From: Michal Hocko <mhocko@kernel.org>
To: Roman Gushchin <guro@fb.com>
Cc: linux-mm@kvack.org, Vladimir Davydov <vdavydov.dev@gmail.com>,
Johannes Weiner <hannes@cmpxchg.org>,
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>,
David Rientjes <rientjes@google.com>,
Andrew Morton <akpm@linux-foundation.org>,
Tejun Heo <tj@kernel.org>,
kernel-team@fb.com, cgroups@vger.kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [v7 5/5] mm, oom: cgroup v2 mount option to disable cgroup-aware OOM killer
Date: Wed, 6 Sep 2017 10:42:42 +0200 [thread overview]
Message-ID: <20170906084242.l4rcx6n3hdzxvil6@dhcp22.suse.cz> (raw)
In-Reply-To: <20170905191609.GA19687@castle.dhcp.TheFacebook.com>
On Tue 05-09-17 20:16:09, Roman Gushchin wrote:
> On Tue, Sep 05, 2017 at 05:12:51PM +0200, Michal Hocko wrote:
[...]
> > > Then we should probably hide corresponding
> > > cgroup interface (oom_group and oom_priority knobs) by default,
> > > and it feels as unnecessary complication and is overall against
> > > cgroup v2 interface design.
> >
> > Why. If we care enough, we could simply return EINVAL when those knobs
> > are written while the corresponding strategy is not used.
>
> It doesn't look as a nice default interface.
I do not have a strong opinion on this. A printk_once could explain why
the knob is ignored and instruct the admin how to enable the feature
completely.
> > > > I think we should instead go with
> > > > oom_strategy=[alloc_task,biggest_task,cgroup]
> > >
> > > It would be a really nice interface; although I've no idea how to implement it:
> > > "alloc_task" is an existing sysctl, which we have to preserve;
> >
> > I would argue that we should simply deprecate and later drop the sysctl.
> > I _strongly_ suspect anybody is using this. If yes it is not that hard
> > to change the kernel command like rather than select the sysctl.
>
> I agree. And if so, why do we need a new interface for an useless feature?
Well, I won't be opposed just deprecating the sysfs and only add a
"real" kill-allocate strategy if somebody explicitly asks for it.
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2017-09-06 8:42 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-09-04 14:21 [v7 0/5] cgroup-aware OOM killer Roman Gushchin
2017-09-04 14:21 ` [v7 1/5] mm, oom: refactor the oom_kill_process() function Roman Gushchin
2017-09-05 13:34 ` Michal Hocko
2017-09-04 14:21 ` [v7 2/5] mm, oom: cgroup-aware OOM killer Roman Gushchin
2017-09-05 14:57 ` Michal Hocko
2017-09-05 20:23 ` Roman Gushchin
2017-09-06 8:31 ` Michal Hocko
2017-09-06 12:57 ` Roman Gushchin
2017-09-06 13:22 ` Michal Hocko
2017-09-06 13:41 ` Roman Gushchin
2017-09-06 14:10 ` Michal Hocko
2017-09-06 8:34 ` Michal Hocko
2017-09-06 12:33 ` Roman Gushchin
2017-09-07 16:18 ` Christopher Lameter
2017-09-11 8:49 ` Michal Hocko
2017-09-04 14:21 ` [v7 3/5] mm, oom: introduce oom_priority for memory cgroups Roman Gushchin
2017-09-04 14:21 ` [v7 4/5] mm, oom, docs: describe the cgroup-aware OOM killer Roman Gushchin
2017-09-04 14:21 ` [v7 5/5] mm, oom: cgroup v2 mount option to disable " Roman Gushchin
2017-09-04 17:32 ` Shakeel Butt
2017-09-04 17:51 ` Roman Gushchin
2017-09-05 13:44 ` Michal Hocko
2017-09-05 14:30 ` Roman Gushchin
2017-09-05 15:12 ` Michal Hocko
2017-09-05 19:16 ` Roman Gushchin
2017-09-06 8:42 ` Michal Hocko [this message]
2017-09-06 17:40 ` Roman Gushchin
2017-09-06 17:59 ` Michal Hocko
2017-09-06 20:59 ` David Rientjes
2017-09-07 14:43 ` Christopher Lameter
2017-09-07 14:52 ` Roman Gushchin
2017-09-07 15:03 ` Christopher Lameter
2017-09-07 16:42 ` Roman Gushchin
2017-09-07 17:03 ` Christopher Lameter
2017-09-07 21:55 ` David Rientjes
2017-09-07 16:21 ` Christopher Lameter
2017-09-05 21:53 ` Johannes Weiner
2017-09-06 8:28 ` Michal Hocko
2017-09-07 16:14 ` Johannes Weiner
2017-09-11 9:05 ` Michal Hocko
2017-09-11 12:50 ` Roman Gushchin
2017-09-07 16:27 ` Christopher Lameter
2017-09-07 22:03 ` David Rientjes
2017-09-08 21:07 ` Christopher Lameter
2017-09-09 8:45 ` David Rientjes
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