lkml.org 
[lkml]   [2008]   [Aug]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] x86: fix /proc/meminfo DirectMap
On Fri, 15 Aug 2008, Ingo Molnar wrote:
> * Hugh Dickins <hugh@veritas.com> wrote:
>
> > Should we really be using level2_ident_pgt (which needs to avoid NX)
> > for the final direct map (which wants to use NX)? But my attempt to
> > build up a fresh pagetable there failed miserably to boot!
>
> hm, exactly what change have you tried? (patch?)

As soon as that kernel failed to boot, I chucked the patch away and
erased it from my mind: much better to leave such a change to the
people who are intimate with this sequence and can debug it.

It wasn't anything much, the page to use has already been set aside
for alloc_low_page, I thought it was just a matter of breaking the
association with level2_ident_pgt at the right level then letting
phys_pmd_init do its usual setup from scratch.

Maybe it didn't work because I got it slightly wrong, or maybe it
it didn't work for more subtle reasons e.g. I was then building up
the first 1GB of direct map 2MB by 2MB: if direct map is actually
used in there and falls out of TLB, I'd certainly be in trouble.

Hugh


\
 
 \ /
  Last update: 2008-08-15 16:33    [W:0.072 / U:0.628 seconds]
©2003-2014 Jasper Spaans. Advertise on this site