> >even on machines with 32 bit addressing you could swap ... not all
> >that that memory is going to mapped into one process...
> 
> of course not, no.  but how can you can address more than 4gb on a 32
> bit machine?  really big page tables?

yup.

While our pmap doesn't support it, recent x86 processors (Pentium Pro
and Pentium II) support a page table format extension which allows use
of 36-bit physical addresses (although the virtual address space per
process is still limited to 32 bits).

					- Bill