From 75c690243866d3f6b476ecfb9c249da8098122f0 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 1 Sep 2024 00:42:27 -0400 Subject: [PATCH v2 19/20] Temporary: Increase BAS_BULKREAD size Without this we only can execute very little AIO for sequential scans, as there's just not enough buffers in the ring. This isn't the right fix, as just increasing the ring size can have negative performance implications in workloads where the kernel has all the data cached. Author: Reviewed-By: Discussion: https://postgr.es/m/ Backpatch: --- src/backend/storage/buffer/freelist.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/src/backend/storage/buffer/freelist.c b/src/backend/storage/buffer/freelist.c index dffdd57e9b5..f5795b509c7 100644 --- a/src/backend/storage/buffer/freelist.c +++ b/src/backend/storage/buffer/freelist.c @@ -555,7 +555,12 @@ GetAccessStrategy(BufferAccessStrategyType btype) return NULL; case BAS_BULKREAD: - ring_size_kb = 256; + + /* + * FIXME: Temporary increase to allow large enough streaming reads + * to actually benefit from AIO. This needs a better solution. + */ + ring_size_kb = 2 * 1024; break; case BAS_BULKWRITE: ring_size_kb = 16 * 1024; -- 2.45.2.746.g06e570c0df.dirty