From 049d9b872db8a24b45709dbaed9a1051e92ed513 Mon Sep 17 00:00:00 2001 From: Thomas Munro Date: Thu, 11 Mar 2021 15:58:05 +1300 Subject: [PATCH] Improve comment for struct BufferDesc. Add a note that per-buffer I/O condition variables currently live outside the BufferDesc struct. Follow-up for commit d8725104. Reported-by: Julien Rouhaud Discussion: https://postgr.es/m/20210311031118.hucytmrgwlktjxgq%40nol --- src/include/storage/buf_internals.h | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/src/include/storage/buf_internals.h b/src/include/storage/buf_internals.h index 9cbf1fc3fad..33fcaf5c9a8 100644 --- a/src/include/storage/buf_internals.h +++ b/src/include/storage/buf_internals.h @@ -174,6 +174,10 @@ typedef struct buftag * Be careful to avoid increasing the size of the struct when adding or * reordering members. Keeping it below 64 bytes (the most common CPU * cache line size) is fairly important for performance. + * + * Per-buffer I/O condition variables are currently kept outside this struct in + * a separate array. They could be moved in here and still fit within that + * limit on common systems, but for now that is not done. */ typedef struct BufferDesc {