diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8be81422d4bd8de1d81d522884f159fa54e25f97..6e62d5f9d40b7260d9f933a3570f4e622f62b9dd 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -357,6 +357,7 @@ void prep_compound_page(struct page *page, unsigned long order)
 	}
 }
 
+/* update __split_huge_page_refcount if you change this function */
 static int destroy_compound_page(struct page *page, unsigned long order)
 {
 	int i;