Re: [patch 0/4] ia64 SPARSEMEM

Dave Hansen
2005-05-26T21:02:18Z

On Thu, 2005-05-26 at 16:54 -0400, Bob Picco wrote:
> luck wrote: [Wed May 25 2005, 08:32:54PM EDT]
> >
> > >+#ifdef CONFIG_SPARSEMEM
> > >+ /*
> > >+ * SECTION_SIZE_BITS 2^N: how big each section will be
> > >+ * MAX_PHYSADDR_BITS 2^N: how much physical address space we have
> > >+ * MAX_PHYSMEM_BITS 2^N: how much memory we can have in that space
> > >+ */
> >
> > MAX_PHYSADDR_BITS is apparently never used ... what's the distinction
>
> Ah MAX_PHYSADDR_BITS appears not used by all arches ported to SPARSEMEM. I
> wonder if it's a remnant of NONLINEAR. Dave, do you recall?

Yep, I think it's a remnant from nonlinear. Something about how sparse
the memory will be. We can compress the virtual address space if we're
careful.

-- Dave