memcg: add mem_cgroup_disabled()

We check mem_cgroup is disabled or not by checking
mem_cgroup_subsys.disabled.  I think it has more references than expected,
now.

replacing
   if (mem_cgroup_subsys.disabled)
with
   if (mem_cgroup_disabled())

give us good look, I think.

[kamezawa.hiroyu@jp.fujitsu.com: fix typo]
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Li Zefan <lizf@cn.fujitsu.com>
Cc: Balbir Singh <balbir@in.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 74ae8e01d071..7006a11350c8 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -74,7 +74,7 @@ void __init page_cgroup_init(void)
 
         int nid, fail;
 
-        if (mem_cgroup_subsys.disabled)
+        if (mem_cgroup_disabled())
                 return;
 
         for_each_online_node(nid)  {
@@ -247,7 +247,7 @@ void __init page_cgroup_init(void)
         unsigned long pfn;
         int fail = 0;
 
-        if (mem_cgroup_subsys.disabled)
+        if (mem_cgroup_disabled())
                 return;
 
         for (pfn = 0; !fail && pfn < max_pfn; pfn += PAGES_PER_SECTION) {