From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> To: mhocko@kernel.org, linux-mm@kvack.org Cc: rientjes@google.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, mhocko@suse.com, oleg@redhat.com Subject: Re: [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skip regular OOM killer path Date: Thu, 7 Apr 2016 20:38:43 +0900 [thread overview] Message-ID: <201604072038.CHC51027.MSJOFVLHOFFtQO@I-love.SAKURA.ne.jp> (raw) In-Reply-To: <1459951996-12875-3-git-send-email-mhocko@kernel.org> Michal Hocko wrote: > @@ -563,6 +582,53 @@ static void wake_oom_reaper(struct task_struct *tsk) > wake_up(&oom_reaper_wait); > } > > +/* Check if we can reap the given task. This has to be called with stable > + * tsk->mm > + */ > +static void try_oom_reaper(struct task_struct *tsk) > +{ > + struct mm_struct *mm = tsk->mm; > + struct task_struct *p; > + > + if (!mm) > + return; > + > + /* > + * There might be other threads/processes which are either not > + * dying or even not killable. > + */ > + if (atomic_read(&mm->mm_users) > 1) { > + rcu_read_lock(); > + for_each_process(p) { > + bool exiting; > + > + if (!process_shares_mm(p, mm)) > + continue; > + if (same_thread_group(p, tsk)) > + continue; > + if (fatal_signal_pending(p)) > + continue; > + > + /* > + * If the task is exiting make sure the whole thread group > + * is exiting and cannot acces mm anymore. > + */ > + spin_lock_irq(&p->sighand->siglock); > + exiting = signal_group_exit(p->signal); > + spin_unlock_irq(&p->sighand->siglock); > + if (exiting) > + continue; > + > + /* Give up */ > + rcu_read_unlock(); > + return; > + } > + rcu_read_unlock(); > + } > + > + wake_oom_reaper(tsk); > +} > + I think you want to change "try_oom_reaper() without wake_oom_reaper()" as mm_is_reapable() and use it from oom_kill_process() in order to skip p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN test which needlessly makes can_oom_reap false. > @@ -694,6 +746,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > task_lock(p); > if (p->mm && task_will_free_mem(p)) { > mark_oom_victim(p); > + try_oom_reaper(p); > task_unlock(p); > put_task_struct(p); > return; > @@ -873,6 +926,7 @@ bool out_of_memory(struct oom_control *oc) > if (current->mm && > (fatal_signal_pending(current) || task_will_free_mem(current))) { > mark_oom_victim(current); > + try_oom_reaper(current); > return true; > } > Why don't you call try_oom_reaper() from the shortcuts in mem_cgroup_out_of_memory() as well? Why don't you embed try_oom_reaper() into mark_oom_victim() like I did at http://lkml.kernel.org/r/201602052014.HBG52666.HFMOQVLFOSFJtO@I-love.SAKURA.ne.jp ?
WARNING: multiple messages have this Message-ID (diff)
From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> To: mhocko@kernel.org, linux-mm@kvack.org Cc: rientjes@google.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, mhocko@suse.com, oleg@redhat.com Subject: Re: [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skip regular OOM killer path Date: Thu, 7 Apr 2016 20:38:43 +0900 [thread overview] Message-ID: <201604072038.CHC51027.MSJOFVLHOFFtQO@I-love.SAKURA.ne.jp> (raw) In-Reply-To: <1459951996-12875-3-git-send-email-mhocko@kernel.org> Michal Hocko wrote: > @@ -563,6 +582,53 @@ static void wake_oom_reaper(struct task_struct *tsk) > wake_up(&oom_reaper_wait); > } > > +/* Check if we can reap the given task. This has to be called with stable > + * tsk->mm > + */ > +static void try_oom_reaper(struct task_struct *tsk) > +{ > + struct mm_struct *mm = tsk->mm; > + struct task_struct *p; > + > + if (!mm) > + return; > + > + /* > + * There might be other threads/processes which are either not > + * dying or even not killable. > + */ > + if (atomic_read(&mm->mm_users) > 1) { > + rcu_read_lock(); > + for_each_process(p) { > + bool exiting; > + > + if (!process_shares_mm(p, mm)) > + continue; > + if (same_thread_group(p, tsk)) > + continue; > + if (fatal_signal_pending(p)) > + continue; > + > + /* > + * If the task is exiting make sure the whole thread group > + * is exiting and cannot acces mm anymore. > + */ > + spin_lock_irq(&p->sighand->siglock); > + exiting = signal_group_exit(p->signal); > + spin_unlock_irq(&p->sighand->siglock); > + if (exiting) > + continue; > + > + /* Give up */ > + rcu_read_unlock(); > + return; > + } > + rcu_read_unlock(); > + } > + > + wake_oom_reaper(tsk); > +} > + I think you want to change "try_oom_reaper() without wake_oom_reaper()" as mm_is_reapable() and use it from oom_kill_process() in order to skip p->signal->oom_score_adj == OOM_SCORE_ADJ_MIN test which needlessly makes can_oom_reap false. > @@ -694,6 +746,7 @@ void oom_kill_process(struct oom_control *oc, struct task_struct *p, > task_lock(p); > if (p->mm && task_will_free_mem(p)) { > mark_oom_victim(p); > + try_oom_reaper(p); > task_unlock(p); > put_task_struct(p); > return; > @@ -873,6 +926,7 @@ bool out_of_memory(struct oom_control *oc) > if (current->mm && > (fatal_signal_pending(current) || task_will_free_mem(current))) { > mark_oom_victim(current); > + try_oom_reaper(current); > return true; > } > Why don't you call try_oom_reaper() from the shortcuts in mem_cgroup_out_of_memory() as well? Why don't you embed try_oom_reaper() into mark_oom_victim() like I did at http://lkml.kernel.org/r/201602052014.HBG52666.HFMOQVLFOSFJtO@I-love.SAKURA.ne.jp ? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2016-04-07 11:39 UTC|newest] Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-04-06 14:13 [PATCH 0/3] oom reaper follow ups v1 Michal Hocko 2016-04-06 14:13 ` Michal Hocko 2016-04-06 14:13 ` [PATCH 1/3] mm, oom: move GFP_NOFS check to out_of_memory Michal Hocko 2016-04-06 14:13 ` Michal Hocko 2016-04-06 14:13 ` [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skip regular OOM killer path Michal Hocko 2016-04-06 14:13 ` Michal Hocko 2016-04-07 11:38 ` Tetsuo Handa [this message] 2016-04-07 11:38 ` Tetsuo Handa 2016-04-08 11:19 ` Tetsuo Handa 2016-04-08 11:19 ` Tetsuo Handa 2016-04-08 11:50 ` Michal Hocko 2016-04-08 11:50 ` Michal Hocko 2016-04-09 4:39 ` [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skipregular " Tetsuo Handa 2016-04-09 4:39 ` Tetsuo Handa 2016-04-11 12:02 ` Michal Hocko 2016-04-11 12:02 ` Michal Hocko 2016-04-11 13:26 ` [PATCH 2/3] oom, oom_reaper: Try to reap tasks which skip regular " Tetsuo Handa 2016-04-11 13:26 ` Tetsuo Handa 2016-04-11 13:43 ` Michal Hocko 2016-04-11 13:43 ` Michal Hocko 2016-04-13 11:08 ` Tetsuo Handa 2016-04-13 11:08 ` Tetsuo Handa 2016-04-08 11:34 ` Michal Hocko 2016-04-08 11:34 ` Michal Hocko 2016-04-08 13:14 ` Michal Hocko 2016-04-08 13:14 ` Michal Hocko 2016-04-06 14:13 ` [PATCH 3/3] mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper Michal Hocko 2016-04-06 14:13 ` Michal Hocko 2016-04-07 11:55 ` Tetsuo Handa 2016-04-07 11:55 ` Tetsuo Handa 2016-04-08 11:34 ` Michal Hocko 2016-04-08 11:34 ` Michal Hocko 2016-04-16 2:51 ` Tetsuo Handa 2016-04-17 11:54 ` Michal Hocko 2016-04-18 11:59 ` Tetsuo Handa 2016-04-19 14:17 ` Michal Hocko 2016-04-19 15:07 ` Tetsuo Handa 2016-04-19 19:32 ` Michal Hocko 2016-04-08 13:07 ` Michal Hocko 2016-04-08 13:07 ` Michal Hocko
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