Re: [patch] oom: thaw threads if oom killed thread is frozen before deferring

Michal Hocko
2011-09-30T08:04:52Z

On Fri 30-09-11 00:46:41, Tejun Heo wrote:
> Hello,
>
> On Fri, Sep 30, 2011 at 09:41:25AM +0200, Michal Hocko wrote:
> > > With pending freezer changes, allowing TIF_MEMDIE tasks to exit
> > > freezer by modifying freezing() shouldn't be difficult, which should
> > > be race-free and much simpler than diddling with thaw_task().
> >
> > Will the rework help with the initial problem of unkillable OOM selected
> > frozen tasks or it will just help with other races that might be present
> > with the patch? In other words will this work deprecate the 2 patches
> > sent earlier in this thread?
>
> I think it shouldn't be difficult to allow OOM-killing frozen tasks.
> That should be good enough, right?

Yes, if you could just force_sig(SIGKILL, p) frozen task then it would
be ideal because we wouldn't have to call thaw_process from OOM path.

>
> > > How urgent is this? Can we wait for the next merge window?
> >
> > Yes, I think we can wait some more.
>
> I'm still processing rather large backlog. I'll ping you back once I
> sort out the pending freezer changes.

You were on the CC quite early but it was quite late when I noticed that
I have accidentally used your kernel.org address. Just for reference the
original discussion started here: https://lkml.org/lkml/2011/8/23/45 and
this thread started here:
http://www.spinics.net/lists/linux-mm/msg24693.html

>
> Thanks.
>
> --
> tejun
>
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