From: Johannes Weiner <hannes@cmpxchg.org>
To: Yang Shi <yang.shi@linux.alibaba.com>
Cc: mhocko@suse.com, shakeelb@google.com, akpm@linux-foundation.org,
linux-mm@kvack.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC v3 PATCH 0/5] mm: memcontrol: do memory reclaim when offlining
Date: Wed, 9 Jan 2019 14:32:47 -0500 [thread overview]
Message-ID: <20190109193247.GA16319@cmpxchg.org> (raw)
In-Reply-To: <1547061285-100329-1-git-send-email-yang.shi@linux.alibaba.com>
On Thu, Jan 10, 2019 at 03:14:40AM +0800, Yang Shi wrote:
>
> We have some usecases which create and remove memcgs very frequently,
> and the tasks in the memcg may just access the files which are unlikely
> accessed by anyone else. So, we prefer force_empty the memcg before
> rmdir'ing it to reclaim the page cache so that they don't get
> accumulated to incur unnecessary memory pressure. Since the memory
> pressure may incur direct reclaim to harm some latency sensitive
> applications.
We have kswapd for exactly this purpose. Can you lay out more details
on why that is not good enough, especially in conjunction with tuning
the watermark_scale_factor etc.?
We've been pretty adamant that users shouldn't use drop_caches for
performance for example, and that the need to do this usually is
indicative of a problem or suboptimal tuning in the VM subsystem.
How is this different?
next prev parent reply other threads:[~2019-01-09 19:32 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-09 19:14 [RFC v3 PATCH 0/5] mm: memcontrol: do memory reclaim when offlining Yang Shi
2019-01-09 19:14 ` [v3 PATCH 1/5] doc: memcontrol: fix the obsolete content about force empty Yang Shi
2019-01-09 19:14 ` [v3 PATCH 2/5] mm: memcontrol: add may_swap parameter to mem_cgroup_force_empty() Yang Shi
2019-01-09 19:14 ` [v3 PATCH 3/5] mm: memcontrol: introduce wipe_on_offline interface Yang Shi
2019-01-09 19:14 ` [v3 PATCH 4/5] mm: memcontrol: bring force_empty into default hierarchy Yang Shi
2019-01-09 19:14 ` [v3 PATCH 5/5] doc: memcontrol: add description for wipe_on_offline Yang Shi
2019-01-10 12:00 ` William Kucharski
2019-01-09 19:32 ` Johannes Weiner [this message]
2019-01-09 20:36 ` [RFC v3 PATCH 0/5] mm: memcontrol: do memory reclaim when offlining Yang Shi
2019-01-09 21:23 ` Johannes Weiner
2019-01-09 22:09 ` Yang Shi
2019-01-09 22:51 ` Johannes Weiner
2019-01-10 1:47 ` Yang Shi
2019-01-14 19:01 ` Johannes Weiner
2019-01-17 22:55 ` Yang Shi
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