[RFC/PATCH 2/2] handle cpu device node addition and removal

[Nathan Lynch]

On Tue, 2005-01-25 at 23:11 -0600, Nathan Lynch wrote:
> Using the notifier chain in a previous patch, handle addition and
> removal of processors on pSeries LPAR.  The new notifier call updates
> cpu_present_map and sets hw_cpu_id in the paca appropriately.  Note
> that we must handle more than one cpu being added or going away to
> account for SMT processors.
> 
> This allows us to stop abusing cpu_present_map, and lets us get rid of
> find_physical_cpu_to_start, which has always been a bit dodgy.
> 
> The code which updates cpu_present_map I plan to move to the generic
> hotplug cpu code someday, but I think this is a good intermediate
> step for now.
> 
> Tested on Power5.

Hmm, just noticed that this does not allow us to online secondary
threads when booting with smt-enabled=off.  Will need to respin this
one.

Nathan