Messages in this thread |  | | Date | Fri, 16 Dec 2022 09:43:02 +0800 | Subject | Re: [PATCH] mm/memcontrol: Skip root memcg in memcg_memory_event_mm | From | Haifeng Xu <> |
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On 2022/12/16 02:18, Shakeel Butt wrote: > On Thu, Dec 15, 2022 at 09:19:07AM +0000, Haifeng Xu wrote: >> The memory events aren't supported on root cgroup, so there is no need >> to account MEMCG_OOM_KILL on root memcg. >> > > Can you explain the scenario where this is happening and causing issue > for you? > If the victim selected by oom killer belongs to root memcg, memcg_memory_event_mm still counts the MEMCG_OOM_KILL event. This behavior is meaningless because the flag of events/events.local in memory_files is CFTYPE_NOT_ON_ROOT. The root memcg does not count any memory event.
>> Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com> >> --- >> include/linux/memcontrol.h | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h >> index 567f12323f55..09f75161a3bc 100644 >> --- a/include/linux/memcontrol.h >> +++ b/include/linux/memcontrol.h >> @@ -1142,7 +1142,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm, >> >> rcu_read_lock(); >> memcg = mem_cgroup_from_task(rcu_dereference(mm->owner)); >> - if (likely(memcg)) >> + if (likely(memcg && !mem_cgroup_is_root(memcg))) > > Even if we need this additional check, this is not the right place. > >> memcg_memory_event(memcg, event); >> rcu_read_unlock(); >> } >> -- >> 2.25.1 >>
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