mm, memcg: don't take task_lock in task_in_mem_cgroup
For processes that have detached their mm's, task_in_mem_cgroup()
unnecessarily takes task_lock() when rcu_read_lock() is all that is
necessary to call mem_cgroup_from_task().
While we're here, switch task_in_mem_cgroup() to return bool.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index d6183f0..7b4d9d7 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -77,7 +77,8 @@
bool __mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
struct mem_cgroup *memcg);
-int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *memcg);
+bool task_in_mem_cgroup(struct task_struct *task,
+ const struct mem_cgroup *memcg);
extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);
extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);
@@ -273,10 +274,10 @@
return true;
}
-static inline int task_in_mem_cgroup(struct task_struct *task,
- const struct mem_cgroup *memcg)
+static inline bool task_in_mem_cgroup(struct task_struct *task,
+ const struct mem_cgroup *memcg)
{
- return 1;
+ return true;
}
static inline struct cgroup_subsys_state