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From:   Shakeel Butt <shakeelb@google.com>
Date:   Mon, 26 Jul 2021 09:57:15 -0700
Message-ID: <CALvZod5Vj-_S2gRYpGgwhiCysXuA8z1WEV2ttP0t3Tdy2MU7KQ@mail.gmail.com>
Subject: Re: [PATCH] memcg: replace in_interrupt() by !in_task() in active_memcg()
To:     Vasily Averin <vvs@virtuozzo.com>
Cc:     Johannes Weiner <hannes@cmpxchg.org>,
        Michal Hocko <mhocko@kernel.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Roman Gushchin <guro@fb.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Cgroups <cgroups@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Linux MM <linux-mm@kvack.org>
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On Mon, Jul 26, 2021 at 9:53 AM Vasily Averin <vvs@virtuozzo.com> wrote:
>
> set_active_memcg() uses in_interrupt() check to select proper storage for
> cgroup: pointer on task struct or per-cpu pointer.
>
> It isn't fully correct: obsoleted in_interrupt() includes tasks with disabled BH.
> It's better to use '!in_task()' instead.
>
> Link: https://lkml.org/lkml/2021/7/26/487
> Fixes: 37d5985c003d ("mm: kmem: prepare remote memcg charging infra for interrupt contexts")
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>

Thanks.

Reviewed-by: Shakeel Butt <shakeelb@google.com>