Re: [Patch] freezer: check OOM kill signal while being frozen

From: David Rientjes
Date: Sat Aug 09 2014 - 04:55:22 EST


On Fri, 8 Aug 2014, Cong Wang wrote:

> diff --git a/kernel/freezer.c b/kernel/freezer.c
> index aa6a8aa..c6d189d 100644
> --- a/kernel/freezer.c
> +++ b/kernel/freezer.c
> @@ -68,7 +68,9 @@ bool __refrigerator(bool check_kthr_stop)
> spin_lock_irq(&freezer_lock);
> current->flags |= PF_FROZEN;
> if (!freezing(current) ||
> - (check_kthr_stop && kthread_should_stop()))
> + (check_kthr_stop && kthread_should_stop()) ||
> + (test_tsk_thread_flag(current, TIF_MEMDIE) &&
> + fatal_signal_pending(current)))
> current->flags &= ~PF_FROZEN;
> spin_unlock_irq(&freezer_lock);
>

All threads with TIF_MEMDIE set would have been killed, why is the check
for fatal_signal_pending(current) needed?

You can also use test_thread_flag(TIF_MEMDIE) instead since you're only
concerned with current.

Furthermore, that conditional is getting difficult to read. Maybe it
would help to have a helper function that returns bool that determines
whether PF_FROZEN should be cleared?
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