Re: oom-kill && frozen()

From: Peter Zijlstra
Date: Wed Nov 13 2013 - 12:42:52 EST


On Wed, Nov 13, 2013 at 06:07:24PM +0100, Oleg Nesterov wrote:
> 4. Finally, change try_to_wake_up() path to do
>
> - p->state = TASK_WAKING;
> + p->state &= ~state;
> + if (p->state & ~(TASK_DEAD | TASK_WAKEKILL | TASK_PARKED))
> + return;
> + else
> + p->state = TASK_WAKING;
>
> IOW, if the task sleeps in, say, TASK_INTERRUPTIBLE | __TASK_FROZEN
> then it need both try_to_wake_up(TASK_INTERRUPTIBLE) and
> try_to_wake_up(__TASK_FROZEN) to wake up.

> Tejun, Peter, do you think this makes any sense? I am just curious, but
> "selective wakeup" looks potentially useful.

I've never looked at any of this freeze stuff, so I cannot comment too
much. However we should be very careful not to add too much to relative
hot paths for the relative rare case of freezing stuff.


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