mm: memcontrol: remove bogus NULL check after mem_cgroup_from_task()

That function acts like a typecast - unless NULL is passed in, no NULL can
come out.  task_in_mem_cgroup() callers don't pass NULL tasks.

Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Vladimir Davydov <vdavydov@parallels.com>
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/mm/memcontrol.c b/mm/memcontrol.c
index 9073d07..367cc57 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1356,7 +1356,7 @@ static bool mem_cgroup_same_or_subtree(const struct mem_cgroup *root_memcg,
 bool task_in_mem_cgroup(struct task_struct *task,
                        const struct mem_cgroup *memcg)
 {
-       struct mem_cgroup *curr = NULL;
+       struct mem_cgroup *curr;
        struct task_struct *p;
        bool ret;
 
@@ -1372,8 +1372,7 @@ bool task_in_mem_cgroup(struct task_struct *task,
                 */
                rcu_read_lock();
                curr = mem_cgroup_from_task(task);
-               if (curr)
-                       css_get(&curr->css);
+               css_get(&curr->css);
                rcu_read_unlock();
        }
        /*