1 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 5407e4200460..8170bb8066a2 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1493,6 +1493,31 @@ static inline void lruvec_lock_irq(struct lruvec *lruvec)
 	spin_lock_irq(&lruvec->lru_lock);
 }
 
+static inline struct lruvec *lruvec_live_lock_irq(struct lruvec *lruvec)
+{
+#ifdef CONFIG_MEMCG
+	struct pglist_data *pgdat = lruvec_pgdat(lruvec);
+	struct mem_cgroup *memcg = lruvec_memcg(lruvec);
+
+	rcu_read_lock();
+
+	/*
+	 * The memcg can be NULL when the memory controller is disabled.
+	 * Otherwise, the caller keeps the memcg owning @lruvec alive.
+	 */
+	while (unlikely(memcg && css_is_dying(&memcg->css))) {
+		memcg = parent_mem_cgroup(memcg);
+		lruvec = mem_cgroup_lruvec(memcg, pgdat);
+	}
+
+	spin_lock_irq(&lruvec->lru_lock);
+#else
+	lruvec_lock_irq(lruvec);
+#endif
+
+	return lruvec;
+}
+
 static inline void lruvec_unlock(struct lruvec *lruvec)
 {
 	spin_unlock(&lruvec->lru_lock);