v7-0001-Count-IO-time-for-temp-relation-writes.patch

From 1088cde0ea0d39b7e55cd919f4c9151136f36e28 Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplageman@gmail.com>
Date: Tue, 21 Mar 2023 16:00:55 -0400
Subject: [PATCH v7 1/4] Count IO time for temp relation writes

Both pgstat_database and pgBufferUsage write times failed to count
timing for flushes of dirty local buffers when acquiring a new local
buffer for a temporary relation block.
---
 src/backend/storage/buffer/localbuf.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/src/backend/storage/buffer/localbuf.c b/src/backend/storage/buffer/localbuf.c
index 5325ddb663..80510411ae 100644
--- a/src/backend/storage/buffer/localbuf.c
+++ b/src/backend/storage/buffer/localbuf.c
@@ -114,6 +114,8 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
 	LocalBufferLookupEnt *hresult;
 	BufferDesc *bufHdr;
 	int			b;
+	instr_time	io_start,
+				io_time;
 	int			trycounter;
 	bool		found;
 	uint32		buf_state;
@@ -228,6 +230,11 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
 
 		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),
@@ -240,6 +247,15 @@ LocalBufferAlloc(SMgrRelation smgr, ForkNumber forkNum, BlockNumber blockNum,
 		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++;
 	}
 
-- 
2.37.2