Messages in this thread |  | | Date | Wed, 6 Feb 2013 10:47:49 -0800 | From | Tejun Heo <> | Subject | Re: [PATCH 2/3] stop_machine: dequeue work before signal completion |
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On Wed, Feb 06, 2013 at 08:38:43PM +0800, Hillf Danton wrote: > As handled by the kernel thread, work is dequeued first for further actions.
Ditto as the previous patch.
> Signed-off-by: Hillf Danton <dhillf@gmail.com> > --- > > --- a/kernel/stop_machine.c Wed Feb 6 19:57:12 2013 > +++ b/kernel/stop_machine.c Wed Feb 6 20:02:12 2013 > @@ -334,23 +334,24 @@ static int __cpuinit cpu_stop_cpu_callba > #ifdef CONFIG_HOTPLUG_CPU > case CPU_UP_CANCELED: > case CPU_POST_DEAD: > - { > - struct cpu_stop_work *work; > - > sched_set_stop_task(cpu, NULL); > /* kill the stopper */ > kthread_stop(stopper->thread); > /* drain remaining works */ > spin_lock_irq(&stopper->lock); > - list_for_each_entry(work, &stopper->works, list) > + while (!list_empty(&stopper->works)) { > + struct cpu_stop_work *work; > + work = list_first_entry(&stopper->works, > + struct cpu_stop_work, list); > + list_del_init(&work->list); > cpu_stop_signal_done(work->done, false, 0); > + } > stopper->enabled = false; > spin_unlock_irq(&stopper->lock);
Why does this matter? It's inside spinlock. What's being made better by this change?
-- tejun
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