Re: WARNING in task_participate_group_stop

From: Oleg Nesterov
Date: Mon Nov 02 2015 - 10:40:53 EST


On 11/02, Oleg Nesterov wrote:
>
> On 11/02, Dmitry Vyukov wrote:
> >
> > But I wasn't able
> > to figure out what's the root cause (why task does not have
> > JOBCTL_STOP_PENDING) and maybe the same WARNING can be triggered
> > without root and/or with other than init process. So still posting it
> > here.
>
> Yes I think you are right. SIGSTOP can race with SIGKILL which (unlike SIGCONT)
> doesn't clear JOBCTL_STOP_DEQUEUED/PENDING/etc.

I was wrong... I forgot that complete_signal(SIGKILL) sets SIGNAL_GROUP_EXIT.
Unless SIGNAL_UNKILLABLE is set, and this is what makes init "special".

So it seems that everything is clear. Except I can't understand why your
test-case doesn't work for me ;) It should.

Oleg.

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