Author: jeff Date: Thu Feb 27 08:23:10 2020 New Revision: 358377 URL: https://svnweb.freebsd.org/changeset/base/358377
Log: A pair of performance improvements. Swap buckets on free as well as alloc so that alloc is always the most cache-hot data. When selecting a zone domain for the round-robin bucket cache use the local domain unless there is a severe imbalance. This does not affinitize memory, only locks and queues. Reviewed by: markj, rlibby Differential Revision: https://reviews.freebsd.org/D23824 Modified: head/sys/vm/uma_core.c Modified: head/sys/vm/uma_core.c ============================================================================== --- head/sys/vm/uma_core.c Thu Feb 27 07:02:33 2020 (r358376) +++ head/sys/vm/uma_core.c Thu Feb 27 08:23:10 2020 (r358377) @@ -564,26 +564,29 @@ zone_domain_lock(uma_zone_t zone, int domain) } /* - * Search for the domain with the least cached items and return it, breaking - * ties with a preferred domain by returning it. + * Search for the domain with the least cached items and return it if it + * is out of balance with the preferred domain. */ static __noinline int zone_domain_lowest(uma_zone_t zone, int pref) { - long least, nitems; + long least, nitems, prefitems; int domain; int i; - least = LONG_MAX; + prefitems = least = LONG_MAX; domain = 0; for (i = 0; i < vm_ndomains; i++) { nitems = ZDOM_GET(zone, i)->uzd_nitems; if (nitems < least) { domain = i; least = nitems; - } else if (nitems == least && (i == pref || domain == pref)) - domain = pref; + } + if (domain == pref) + prefitems = nitems; } + if (prefitems < least * 2) + return (pref); return (domain); } @@ -4102,8 +4105,11 @@ uma_zfree_arg(uma_zone_t zone, void *item, void *udata bucket = &cache->uc_crossbucket; } else #endif - if (bucket->ucb_cnt >= bucket->ucb_entries) - bucket = &cache->uc_freebucket; + if (bucket->ucb_cnt == bucket->ucb_entries && + cache->uc_freebucket.ucb_cnt < + cache->uc_freebucket.ucb_entries) + cache_bucket_swap(&cache->uc_freebucket, + &cache->uc_allocbucket); if (__predict_true(bucket->ucb_cnt < bucket->ucb_entries)) { cache_bucket_push(cache, bucket, item); critical_exit(); _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
