diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index 760dfc2..c09605f 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -56,7 +56,10 @@ static atomic_t rcu_barrier_cpu_count;
 static DEFINE_MUTEX(rcu_barrier_mutex);
 static struct completion rcu_barrier_completion;
 
-/* Because of FASTCALL declaration of complete, we use this wrapper */
+/*
+ * Awaken the corresponding synchronize_rcu() instance now that a
+ * grace period has elapsed.
+ */
 static void wakeme_after_rcu(struct rcu_head  *head)
 {
 	struct rcu_synchronize *rcu;