Re: [PATCh] x86: overmapped fix when 4K pages on tail - 64bit

[Arjan van de Ven <arjan@infradead.org>]

On Sun, 13 Jul 2008 16:57:50 +0200
Andi Kleen <andi@firstfloor.org> wrote:

> Arjan van de Ven <arjan@infradead.org> writes:
> 
> > On Wed, 9 Jul 2008 20:15:02 -0700
> > Yinghai Lu <yhlu.kernel@gmail.com> wrote:
> >
> >> 
> >> 
> >> fix phys_pmd_init to make sure not to return big value than end.
> >> 
> >> also print out range split:1G/2M/4K
> >> 
> >> Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
> >
> >
> > Making an accurate mapping solves a lot of potentially nasty/tricky
> > corner cases, so I like the approach
> 
> It also means that e.g. on a 1GB system the direct mapping will 
> never use 1GB pages.
> 
> And the CPU has to handle this anyways because all the old 
> kernels overmap and no x86 CPU can drop support for all old
> kernels.

for the 2mb case.. please find me a dimm which isn't a multiple of
2Mb ;-)