Re: [PATCH 1/8] cgroup: killcgroup_subsys->__DEPRECATED_clear_css_refs

From: Michal Hocko
Date: Wed Oct 31 2012 - 16:14:12 EST


On Wed 31-10-12 13:11:02, Tejun Heo wrote:
> Hello,
>
> On Wed, Oct 31, 2012 at 1:08 PM, Michal Hocko <mhocko@xxxxxxx> wrote:
> > local_irq_disable doesn't guarantee atomicity, because other CPUs will
>
> Maybe it should say atomicity on the local CPU.

That would be more clear but being more verbose doesn't hurt either :P

> > see the change in steps so this is a bit misleading. The real reason
> > AFAICS is that we do not want to hang in css_tryget from IRQ context
> > (does this really happen btw.?) which would interrupt cgroup_rmdir
> > between we add CSS_DEACT_BIAS and the group is marked CGRP_REMOVED.
> > Or am I still missing the point?
>
> Yeah, that's the correct one. We don't want tryget happening between
> DEACT_BIAS and REMOVED as it can hang forever there.

--
Michal Hocko
SUSE Labs
--
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/