diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3a2d54b..0356cb6 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3046,6 +3046,52 @@
 	return ret;
 }
 
+#ifdef CONFIG_DEBUG_VM
+static struct page_cgroup *lookup_page_cgroup_used(struct page *page)
+{
+	struct page_cgroup *pc;
+
+	pc = lookup_page_cgroup(page);
+	if (likely(pc) && PageCgroupUsed(pc))
+		return pc;
+	return NULL;
+}
+
+bool mem_cgroup_bad_page_check(struct page *page)
+{
+	if (mem_cgroup_disabled())
+		return false;
+
+	return lookup_page_cgroup_used(page) != NULL;
+}
+
+void mem_cgroup_print_bad_page(struct page *page)
+{
+	struct page_cgroup *pc;
+
+	pc = lookup_page_cgroup_used(page);
+	if (pc) {
+		int ret = -1;
+		char *path;
+
+		printk(KERN_ALERT "pc:%p pc->flags:%lx pc->mem_cgroup:%p",
+		       pc, pc->flags, pc->mem_cgroup);
+
+		path = kmalloc(PATH_MAX, GFP_KERNEL);
+		if (path) {
+			rcu_read_lock();
+			ret = cgroup_path(pc->mem_cgroup->css.cgroup,
+							path, PATH_MAX);
+			rcu_read_unlock();
+		}
+
+		printk(KERN_CONT "(%s)\n",
+				(ret < 0) ? "cannot get the path" : path);
+		kfree(path);
+	}
+}
+#endif
+
 static DEFINE_MUTEX(set_limit_mutex);
 
 static int mem_cgroup_resize_limit(struct mem_cgroup *memcg,