Then I would make the trivial change to respect the new
io_combine_limit GUC that I'm gearing up to commit in another thread.
As attached.
From 7993cede8939cad9172867ccc690a44ea25d1ad6 Mon Sep 17 00:00:00 2001
From: Thomas Munro <[email protected]>
Date: Fri, 29 Mar 2024 00:22:53 +1300
Subject: [PATCH] fixup: respect io_combine_limit in bulk_write.c
---
src/backend/storage/smgr/bulk_write.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/src/backend/storage/smgr/bulk_write.c
b/src/backend/storage/smgr/bulk_write.c
index 848c3054f5..612a9a23b3 100644
--- a/src/backend/storage/smgr/bulk_write.c
+++ b/src/backend/storage/smgr/bulk_write.c
@@ -45,12 +45,6 @@
#define MAX_PENDING_WRITES XLR_MAX_BLOCK_ID
-/*
- * How many blocks to send to smgrwritev() at a time. Arbitrary value for
- * now.
- */
-#define MAX_BLOCKS_PER_WRITE ((128 * 1024) / BLCKSZ)
-
static const PGIOAlignedBlock zero_buffer = {{0}}; /* worth BLCKSZ */
typedef struct PendingWrite
@@ -232,7 +226,7 @@ smgr_bulk_flush(BulkWriteState *bulkstate)
for (int i = 0; i < npending; i++)
{
Page page;
- const void *pages[MAX_BLOCKS_PER_WRITE];
+ const void *pages[MAX_IO_COMBINE_LIMIT];
BlockNumber blkno;
int nblocks;
int max_nblocks;
@@ -266,14 +260,14 @@ smgr_bulk_flush(BulkWriteState *bulkstate)
* We're overwriting. Clamp at the existing size,
because we
* can't mix writing and extending in a single
operation.
*/
- max_nblocks = Min(lengthof(pages),
+ max_nblocks = Min(io_combine_limit,
bulkstate->pages_written - blkno);
}
else
{
/* We're extending. */
Assert(blkno == bulkstate->pages_written);
- max_nblocks = lengthof(pages);
+ max_nblocks = io_combine_limit;
}
/* Find as many consecutive blocks as we can. */
--
2.39.3 (Apple Git-146)
