Re: [PATCH 1/2] oom: do not live lock on frozen tasks

From: Rusty Russell
Date: Mon Sep 26 2011 - 22:39:21 EST


On Mon, 26 Sep 2011 13:05:59 +0200, Michal Hocko <mhocko@xxxxxxx> wrote:
> On Mon 26-09-11 19:58:50, Rusty Russell wrote:
> > On Mon, 26 Sep 2011 10:28:37 +0200, Michal Hocko <mhocko@xxxxxxx> wrote:
> > > On Fri 26-08-11 11:13:40, David Rientjes wrote:
> > > > I'd love to be able to do a thaw on a PF_FROZEN task in the oom killer
> > > > followed by a SIGKILL if that task is selected for oom kill without an
> > > > heuristic change. Not sure if that's possible, so we'll wait for Rafael
> > > > to chime in.
> > >
> > > We have discussed that with Rafael and it should be safe to do that. See
> > > the patch bellow.
> > > The only place I am not entirely sure about is run_guest
> > > (drivers/lguest/core.c). It seems that the code is able to cope with
> > > signals but it also calls lguest_arch_run_guest after try_to_freeze.
> >
> > Yes; if you want to kill things in the refrigerator(), then will a
> >
> > if (cpu->lg->dead || task_is_dead(current))
> > break;
> >
> > Work?
>
> The task is not dead yet. We should rather check for pending signals.
> Can we just move try_to_freeze up before the pending signals check?

Yep, that works.

Acked-by: Rusty Russell <rusty@xxxxxxxxxxxxxxx>

Cheers,
Rusty.
--
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/