mm: memcontrol: zap oom_info_lock

mem_cgroup_print_oom_info is always called under oom_lock, so
oom_info_lock is redundant.

Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
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 fa7bf35..36db05f 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1150,12 +1150,9 @@ static bool mem_cgroup_wait_acct_move(struct mem_cgroup *memcg)
  */
 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
-       /* oom_info_lock ensures that parallel ooms do not interleave */
-       static DEFINE_MUTEX(oom_info_lock);
        struct mem_cgroup *iter;
        unsigned int i;
 
-       mutex_lock(&oom_info_lock);
        rcu_read_lock();
 
        if (p) {
@@ -1199,7 +1196,6 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 
                pr_cont("\n");
        }
-       mutex_unlock(&oom_info_lock);
 }
 
 /*