diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 5f228cd..5f4213d 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1089,6 +1089,12 @@ static bool zone_spans_last_pfn(const struct zone *zone,
 	return zone_spans_pfn(zone, last_pfn);
 }
 
+/*
+ * Allocate a gigantic page from @nid node.
+ *
+ * Scan the zones of @nid node, and try to allocate a number of contiguous
+ * pages (1 << order).
+ */
 static struct page *alloc_gigantic_page(int nid, unsigned int order)
 {
 	unsigned long nr_pages = 1 << order;
@@ -1157,6 +1163,10 @@ static int alloc_fresh_gigantic_page(struct hstate *h,
 
 static inline bool gigantic_page_supported(void) { return true; }
 #else
+static inline struct page *alloc_gigantic_page(int nid, unsigned int order)
+{
+	return NULL;
+}
 static inline bool gigantic_page_supported(void) { return false; }
 static inline void free_gigantic_page(struct page *page, unsigned int order) { }
 static inline void destroy_compound_gigantic_page(struct page *page,
@@ -1568,7 +1578,7 @@ static struct page *__hugetlb_alloc_buddy_huge_page(struct hstate *h,
  * For (2), we ignore 'vma' and 'addr' and use 'nid' exclusively. This
  * implies that memory policies will not be taken in to account.
  */
-static struct page *__alloc_buddy_huge_page(struct hstate *h,
+static struct page *__alloc_huge_page(struct hstate *h,
 		struct vm_area_struct *vma, unsigned long addr, int nid)
 {
 	struct page *page;
@@ -1649,21 +1659,21 @@ static struct page *__alloc_buddy_huge_page(struct hstate *h,
  * anywhere.
  */
 static
-struct page *__alloc_buddy_huge_page_no_mpol(struct hstate *h, int nid)
+struct page *__alloc_huge_page_no_mpol(struct hstate *h, int nid)
 {
 	unsigned long addr = -1;
 
-	return __alloc_buddy_huge_page(h, NULL, addr, nid);
+	return __alloc_huge_page(h, NULL, addr, nid);
 }
 
 /*
  * Use the VMA's mpolicy to allocate a huge page from the buddy.
  */
 static
-struct page *__alloc_buddy_huge_page_with_mpol(struct hstate *h,
+struct page *__alloc_huge_page_with_mpol(struct hstate *h,
 		struct vm_area_struct *vma, unsigned long addr)
 {
-	return __alloc_buddy_huge_page(h, vma, addr, NUMA_NO_NODE);
+	return __alloc_huge_page(h, vma, addr, NUMA_NO_NODE);
 }
 
 /*
@@ -1681,7 +1691,7 @@ struct page *alloc_huge_page_node(struct hstate *h, int nid)
 	spin_unlock(&hugetlb_lock);
 
 	if (!page)
-		page = __alloc_buddy_huge_page_no_mpol(h, nid);
+		page = __alloc_huge_page_no_mpol(h, nid);
 
 	return page;
 }
@@ -1711,7 +1721,7 @@ static int gather_surplus_pages(struct hstate *h, int delta)
 retry:
 	spin_unlock(&hugetlb_lock);
 	for (i = 0; i < needed; i++) {
-		page = __alloc_buddy_huge_page_no_mpol(h, NUMA_NO_NODE);
+		page = __alloc_huge_page_no_mpol(h, NUMA_NO_NODE);
 		if (!page) {
 			alloc_ok = false;
 			break;
@@ -2027,7 +2037,7 @@ struct page *alloc_huge_page(struct vm_area_struct *vma,
 	page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve, gbl_chg);
 	if (!page) {
 		spin_unlock(&hugetlb_lock);
-		page = __alloc_buddy_huge_page_with_mpol(h, vma, addr);
+		page = __alloc_huge_page_with_mpol(h, vma, addr);
 		if (!page)
 			goto out_uncharge_cgroup;
 		if (!avoid_reserve && vma_has_reserves(vma, gbl_chg)) {
@@ -2285,7 +2295,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
 	 * First take pages out of surplus state.  Then make up the
 	 * remaining difference by allocating fresh huge pages.
 	 *
-	 * We might race with __alloc_buddy_huge_page() here and be unable
+	 * We might race with __alloc_huge_page() here and be unable
 	 * to convert a surplus huge page to a normal huge page. That is
 	 * not critical, though, it just means the overall size of the
 	 * pool might be one hugepage larger than it needs to be, but
@@ -2331,7 +2341,7 @@ static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count,
 	 * By placing pages into the surplus state independent of the
 	 * overcommit value, we are allowing the surplus pool size to
 	 * exceed overcommit. There are few sane options here. Since
-	 * __alloc_buddy_huge_page() is checking the global counter,
+	 * __alloc_huge_page() is checking the global counter,
 	 * though, we'll note that we're not allowed to exceed surplus
 	 * and won't grow the pool anywhere else. Not until one of the
 	 * sysctls are changed, or the surplus pages go out of use.
