Re: [RFC patch 2/5] smpboot: Provide infrastructure for percpu hotplug threads

Paul E. McKenney
2012-06-14T16:58:44Z

On Thu, Jun 14, 2012 at 06:19:50PM +0200, Thomas Gleixner wrote:
> On Thu, 14 Jun 2012, Paul E. McKenney wrote:
>
> > On Thu, Jun 14, 2012 at 07:50:38AM -0700, Paul E. McKenney wrote:
> > > On Thu, Jun 14, 2012 at 03:32:19PM +0200, Thomas Gleixner wrote:
> > > > On Thu, 14 Jun 2012, Paul E. McKenney wrote:
> > > > > On Thu, Jun 14, 2012 at 01:20:39PM +0200, Thomas Gleixner wrote:
> > > > > > I gave it a quick shot, but I was not able to reproduce the hang yet.
> > > > >
> > > > > Really? I have a strictly Western-Hemisphere bug? ;-)
> > > >
> > > > I guess I need to fire up rcu torture to make it surface.
> > >
> > > A simple offline was triggering it for me. Perhaps some of my debug
> > > code was inappropriate, will retry.
> >
> > And removing my debug code did the trick. I guess some of it was really
> > just bug code. In any case, it now passes short rcutorture testing for
> > me as well.
> >
> > However, I do see the splat shown below. The splat confuses me greatly,
> > as I thought that this kthread should be affinitied to a single CPU and
> > thus smp_processor_id() should refrain from splatting. I don't see any
> > sort of "I broke affinity" message from the scheduler.
>
> Hmm. Is that reproducible ?

Twice so far, will retry.

Thanx, Paul