diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ee9e314..2f1544e 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -784,6 +784,18 @@
 void memory_present(int nid, unsigned long start, unsigned long end);
 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 
+/*
+ * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
+ * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
+ * pfn_valid_within() should be used in this case; we optimise this away
+ * when we have no holes within a MAX_ORDER_NR_PAGES block.
+ */
+#ifdef CONFIG_HOLES_IN_ZONE
+#define pfn_valid_within(pfn) pfn_valid(pfn)
+#else
+#define pfn_valid_within(pfn) (1)
+#endif
+
 #endif /* !__ASSEMBLY__ */
 #endif /* __KERNEL__ */
 #endif /* _LINUX_MMZONE_H */
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 019ceda..f564717 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -156,10 +156,8 @@
 
 static int page_is_consistent(struct zone *zone, struct page *page)
 {
-#ifdef CONFIG_HOLES_IN_ZONE
-	if (!pfn_valid(page_to_pfn(page)))
+	if (!pfn_valid_within(page_to_pfn(page)))
 		return 0;
-#endif
 	if (zone != page_zone(page))
 		return 0;
 
@@ -346,10 +344,8 @@
 static inline int page_is_buddy(struct page *page, struct page *buddy,
 								int order)
 {
-#ifdef CONFIG_HOLES_IN_ZONE
-	if (!pfn_valid(page_to_pfn(buddy)))
+	if (!pfn_valid_within(page_to_pfn(buddy)))
 		return 0;
-#endif
 
 	if (page_zone_id(page) != page_zone_id(buddy))
 		return 0;