---

yaml
---
r: 87091
b: refs/heads/master
c: 2668db9
h: refs/heads/master
i:
  87089: 97e2539
  87087: f49b2b3
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 842078054da2d754c6b998b116d7c468abbfaaca
+refs/heads/master: 2668db9111bb1a6ab5a54f41f703179f35c7d098

trunk/mm/hugetlb.c

@@ -286,6 +286,12 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
 
 	spin_lock(&hugetlb_lock);
 	if (page) {
+		/*
+		 * This page is now managed by the hugetlb allocator and has
+		 * no users -- drop the buddy allocator's reference.
+		 */
+		put_page_testzero(page);
+		VM_BUG_ON(page_count(page));
 		nid = page_to_nid(page);
 		set_compound_page_dtor(page, free_huge_page);
 		/*
@@ -369,13 +375,14 @@ static int gather_surplus_pages(int delta)
 			enqueue_huge_page(page);
 		else {
 			/*
-			 * Decrement the refcount and free the page using its
-			 * destructor.  This must be done with hugetlb_lock
+			 * The page has a reference count of zero already, so
+			 * call free_huge_page directly instead of using
+			 * put_page.  This must be done with hugetlb_lock
 			 * unlocked which is safe because free_huge_page takes
 			 * hugetlb_lock before deciding how to free the page.
 			 */
 			spin_unlock(&hugetlb_lock);
-			put_page(page);
+			free_huge_page(page);
 			spin_lock(&hugetlb_lock);
 		}
 	}