Introduce the mem_cgroup_put() helper, which helps to eliminate guarding memcg css release with "#ifdef CONFIG_MEMCG" in multiple places. Link: http://lkml.kernel.org/r/20180623000600.5818-2-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Cc: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 6c6fb116e925..e53e00cdbe3f 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -375,6 +375,11 @@ 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) @@ -837,6 +842,10 @@ 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