X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=mm%2Fmemcontrol.c;h=57b16083f04603cdef5c4c9b98b95b9a75202f8a;hb=32665f2bbfed2e325d37236d9b0071a11a69124e;hp=08541f680d90ff3189fee0270e36d6f17548dd2c;hpb=2753b35bcd3156727138cd2305b825611a571a3f;p=firefly-linux-kernel-4.4.55.git

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 08541f680d90..57b16083f046 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -1647,13 +1647,13 @@ 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;
@@ -1662,6 +1662,7 @@ 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;
@@ -1730,6 +1731,7 @@ done:
 
 		pr_cont("\n");
 	}
+	spin_unlock(&oom_info_lock);
 }
 
 /*