From: Johannes Weiner <hannes@cmpxchg.org>
To: jingrui <jingrui@huawei.com>
Cc: "tj@kernel.org" <tj@kernel.org>, Lizefan <lizefan@huawei.com>,
"mhocko@kernel.org" <mhocko@kernel.org>,
"vdavydov.dev@gmail.com" <vdavydov.dev@gmail.com>,
"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
"linux-mm@kvack.org" <linux-mm@kvack.org>,
"cgroups@vger.kernel.org" <cgroups@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
caihaomin <caihaomin@huawei.com>,
"Weiwei (N)" <wick.wei@huawei.com>,
guro@cmpxchg.org
Subject: Re: PROBLEM: cgroup cost too much memory when transfer small files to tmpfs
Date: Tue, 21 Jul 2020 13:41:26 -0400 [thread overview]
Message-ID: <20200721174126.GA271870@cmpxchg.org> (raw)
In-Reply-To: <2E04DD7753BE0E4ABABF0B664610AD6F2620CAF7@dggeml528-mbx.china.huawei.com>
On Tue, Jul 21, 2020 at 11:19:52AM +0000, jingrui wrote:
> Cc: Johannes Weiner <hannes@cmpxchg.org> ; Michal Hocko <mhocko@kernel.org>; Vladimir Davydov <vdavydov.dev@gmail.com>
>
> Thanks.
>
> ---
> PROBLEM: cgroup cost too much memory when transfer small files to tmpfs.
>
> keywords: cgroup PERCPU/memory cost too much.
>
> description:
>
> We send small files from node-A to node-B tmpfs /tmp directory using sftp. On
> node-B the systemd configured with pam on like below.
>
> cat /etc/pam.d/password-auth | grep systemd
> -session optional pam_systemd.so
>
> So when transfer a file, a systemd session is created, that means a cgroup is
> created, then file saved at /tmp will associated with a cgroup object. After
> file transferred, session and cgroup-dir will be removed, but the file in /tmp
> still associated with the cgroup object. The PERCPU memory in cgroup/css object
> cost a lot(about 0.5MB/per-cgroup-object) on 200/cpus machine.
CC Roman who had a patch series to free all this extended (percpu)
memory upon cgroup deletion:
https://lore.kernel.org/patchwork/cover/1050508/
It looks like it never got merged for some reason.
next prev parent reply other threads:[~2020-07-21 17:43 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-21 11:19 jingrui
2020-07-21 14:45 ` Shakeel Butt
2020-07-21 17:41 ` Johannes Weiner [this message]
2020-07-21 18:49 ` Roman Gushchin
2020-07-21 19:12 ` Shakeel Butt
2020-07-21 19:27 ` Roman Gushchin
2020-07-24 7:55 ` Michal Hocko
2020-07-24 9:35 ` 答复: " jingrui
2020-07-24 11:35 ` Michal Hocko
2020-07-27 3:14 ` jingrui
2020-07-27 13:40 ` 答复: " Fangxiuning (Jack, EulerOS)
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