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From: Johannes Weiner <hannes@cmpxchg.org>
To: Yafang Shao <laoar.shao@gmail.com>
Cc: mhocko@kernel.org, vdavydov.dev@gmail.com,
	akpm@linux-foundation.org, linux-mm@kvack.org,
	Michal Hocko <mhocko@suse.com>
Subject: Re: [PATCH] mm, memcg: avoid oom if cgroup is not populated
Date: Tue, 26 Nov 2019 11:30:16 -0500	[thread overview]
Message-ID: <20191126163016.GB609004@cmpxchg.org> (raw)
In-Reply-To: <1574773369-1634-1-git-send-email-laoar.shao@gmail.com>

On Tue, Nov 26, 2019 at 08:02:49AM -0500, Yafang Shao wrote:
> There's one case that the processes in a memcg are all exit (due to OOM
> group or some other reasons), but the file page caches are still exist.
> These file page caches may be protected by memory.min so can't be
> reclaimed. If we can't success to restart the processes in this memcg or
> don't want to make this memcg offline, then we want to drop the file page
> caches.
> The advantage of droping this file caches is it can avoid the reclaimer
> (either kswapd or direct) scanning and reclaiming pages from all memcgs
> exist in this system, because currently the reclaimer will fairly reclaim
> pages from all memcgs if the system is under memory pressure.
> The possible method to drop these file page caches is setting the
> hard limit of this memcg to 0. Unfortunately this may invoke the OOM killer
> and generates lots of misleading outputs, that should not happen.

You can set memory.high instead...?


  parent reply	other threads:[~2019-11-26 16:30 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-26 13:02 Yafang Shao
2019-11-26 13:16 ` Michal Hocko
2019-11-26 14:25   ` Yafang Shao
2019-11-26 14:45     ` Michal Hocko
2019-11-26 14:51       ` Yafang Shao
2019-11-26 15:06         ` Michal Hocko
2019-11-26 16:30 ` Johannes Weiner [this message]
2019-11-27  1:16   ` Yafang Shao

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