[PATCH 1/4] mm, page_alloc: add likely macro to help compiler optimization

Joonsoo Kim
2013-08-02T02:08:04Z

We rarely allocate a page with ALLOC_NO_WATERMARKS and it is used
in slow path. For making fast path more faster, add likely macro to
help compiler optimization.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index b100255..86ad44b 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1901,7 +1901,7 @@ zonelist_scan:
goto this_zone_full;

BUILD_BUG_ON(ALLOC_NO_WATERMARKS < NR_WMARK);
- if (!(alloc_flags & ALLOC_NO_WATERMARKS)) {
+ if (likely(!(alloc_flags & ALLOC_NO_WATERMARKS))) {
unsigned long mark;
int ret;

--
1.7.9.5