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Date:   Fri, 16 Dec 2022 06:42:10 +0000
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References: <20221215091907.763801-1-haifeng.xu@shopee.com>
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Message-ID: <20221216064210.krxtxebuwc7dijzu@google.com>
Subject: Re: [PATCH] mm/memcontrol: Skip root memcg in memcg_memory_event_mm
From:   Shakeel Butt <shakeelb@google.com>
To:     Haifeng Xu <haifeng.xu@shopee.com>
Cc:     akpm@linux-foundation.org, roman.gushchin@linux.dev,
        songmuchun@bytedance.com, hannes@cmpxchg.org, vbabka@suse.cz,
        willy@infradead.org, vasily.averin@linux.dev,
        linux-kernel@vger.kernel.org
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On Fri, Dec 16, 2022 at 09:43:02AM +0800, Haifeng Xu wrote:
> 
> 
> 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.
> 

What about v1's memory.oom_control?