diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 377afb87324..18af3d41209 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -110,6 +110,7 @@ int CommitDelay = 0; /* precommit delay in microseconds */ int CommitSiblings = 5; /* # concurrent xacts needed to sleep */ int wal_retrieve_retry_interval = 5000; int max_slot_wal_keep_size_mb = -1; +bool track_wal_io_timing = false; #ifdef WAL_DEBUG bool XLOG_DEBUG = false; @@ -2533,6 +2534,7 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) Size nbytes; Size nleft; int written; + instr_time start; /* OK to write the page(s) */ from = XLogCtl->pages + startidx * (Size) XLOG_BLCKSZ; @@ -2541,9 +2543,30 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible) do { errno = 0; + + /* Measure I/O timing to write WAL data */ + if (track_wal_io_timing) + INSTR_TIME_SET_CURRENT(start); + pgstat_report_wait_start(WAIT_EVENT_WAL_WRITE); written = pg_pwrite(openLogFile, from, nleft, startoffset); pgstat_report_wait_end(); + + /* + * Increment the I/O timing and the number of times WAL data + * were written out to disk. + */ + if (track_wal_io_timing) + { + instr_time duration; + + INSTR_TIME_SET_CURRENT(duration); + INSTR_TIME_SUBTRACT(duration, start); + WalStats.m_wal_write_time += INSTR_TIME_GET_MICROSEC(duration); + } + + WalStats.m_wal_write++; + if (written <= 0) { char xlogfname[MAXFNAMELEN]; @@ -10524,6 +10547,20 @@ void issue_xlog_fsync(int fd, XLogSegNo segno) { char *msg = NULL; + instr_time start; + + /* + * Quick exit if fsync is disabled or write() has already synced the WAL + * file. + */ + if (!enableFsync || + sync_method == SYNC_METHOD_OPEN || + sync_method == SYNC_METHOD_OPEN_DSYNC) + return; + + /* Measure I/O timing to sync the WAL file */ + if (track_wal_io_timing) + INSTR_TIME_SET_CURRENT(start); pgstat_report_wait_start(WAIT_EVENT_WAL_SYNC); switch (sync_method) @@ -10546,7 +10583,8 @@ issue_xlog_fsync(int fd, XLogSegNo segno) #endif case SYNC_METHOD_OPEN: case SYNC_METHOD_OPEN_DSYNC: - /* write synced it already */ + /* not reachable */ + Assert(false); break; default: elog(PANIC, "unrecognized wal_sync_method: %d", sync_method); @@ -10568,6 +10606,20 @@ issue_xlog_fsync(int fd, XLogSegNo segno) } pgstat_report_wait_end(); + + /* + * Increment the I/O timing and the number of times WAL files were synced. + */ + if (track_wal_io_timing) + { + instr_time duration; + + INSTR_TIME_SET_CURRENT(duration); + INSTR_TIME_SUBTRACT(duration, start); + WalStats.m_wal_sync_time += INSTR_TIME_GET_MICROSEC(duration); + } + + WalStats.m_wal_sync++; } /* |