From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: mhocko@kernel.org, akpm@linux-foundation.org
Cc: rientjes@google.com, mgorman@suse.de, oleg@redhat.com,
torvalds@linux-foundation.org, hughd@google.com,
andrea@kernel.org, riel@redhat.com, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task
Date: Sat, 20 Feb 2016 11:32:07 +0900 [thread overview]
Message-ID: <201602201132.EFG90182.FOVtSOJHFOLFQM@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20160219183419.GA30059@dhcp22.suse.cz>
Michal Hocko wrote:
> On Wed 17-02-16 10:48:55, Michal Hocko wrote:
> > Hi Andrew,
> > although this can be folded into patch 5
> > (mm-oom_reaper-implement-oom-victims-queuing.patch) I think it would be
> > better to have it separate and revert after we sort out the proper
> > oom_kill_allocating_task behavior or handle exclusion at oom_reaper
> > level.
>
> An alternative would be something like the following. It is definitely
> less hackish but it steals one bit in mm->flags. We do not seem to be
> in shortage there now but who knows. Does this sound better? Later
> changes might even consider the flag for the victim selection and ignore
> those which already have the flag set. But I didn't think about it more
> to form a patch yet.
This sounds better than "can_oom_reap = !sysctl_oom_kill_allocating_task;".
> @@ -740,6 +740,10 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p,
> /* Get a reference to safely compare mm after task_unlock(victim) */
> mm = victim->mm;
> atomic_inc(&mm->mm_count);
> +
> + /* Make sure we do not try to oom reap the mm multiple times */
> + can_oom_reap = !test_and_set_bit(MMF_OOM_KILLED, &mm->flags);
> +
> /*
> * We should send SIGKILL before setting TIF_MEMDIE in order to prevent
> * the OOM victim from depleting the memory reserves from the user
But as of this line we don't know whether this mm is reapable.
Shouldn't this be done like
static void wake_oom_reaper(struct task_struct *tsk)
{
/* Make sure we do not try to oom reap the mm multiple times */
if (!oom_reaper_th || !test_and_set_bit(MMF_OOM_KILLED, &mm->flags))
return;
get_task_struct(tsk);
spin_lock(&oom_reaper_lock);
list_add(&tsk->oom_reaper_list, &oom_reaper_list);
spin_unlock(&oom_reaper_lock);
wake_up(&oom_reaper_wait);
}
?
Moreover, why don't you do like
struct mm_struct {
(...snipped...)
struct list_head oom_reaper_list;
(...snipped...)
}
than
struct task_struct {
(...snipped...)
struct list_head oom_reaper_list;
(...snipped...)
}
so that we can update all ->oom_score_adj using this mm_struct for handling
crazy combo ( http://lkml.kernel.org/r/20160204163113.GF14425@dhcp22.suse.cz ) ?
next prev parent reply other threads:[~2016-02-20 2:32 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 13:13 [PATCH 0/5] oom reaper v5 Michal Hocko
2016-02-03 13:13 ` [PATCH 1/5] mm, oom: introduce oom reaper Michal Hocko
2016-02-03 23:48 ` David Rientjes
2016-02-04 6:41 ` Michal Hocko
2016-02-06 13:22 ` Tetsuo Handa
2016-02-15 20:50 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 2/5] oom reaper: handle mlocked pages Michal Hocko
2016-02-03 23:57 ` David Rientjes
2016-02-23 1:36 ` David Rientjes
2016-02-23 13:21 ` Michal Hocko
2016-02-29 3:19 ` Hugh Dickins
2016-02-29 13:41 ` Michal Hocko
2016-03-08 13:40 ` Michal Hocko
2016-03-08 20:07 ` Hugh Dickins
2016-03-09 8:26 ` Michal Hocko
2016-02-03 13:13 ` [PATCH 3/5] oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space Michal Hocko
2016-02-04 14:22 ` Tetsuo Handa
2016-02-04 14:43 ` Michal Hocko
2016-02-04 15:08 ` Tetsuo Handa
2016-02-04 16:31 ` Michal Hocko
2016-02-05 11:14 ` Tetsuo Handa
2016-02-06 8:30 ` Michal Hocko
2016-02-06 11:23 ` Tetsuo Handa
2016-02-15 20:47 ` Michal Hocko
2016-02-06 6:45 ` Michal Hocko
2016-02-06 14:33 ` Tetsuo Handa
2016-02-15 20:40 ` [PATCH 3.1/5] oom: make oom_reaper freezable Michal Hocko
2016-02-03 13:13 ` [PATCH 4/5] mm, oom_reaper: report success/failure Michal Hocko
2016-02-03 23:10 ` David Rientjes
2016-02-04 6:46 ` Michal Hocko
2016-02-04 22:31 ` David Rientjes
2016-02-05 9:26 ` Michal Hocko
2016-02-06 6:34 ` Michal Hocko
2016-02-03 13:14 ` [PATCH 5/5] mm, oom_reaper: implement OOM victims queuing Michal Hocko
2016-02-04 10:49 ` Tetsuo Handa
2016-02-04 14:53 ` Michal Hocko
2016-02-06 5:54 ` Tetsuo Handa
2016-02-06 8:37 ` Michal Hocko
2016-02-06 15:33 ` Tetsuo Handa
2016-02-15 20:15 ` Michal Hocko
2016-02-16 11:11 ` Tetsuo Handa
2016-02-16 15:53 ` Michal Hocko
2016-02-17 9:48 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for Michal Hocko
2016-02-17 10:41 ` Tetsuo Handa
2016-02-17 11:33 ` Michal Hocko
2016-02-19 18:34 ` Michal Hocko
2016-02-20 2:32 ` Tetsuo Handa [this message]
2016-02-22 9:41 ` [PATCH 6/5] oom, oom_reaper: disable oom_reaper for oom_kill_allocating_task Michal Hocko
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