MAXCPU preparations

[Robert Watson]

On Mon, 27 Sep 2010, John Baldwin wrote:

> Also, I think we should either fix MAXCPU to export the SMP value to 
> userland, or hide it from userland completely.  Exporting the UP value is 
> Just Wrong (tm).

Well, it's useful in the sense that it tells you what the maximum number of 
CPUs a kernel can support is, which is helpful, especially if you're futzing 
with MAXCPU as a kernel option :-).

But, more generally, many things that use MAXCPU should probably use either 
mp_maxid or DPCPU.  Not everything, but most things.

Robert