Introduce the mem_cgroup_put() helper, which helps to eliminate
guarding memcg css release with "#ifdef CONFIG_MEMCG" in multiple
places.

Signed-off-by: Roman Gushchin <g...@fb.com>
Cc: Shakeel Butt <shake...@google.com>
Cc: Johannes Weiner <han...@cmpxchg.org>
Cc: Michal Hocko <mho...@kernel.org>
Cc: Andrew Morton <a...@linux-foundation.org>
---
 include/linux/memcontrol.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index cf1c3555328f..3607913032be 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -383,6 +383,11 @@ struct mem_cgroup *mem_cgroup_from_css(struct 
cgroup_subsys_state *css){
        return css ? container_of(css, struct mem_cgroup, css) : NULL;
 }
 
+static inline void mem_cgroup_put(struct mem_cgroup *memcg)
+{
+       css_put(&memcg->css);
+}
+
 #define mem_cgroup_from_counter(counter, member)       \
        container_of(counter, struct mem_cgroup, member)
 
@@ -852,6 +857,10 @@ static inline bool task_in_mem_cgroup(struct task_struct 
*task,
        return true;
 }
 
+static inline void mem_cgroup_put(struct mem_cgroup *memcg)
+{
+}
+
 static inline struct mem_cgroup *
 mem_cgroup_iter(struct mem_cgroup *root,
                struct mem_cgroup *prev,
-- 
2.14.4

Reply via email to