From: "T.J. Mercier" <tjmercier@google.com> 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=... ---------------------------------------------------------------------- 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 <tjmercier@google.com> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Chris Li <chrisl@kernel.org> Reported-by: Minchan Kim <minchan@google.com> Reviewed-by: Yosry Ahmed <yosryahmed@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Michal Koutn <mkoutny@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Conflicts: mm/memcontrol.c [context can not be matched] Signed-off-by: Chen Ridong <chenridong@huawei.com> --- 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; -- 2.34.1