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From:   Shakeel Butt <shakeelb@google.com>
Date:   Tue, 27 Jul 2021 15:33:35 -0700
Message-ID: <CALvZod6avZ=1qHug1ziLwYPNf1c0366Fb9pvYXBx9gh1HBcr6A@mail.gmail.com>
Subject: Re: [PATCH v7 08/10] memcg: enable accounting for posix_timers_cache slab
To:     Vasily Averin <vvs@virtuozzo.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Cgroups <cgroups@vger.kernel.org>,
        Michal Hocko <mhocko@kernel.org>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Vladimir Davydov <vdavydov.dev@gmail.com>,
        Roman Gushchin <guro@fb.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Jul 26, 2021 at 10:34 PM Vasily Averin <vvs@virtuozzo.com> wrote:
>
> A program may create multiple interval timers using timer_create().
> For each timer the kernel preallocates a "queued real-time signal",
> Consequently, the number of timers is limited by the RLIMIT_SIGPENDING
> resource limit. The allocated object is quite small, ~250 bytes,
> but even the default signal limits allow to consume up to 100 megabytes
> per user.
>
> It makes sense to account for them to limit the host's memory consumption
> from inside the memcg-limited container.
>
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
> Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

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