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

[Oleksandr Natalenko]

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?

> Or maybe we should just set up smpboot_control for the CPU to find its
> own stuff, *even* on waking. Since the structures are already set up,
> it isn't like a clean boot.
>
> If you let it boot in parallel mode, what if you just *remove* the line
> that sets smpboot_control=0 ?

If the `smpboot_control = 0;` line in 
arch/x86/kernel/acpi/sleep.c::x86_acpi_suspend_lowlevel() is commented 
out, and the system is booted in parallel mode, then suspend/resume 
works.

--
  Oleksandr Natalenko (post-factum)