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authorMichael S. Tsirkin <mst@redhat.com>2009-09-22 02:03:52 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2009-09-22 16:17:42 +0200
commitf68e14805085972b4e0b0ab684af37f713b9c262 (patch)
tree6e0cc9e1e3f29b36ec3d7acfaf863cf9bb39ea5b /drivers/pcmcia
parentmm: move use_mm/unuse_mm from aio.c to mm/ (diff)
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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')
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