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

Benjamin Herrenschmidt
2009-09-24T00:54:18Z

On Tue, 2009-09-15 at 14:11 +0200, Peter Zijlstra wrote:
> I still think its a layering violation... its the hypervisor manager
> that should be bothered in what state an off-lined cpu is in.
>
That's not how our hypervisor works.

If you ask through the management interface, to remove a CPU from a
partition, the HV will communicate with a daemon inside the partition
that will then unplug the CPU via the right call.

I don't really understand your objections to be honest. And I fail to
see why it would be a layering violation to have the ability for the OS
to indicate in what state it wishes to relinguish a CPU to the
hypervisor, which more or less defines what is the expected latency for
getting it back later on.

Ben.