diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 570d944..3f8bce2 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2358,6 +2358,7 @@
 /**
  * alloc_pages_exact_nid - allocate an exact number of physically-contiguous
  *			   pages on a node.
+ * @nid: the preferred node ID where memory should be allocated
  * @size: the number of bytes to allocate
  * @gfp_mask: GFP flags for the allocation
  *