From 2dea8961fd6383afe1e457926131c2213db211f0 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Sun, 1 Sep 2024 00:42:27 -0400 Subject: [PATCH v2.3 28/30] 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 1f757d96f07..ac19fb87433 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; -- 2.48.1.76.g4e746b1a31.dirty