Re: [rfc] fix Kconfig, hotplug_cpu is needed for swsusp

[Ashok Raj]

On Wed, Mar 29, 2006 at 02:47:46PM -0800, Andrew Morton wrote:
> Pavel Machek <pavel@xxxxxx> wrote:
> >
> > HOTPLUG_CPU is needed on normal PCs, too -- it is neccessary for
> > software suspend.
> > 
> 
> OK, this will get ugly.  APICs are involved.

I guess you need only on systems that support >1 cpu right? I doubt you will need
it on a system that cannot run with the config-generic-arch on. although we use bigsmp 
when hotplug is turned on, all we really end up is using flat physical mode instead
of using logical mode.

I still havent understood why this wont work. Choosing CONFIG_X86_GENERICARCH shouldnt
break anything AFAICT.

Pavel, you could use CONFIG_HOTPLUG_CPU, just need to enable X86_GENERICARCH now. 
Is there a reason you think that wont work? I wish we would revert it for a strong 
reason that we know will not make hotplug work on certain systems because of this choise
not that we currently have X86_PC now, and are unwiling to change the config.

(PS: the word bigsmp although sounds like some large NR_CPUS, its just using a mode that
permits the system to work from 1 .. >8 cpus. So there is really nothing determental 
to selecting this.)


-- 
Cheers,
Ashok Raj
- Open Source Technology Center
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