[PATCH] Reorganise and then fixup the pseries cpu hotplug code

[Nathan Lynch]

Michael Ellerman wrote:
> 
> OK, it didn't occur to me that it was referring to userspace. I'll
> change it to:
> 
> /*
>  * Isolation and deallocation occur in userspace, so just stop the cpu.
>  * If isolation and deallocation ever move from userpace to kernel space
>  * we would do them here.
>  */
> 
> Sound OK?

I favor just dropping the comment.  Offline and isolate are distinct
-- offline is a per-thread operation while isolate is per-processor.
Offlining a thread does not imply that its processor will be returned
to the hypervisor (e.g. going to single thread mode from SMT).