[PATCH 2/2] mm: introduce mem_cgroup_put() helper

Roman Gushchin
2018-06-23T00:06:46Z

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 <guro@fb.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Andrew Morton <akpm@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