From: Michal Hocko <mhocko@kernel.org>
To: Roman Gushchin <guro@fb.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>, Tejun Heo <tj@kernel.org>,
kernel-team@fb.com, David Rientjes <rientjes@google.com>,
linux-mm@kvack.org, Vladimir Davydov <vdavydov.dev@gmail.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Andrew Morton <akpm@linux-foundation.org>,
cgroups@vger.kernel.org, linux-doc@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [v8 0/4] cgroup-aware OOM killer
Date: Tue, 26 Sep 2017 15:30:40 +0200 [thread overview]
Message-ID: <20170926133040.uupv3ibkt3jtbotf@dhcp22.suse.cz> (raw)
In-Reply-To: <20170926121300.GB23139@castle.dhcp.TheFacebook.com>
On Tue 26-09-17 13:13:00, Roman Gushchin wrote:
> On Tue, Sep 26, 2017 at 01:21:34PM +0200, Michal Hocko wrote:
> > On Tue 26-09-17 11:59:25, Roman Gushchin wrote:
> > > On Mon, Sep 25, 2017 at 10:25:21PM +0200, Michal Hocko wrote:
> > > > On Mon 25-09-17 19:15:33, Roman Gushchin wrote:
> > > > [...]
> > > > > I'm not against this model, as I've said before. It feels logical,
> > > > > and will work fine in most cases.
> > > > >
> > > > > In this case we can drop any mount/boot options, because it preserves
> > > > > the existing behavior in the default configuration. A big advantage.
> > > >
> > > > I am not sure about this. We still need an opt-in, ragardless, because
> > > > selecting the largest process from the largest memcg != selecting the
> > > > largest task (just consider memcgs with many processes example).
> > >
> > > As I understand Johannes, he suggested to compare individual processes with
> > > group_oom mem cgroups. In other words, always select a killable entity with
> > > the biggest memory footprint.
> > >
> > > This is slightly different from my v8 approach, where I treat leaf memcgs
> > > as indivisible memory consumers independent on group_oom setting, so
> > > by default I'm selecting the biggest task in the biggest memcg.
> >
> > My reading is that he is actually proposing the same thing I've been
> > mentioning. Simply select the biggest killable entity (leaf memcg or
> > group_oom hierarchy) and either kill the largest task in that entity
> > (for !group_oom) or the whole memcg/hierarchy otherwise.
>
> He wrote the following:
> "So I'm leaning toward the second model: compare all oomgroups and
> standalone tasks in the system with each other, independent of the
> failed hierarchical control structure. Then kill the biggest of them."
I will let Johannes to comment but I believe this is just a
misunderstanding. If we compared only the biggest task from each memcg
then we are basically losing our fairness objective, aren't we?
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2017-09-26 13:30 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-11 13:17 [v8 0/4] cgroup-aware OOM killer Roman Gushchin
2017-09-11 13:17 ` [v8 1/4] mm, oom: refactor the oom_kill_process() function Roman Gushchin
2017-09-11 20:51 ` David Rientjes
2017-09-14 13:42 ` Michal Hocko
2017-09-11 13:17 ` [v8 2/4] mm, oom: cgroup-aware OOM killer Roman Gushchin
2017-09-13 20:46 ` David Rientjes
2017-09-13 21:59 ` Roman Gushchin
2017-09-11 13:17 ` [v8 3/4] mm, oom: add cgroup v2 mount option for " Roman Gushchin
2017-09-11 20:48 ` David Rientjes
2017-09-12 20:01 ` Roman Gushchin
2017-09-12 20:23 ` David Rientjes
2017-09-13 12:23 ` Michal Hocko
2017-09-11 13:17 ` [v8 4/4] mm, oom, docs: describe the " Roman Gushchin
2017-09-11 20:44 ` [v8 0/4] " David Rientjes
2017-09-13 12:29 ` Michal Hocko
2017-09-13 20:46 ` David Rientjes
2017-09-14 13:34 ` Michal Hocko
2017-09-14 20:07 ` David Rientjes
2017-09-13 21:56 ` Roman Gushchin
2017-09-14 13:40 ` Michal Hocko
2017-09-14 16:05 ` Roman Gushchin
2017-09-15 10:58 ` Michal Hocko
2017-09-15 15:23 ` Roman Gushchin
2017-09-15 19:55 ` David Rientjes
2017-09-15 21:08 ` Roman Gushchin
2017-09-18 6:20 ` Michal Hocko
2017-09-18 15:02 ` Roman Gushchin
2017-09-21 8:30 ` David Rientjes
2017-09-19 20:54 ` David Rientjes
2017-09-20 22:24 ` Roman Gushchin
2017-09-21 8:27 ` David Rientjes
2017-09-18 6:16 ` Michal Hocko
2017-09-19 20:51 ` David Rientjes
2017-09-18 6:14 ` Michal Hocko
2017-09-20 21:53 ` Roman Gushchin
2017-09-25 12:24 ` Michal Hocko
2017-09-25 17:00 ` Johannes Weiner
2017-09-25 18:15 ` Roman Gushchin
2017-09-25 20:25 ` Michal Hocko
2017-09-26 10:59 ` Roman Gushchin
2017-09-26 11:21 ` Michal Hocko
2017-09-26 12:13 ` Roman Gushchin
2017-09-26 13:30 ` Michal Hocko [this message]
2017-09-26 17:26 ` Johannes Weiner
2017-09-27 3:37 ` Tim Hockin
2017-09-27 7:43 ` Michal Hocko
2017-09-27 10:19 ` Roman Gushchin
2017-09-27 15:35 ` Tim Hockin
2017-09-27 16:23 ` Roman Gushchin
2017-09-27 18:11 ` Tim Hockin
2017-10-01 23:29 ` Shakeel Butt
2017-10-02 11:56 ` Tetsuo Handa
2017-10-02 12:24 ` Michal Hocko
2017-10-02 12:47 ` Roman Gushchin
2017-10-02 14:29 ` Michal Hocko
2017-10-02 19:00 ` Shakeel Butt
2017-10-02 19:28 ` Michal Hocko
2017-10-02 19:45 ` Shakeel Butt
2017-10-02 19:56 ` Michal Hocko
2017-10-02 20:00 ` Tim Hockin
2017-10-02 20:08 ` Michal Hocko
2017-10-02 20:20 ` Shakeel Butt
2017-10-02 20:24 ` Shakeel Butt
2017-10-02 20:34 ` Johannes Weiner
2017-10-02 20:55 ` Michal Hocko
2017-09-25 22:21 ` David Rientjes
2017-09-26 8:46 ` Michal Hocko
2017-09-26 21:04 ` David Rientjes
2017-09-27 7:37 ` Michal Hocko
2017-09-27 9:57 ` Roman Gushchin
2017-09-21 14:21 ` Johannes Weiner
2017-09-21 21:17 ` David Rientjes
2017-09-21 21:51 ` Johannes Weiner
2017-09-22 20:53 ` David Rientjes
2017-09-22 15:44 ` Tejun Heo
2017-09-22 20:39 ` David Rientjes
2017-09-22 21:05 ` Tejun Heo
2017-09-23 8:16 ` David Rientjes
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