diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 28bf65560084e8be50d0cae2bca4a3fd8ad6d974..1f0f64fa3ccd28f3612772d111a8917f9cf47d45 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -296,7 +296,6 @@ struct mem_cgroup {
 	int			tcpmem_pressure;
 
 #ifdef CONFIG_MEMCG_KMEM
-        /* Index in the kmem_cache->memcg_params.memcg_caches array */
 	int kmemcg_id;
 	enum memcg_kmem_state kmem_state;
 	struct obj_cgroup __rcu *objcg;
@@ -1562,9 +1561,8 @@ static inline void memcg_kmem_uncharge(struct mem_cgroup *memcg,
 }
 
 /*
- * helper for accessing a memcg's index. It will be used as an index in the
- * child cache array in kmem_cache, and also to derive its name. This function
- * will return -1 when this is not a kmem-limited memcg.
+ * A helper for accessing memcg's kmem_id, used for getting
+ * corresponding LRU lists.
  */
 static inline int memcg_cache_id(struct mem_cgroup *memcg)
 {
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 758613277286ba96e724f5bb8c5bb727411a7b53..466d9aed6cc825dc1b151dca9f28300ecd367213 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3703,12 +3703,6 @@ static int memcg_online_kmem(struct mem_cgroup *memcg)
 
 	static_branch_enable(&memcg_kmem_enabled_key);
 
-	/*
-	 * A memory cgroup is considered kmem-online as soon as it gets
-	 * kmemcg_id. Setting the id after enabling static branching will
-	 * guarantee no one starts accounting before all call sites are
-	 * patched.
-	 */
 	memcg->kmemcg_id = memcg_id;
 	memcg->kmem_state = KMEM_ONLINE;