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

Qais Yousef
2019-11-19T22:32:41Z

On 11/19/19 23:21, Thomas Gleixner wrote:
> On Wed, 30 Oct 2019, Qais Yousef wrote:
>
> > Use freeze_secondary_cpus() instead of open coding using cpu_down()
> > directly.
> >
> > This also prepares to make cpu_up/down a private interface for anything
> > but the cpu subsystem.
> >
> > Signed-off-by: Qais Yousef <qais.yousef@arm.com>
> > CC: Tony Luck <tony.luck@intel.com>
> > CC: Fenghua Yu <fenghua.yu@intel.com>
> > CC: linux-ia64@vger.kernel.org
> > CC: linux-kernel@vger.kernel.org
> > ---
> > arch/ia64/kernel/process.c | 8 ++------
> > 1 file changed, 2 insertions(+), 6 deletions(-)
> >
> > diff --git a/arch/ia64/kernel/process.c b/arch/ia64/kernel/process.c
> > index 968b5f33e725..70b433eafa5c 100644
> > --- a/arch/ia64/kernel/process.c
> > +++ b/arch/ia64/kernel/process.c
> > @@ -647,12 +647,8 @@ cpu_halt (void)
> > void machine_shutdown(void)
> > {
> > #ifdef CONFIG_HOTPLUG_CPU
> > - int cpu;
> > -
> > - for_each_online_cpu(cpu) {
> > - if (cpu != smp_processor_id())
> > - cpu_down(cpu);
> > - }
> > + /* TODO: Can we use disable_nonboot_cpus()? */
> > + freeze_secondary_cpus(smp_processor_id());
>
> freeze_secondary_cpus() is only available for CONFIG_PM_SLEEP_SMP=y and
> disable_nonboot_cpus() is a NOOP for CONFIG_PM_SLEEP_SMP=n :)

I thought I replied to this :-(

My plan was to simply make freeze_secondary_cpus() available and protected by
CONFIG_SMP only instead.

Good plan?

I'll probably do it as a separate patch before this one.

Thanks

--
Qais Yousef