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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org
Cc: linux-mm@kvack.org, rientjes@google.com, oleg@redhat.com,
	vdavydov@parallels.com, akpm@linux-foundation.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/6] mm, oom: do not loop over all tasks if there are no external tasks sharing mm
Date: Fri, 27 May 2016 01:14:35 +0900	[thread overview]
Message-ID: <201605270114.IEI48969.MFFtFOJLQOOHSV@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20160526153532.GG23675@dhcp22.suse.cz>

Michal Hocko wrote:
> On Fri 27-05-16 00:25:23, Tetsuo Handa wrote:
> > I think that remembering whether this mm might be shared between
> > multiple thread groups at clone() time (i.e. whether
> > clone(CLONE_VM without CLONE_SIGHAND) was ever requested on this mm)
> > is safe (given that that thread already got SIGKILL or is exiting).
> 
> I was already playing with that idea but I didn't want to add anything
> to the fork path which is really hot. This patch is not really needed
> for the rest. It just felt like a nice optimization. I do not think it
> is worth deeper changes in the fast paths.

"[PATCH 6/6] mm, oom: fortify task_will_free_mem" depends on [PATCH 1/6].
You will need to update [PATCH 6/6].

It seems to me that [PATCH 6/6] resembles
http://lkml.kernel.org/r/201605250005.GHH26082.JOtQOSLMFFOFVH@I-love.SAKURA.ne.jp .
I think we will be happy if we can speed up mm_is_reapable() test using
"whether this mm might be shared between multiple thread groups" flag.
I don't think updating such flag at clone() is too heavy operation to add.

  reply	other threads:[~2016-05-26 16:14 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-05-26 12:40 [PATCH 0/5] Handle oom bypass more gracefully Michal Hocko
2016-05-26 12:40 ` [PATCH 1/6] mm, oom: do not loop over all tasks if there are no external tasks sharing mm Michal Hocko
2016-05-26 14:30   ` Tetsuo Handa
2016-05-26 14:59     ` Michal Hocko
2016-05-26 15:25       ` [PATCH 1/6] mm, oom: do not loop over all tasks if there are noexternal " Tetsuo Handa
2016-05-26 15:35         ` Michal Hocko
2016-05-26 16:14           ` Tetsuo Handa [this message]
2016-05-27  6:45             ` [PATCH 1/6] mm, oom: do not loop over all tasks if there are no external " Michal Hocko
2016-05-27  7:15               ` Michal Hocko
2016-05-27  8:03                 ` Michal Hocko
2016-05-26 12:40 ` [PATCH 2/6] proc, oom_adj: extract oom_score_adj setting into a helper Michal Hocko
2016-05-26 12:40 ` [PATCH 3/6] mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj Michal Hocko
2016-05-27 11:18   ` Michal Hocko
2016-05-27 16:18     ` Vladimir Davydov
2016-05-30  7:07       ` Michal Hocko
2016-05-30  8:47         ` Vladimir Davydov
2016-05-30  9:39           ` Michal Hocko
2016-05-30 10:26             ` Vladimir Davydov
2016-05-30 11:11               ` Michal Hocko
2016-05-30 12:19                 ` Vladimir Davydov
2016-05-30 12:28                   ` Michal Hocko
2016-05-26 12:40 ` [PATCH 4/6] mm, oom: skip over vforked tasks Michal Hocko
2016-05-27 16:48   ` Vladimir Davydov
2016-05-30  7:13     ` Michal Hocko
2016-05-30  9:52       ` Michal Hocko
2016-05-30 10:40         ` Vladimir Davydov
2016-05-30 10:53           ` Michal Hocko
2016-05-30 12:03   ` Michal Hocko
2016-05-26 12:40 ` [PATCH 5/6] mm, oom: kill all tasks sharing the mm Michal Hocko
2016-05-26 12:40 ` [PATCH 6/6] mm, oom: fortify task_will_free_mem Michal Hocko
2016-05-26 14:11   ` Tetsuo Handa
2016-05-26 14:23     ` Michal Hocko
2016-05-26 14:41       ` Tetsuo Handa
2016-05-26 14:56         ` Michal Hocko
2016-05-27 11:07   ` Michal Hocko
2016-05-27 16:00 ` [PATCH 0/5] Handle oom bypass more gracefully Michal Hocko

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