From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org
Cc: linux-mm@kvack.org, rientjes@google.com, oleg@redhat.com,
vdavydov@parallels.com, akpm@linux-foundation.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/10] mm, oom: fortify task_will_free_mem
Date: Fri, 17 Jun 2016 20:38:01 +0900 [thread overview]
Message-ID: <201606172038.IIE43237.FtLMVSFOOHJFQO@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20160616155347.GO6836@dhcp22.suse.cz>
Michal Hocko wrote:
> > > Anyway, would you be OK with the patch if I added the current->mm check
> > > and resolve its necessity in a separate patch?
> >
> > Please correct task_will_free_mem() in oom_kill_process() as well.
>
> We cannot hold task_lock over all task_will_free_mem I am even not sure
> we have to develop an elaborate way to make it raceless just for the nommu
> case. The current case is simple as we cannot race here. Is that
> sufficient for you?
We can use find_lock_task_mm() inside mark_oom_victim().
That is, call wake_oom_reaper() from mark_oom_victim() like
void mark_oom_victim(struct task_struct *tsk, bool can_use_oom_reaper)
{
WARN_ON(oom_killer_disabled);
/* OOM killer might race with memcg OOM */
tsk = find_lock_task_mm(tsk);
if (!tsk)
return;
if (test_and_set_tsk_thread_flag(tsk, TIF_MEMDIE)) {
task_unlock(tsk);
return;
}
task_unlock(tsk);
atomic_inc(&tsk->signal->oom_victims);
/*
* Make sure that the task is woken up from uninterruptible sleep
* if it is frozen because OOM killer wouldn't be able to free
* any memory and livelock. freezing_slow_path will tell the freezer
* that TIF_MEMDIE tasks should be ignored.
*/
__thaw_task(tsk);
atomic_inc(&oom_victims);
if (can_use_oom_reaper)
wake_oom_reaper(tsk);
}
and move mark_oom_victim() by normal path to after task_unlock(victim).
do_send_sig_info(SIGKILL, SEND_SIG_FORCED, victim, true);
- mark_oom_victim(victim);
- if (can_oom_reap)
- wake_oom_reaper(victim);
+ wake_oom_reaper(victim, can_oom_reap);
If you don't like possibility of showing different pid for
pr_err("Killed process %d (%s)
and
pr_info("oom_reaper: reaped process %d (%s)
messages, you can defer the former till mark_oom_victim() locks that task.
next prev parent reply other threads:[~2016-06-17 11:38 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-09 11:52 [PATCH 0/10 -v4] Handle oom bypass more gracefully Michal Hocko
2016-06-09 11:52 ` [PATCH 01/10] proc, oom: drop bogus task_lock and mm check Michal Hocko
2016-06-09 11:52 ` [PATCH 02/10] proc, oom: drop bogus sighand lock Michal Hocko
2016-06-09 11:52 ` [PATCH 03/10] proc, oom_adj: extract oom_score_adj setting into a helper Michal Hocko
2016-06-09 11:52 ` [PATCH 04/10] mm, oom_adj: make sure processes sharing mm have same view of oom_score_adj Michal Hocko
2016-06-15 15:03 ` Oleg Nesterov
2016-06-09 11:52 ` [PATCH 05/10] mm, oom: skip vforked tasks from being selected Michal Hocko
2016-06-15 14:51 ` Oleg Nesterov
2016-06-16 6:24 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 06/10] mm, oom: kill all tasks sharing the mm Michal Hocko
2016-06-09 11:52 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
2016-06-09 13:18 ` Tetsuo Handa
2016-06-09 14:20 ` Michal Hocko
2016-06-11 8:10 ` Tetsuo Handa
2016-06-13 11:27 ` Michal Hocko
2016-06-16 12:54 ` Tetsuo Handa
2016-06-16 14:29 ` Michal Hocko
2016-06-16 15:40 ` Tetsuo Handa
2016-06-16 15:53 ` Michal Hocko
2016-06-17 11:38 ` Tetsuo Handa [this message]
2016-06-17 12:26 ` Michal Hocko
2016-06-17 13:12 ` Tetsuo Handa
2016-06-17 13:29 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 08/10] mm, oom: task_will_free_mem should skip oom_reaped tasks Michal Hocko
2016-06-17 11:35 ` Tetsuo Handa
2016-06-17 12:56 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 09/10] mm, oom_reaper: do not attempt to reap a task more than twice Michal Hocko
2016-06-15 14:48 ` Oleg Nesterov
2016-06-16 6:28 ` Michal Hocko
2016-06-09 11:52 ` [PATCH 10/10] mm, oom: hide mm which is shared with kthread or global init Michal Hocko
2016-06-09 15:15 ` Tetsuo Handa
2016-06-09 15:41 ` Michal Hocko
2016-06-16 13:15 ` Tetsuo Handa
2016-06-16 13:36 ` Tetsuo Handa
2016-06-15 14:37 ` Oleg Nesterov
2016-06-16 6:31 ` Michal Hocko
2016-06-13 11:23 ` [PATCH 0/10 -v4] Handle oom bypass more gracefully Michal Hocko
2016-06-13 14:13 ` Michal Hocko
2016-06-14 20:17 ` Oleg Nesterov
2016-06-14 20:44 ` Oleg Nesterov
2016-06-16 6:33 ` Michal Hocko
2016-06-15 15:09 ` Oleg Nesterov
2016-06-16 6:34 ` Michal Hocko
-- strict thread matches above, loose matches on Subject: below --
2016-06-20 12:43 [PATCH 0/10 -v5] " Michal Hocko
2016-06-20 12:43 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
2016-06-03 9:16 [PATCH 0/10 -v3] Handle oom bypass more gracefully Michal Hocko
2016-06-03 9:16 ` [PATCH 07/10] mm, oom: fortify task_will_free_mem Michal Hocko
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