diff options
| -rw-r--r-- | src/backend/access/transam/xlog.c | 34 | ||||
| -rw-r--r-- | src/backend/utils/misc/guc.c | 11 | ||||
| -rw-r--r-- | src/include/access/xlog.h | 1 |
3 files changed, 20 insertions, 26 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 981d4e55274..5a4dbb9c532 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -91,13 +91,19 @@ int sync_method = DEFAULT_SYNC_METHOD; int wal_level = WAL_LEVEL_MINIMAL; int CommitDelay = 0; /* precommit delay in microseconds */ int CommitSiblings = 5; /* # concurrent xacts needed to sleep */ -int num_xloginsert_locks = 8; #ifdef WAL_DEBUG bool XLOG_DEBUG = false; #endif /* + * Number of WAL insertion locks to use. A higher value allows more insertions + * to happen concurrently, but adds some CPU overhead to flushing the WAL, + * which needs to iterate all the locks. + */ +#define NUM_XLOGINSERT_LOCKS 8 + +/* * XLOGfileslop is the maximum number of preallocated future XLOG segments. * When we are done with an old XLOG segment file, we will recycle it as a * future XLOG segment as long as there aren't already XLOGfileslop future @@ -1095,9 +1101,9 @@ begin:; * inserter acquires an insertion lock. In addition to just indicating that * an insertion is in progress, the lock tells others how far the inserter * has progressed. There is a small fixed number of insertion locks, - * determined by the num_xloginsert_locks GUC. When an inserter crosses a - * page boundary, it updates the value stored in the lock to the how far it - * has inserted, to allow the previous buffer to be flushed. + * determined by NUM_XLOGINSERT_LOCKS. When an inserter crosses a page + * boundary, it updates the value stored in the lock to the how far it has + * inserted, to allow the previous buffer to be flushed. * * Holding onto an insertion lock also protects RedoRecPtr and * fullPageWrites from changing until the insertion is finished. @@ -1578,7 +1584,7 @@ WALInsertLockAcquire(void) static int lockToTry = -1; if (lockToTry == -1) - lockToTry = MyProc->pgprocno % num_xloginsert_locks; + lockToTry = MyProc->pgprocno % NUM_XLOGINSERT_LOCKS; MyLockNo = lockToTry; /* @@ -1598,7 +1604,7 @@ WALInsertLockAcquire(void) * than locks, it still helps to distribute the inserters evenly * across the locks. */ - lockToTry = (lockToTry + 1) % num_xloginsert_locks; + lockToTry = (lockToTry + 1) % NUM_XLOGINSERT_LOCKS; } } @@ -1617,7 +1623,7 @@ WALInsertLockAcquireExclusive(void) * than any real XLogRecPtr value, to make sure that no-one blocks waiting * on those. */ - for (i = 0; i < num_xloginsert_locks - 1; i++) + for (i = 0; i < NUM_XLOGINSERT_LOCKS - 1; i++) { LWLockAcquireWithVar(&WALInsertLocks[i].l.lock, &WALInsertLocks[i].l.insertingAt, @@ -1640,7 +1646,7 @@ WALInsertLockRelease(void) { int i; - for (i = 0; i < num_xloginsert_locks; i++) + for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++) LWLockRelease(&WALInsertLocks[i].l.lock); holdingAllLocks = false; @@ -1664,8 +1670,8 @@ WALInsertLockUpdateInsertingAt(XLogRecPtr insertingAt) * We use the last lock to mark our actual position, see comments in * WALInsertLockAcquireExclusive. */ - LWLockUpdateVar(&WALInsertLocks[num_xloginsert_locks - 1].l.lock, - &WALInsertLocks[num_xloginsert_locks - 1].l.insertingAt, + LWLockUpdateVar(&WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.lock, + &WALInsertLocks[NUM_XLOGINSERT_LOCKS - 1].l.insertingAt, insertingAt); } else @@ -1732,7 +1738,7 @@ WaitXLogInsertionsToFinish(XLogRecPtr upto) * out for any insertion that's still in progress. */ finishedUpto = reservedUpto; - for (i = 0; i < num_xloginsert_locks; i++) + for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++) { XLogRecPtr insertingat = InvalidXLogRecPtr; @@ -4752,7 +4758,7 @@ XLOGShmemSize(void) size = sizeof(XLogCtlData); /* WAL insertion locks, plus alignment */ - size = add_size(size, mul_size(sizeof(WALInsertLockPadded), num_xloginsert_locks + 1)); + size = add_size(size, mul_size(sizeof(WALInsertLockPadded), NUM_XLOGINSERT_LOCKS + 1)); /* xlblocks array */ size = add_size(size, mul_size(sizeof(XLogRecPtr), XLOGbuffers)); /* extra alignment padding for XLOG I/O buffers */ @@ -4829,7 +4835,7 @@ XLOGShmemInit(void) ((uintptr_t) allocptr) %sizeof(WALInsertLockPadded); WALInsertLocks = XLogCtl->Insert.WALInsertLocks = (WALInsertLockPadded *) allocptr; - allocptr += sizeof(WALInsertLockPadded) * num_xloginsert_locks; + allocptr += sizeof(WALInsertLockPadded) * NUM_XLOGINSERT_LOCKS; XLogCtl->Insert.WALInsertLockTrancheId = LWLockNewTrancheId(); @@ -4838,7 +4844,7 @@ XLOGShmemInit(void) XLogCtl->Insert.WALInsertLockTranche.array_stride = sizeof(WALInsertLockPadded); LWLockRegisterTranche(XLogCtl->Insert.WALInsertLockTrancheId, &XLogCtl->Insert.WALInsertLockTranche); - for (i = 0; i < num_xloginsert_locks; i++) + for (i = 0; i < NUM_XLOGINSERT_LOCKS; i++) { LWLockInitialize(&WALInsertLocks[i].l.lock, XLogCtl->Insert.WALInsertLockTrancheId); diff --git a/src/backend/utils/misc/guc.c b/src/backend/utils/misc/guc.c index d2083142589..8111b93074a 100644 --- a/src/backend/utils/misc/guc.c +++ b/src/backend/utils/misc/guc.c @@ -2144,17 +2144,6 @@ static struct config_int ConfigureNamesInt[] = }, { - {"xloginsert_locks", PGC_POSTMASTER, WAL_SETTINGS, - gettext_noop("Sets the number of locks used for concurrent xlog insertions."), - NULL, - GUC_NOT_IN_SAMPLE - }, - &num_xloginsert_locks, - 8, 1, 1000, - NULL, NULL, NULL - }, - - { /* see max_connections */ {"max_wal_senders", PGC_POSTMASTER, REPLICATION_SENDING, gettext_noop("Sets the maximum number of simultaneously running WAL sender processes."), diff --git a/src/include/access/xlog.h b/src/include/access/xlog.h index 0b7bfa5f30e..0f068d91f38 100644 --- a/src/include/access/xlog.h +++ b/src/include/access/xlog.h @@ -194,7 +194,6 @@ extern bool EnableHotStandby; extern bool fullPageWrites; extern bool wal_log_hints; extern bool log_checkpoints; -extern int num_xloginsert_locks; /* WAL levels */ typedef enum WalLevel |