Re: [PATCH 04/12] ia64: Replace cpu_down with freeze_secondary_cpus

From: Thomas Gleixner
Date: Wed Nov 20 2019 - 03:46:19 EST


On Tue, 19 Nov 2019, Qais Yousef wrote:
> On 11/19/19 23:59, Thomas Gleixner wrote:
> > On Tue, 19 Nov 2019, Qais Yousef wrote:
> > > My plan was to simply make freeze_secondary_cpus() available and protected by
> > > CONFIG_SMP only instead.
> > >
> > > Good plan?
> >
> > No. freeze_secondary_cpus() is really for hibernation. Look at the exit
> > conditions there.
>
> Hmm do you mean the pm_wakeup_pending() abort?
>
> In arm64 we machine_shutdown() calls disable_nonboot_cpus(), which in turn
> a wrapper around freeze_secondary_cpus() with 0 passed as an argument.
>
> IIUC this means arm64 could fail to offline all CPUs on machine_shutdown(),
> correct?

Looks like.

Thanks,

tglx