From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
To: Michal Hocko <mhocko@kernel.org>, Shakeel Butt <shakeelb@google.com>
Cc: syzbot <syzbot+d0fc9d3c166bc5e4a94b@syzkaller.appspotmail.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Roman Gushchin" <guro@fb.com>,
"Johannes Weiner" <hannes@cmpxchg.org>,
"Jérôme Glisse" <jglisse@redhat.com>,
LKML <linux-kernel@vger.kernel.org>,
"Linux MM" <linux-mm@kvack.org>,
syzkaller-bugs <syzkaller-bugs@googlegroups.com>,
yuzhoujian@didichuxing.com
Subject: Re: general protection fault in oom_unkillable_task
Date: Mon, 17 Jun 2019 18:56:47 +0900 [thread overview]
Message-ID: <268214f9-18ef-b63e-2d4f-c344a7dd5e72@i-love.sakura.ne.jp> (raw)
In-Reply-To: <20190617063319.GB30420@dhcp22.suse.cz>
On 2019/06/17 15:33, Michal Hocko wrote:
> On Sat 15-06-19 09:11:37, Shakeel Butt wrote:
>> On Sat, Jun 15, 2019 at 6:50 AM Michal Hocko <mhocko@kernel.org> wrote:
> [...]
>>> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
>>> index 5a58778c91d4..43eb479a5dc7 100644
>>> --- a/mm/oom_kill.c
>>> +++ b/mm/oom_kill.c
>>> @@ -161,8 +161,8 @@ static bool oom_unkillable_task(struct task_struct *p,
>>> return true;
>>>
>>> /* When mem_cgroup_out_of_memory() and p is not member of the group */
>>> - if (memcg && !task_in_mem_cgroup(p, memcg))
>>> - return true;
>>> + if (memcg)
>>> + return false;
>>
>> This will break the dump_tasks() usage of oom_unkillable_task(). We
>> can change dump_tasks() to traverse processes like
>> mem_cgroup_scan_tasks() for memcg OOMs.
>
> Right you are. Doing a similar trick to the oom victim selection is
> indeed better. We should really strive to not doing a global process
> iteration when we can do a targeted scan. Care to send a patch?
I posted a patch that (as a side effect) avoids oom_unkillable_task() from dump_tasks() at
https://lore.kernel.org/linux-mm/1558519686-16057-2-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp/ .
What do you think?
next prev parent reply other threads:[~2019-06-17 9:57 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-15 1:08 general protection fault in oom_unkillable_task syzbot
2019-06-15 1:10 ` Tetsuo Handa
2019-06-15 15:59 ` Tetsuo Handa
2019-06-15 3:15 ` Shakeel Butt
2019-06-15 13:49 ` Michal Hocko
2019-06-15 16:11 ` Shakeel Butt
2019-06-15 16:48 ` Tetsuo Handa
2019-06-15 18:50 ` Shakeel Butt
2019-06-15 21:33 ` Tetsuo Handa
2019-06-16 7:37 ` Tetsuo Handa
2019-06-16 15:13 ` Tetsuo Handa
2019-06-17 6:31 ` Michal Hocko
2019-06-17 13:23 ` Shakeel Butt
2019-06-18 1:45 ` Andrew Morton
2019-06-18 4:21 ` Shakeel Butt
2019-06-17 6:33 ` Michal Hocko
2019-06-17 9:56 ` Tetsuo Handa [this message]
2019-06-17 10:13 ` Michal Hocko
2019-06-16 5:48 ` Hillf Danton
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