diff options
| author | Robert Haas <rhaas@postgresql.org> | 2012-03-27 14:52:37 -0400 |
|---|---|---|
| committer | Robert Haas <rhaas@postgresql.org> | 2012-03-27 14:55:02 -0400 |
| commit | 40b9b957694cf7749c420c6c51a7e1d3c9b1fec1 (patch) | |
| tree | ab94826c3e20f7fe0a63edb3370be8a8988fd31f /src/backend/storage/buffer/bufmgr.c | |
| parent | 98316e211b60cb160247171e3557b40a247c4610 (diff) | |
New GUC, track_iotiming, to track I/O timings.
Currently, the only way to see the numbers this gathers is via
EXPLAIN (ANALYZE, BUFFERS), but the plan is to add visibility through
the stats collector and pg_stat_statements in subsequent patches.
Ants Aasma, reviewed by Greg Smith, with some further changes by me.
Diffstat (limited to 'src/backend/storage/buffer/bufmgr.c')
| -rw-r--r-- | src/backend/storage/buffer/bufmgr.c | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 3924a51c0c6..4de6a7212cc 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -67,6 +67,7 @@ bool zero_damaged_pages = false; int bgwriter_lru_maxpages = 100; double bgwriter_lru_multiplier = 2.0; +bool track_iotiming = false; /* * How many buffers PrefetchBuffer callers should try to stay ahead of their @@ -437,8 +438,21 @@ ReadBuffer_common(SMgrRelation smgr, char relpersistence, ForkNumber forkNum, MemSet((char *) bufBlock, 0, BLCKSZ); else { + instr_time io_start, + io_time; + + if (track_iotiming) + INSTR_TIME_SET_CURRENT(io_start); + smgrread(smgr, forkNum, blockNum, (char *) bufBlock); + if (track_iotiming) + { + INSTR_TIME_SET_CURRENT(io_time); + INSTR_TIME_SUBTRACT(io_time, io_start); + INSTR_TIME_ADD(pgBufferUsage.time_read, io_time); + } + /* check for garbage data */ if (!PageHeaderIsValid((PageHeader) bufBlock)) { @@ -1874,6 +1888,7 @@ FlushBuffer(volatile BufferDesc *buf, SMgrRelation reln) { XLogRecPtr recptr; ErrorContextCallback errcontext; + instr_time io_start, io_end; /* * Acquire the buffer's io_in_progress lock. If StartBufferIO returns @@ -1921,12 +1936,21 @@ FlushBuffer(volatile BufferDesc *buf, SMgrRelation reln) buf->flags &= ~BM_JUST_DIRTIED; UnlockBufHdr(buf); + if (track_iotiming) + INSTR_TIME_SET_CURRENT(io_start); + smgrwrite(reln, buf->tag.forkNum, buf->tag.blockNum, (char *) BufHdrGetBlock(buf), false); + if (track_iotiming) + { + INSTR_TIME_SET_CURRENT(io_end); + INSTR_TIME_ACCUM_DIFF(pgBufferUsage.time_write, io_end, io_start); + } + pgBufferUsage.shared_blks_written++; /* |