Re: [PATCH v3 5/6] virt, sched: add cpu pinning to smp_call_sync_on_phys_cpu()

From: Peter Zijlstra
Date: Fri Apr 01 2016 - 05:15:25 EST


On Fri, Apr 01, 2016 at 11:03:21AM +0200, Juergen Gross wrote:
> > Maybe just make the vpin thing an option like:
> >
> > smp_call_on_cpu(int (*func)(void *), int phys_cpu);

> > Also; is something like the vpin thing possible on KVM? because if we're
> > going to expose it to generic code like this we had maybe look at wider
> > support.
>
> It is necessary for dom0 under Xen. I don't think there is a need to do
> this on KVM as a guest has no direct access to e.g. BIOS functions of
> the real hardware and the host system needs no vcpu pinning. I'm not
> sure about VMWare.

OK, then can we WARN if .phys=1 and the platform doesn't support it?