Re: Deadlock on poweroff

[Kirill A. Shutemov]

On Sun, Oct 07, 2012 at 09:41:28PM -0700, Paul E. McKenney wrote:
> On Sun, Oct 07, 2012 at 07:50:12PM +0300, Kirill A. Shutemov wrote:
> > On Sun, Oct 07, 2012 at 09:03:11AM -0700, Paul E. McKenney wrote:
> > > On Sun, Oct 07, 2012 at 05:47:11AM +0300, Kirill A. Shutemov wrote:
> > > > Hi Paul and all,
> > > > 
> > > > With commit 755609a9087fa983f567dc5452b2fa7b089b591f I've got deadlock on
> > > > poweroff.
> > > > 
> > > > It guess it happens because of race for cpu_hotplug.lock:
> > > > 
> > > > 	CPU A					CPU B
> > > > disable_nonboot_cpus()
> > > > _cpu_down()
> > > > cpu_hotplug_begin()
> > > >  mutex_lock(&cpu_hotplug.lock);
> > > > __cpu_notify()
> > > > padata_cpu_callback()
> > > > __padata_remove_cpu()
> > > > padata_replace()
> > > > synchronize_rcu()
> > > > 					rcu_gp_kthread()
> > > > 					get_online_cpus();
> > > > 					mutex_lock(&cpu_hotplug.lock);
> > > > 
> > > > Have you seen the issue before?
> > > 
> > > This is a new one for me.  Does the following (very lightly tested)
> > > patch help?
> > 
> > Works for me. Thanks.
> 
> May I add your Tested-by?

Yep.

Tested-by: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx>

-- 
 Kirill A. Shutemov
--
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/