Re: [RFC] oom-kill: give the dying task a higher priority

From: Minchan Kim
Date: Mon May 31 2010 - 01:46:27 EST


On Mon, May 31, 2010 at 2:04 PM, KAMEZAWA Hiroyuki
<kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
> On Mon, 31 May 2010 14:01:03 +0900
> Minchan Kim <minchan.kim@xxxxxxxxx> wrote:
>
>> Hi, Kame.
>>
>> On Mon, May 31, 2010 at 9:21 AM, KAMEZAWA Hiroyuki
>> <kamezawa.hiroyu@xxxxxxxxxxxxxx> wrote:
>> > On Fri, 28 May 2010 13:48:26 -0300
>> > "Luis Claudio R. Goncalves" <lclaudio@xxxxxxxx> wrote:
>> >>
>> >> oom-killer: give the dying task rt priority (v3)
>> >>
>> >> Give the dying task RT priority so that it can be scheduled quickly and die,
>> >> freeing needed memory.
>> >>
>> >> Signed-off-by: Luis Claudio R. GonÃalves <lgoncalv@xxxxxxxxxx>
>> >>
>> >> diff --git a/mm/oom_kill.c b/mm/oom_kill.c
>> >> index 84bbba2..2b0204f 100644
>> >> --- a/mm/oom_kill.c
>> >> +++ b/mm/oom_kill.c
>> >> @@ -266,6 +266,8 @@ static struct task_struct *select_bad_process(unsigned long *ppoints)
>> >> Â */
>> >> Âstatic void __oom_kill_task(struct task_struct *p, int verbose)
>> >> Â{
>> >> + Â Â struct sched_param param;
>> >> +
>> >> Â Â Â if (is_global_init(p)) {
>> >> Â Â Â Â Â Â Â WARN_ON(1);
>> >> Â Â Â Â Â Â Â printk(KERN_WARNING "tried to kill init!\n");
>> >> @@ -288,6 +290,8 @@ static void __oom_kill_task(struct task_struct *p, int verbose)
>> >> Â Â Â Â* exit() and clear out its resources quickly...
>> >> Â Â Â Â*/
>> >> Â Â Â p->time_slice = HZ;
>> >> + Â Â param.sched_priority = MAX_RT_PRIO-10;
>> >> + Â Â sched_setscheduler(p, SCHED_FIFO, &param);
>> >> Â Â Â set_tsk_thread_flag(p, TIF_MEMDIE);
>> >>
>> >
>> > BTW, how about the other threads which share mm_struct ?
>>
>> Could you elaborate your intention? :)
>>
>
> IIUC, the purpose of rising priority is to accerate dying thread to exit()
> for freeing memory AFAP. But to free memory, exit, all threads which share
> mm_struct should exit, too. I'm sorry if I miss something.

How do we kill only some thread and what's the benefit of it?
I think when if some thread receives KILL signal, the process include
the thread will be killed.

I think
> Thanks,
> -Kame
>
>
>
>



--
Kind regards,
Minchan Kim
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/