Re: Virtual address space exhaustion (was Discontigmem virt_to_page() )

[Martin J. Bligh]

> Another interesting problem is that 'struct page *' will be as best a
> cookie, not a valid pointer anymore, not sure what's the best way to
> handle that. Working with pfn would be cleaner rather than working with
> a cookie (somebody could dereference the cookie by mistake thinking it's
> a page structure old style), but if __alloc_pages returns a pfn a whole
> lot of kernel code will break.

Yup, a physical address pfn would probably be best.

(such as tlb size, which is something stupid like 4 pages, IIRC)

> it has 8 pages for data and 2 for instructions, that's 16M data and 4M
> of instructions with PAE

What is "it", a P4? I think the sizes are dependant on which chip you're
using. The x440 has the P4 chips, but the NUMA-Q is is P2 or P3 (even
PPro for the oldest ones, but those don't work at the moment with Linux
on multiquad).

M.