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Subject: Re: [PATCH RFC] mm: don't raise MEMCG_OOM event due to failed
 high-order allocation
To:     Michal Hocko <mhocko@kernel.org>, Roman Gushchin <guro@fb.com>
CC:     <linux-mm@kvack.org>, <linux-kernel@vger.kernel.org>,
        <kernel-team@fb.com>, Johannes Weiner <hannes@cmpxchg.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>
References: <20180910215622.4428-1-guro@fb.com>
 <20180911121141.GS10951@dhcp22.suse.cz>
From:   peter enderborg <peter.enderborg@sony.com>
Message-ID: <0ea4cdbd-dc3f-1b66-8a5f-8d67ab0e2bc9@sony.com>
Date:   Tue, 11 Sep 2018 14:41:04 +0200
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On 09/11/2018 02:11 PM, Michal Hocko wrote:
> Why is this a problem though? IIRC this event was deliberately placed
> outside of the oom path because we wanted to count allocation failures
> and this is also documented that way
>
>           oom
>                 The number of time the cgroup's memory usage was
>                 reached the limit and allocation was about to fail.
>
>                 Depending on context result could be invocation of OOM
>                 killer and retrying allocation or failing a
>
> One could argue that we do not apply the same logic to GFP_NOWAIT
> requests but in general I would like to see a good reason to change
> the behavior and if it is really the right thing to do then we need to
> update the documentation as well.
>

Why not introduce a MEMCG_ALLOC_FAIL in to memcg_memory_event?