Re: [PATCH 01/40] sched: consult online mask instead of active in select_fallback_rq()

Tejun Heo
2010-01-18T11:27:30Z

Hello,

On 01/18/2010 07:13 PM, Peter Zijlstra wrote:
> On Mon, 2010-01-18 at 09:57 +0900, Tejun Heo wrote:
>> If called after sched_class chooses a CPU which isn't in a task's
>> cpus_allowed mask,
>
> I can only see this happening when you're changing cpus_allowed after
> starting to take down the cpu. IOW you're moving a thread to a dying
> cpu.
>
> This is because you're spawning workqueue threads while we're going
> down?

It got triggered by the hotplug callback creating the trustee kthread
and kthread_bind()ing it to the target cpu during CPU_DOWN_PREPARE.

Thanks.

--
tejun