tree e9719788c751c1d4a437c98056e2ddd7e34d5dfa
parent a600388d28419305aad3c4c0af52c223cf6fa0af
author Zachary Amsden <zach@vmware.com> 1125788106 -0700
committer Linus Torvalds <torvalds@evo.osdl.org> 1125903948 -0700

[PATCH] x86_64: avoid some atomic operations during address space destruction

Any architecture that has hardware updated A/D bits that require
synchronization against other processors during PTE operations can benefit
from doing non-atomic PTE updates during address space destruction.
Originally done on i386, now ported to x86_64.

Doing a read/write pair instead of an xchg() operation saves the implicit
lock, which turns out to be a big win on 32-bit (esp w PAE).

Signed-off-by: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>