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| author |   Michael S. Tsirkin <mst@redhat.com> | 2009-09-21 17:03:52 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-22 07:17:42 -0700 |
| commit | f68e14805085972b4e0b0ab684af37f713b9c262 (patch) | |
| tree | 6e0cc9e1e3f29b36ec3d7acfaf863cf9bb39ea5b /drivers/pcmcia | |
| parent | mm: move use_mm/unuse_mm from aio.c to mm/ (diff) | |
| download | linux-dev-f68e14805085972b4e0b0ab684af37f713b9c262.tar.xz linux-dev-f68e14805085972b4e0b0ab684af37f713b9c262.zip | |
mm: reduce atomic use on use_mm fast path
When the mm being switched to matches the active mm, we don't need to
increment and then drop the mm count. In a simple benchmark this happens
in about 50% of time. Making that conditional reduces contention on that
cacheline on SMP systems.
Acked-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/pcmcia')
0 files changed, 0 insertions, 0 deletions