linux-kernel - Re: [PATCH v4 12/16] memcg: enable accounting for posix_timers

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Message-ID: <87r1iimtof.ffs@nanos.tec.linutronix.de>
Date:   Fri, 07 May 2021 17:48:16 +0200
From:   Thomas Gleixner <tglx@...utronix.de>
To:     Vasily Averin <vvs@...tuozzo.com>, cgroups@...r.kernel.org,
        Michal Hocko <mhocko@...nel.org>,
        Shakeel Butt <shakeelb@...gle.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Vladimir Davydov <vdavydov.dev@...il.com>
Cc:     Roman Gushchin <guro@...com>, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v4 12/16] memcg: enable accounting for posix_timers_cache slab

On Wed, Apr 28 2021 at 09:53, Vasily Averin 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@...tuozzo.com>

Reviewed-by: Thomas Gleixner <tglx@...utronix.de>