mm/memcontrol.c: export mem_cgroup_is_root()

This will be used in next patch.

Link: http://lkml.kernel.org/r/153063064347.1818.1987011484100392706.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai <[email protected]>
Acked-by: Vladimir Davydov <[email protected]>
Tested-by: Shakeel Butt <[email protected]>
Cc: Al Viro <[email protected]>
Cc: Andrey Ryabinin <[email protected]>
Cc: Chris Wilson <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Josef Bacik <[email protected]>
Cc: Li RongQing <[email protected]>
Cc: Matthew Wilcox <[email protected]>
Cc: Matthias Kaehlcke <[email protected]>
Cc: Mel Gorman <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Minchan Kim <[email protected]>
Cc: Philippe Ombredanne <[email protected]>
Cc: Roman Gushchin <[email protected]>
Cc: Sahitya Tummala <[email protected]>
Cc: Stephen Rothwell <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Waiman Long <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 2cccbb9e1b3e..258c8a46959a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -318,6 +318,11 @@ struct mem_cgroup {
 
 extern struct mem_cgroup *root_mem_cgroup;
 
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+	return (memcg == root_mem_cgroup);
+}
+
 static inline bool mem_cgroup_disabled(void)
 {
 	return !cgroup_subsys_enabled(memory_cgrp_subsys);
@@ -784,6 +789,11 @@ void mem_cgroup_split_huge_fixup(struct page *head);
 
 struct mem_cgroup;
 
+static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg)
+{
+	return true;
+}
+
 static inline bool mem_cgroup_disabled(void)
 {
 	return true;