From: Roman Gushchin <guro@xxxxxx> Subject: mm: introduce mem_cgroup_put() helper 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> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/memcontrol.h | 9 +++++++++ 1 file changed, 9 insertions(+) --- a/include/linux/memcontrol.h~mm-introduce-mem_cgroup_put-helper +++ a/include/linux/memcontrol.h @@ -378,6 +378,11 @@ struct mem_cgroup *mem_cgroup_from_css(s 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) @@ -850,6 +855,10 @@ static inline bool task_in_mem_cgroup(st 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, _
