v8-0002-FlushRelationBuffers-counts-temp-relation-IO-timi.patch

From f4e0db5c833f33b30d4c0b4bebec1096a1745d81 Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplageman@gmail.com>
Date: Tue, 21 Mar 2023 18:20:44 -0400
Subject: [PATCH v8 2/4] FlushRelationBuffers() counts temp relation IO timing

Add pgstat_database and pgBufferUsage IO timing counting to
FlushRelationBuffers() for writes of temporary relations.
---
 src/backend/storage/buffer/bufmgr.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index b3adbbe7d2..05e98d5994 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -3571,6 +3571,8 @@ FlushRelationBuffers(Relation rel)
 {
 	int			i;
 	BufferDesc *bufHdr;
+	instr_time	io_start,
+				io_time;
 
 	if (RelationUsesLocalBuffers(rel))
 	{
@@ -3596,17 +3598,33 @@ 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,
 						  localpage,
 						  false);
 
+
 				buf_state &= ~(BM_DIRTY | BM_JUST_DIRTIED);
 				pg_atomic_unlocked_write_u32(&bufHdr->state, buf_state);
 
 				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;
 			}
-- 
2.37.2