[PATCH] mm, slab_common: add 'unlikely' to size check of kmalloc_slab()

From: Joonsoo Kim
Date: Thu Aug 01 2013 - 22:02:51 EST

Size is usually below than KMALLOC_MAX_SIZE.
If we add a 'unlikely' macro, compiler can make better code.

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

diff --git a/mm/slab_common.c b/mm/slab_common.c
index 538bade..f0410eb 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -373,7 +373,7 @@ struct kmem_cache *kmalloc_slab(size_t size, gfp_t flags)
int index;

- if (size > KMALLOC_MAX_SIZE) {
+ if (unlikely(size > KMALLOC_MAX_SIZE)) {
WARN_ON_ONCE(!(flags & __GFP_NOWARN));
return NULL;

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