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From:   Shakeel Butt <shakeelb@google.com>
Date:   Mon, 26 Jul 2021 23:44:40 -0700
Message-ID: <CALvZod6YaVBqV_LrqgXO13kBS20uoXdm5EGx2CJfBfPC9yj6Cg@mail.gmail.com>
Subject: Re: [PATCH v7 01/10] memcg: enable accounting for mnt_cache entries
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>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
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On Mon, Jul 26, 2021 at 10:33 PM Vasily Averin <vvs@virtuozzo.com> wrote:
>
> The kernel allocates ~400 bytes of 'strcut mount' for any new mount.

*struct mount*

> Creating a new mount namespace clones most of the parent mounts,
> and this can be repeated many times. Additionally, each mount allocates
> up to PATH_MAX=4096 bytes for mnt->mnt_devname.
>
> It makes sense to account for these allocations to restrict the host's
> memory consumption from inside the memcg-limited container.
>
> Signed-off-by: Vasily Averin <vvs@virtuozzo.com>

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