linux-kernel - Re: [RFC] 3.10 kernel- oom with about 24G free memory

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Date:   Fri, 10 Feb 2017 10:24:35 +0100
From:   Michal Hocko <mhocko@...nel.org>
To:     Yisheng Xie <xieyisheng1@...wei.com>
Cc:     Vlastimil Babka <vbabka@...e.cz>, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        Tetsuo Handa <penguin-kernel@...ove.SAKURA.ne.jp>,
        Hanjun Guo <guohanjun@...wei.com>
Subject: Re: [RFC] 3.10 kernel- oom with about 24G free memory

On Fri 10-02-17 17:15:59, Yisheng Xie wrote:
> Hi Michal,
> 
> Thanks for comment!
> On 2017/2/10 16:52, Michal Hocko wrote:
> > On Fri 10-02-17 16:48:58, Yisheng Xie wrote:
> >> Hi Michal,
> >>
> >> Thanks for comment!
> >> On 2017/2/10 15:09, Michal Hocko wrote:
> >>> On Fri 10-02-17 09:13:58, Yisheng Xie wrote:
> >>>> hi Michal,
> >>>> Thanks for your comment.
> >>>>
> >>>> On 2017/2/9 21:41, Michal Hocko wrote:
> > [...]
> >>>>>> OK, so this is a memcg OOM killer which panics because the configuration
> >>>>>> says so. The OOM report doesn't say so and that is the bug. dump_header
> >>>>>> is memcg aware and mem_cgroup_out_of_memory initializes oom_control
> >>>>>> properly. Is this Vanilla kernel?
> >>>>
> >>>> That means we should raise the limit of that memcg to avoid memcg OOM killer, right?
> >>>
> >>> Why do you configure the system to panic on memcg OOM in the first
> >>> place. This is a wrong thing to do in 99% of cases.
> >>
> >> For our production think it should use reboot to recovery the system when OOM,
> >> instead of killing user's key process. Maybe not the right thing.
> > 
> > I can understand that for the global oom killer but not for memcg. You
> > can recover the oom even without killing any process. You can simply
> > increase the limit from the userspace when the oom event is triggered.
>
> So you mean set oom_kill_disable and increase the limit from userspace
> when memcg under_oom, right?

yes
-- 
Michal Hocko
SUSE Labs