33e70..b422049920 100644 --- a/src/backend/access/spgist/spgxlog.c +++ b/src/backend/access/spgist/spgxlog.c @@ -22,9 +22,6 @@ #include "utils/memutils.h" -static MemoryContext opCtx; /* working memory for operations */ - - /* * Prepare a dummy SpGistState, with just the minimum info needed for replay. * @@ -935,9 +932,7 @@ void spg_redo(XLogReaderState *record) { uint8 info = XLogRecGetInfo(record) & ~XLR_INFO_MASK; - MemoryContext oldCxt; - oldCxt = MemoryContextSwitchTo(opCtx); switch (info) { case XLOG_SPGIST_ADD_LEAF: @@ -967,24 +962,6 @@ spg_redo(XLogReaderState *record) default: elog(PANIC, "spg_redo: unknown op code %u", info); } - - MemoryContextSwitchTo(oldCxt); - MemoryContextReset(opCtx); -} - -void -spg_xlog_startup(void) -{ - opCtx = AllocSetContextCreate(CurrentMemoryContext, - "SP-GiST temporary context", - ALLOCSET_DEFAULT_SIZES); -} - -void -spg_xlog_cleanup(void) -{ - MemoryContextDelete(opCtx); - opCtx = NULL; } /* diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c index ad817fbca6..b884f84974 100644 --- a/src/backend/access/transam/xlogrecovery.c +++ b/src/backend/access/transam/xlogrecovery.c @@ -61,6 +61,7 @@ #include "utils/datetime.h" #include "utils/fmgrprotos.h" #include "utils/guc_hooks.h" +#include "utils/memutils.h" #include "utils/pg_lsn.h" #include "utils/ps_status.h" #include "utils/pg_rusage.h" @@ -1728,6 +1729,8 @@ PerformWalRecovery(void) if (record != NULL) { + MemoryContext oldCtx; + MemoryContext redoCtx; TimestampTz xtime; PGRUsage ru0; @@ -1745,6 +1748,10 @@ PerformWalRecovery(void) if (!StandbyMode) begin_startup_progress_phase(); + redoCtx = AllocSetContextCreate(CurrentMemoryContext, + "recovery temporary context", + ALLOCSET_DEFAULT_SIZES); + /* * main redo apply loop */ @@ -1820,7 +1827,10 @@ PerformWalRecovery(void) /* * Apply the record */ + oldCtx = MemoryContextSwitchTo(redoCtx); ApplyWalRecord(xlogreader, record, &replayTLI); + MemoryContextSwitchTo(oldCtx); + MemoryContextReset(redoCtx); /* Exit loop if we reached inclusive recovery target */ if (recoveryStopsAfter(xlogreader)) @@ -1847,6 +1857,8 @@ PerformWalRecovery(void) * end of main redo apply loop */ + MemoryContextSwitchTo(oldCtx); + if (reachedRecoveryTarget) { if (!reachedConsistency) diff --git a/src/include/access/ginxlog.h b/src/include/access/ginxlog.h index 0c2ddbd82a..3e5185fbdc 100644 --- a/src/include/access/ginxlog.h +++ b/src/include/access/ginxlog.h @@ -209,8 +209,6 @@ typedef struct ginxlogDeleteListPages extern void gin_redo(XLogReaderState *record); extern void gin_desc(StringInfo buf, XLogReaderState *record); extern const char *gin_identify(uint8 info); -extern void gin_xlog_startup(void); -extern void gin_xlog_cleanup(void); extern void gin_mask(char *pagedata, BlockNumber blkno); #endif /* GINXLOG_H */ diff --git a/src/include/access/gistxlog.h b/src/include/access/gistxlog.h index a0bdc5d7d7..809512acd9 100644 --- a/src/include/access/gistxlog.h +++ b/src/include/access/gistxlog.h @@ -110,8 +110,6 @@ typedef struct gistxlogPageReuse extern void gist_redo(XLogReaderState *record); extern void gist_desc(StringInfo buf, XLogReaderState *record); extern const char *gist_identify(uint8 info); -extern void gist_xlog_startup(void); -extern void gist_xlog_cleanup(void); extern void gist_mask(char *pagedata, BlockNumber blkno); #endif diff --git a/src/include/access/nbtxlog.h b/src/include/access/nbtxlog.h index e42ac1611c..3922687858 100644 --- a/src/include/access/nbtxlog.h +++ b/src/include/access/nbtxlog.h @@ -354,8 +354,6 @@ typedef struct xl_btree_newroot * prototypes for functions in nbtxlog.c */ extern void btree_redo(XLogReaderState *record); -extern void btree_xlog_startup(void); -extern void btree_xlog_cleanup(void); extern void btree_mask(char *pagedata, BlockNumber blkno); /* diff --git a/src/include/access/rmgrlist.h b/src/include/access/rmgrlist.h index 78e6b908c6..8bcc82cb54 100644 --- a/src/include/access/rmgrlist.h +++ b/src/include/access/rmgrlist.h @@ -36,12 +36,12 @@ PG_RMGR(RM_RELMAP_ID, "RelMap", relmap_redo, relmap_desc, relmap_identify, NULL, PG_RMGR(RM_STANDBY_ID, "Standby", standby_redo, standby_desc, standby_identify, NULL, NULL, NULL, standby_decode) PG_RMGR(RM_HEAP2_ID, "Heap2", heap2_redo, heap2_desc, heap2_identify, NULL, NULL, heap_mask, heap2_decode) PG_RMGR(RM_HEAP_ID, "Heap", heap_redo, heap_desc, heap_identify, NULL, NULL, heap_mask, heap_decode) -PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, btree_identify, btree_xlog_startup, btree_xlog_cleanup, btree_mask, NULL) +PG_RMGR(RM_BTREE_ID, "Btree", btree_redo, btree_desc, btree_identify, NULL, NULL, btree_mask, NULL) PG_RMGR(RM_HASH_ID, "Hash", hash_redo, hash_desc, hash_identify, NULL, NULL, hash_mask, NULL) -PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_identify, gin_xlog_startup, gin_xlog_cleanup, gin_mask, NULL) -PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_identify, gist_xlog_startup, gist_xlog_cleanup, gist_mask, NULL) +PG_RMGR(RM_GIN_ID, "Gin", gin_redo, gin_desc, gin_identify, NULL, NULL, gin_mask, NULL) +PG_RMGR(RM_GIST_ID, "Gist", gist_redo, gist_desc, gist_identify, NULL, NULL, gist_mask, NULL) PG_RMGR(RM_SEQ_ID, "Sequence", seq_redo, seq_desc, seq_identify, NULL, NULL, seq_mask, NULL) -PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, spg_xlog_startup, spg_xlog_cleanup, spg_mask, NULL) +PG_RMGR(RM_SPGIST_ID, "SPGist", spg_redo, spg_desc, spg_identify, NULL, NULL, spg_mask, NULL) PG_RMGR(RM_BRIN_ID, "BRIN", brin_redo, brin_desc, brin_identify, NULL, NULL, brin_mask, NULL) PG_RMGR(RM_COMMIT_TS_ID, "CommitTs", commit_ts_redo, commit_ts_desc, commit_ts_identify, NULL, NULL, NULL, NULL) PG_RMGR(RM_REPLORIGIN_ID, "ReplicationOrigin", replorigin_redo, replorigin_desc, replorigin_identify, NULL, NULL, NULL, NULL) diff --git a/src/include/access/spgxlog.h b/src/include/access/spgxlog.h index 16cc735001..fcd768a1c1 100644 --- a/src/include/access/spgxlog.h +++ b/src/include/access/spgxlog.h @@ -252,8 +252,6 @@ typedef struct spgxlogVacuumRedirect extern void spg_redo(XLogReaderState *record); extern void spg_desc(StringInfo buf, XLogReaderState *record); extern const char *spg_identify(uint8 info); -extern void spg_xlog_startup(void); -extern void spg_xlog_cleanup(void); extern void spg_mask(char *pagedata, BlockNumber blkno); #endif /* SPGXLOG_H */ diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h index c6a91fb456..4df224bb16 100644 --- a/src/include/access/xlog_internal.h +++ b/src/include/access/xlog_internal.h @@ -335,6 +335,11 @@ struct XLogRecordBuffer; * This struct must be kept in sync with the PG_RMGR definition in * rmgr.c. * + * rm_redo is the core function that replays one WAL record. During WAL + * recovery, it is called once for every WAL record belonging to the resource + * manager. It's called in a temporary memory context that is reset between + * every record. + * * rm_identify must return a name for the record based on xl_info (without * reference to the rmid). For example, XLOG_BTREE_VACUUM would be named * "VACUUM". rm_desc can then be called to obtain additional detail for the -- 2.39.2