Re: [PATCH v3 0/3] cpu: pseries: Cpu offline states framework

Michael Ellerman
2009-09-15T13:21:50Z

[-- Attachment #1: Type: text/plain, Size: 1452 bytes --]

On Tue, 2009-09-15 at 14:11 +0200, Peter Zijlstra wrote:
> On Tue, 2009-09-15 at 17:36 +0530, Gautham R Shenoy wrote:
> > This patchset contains the offline state driver implemented for
> > pSeries. For pSeries, we define three available_hotplug_states. They are:
> >
> > online: The processor is online.
> >
> > offline: This is the the default behaviour when the cpu is offlined
> > even in the absense of this driver. The CPU would call make an
> > rtas_stop_self() call and hand over the CPU back to the resource pool,
> > thereby effectively deallocating that vCPU from the LPAR.
> > NOTE: This would result in a configuration change to the LPAR
> > which is visible to the outside world.
> >
> > inactive: This cedes the vCPU to the hypervisor with a cede latency
> > specifier value 2.
> > NOTE: This option does not result in a configuration change
> > and the vCPU would be still entitled to the LPAR to which it earlier
> > belong to.
> >
> > Any feedback on the patchset will be immensely valuable.
>
> I still think its a layering violation... its the hypervisor manager
> that should be bothered in what state an off-lined cpu is in.

Yeah it probably is a layering violation, but when has that stopped us
before :)

Is it anticipated that this will be useful on platforms other than
pseries?

cheers

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 197 bytes --]