diff --git a/mm/slab.c b/mm/slab.c
index 1db4d73..e291f5e 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3263,6 +3263,7 @@
 
 /**
  * cache_reap - Reclaim memory from caches.
+ * @unused: unused parameter
  *
  * Called from workqueue/eventd every few seconds.
  * Purpose: