Re: [patch] cgroups: disallow attaching kthreadd

From: Tejun Heo
Date: Wed Apr 04 2012 - 19:09:24 EST


On Wed, Apr 04, 2012 at 02:17:36PM -0700, David Rientjes wrote:
> On Wed, 4 Apr 2012, Mike Galbraith wrote:
>
> > > I've never seen a nack from Peter on this, I only remember discussing
> > > whether this needs to be isolated to only cpusets or whether it needs to
> > > be a generic cgroup thing and I've always argued in favor of localizing it
> > > to cpusets because that cgroup happens to care about cpu affinity where
> > > others don't and this is why cgroups have ->can_attach() functions. If a
> > > cgroup were created to have nothing to do with cpu affinity (only for
> > > collecting statistics for threads within it, for example), there's
> > > absolutely no reason why we need to exclude kthreadd.
> >
> > Well, he didn't actually say "NAK", but was against it, which means
> > pretty much the same thing as NAK to me.. we can call it a nak.
> >
>
> People are able to change their minds and after our discussion about
> cgroups vs cpusets, I was under the impression we were at a common
> understanding of the problem.
>
> Cpusets are a cgroup. It wouldn't make much sense to NACK a patch that
> does this to cpusets if you're arguing in favor of doing it for all
> cgroups.
>
> Your changelog mentions only cpusets issues, not cgroup issues.
>
> So please propose your cpusets version so that the issue can be fixed. If
> Peter wants to extend that to cgroups later, that's a discussion we can
> have at that time. However, the bug being addressed here is for cpusets
> and is deserving of a patch now rather than later. I'm concerned we're
> just going to drop this again and it will live on.

I don't see much problem with the proposed solution and am gonna take
it unless there are pretty good reasons not to.

Thanks.

--
tejun
--
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/