Re: 2.6.13-rc3-mm3

[Russell King <rmk+lkml@arm.linux.org.uk>]

On Thu, Jul 28, 2005 at 10:11:18AM -0700, Christoph Lameter wrote:
> On Thu, 28 Jul 2005, Andrew Morton wrote:
> >   The patches at present spit warnings or don't compile on lots of
> >   architectures.  x86, x86_64, ppc64 and ia64 are OK.
> 
> I have just sent a fix to you this morning when I got your messages. 
> Sadly I do not have access to the architectures that failed (arm, alpha 
> and ppc32) but the fix simply removes code that is not used for these 
> arches.

ARM can't support atomic page table operations as such - the Linux view
of the page table is separate from the hardware view, and there's some
CPU specific code which translates from the Linux view to the hardware
view.

Looking at the actual patches, particularly pte_xchg-and-pte_cmpxchg.patch
combined with the above, the ARM solution would be to go back to using
non-atomic operations here (since we can't do this atomically.)  Also,
since the MMU will only ever read from the page tables, I don't think
we need to play any games with clearing out ptes before we replace the
value.

-- 
Russell King
 Linux kernel    2.6 ARM Linux   - http://www.arm.linux.org.uk/
 maintainer of:  2.6 Serial core