From d4a5b369ad6d8aae552752ff438dddde653a72ec Mon Sep 17 00:00:00 2001 From: Shakeel Butt Date: Thu, 28 Dec 2023 07:30:55 +0000 Subject: mm: ratelimit stat flush from workingset shrinker One of our workloads (Postgres 14 + sysbench OLTP) regressed on newer upstream kernel and on further investigation, it seems like the cause is the always synchronous rstat flush in the count_shadow_nodes() added by the commit f82e6bf9bb9b ("mm: memcg: use rstat for non-hierarchical stats"). On further inspection it seems like we don't really need accurate stats in this function as it was already approximating the amount of appropriate shadow entries to keep for maintaining the refault information. Since there is already 2 sec periodic rstat flush, we don't need exact stats here. Let's ratelimit the rstat flush in this code path. Link: https://lkml.kernel.org/r/20231228073055.4046430-1-shakeelb@google.com Fixes: f82e6bf9bb9b ("mm: memcg: use rstat for non-hierarchical stats") Signed-off-by: Shakeel Butt Cc: Johannes Weiner Cc: Yosry Ahmed Cc: Yu Zhao Cc: Michal Hocko Cc: Roman Gushchin Cc: Muchun Song Signed-off-by: Andrew Morton --- mm/workingset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'mm/workingset.c') diff --git a/mm/workingset.c b/mm/workingset.c index 2a2a34234df9..226012974328 100644 --- a/mm/workingset.c +++ b/mm/workingset.c @@ -680,7 +680,7 @@ static unsigned long count_shadow_nodes(struct shrinker *shrinker, struct lruvec *lruvec; int i; - mem_cgroup_flush_stats(sc->memcg); + mem_cgroup_flush_stats_ratelimited(sc->memcg); lruvec = mem_cgroup_lruvec(sc->memcg, NODE_DATA(sc->nid)); for (pages = 0, i = 0; i < NR_LRU_LISTS; i++) pages += lruvec_page_state_local(lruvec, -- cgit v1.2.3