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Mercier" To: tjmercier@google.com, Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Andrew Morton Cc: android-mm@google.com, Minchan Kim , cgroups@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" 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. Fixes: aa48e47e3906 ("memcg: infrastructure to flush memcg stats") Reported-by: Minchan Kim Signed-off-by: T.J. Mercier Acked-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Chris Li Reviewed-by: Yosry Ahmed --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index e4c8735e7c85..bad8f9dfc9ab 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -5586,7 +5586,7 @@ static int mem_cgroup_css_online(struct cgroup_subsys= _state *css) if (alloc_shrinker_info(memcg)) goto offline_kmem; =20 - 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, FLUSH_TIME); lru_gen_online_memcg(memcg); --=20 2.43.0.429.g432eaa2c6b-goog