From c5d258e2ed8654fdf43d19c7358b5660827a6344 Mon Sep 17 00:00:00 2001 From: "T.J. Mercier" Date: Wed, 30 Oct 2024 06:16:02 +0000 Subject: [PATCH] mm: memcg: don't periodically flush stats when memcg is disabled mainline inclusion from mainline-v6.9-rc1 commit 13ef7424577ff9b663aeaa4fda67e186d9856df3 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IB0CT3 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=13ef7424577ff9b663aeaa4fda67e186d9856df3 ---------------------------------------------------------------------- The root memcg is onlined even when memcg is disabled. When it's onlined a 2 second periodic stat flush is started, but no stat flushing is required when memcg is disabled because there can be no child memcgs. Most calls to flush memcg stats are avoided when memcg is disabled as a result of the mem_cgroup_disabled check added in 7d7ef0a4686a ("mm: memcg: restore subtree stats flushing"), but the periodic flushing started in mem_cgroup_css_online is not. Skip it. Link: https://lkml.kernel.org/r/20240126211927.1171338-1-tjmercier@google.com Fixes: aa48e47e3906 ("memcg: infrastructure to flush memcg stats") Signed-off-by: T.J. Mercier Acked-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Chris Li Reported-by: Minchan Kim Reviewed-by: Yosry Ahmed Cc: Michal Hocko Cc: Muchun Song Cc: Roman Gushchin Cc: Michal Koutn Signed-off-by: Andrew Morton Conflicts: mm/memcontrol.c [context can not be matched] Signed-off-by: Chen Ridong --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index aefaa33147b1..3e928581ab47 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -6581,7 +6581,7 @@ static int mem_cgroup_css_online(struct cgroup_subsys_state *css) refcount_set(&memcg->id.ref, 1); css_get(css); - if (unlikely(mem_cgroup_is_root(memcg))) + if (unlikely(mem_cgroup_is_root(memcg)) && !mem_cgroup_disabled()) queue_delayed_work(system_unbound_wq, &stats_flush_dwork, 2UL*HZ); return 0; -- Gitee