Re: [PATCH] xen/acpi-processor: C and P-state driver that uploadssaid data to hypervisor.

From: Konrad Rzeszutek Wilk
Date: Mon Mar 12 2012 - 23:39:53 EST


> >> > + register_hotcpu_notifier(&xen_cpu_notifier);
> >>
> >> This is pointless - you'd get notified of vCPU-s arrival/departure only.
> >> Without pCPU hotplug code in place, there's just nothing you can (and
> >> need to) do here.
> >
> > I hadn't actually looked in details on the pCPU hotplug code to see how it
> > works.
> >
> > I presume I need special hardware for this to work as well as the ACPI
> > is involved in triggering the hotplug CPU up calls?
>
> For exercising the ACPI code paths - yes, you'll need suitable
> hardware. But for just exercising the notifier logic, as said above,
> you don't.

I think I can do the pCPU hotplug code later - as the driver to do the hypercall
is not yet in upstream. The TODO after this is to rework the powernow-k8.h to
not cause compile warnings.

So, per your suggestions I've reworked the driver some more. Please
see attached.