Re: Help needed: Resume problems in 2.6.32-rc, perhaps related topreempt_count leakage in keventd
From: Mike Galbraith
Date: Mon Nov 09 2009 - 09:16:25 EST
On Mon, 2009-11-09 at 15:02 +0100, Thomas Gleixner wrote:
> On Mon, 9 Nov 2009, Ingo Molnar wrote:
> >
> > ok, then my observation should not apply.
>
> I think it _IS_ releated because the worker_thread is CPU affine and
> the debug_smp_processor_id() check does:
>
> if (cpumask_equal(¤t->cpus_allowed, cpumask_of(this_cpu)))
>
> which prevents that usage of smp_processor_id() in ksoftirqd and
> keventd in preempt enabled regions is warned on.
>
> We saw exaclty the same back trace with fd21073 (sched: Fix affinity
> logic in select_task_rq_fair()).
>
> Rafael, can you please add a printk to debug_smp_processor_id() so we
> can see on which CPU we are running ? I suspect we are on the wrong
> one.
I wonder if that's not intimately related to the problem I had, namely
newidle balancing offline CPUs as they're coming up, making a mess of
cpu enumeration.
-Mike
--
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/