{slub, slob}: use unlikely() for kfree(ZERO_OR_NULL_PTR) check

Considering kfree(NULL) would normally occur only in error paths and
kfree(ZERO_SIZE_PTR) is uncommon as well, so let's use unlikely() for the
condition check in SLUB's and SLOB's kfree() to optimize for the common
case.  SLAB has this already.

Signed-off-by: Satyam Sharma <satyam@infradead.org>
Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 3 deletions

diff --git a/mm/slob.c b/mm/slob.c
index ec33fcdc852e..a886e83e17ef 100644
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -360,7 +360,7 @@ static void slob_free(void *block, int size)
         slobidx_t units;
         unsigned long flags;
 
-        if (ZERO_OR_NULL_PTR(block))
+        if (unlikely(ZERO_OR_NULL_PTR(block)))
                 return;
         BUG_ON(!size);
 
@@ -466,7 +466,7 @@ void kfree(const void *block)
 {
         struct slob_page *sp;
 
-        if (ZERO_OR_NULL_PTR(block))
+        if (unlikely(ZERO_OR_NULL_PTR(block)))
                 return;
 
         sp = (struct slob_page *)virt_to_page(block);
@@ -484,7 +484,7 @@ size_t ksize(const void *block)
 {
         struct slob_page *sp;
 
-        if (ZERO_OR_NULL_PTR(block))
+        if (unlikely(ZERO_OR_NULL_PTR(block)))
                 return 0;
 
         sp = (struct slob_page *)virt_to_page(block);