Re: Bulk CPU Hotplug (Was Re: [PATCH] Do not force shutdown/rebootto boot cpu.)

[Robin Holt]

On Fri, Apr 12, 2013 at 11:39:51AM +0530, Srivatsa S. Bhat wrote:
> On 04/12/2013 11:07 AM, Ingo Molnar wrote:
> > 
> > * Robin Holt <holt@xxxxxxx> wrote:
> > 
> >> For the v3.9 release, can we consider my awful patch?
> > 
> > How about trying what I suggested, to make reboot affine to the boot CPU 
> > explicitly, not by shutting down all the other CPUs, but by set_cpus_allowed() or 
> > so?
> > 
> 
> I agree, that sounds like the right thing to do for 3.9. Of course, it would be
> nice if Shawn could verify that doing that doesn't break his platform due to
> some unknown corner case.
> 
> > That should solve the regression, without the ugly special-casing - while giving 
> > time to address the hot-unplug performance bottleneck.
> > 
> > Once that is done disable_nonboot_cpus() can be used again for reboot.
> > 
> > (But no strong feelings either way - both solutions are a workaround in a sense.)