]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
mm, page_alloc: add unlikely macro to help compiler optimization
authorJoonsoo Kim <iamjoonsoo.kim@lge.com>
Wed, 11 Sep 2013 21:21:26 +0000 (14:21 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Wed, 11 Sep 2013 22:57:29 +0000 (15:57 -0700)
commite66f09725771ac5b1b868d6b19eba84e30ffad88
tree82cd7bb01c1253efa6c13986882fab63a50201e6
parent1da6f0e1b316d0215989fe4d7c657edead1fdea7
mm, page_alloc: add unlikely macro to help compiler optimization

We rarely allocate a page with ALLOC_NO_WATERMARKS and it is used in slow
path.  For helping compiler optimization, add unlikely macro to
ALLOC_NO_WATERMARKS checking.

This patch doesn't have any effect now, because gcc already optimize this
properly.  But we cannot assume that gcc always does right and nobody
re-evaluate if gcc do proper optimization with their change, for example,
it is not optimized properly on v3.10.  So adding compiler hint here is
reasonable.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/page_alloc.c