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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <42e61739-ddfb-e13e-69e0-d1c1ac948a6d@huawei.com>
Date:   Fri, 10 Feb 2017 17:15:59 +0800
From:   Yisheng Xie <xieyisheng1@...wei.com>
To:     Michal Hocko <mhocko@...nel.org>
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

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?

Thanks
Yisheng Xie.
> 
> Trigerring the panic on memcg oom killer is both dangerous and most
> probably something you do not want.
>