linux-kernel - Re: [PATCH v6 1/2] mm/oom_kill: Do not delay oom reaper when the victim is frozen

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Message-ID: <aLfnldGMZkRkt8Z8@tiehlicka>
Date: Wed, 3 Sep 2025 09:00:37 +0200
From: Michal Hocko <mhocko@...e.com>
To: zhongjinji <zhongjinji@...or.com>
Cc: akpm@...ux-foundation.org, feng.han@...or.com, fengbaopeng@...or.com,
	liam.howlett@...cle.com, linux-kernel@...r.kernel.org,
	linux-mm@...ck.org, liulu.liu@...or.com, lorenzo.stoakes@...cle.com,
	rientjes@...gle.com, shakeel.butt@...ux.dev, surenb@...gle.com,
	tglx@...utronix.de, tianxiaobin@...or.com
Subject: Re: [PATCH v6 1/2] mm/oom_kill: Do not delay oom reaper when the
 victim is frozen

On Wed 03-09-25 00:01:29, zhongjinji wrote:
[...]
> @@ -772,12 +773,18 @@ static void mark_oom_victim(struct task_struct *tsk)
>                 mmgrab(tsk->signal->oom_mm);
> 
>         /*
> -        * Make sure that the task is woken up from uninterruptible sleep
> +        * Make sure that the process 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.
> +        * that TIF_MEMDIE thread should be ignored.
>          */
> -       __thaw_task(tsk);
> +       rcu_read_lock();
> +       for_each_thread(tsk, t) {
> +               set_tsk_thread_flag(t, TIF_MEMDIE);
> +               __thaw_task(t);
> +       }
> +       rcu_read_unlock();
> +

I would prefer if we had thaw_process() rather than open code it here.
But the implementation matches what I would expect it to do.

>         atomic_inc(&oom_victims);
>         cred = get_task_cred(tsk);
>         trace_mark_victim(tsk, cred->uid.val);

-- 
Michal Hocko
SUSE Labs