2.6.24

 mm

diff --git a/mm/internal.h b/mm/internal.h
index a3110c0..953f941 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -37,4 +37,14 @@ static inline void __put_page(struct page *page)
 extern void fastcall __init __free_pages_bootmem(struct page *page,
                   unsigned int order);
 
+/*
+ * function for dealing with page's order in buddy system.
+ * zone->lock is already acquired when we use these.
+ * So, we don't need atomic page->flags operations here.
+ */
+static inline unsigned long page_order(struct page *page)
+{
+   VM_BUG_ON(!PageBuddy(page));
+   return page_private(page);
+}
 #endif