[PATCH 1/9] cpu: Introduce clear_tasks_mm_cpumask() helper
Anton Vorontsov
anton.vorontsov at linaro.org
Fri May 4 21:47:14 EDT 2012
On Thu, Apr 26, 2012 at 04:59:11PM -0700, Andrew Morton wrote:
[...]
> > so its not like new tasks will ever get this cpu set in
> > + * their mm mask. -- Peter Zijlstra
> > + * Thus, we may use rcu_read_lock() here, instead of grabbing
> > + * full-fledged tasklist_lock.
> > + */
> > + rcu_read_lock();
> > + for_each_process(p) {
> > + struct task_struct *t;
> > +
> > + t = find_lock_task_mm(p);
> > + if (!t)
> > + continue;
> > + cpumask_clear_cpu(cpu, mm_cpumask(t->mm));
> > + task_unlock(t);
> > + }
> > + rcu_read_unlock();
> > +}
>
> It is good that this code exists under CONFIG_HOTPLUG_CPU. Did you
> check that everything works correctly with CONFIG_HOTPLUG_CPU=n?
Yeah, only the code under CONFIG_HOTPLUG_CPU calls the function, so
it should be all fine.
Thanks!
--
Anton Vorontsov
Email: cbouatmailru at gmail.com
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