mm: memcontrol: micro-optimize mem_cgroup_split_huge_fixup()
Don't call lookup_page_cgroup() when memcg is disabled.
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 420461b..8c10d4c 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3174,7 +3174,7 @@
*/
void mem_cgroup_split_huge_fixup(struct page *head)
{
- struct page_cgroup *head_pc = lookup_page_cgroup(head);
+ struct page_cgroup *head_pc;
struct page_cgroup *pc;
struct mem_cgroup *memcg;
int i;
@@ -3182,6 +3182,8 @@
if (mem_cgroup_disabled())
return;
+ head_pc = lookup_page_cgroup(head);
+
memcg = head_pc->mem_cgroup;
for (i = 1; i < HPAGE_PMD_NR; i++) {
pc = head_pc + i;