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Groups > linux.kernel > #1306386
| From | Michal Hocko <mhocko@kernel.org> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. |
| Date | 2016-01-11 16:20 +0100 |
| Message-ID | <qPMqe-46s-15@gated-at.bofh.it> (permalink) |
| References | <qL2YH-1hA-9@gated-at.bofh.it> <qOeTE-65o-23@gated-at.bofh.it> <qOiXf-hG-5@gated-at.bofh.it> <qOkcH-137-25@gated-at.bofh.it> <qOkPo-1zT-17@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On Fri 08-01-16 00:38:43, Tetsuo Handa wrote:
> Michal Hocko wrote:
> > @@ -333,6 +333,14 @@ static struct task_struct *select_bad_process(struct oom_control *oc,
> > if (points == chosen_points && thread_group_leader(chosen))
> > continue;
> >
> > + /*
> > + * If the current major task is already ooom killed and this
> > + * is sysrq+f request then we rather choose somebody else
> > + * because the current oom victim might be stuck.
> > + */
> > + if (is_sysrq_oom(sc) && test_tsk_thread_flag(p, TIF_MEMDIE))
> > + continue;
> > +
> > chosen = p;
> > chosen_points = points;
> > }
>
> Do we want to require SysRq-f for each thread in a process?
> If g has 1024 p, dump_tasks() will do
>
> pr_info("[%5d] %5d %5d %8lu %8lu %7ld %7ld %8lu %5hd %s\n",
>
> for 1024 times? I think one SysRq-f per one process is sufficient.
I am not following you here. If we kill the process the whole process
group (aka all threads) will get killed which ever thread we happen to
send the sigkill to.
> How can we guarantee that find_lock_task_mm() from oom_kill_process()
> chooses !TIF_MEMDIE thread when try_to_sacrifice_child() somehow chose
> !TIF_MEMDIE thread? I think choosing !TIF_MEMDIE thread at
> find_lock_task_mm() is the simplest way.
find_lock_task_mm chosing TIF_MEMDIE thread shouldn't change anything
because the whole thread group will go down anyway. If you want to
guarantee that the sysrq+f never choses a task which has a TIF_MEMDIE
thread then we would have to check for fatal_signal_pending as well
AFAIU. Fiddling with find find_lock_task_mm will not help you though
unless I am missing something.
--
Michal Hocko
SUSE Labs
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Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-07 10:20 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-07 14:40 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-07 16:00 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-07 16:40 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-11 16:20 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-12 12:40 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-12 21:00 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-13 11:20 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-13 16:30 +0100
Re: [PATCH] mm,oom: Exclude TIF_MEMDIE processes from candidates. Michal Hocko <mhocko@kernel.org> - 2016-01-07 16:50 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-08 11:20 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. David Rientjes <rientjes@google.com> - 2016-01-13 01:40 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-13 12:00 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. David Rientjes <rientjes@google.com> - 2016-01-14 02:00 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-14 11:30 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. David Rientjes <rientjes@google.com> - 2016-01-14 23:00 +0100
Re: [PATCH v2] mm,oom: Exclude TIF_MEMDIE processes from candidates. Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2016-01-14 23:30 +0100
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