memcg: add hints for branch

Showing brach direction for obvious conditions.

Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Paul Menage <menage@google.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 4 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index f46b8615de6c..04ded27f6226 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -550,7 +550,7 @@ retry:
          * The page_cgroup exists and
          * the page has already been accounted.
          */
-        if (pc) {
+        if (unlikely(pc)) {
                 VM_BUG_ON(pc->page != page);
                 VM_BUG_ON(!pc->mem_cgroup);
                 unlock_page_cgroup(page);
@@ -559,7 +559,7 @@ retry:
         unlock_page_cgroup(page);
 
         pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
-        if (pc == NULL)
+        if (unlikely(pc == NULL))
                 goto err;
 
         /*
@@ -616,7 +616,7 @@ retry:
                 pc->flags = PAGE_CGROUP_FLAG_ACTIVE;
 
         lock_page_cgroup(page);
-        if (page_get_page_cgroup(page)) {
+        if (unlikely(page_get_page_cgroup(page))) {
                 unlock_page_cgroup(page);
                 /*
                  * Another charge has been added to this page already.
@@ -690,7 +690,7 @@ __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
          */
         lock_page_cgroup(page);
         pc = page_get_page_cgroup(page);
-        if (!pc)
+        if (unlikely(!pc))
                 goto unlock;
 
         VM_BUG_ON(pc->page != page);