1 files changed, 10 insertions, 7 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 7caff36180cd..67dd2a881433 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1688,13 +1688,13 @@ static void move_unlock_mem_cgroup(struct mem_cgroup *memcg,
  */
 void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
 {
-        struct cgroup *task_cgrp;
-        struct cgroup *mem_cgrp;
         /*
-         * Need a buffer in BSS, can't rely on allocations. The code relies
-         * on the assumption that OOM is serialized for memory controller.
-         * If this assumption is broken, revisit this code.
+         * protects memcg_name and makes sure that parallel ooms do not
+         * interleave
          */
+        static DEFINE_SPINLOCK(oom_info_lock);
+        struct cgroup *task_cgrp;
+        struct cgroup *mem_cgrp;
         static char memcg_name[PATH_MAX];
         int ret;
         struct mem_cgroup *iter;
@@ -1703,6 +1703,7 @@ void mem_cgroup_print_oom_info(struct mem_cgroup *memcg, struct task_struct *p)
         if (!p)
                 return;
 
+        spin_lock(&oom_info_lock);
         rcu_read_lock();
 
         mem_cgrp = memcg->css.cgroup;
@@ -1771,6 +1772,7 @@ done:
 
                 pr_cont("\n");
         }
+        spin_unlock(&oom_info_lock);
 }
 
 /*
@@ -3000,7 +3002,8 @@ static DEFINE_MUTEX(set_limit_mutex);
 static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg)
 {
         return !mem_cgroup_disabled() && !mem_cgroup_is_root(memcg) &&
-                (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK);
+                (memcg->kmem_account_flags & KMEM_ACCOUNTED_MASK) ==
+                                                        KMEM_ACCOUNTED_MASK;
 }
 
 /*
@@ -3126,7 +3129,7 @@ int memcg_cache_id(struct mem_cgroup *memcg)
  * But when we create a new cache, we can call this as well if its parent
  * is kmem-limited. That will have to hold set_limit_mutex as well.
  */
-int memcg_update_cache_sizes(struct mem_cgroup *memcg)
+static int memcg_update_cache_sizes(struct mem_cgroup *memcg)
 {
         int num, ret;