Re: [External] Re: [PATCH v9 0/8] Parallel CPU bringup for x86_64

[Oleksandr Natalenko]

On 21.02.2023 11:47, Usama Arif wrote:
> On 21/02/2023 10:27, David Woodhouse wrote:
> > On 21 February 2023 09:49:51 GMT, Oleksandr Natalenko 
> > <oleksandr@xxxxxxxxxxxxxx> wrote:
> > > On 21.02.2023 10:06, David Woodhouse wrote:
> > > > Why does arch/x86/kernel/acpi/sleep.c::x86_acpi_suspend_lowlevel() 
> > > > set
> > > >
> > > >      initial_gs = per_cpu_offset(smp_processor_id()) ?
> > > >
> > > > Would it not be CPU#0 that comes back up, and should it not get
> > > > per_cpu_offset(0) ?
> > >
> > > Wanna me try `initial_gs = per_cpu_offset(0);` too?
>
> I think it might be smp_processor_id() and not 0 incase CPU0 was 
> offline at the point the system was suspended?

Is it even possible for CPU 0 to be offline, at least on x86?

--
  Oleksandr Natalenko (post-factum)