diff --git a/kernel/rcu/srcu.c b/kernel/rcu/srcu.c
index d51ab05..5aeeaec 100644
--- a/kernel/rcu/srcu.c
+++ b/kernel/rcu/srcu.c
@@ -254,10 +254,9 @@
 }
 
 /*
- * @@@ Wait until all pre-existing readers complete.  Such readers
- * will have used the index specified by "idx".
- * the caller should ensures the ->completed is not changed while checking
- * and idx = (->completed & 1) ^ 1
+ * Wait until all readers counted by array index idx complete, but loop
+ * a maximum of trycount times.  The caller must ensure that ->completed
+ * is not changed while checking.
  */
 static bool try_check_zero(struct srcu_struct *sp, int idx, int trycount)
 {