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| author | Peter Eisentraut <peter@eisentraut.org> | 2021-01-06 10:15:19 +0100 |
|---|---|---|
| committer | Peter Eisentraut <peter@eisentraut.org> | 2021-01-06 10:46:44 +0100 |
| commit | 4656e3d66893f286767285cf74dabb3877068e49 (patch) | |
| tree | b6ab45e6cff78f644d54c532331b7247c864f7c6 /src/backend/utils/adt/lockfuncs.c | |
| parent | 8900b5a9d59a645b3485f5b046c4c7871b2c4026 (diff) | |
| download | postgresql-4656e3d66893f286767285cf74dabb3877068e49.tar.gz postgresql-4656e3d66893f286767285cf74dabb3877068e49.zip | |
Replace CLOBBER_CACHE_ALWAYS with run-time GUC
Forced cache invalidation (CLOBBER_CACHE_ALWAYS) has been impractical
to use for testing in PostgreSQL because it's so slow and because it's
toggled on/off only at build time. It is helpful when hunting bugs in
any code that uses the sycache/relcache because causes cache
invalidations to be injected whenever it would be possible for an
invalidation to occur, whether or not one was really pending.
Address this by providing run-time control over cache clobber
behaviour using the new debug_invalidate_system_caches_always GUC.
Support is not compiled in at all unless assertions are enabled or
CLOBBER_CACHE_ENABLED is explicitly defined at compile time. It
defaults to 0 if compiled in, so it has negligible effect on assert
build performance by default.
When support is compiled in, test code can now set
debug_invalidate_system_caches_always=1 locally to a backend to test
specific queries, functions, extensions, etc. Or tests can toggle it
globally for a specific test case while retaining normal performance
during test setup and teardown.
For backwards compatibility with existing test harnesses and scripts,
debug_invalidate_system_caches_always defaults to 1 if
CLOBBER_CACHE_ALWAYS is defined, and to 3 if CLOBBER_CACHE_RECURSIVE
is defined.
CLOBBER_CACHE_ENABLED is now visible in pg_config_manual.h, as is the
related RECOVER_RELATION_BUILD_MEMORY setting for the relcache.
Author: Craig Ringer <craig.ringer@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/CAMsr+YF=+ctXBZj3ywmvKNUjWpxmuTuUKuv-rgbHGX5i5pLstQ@mail.gmail.com
Diffstat (limited to 'src/backend/utils/adt/lockfuncs.c')
| -rw-r--r-- | src/backend/utils/adt/lockfuncs.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/backend/utils/adt/lockfuncs.c b/src/backend/utils/adt/lockfuncs.c index 0db8be6c917..b1cf5b79a75 100644 --- a/src/backend/utils/adt/lockfuncs.c +++ b/src/backend/utils/adt/lockfuncs.c @@ -629,7 +629,7 @@ pg_isolation_test_session_is_blocked(PG_FUNCTION_ARGS) * Check if any of these are in the list of interesting PIDs, that being * the sessions that the isolation tester is running. We don't use * "arrayoverlaps" here, because it would lead to cache lookups and one of - * our goals is to run quickly under CLOBBER_CACHE_ALWAYS. We expect + * our goals is to run quickly with debug_invalidate_system_caches_always > 0. We expect * blocking_pids to be usually empty and otherwise a very small number in * isolation tester cases, so make that the outer loop of a naive search * for a match. |