Inline initial comparisons in TestForOldSnapshot() Even with old_snapshot_threshold = -1 (which disables the "snapshot too old" feature), performance regressions were seen at moderate to high concurrency. For example, a one-socket, four-core system running 200 connections at saturation could see up to a 2.3% regression, with larger regressions possible on NUMA machines. By inlining the early (smaller, faster) tests in the TestForOldSnapshot() function, the i7 case dropped to a 0.2% regression, which could easily just be noise, and is clearly an improvement. Further testing will show whether more is needed.
Branch ------ master Details ------- http://git.postgresql.org/pg/commitdiff/11e178d0dc4bc2328ae4759090b3c48b07023fab Modified Files -------------- src/backend/storage/buffer/bufmgr.c | 28 +++++----------------------- src/include/storage/bufmgr.h | 32 +++++++++++++++++++++++++++++++- 2 files changed, 36 insertions(+), 24 deletions(-) -- Sent via pgsql-committers mailing list (pgsql-committers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-committers
