From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Cc: Yafang Shao <laoar.shao@gmail.com>,
rientjes@google.com, akpm@linux-foundation.org,
linux-mm@kvack.org
Subject: Re: [PATCH] mm, oom: check memcg margin for parallel oom
Date: Tue, 14 Jul 2020 14:57:21 +0200 [thread overview]
Message-ID: <20200714125721.GK24642@dhcp22.suse.cz> (raw)
In-Reply-To: <83fececb-924c-0e1b-8e48-547b93593650@i-love.sakura.ne.jp>
On Tue 14-07-20 21:47:06, Tetsuo Handa wrote:
> On 2020/07/14 21:37, Michal Hocko wrote:
> > - if (mutex_lock_killable(&oom_lock))
> > + if (!mutex_trylock(&oom_lock))
> > return true;
>
> I don't like this change. The trylock needlessly wastes CPU time which could
> have been utilized by the OOM killer/reaper for reclaiming memory.
Ohh, that was an unintended hunk which stayed there from the previous
discussion. With the margin check the lock itself can stay.
>
> Rather, I want to change
>
> - if (!mutex_trylock(&oom_lock)) {
> + if (mutex_lock_killable(&oom_lock)) {
>
> in __alloc_pages_may_oom() side.
Please do not start a tangent discussion again. If you want to make this
change then post a patch with a justification.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2020-07-14 12:57 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 12:08 Yafang Shao
2020-07-14 12:37 ` Michal Hocko
2020-07-14 12:38 ` Michal Hocko
2020-07-14 13:26 ` Yafang Shao
2020-07-14 12:47 ` Tetsuo Handa
2020-07-14 12:57 ` Michal Hocko [this message]
2020-07-14 13:25 ` Yafang Shao
2020-07-14 13:34 ` Michal Hocko
2020-07-14 13:40 ` Yafang Shao
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