pgsql: Use simplehash for backend-private buffer pin refcounts.

Started by Peter Geoghegan5 months ago1 messagescomitters

pg@bowt.ie

5 months ago

Use simplehash for backend-private buffer pin refcounts.

Replace dynahash with simplehash for the per-backend PrivateRefCountHash
overflow table. Simplehash generates inlined, open-addressed lookup
code, avoiding the per-call overhead of dynahash that becomes noticeable
when many buffers are pinned with a CPU-bound workload.

Motivated by testing of the index prefetching patch, which pins many
more buffers concurrently than typical index scans.

Author: Peter Geoghegan <pg@bowt.ie>
Suggested-by: Andres Freund <andres@anarazel.de>
Reviewed-By: Tomas Vondra <tomas@vondra.me>
Reviewed-By: Andres Freund <andres@anarazel.de>
Discussion: /messages/by-id/CAH2-Wz=g=JTSyDB4UtB5su2ZcvsS7VbP+ZMvvaG6ABoCb+s8Lw@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/a367c433ad015b889ee296b07de00017819915c4

Modified Files
--------------
src/backend/storage/buffer/bufmgr.c | 68 +++++++++++++++++++------------------
src/tools/pgindent/typedefs.list | 2 ++
2 files changed, 37 insertions(+), 33 deletions(-)