From 4656e3d66893f286767285cf74dabb3877068e49 Mon Sep 17 00:00:00 2001 From: Peter Eisentraut Date: Wed, 6 Jan 2021 10:15:19 +0100 Subject: 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 Discussion: https://www.postgresql.org/message-id/flat/CAMsr+YF=+ctXBZj3ywmvKNUjWpxmuTuUKuv-rgbHGX5i5pLstQ@mail.gmail.com --- src/include/pg_config_manual.h | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) (limited to 'src/include/pg_config_manual.h') diff --git a/src/include/pg_config_manual.h b/src/include/pg_config_manual.h index 3cbdc6d180..d27c8601fa 100644 --- a/src/include/pg_config_manual.h +++ b/src/include/pg_config_manual.h @@ -309,6 +309,45 @@ */ /* #define RANDOMIZE_ALLOCATED_MEMORY */ +/* + * For cache invalidation debugging, define CLOBBER_CACHE_ENABLED to enable + * use of the debug_invalidate_system_caches_always GUC to aggressively flush + * syscache/relcache entries whenever it's possible to deliver invalidations. + * See AcceptInvalidationMessages() in src/backend/utils/cache/inval.c for + * details. + * + * USE_ASSERT_CHECKING builds default to enabling this. It's possible to use + * CLOBBER_CACHE_ENABLED without a cassert build and the implied + * CLOBBER_FREED_MEMORY and MEMORY_CONTEXT_CHECKING options but it's unlikely + * to be as effective at identifying problems. + */ +/* #define CLOBBER_CACHE_ENABLED */ + +#if defined(USE_ASSERT_CHECKING) && !defined(CLOBBER_CACHE_ENABLED) +#define CLOBBER_CACHE_ENABLED +#endif + +/* + * Backwards compatibility for the older compile-time-only cache clobber + * macros. + */ +#if !defined(CLOBBER_CACHE_ENABLED) && (defined(CLOBBER_CACHE_ALWAYS) || defined(CLOBBER_CACHE_RECURSIVELY)) +#define CLOBBER_CACHE_ENABLED +#endif + +/* + * Recover memory used for relcache entries when invalidated. See + * RelationBuildDescr() in src/backend/utils/cache/relcache.c. + * + * This is active automatically for clobber cache builds when clobbering is + * active, but can be overridden here by explicitly defining + * RECOVER_RELATION_BUILD_MEMORY. Define to 1 to always free relation cache + * memory even when clobber is off, or to 0 to never free relation cache + * memory even when clobbering is on. + */ +/* #define RECOVER_RELATION_BUILD_MEMORY 0 */ /* Force disable */ +/* #define RECOVER_RELATION_BUILD_MEMORY 1 */ /* Force enable */ + /* * Define this to force all parse and plan trees to be passed through * copyObject(), to facilitate catching errors and omissions in -- cgit v1.2.1