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Date: Thu, 27 May 2010 20:33:19 +0200
From: Oleg Nesterov <oleg@redhat.com>
To: "Luis Claudio R. Goncalves" <lclaudio@uudg.org>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
       Thomas Gleixner <tglx@linutronix.de>,
       Peter Zijlstra <peterz@infradead.org>,
       KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>,
       David Rientjes <rientjes@google.com>, Mel Gorman <mel@csn.ul.ie>,
       williams@redhat.com
Subject: Re: [RFC] oom-kill: give the dying task a higher priority
Message-ID: <20100527183319.GA22313@redhat.com>
References: <20100527180431.GP13035@uudg.org>
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On 05/27, Luis Claudio R. Goncalves wrote:
>
> It sounds plausible giving the dying task an even higher priority to be
> sure it will be scheduled sooner and free the desired memory.

As usual, I can't really comment the changes in oom logic, just minor
nits...

> @@ -413,6 +415,8 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
>  	 */
>  	p->rt.time_slice = HZ;
>  	set_tsk_thread_flag(p, TIF_MEMDIE);
> +	param.sched_priority = MAX_RT_PRIO-1;
> +	sched_setscheduler(p, SCHED_FIFO, &param);
>
>  	force_sig(SIGKILL, p);

Probably sched_setscheduler_nocheck() makes more sense.

Minor, but perhaps it would be a bit better to send SIGKILL first,
then raise its prio.

Oleg.