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>
This commit is contained in:
Michal Hocko 2014-12-10 15:43:51 -08:00 committed by Linus Torvalds
parent 8c0145b62e
commit b9982f8d27
1 changed files with 3 additions and 1 deletions

View File

@ -3174,7 +3174,7 @@ static inline void memcg_unregister_all_caches(struct mem_cgroup *memcg)
*/
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 @@ void mem_cgroup_split_huge_fixup(struct page *head)
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;