From 704261ecc694db11d9b5feb4f05f57778214ba2f Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Fri, 7 Apr 2023 13:24:26 -0700 Subject: [PATCH] Improve IO accounting for temp relation writes Both pgstat_database and pgBufferUsage count IO timing for reads of temporary relation blocks into local buffers. However, both failed to count write IO timing for flushes of dirty local buffers. Fix. Additionally, FlushRelationBuffers() seems to have omitted counting write IO (both count and timing) stats for both pgstat_database and pgBufferUsage. Fix. Author: Melanie Plageman Reviewed-by: Andres Freund Discussion: https://postgr.es/m/20230321023451.7rzy4kjj2iktrg2r%40awork3.anarazel.de --- src/backend/storage/buffer/bufmgr.c | 17 +++++++++++++++++ src/backend/storage/buffer/localbuf.c | 16 ++++++++++++++++ 2 files changed, 33 insertions(+) diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c index 908a8934bd4..ef69f21adf4 100644 --- a/src/backend/storage/buffer/bufmgr.c +++ b/src/backend/storage/buffer/bufmgr.c @@ -4062,6 +4062,8 @@ FlushRelationBuffers(Relation rel) { int i; BufferDesc *bufHdr; + instr_time io_start, + io_time; if (RelationUsesLocalBuffers(rel)) { @@ -4087,6 +4089,11 @@ FlushRelationBuffers(Relation rel) PageSetChecksumInplace(localpage, bufHdr->tag.blockNum); + if (track_io_timing) + INSTR_TIME_SET_CURRENT(io_start); + else + INSTR_TIME_SET_ZERO(io_start); + smgrwrite(RelationGetSmgr(rel), BufTagGetForkNum(&bufHdr->tag), bufHdr->tag.blockNum, @@ -4098,6 +4105,16 @@ FlushRelationBuffers(Relation rel) pgstat_count_io_op(IOOBJECT_TEMP_RELATION, IOCONTEXT_NORMAL, IOOP_WRITE); + if (track_io_timing) + { + INSTR_TIME_SET_CURRENT(io_time); + INSTR_TIME_SUBTRACT(io_time, io_start); + pgstat_count_buffer_write_time(INSTR_TIME_GET_MICROSEC(io_time)); + INSTR_TIME_ADD(pgBufferUsage.blk_write_time, io_time); + } + + pgBufferUsage.local_blks_written++; + /* Pop the error context stack */ error_context_stack = errcallback.previous; } diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c index 3846d3eaca4..3639296bc17 100644 --- a/src/backend/storage/buffer/localbuf.c +++ b/src/backend/storage/buffer/localbuf.c @@ -176,6 +176,8 @@ GetLocalVictimBuffer(void) int trycounter; uint32 buf_state; BufferDesc *bufHdr; + instr_time io_start, + io_time; ResourceOwnerEnlargeBuffers(CurrentResourceOwner); @@ -239,6 +241,11 @@ GetLocalVictimBuffer(void) PageSetChecksumInplace(localpage, bufHdr->tag.blockNum); + if (track_io_timing) + INSTR_TIME_SET_CURRENT(io_start); + else + INSTR_TIME_SET_ZERO(io_start); + /* And write... */ smgrwrite(oreln, BufTagGetForkNum(&bufHdr->tag), @@ -252,6 +259,15 @@ GetLocalVictimBuffer(void) /* Temporary table I/O does not use Buffer Access Strategies */ pgstat_count_io_op(IOOBJECT_TEMP_RELATION, IOCONTEXT_NORMAL, IOOP_WRITE); + + if (track_io_timing) + { + INSTR_TIME_SET_CURRENT(io_time); + INSTR_TIME_SUBTRACT(io_time, io_start); + pgstat_count_buffer_write_time(INSTR_TIME_GET_MICROSEC(io_time)); + INSTR_TIME_ADD(pgBufferUsage.blk_write_time, io_time); + } + pgBufferUsage.local_blks_written++; }