diff options
Diffstat (limited to 'src/include/cache.i')
| -rw-r--r-- | src/include/cache.i | 52 |
1 files changed, 30 insertions, 22 deletions
diff --git a/src/include/cache.i b/src/include/cache.i index ee13eee84c5..8cf7555e716 100644 --- a/src/include/cache.i +++ b/src/include/cache.i @@ -28,34 +28,43 @@ __wt_cache_read_gen_incr(WT_SESSION_IMPL *session) /* * __wt_cache_read_gen_bump -- - * Get the read generation to keep a page in memory. + * Update the page's read generation. */ -static inline uint64_t -__wt_cache_read_gen_bump(WT_SESSION_IMPL *session) +static inline void +__wt_cache_read_gen_bump(WT_SESSION_IMPL *session, WT_PAGE *page) { + /* Ignore pages set for forcible eviction. */ + if (page->read_gen == WT_READGEN_OLDEST) + return; + + /* Ignore pages already in the future. */ + if (page->read_gen > __wt_cache_read_gen(session)) + return; + /* - * We return read-generations from the future (where "the future" is - * measured by increments of the global read generation). The reason - * is because when acquiring a new hazard pointer for a page, we can - * check its read generation, and if the read generation isn't less - * than the current global generation, we don't bother updating the - * page. In other words, the goal is to avoid some number of updates - * immediately after each update we have to make. + * We set read-generations in the future (where "the future" is measured + * by increments of the global read generation). The reason is because + * when acquiring a new hazard pointer for a page, we can check its read + * generation, and if the read generation isn't less than the current + * global generation, we don't bother updating the page. In other + * words, the goal is to avoid some number of updates immediately after + * each update we have to make. */ - return (__wt_cache_read_gen(session) + WT_READGEN_STEP); + page->read_gen = __wt_cache_read_gen(session) + WT_READGEN_STEP; } /* * __wt_cache_read_gen_new -- * Get the read generation for a new page in memory. */ -static inline uint64_t -__wt_cache_read_gen_new(WT_SESSION_IMPL *session) +static inline void +__wt_cache_read_gen_new(WT_SESSION_IMPL *session, WT_PAGE *page) { WT_CACHE *cache; cache = S2C(session)->cache; - return (__wt_cache_read_gen(session) + cache->read_gen_oldest) / 2; + page->read_gen = + (__wt_cache_read_gen(session) + cache->read_gen_oldest) / 2; } /* @@ -119,12 +128,11 @@ __wt_session_can_wait(WT_SESSION_IMPL *session) return (0); /* - * LSM sets the no-eviction flag when holding the LSM tree lock, - * in that case, or when holding the schema lock, we don't want to - * highjack the thread for eviction. + * LSM sets the no-eviction flag when holding the LSM tree lock, in that + * case, or when holding the schema lock, we don't want to highjack the + * thread for eviction. */ - if (F_ISSET(session, - WT_SESSION_NO_EVICTION | WT_SESSION_LOCKED_SCHEMA)) + if (F_ISSET(session, WT_SESSION_NO_EVICTION | WT_SESSION_LOCKED_SCHEMA)) return (0); return (1); @@ -224,11 +232,11 @@ __wt_cache_eviction_check(WT_SESSION_IMPL *session, bool busy, bool *didworkp) return (0); /* - * Threads operating on trees that cannot be evicted are ignored, - * mostly because they're not contributing to the problem. + * Threads operating on cache-resident trees are ignored because they're + * not contributing to the problem. */ btree = S2BT_SAFE(session); - if (btree != NULL && F_ISSET(btree, WT_BTREE_NO_EVICTION)) + if (btree != NULL && F_ISSET(btree, WT_BTREE_IN_MEMORY)) return (0); /* Check if eviction is needed. */ |