page allocator: inline some __alloc_pages() wrappers

Two zonelist patch series rewrote __page_alloc() largely.  Now, it is just
a wrapper function.  Inlining them will save a function call.

[akpm@linux-foundation.org: export __alloc_pages_internal]
Cc: Lee Schermerhorn <lee.schermerhorn@hp.com>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index b414be3..f640ed2 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -173,11 +173,24 @@
 static inline void arch_alloc_page(struct page *page, int order) { }
 #endif
 
-extern struct page *__alloc_pages(gfp_t, unsigned int, struct zonelist *);
+struct page *
+__alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
+		       struct zonelist *zonelist, nodemask_t *nodemask);
 
-extern struct page *
-__alloc_pages_nodemask(gfp_t, unsigned int,
-				struct zonelist *, nodemask_t *nodemask);
+static inline struct page *
+__alloc_pages(gfp_t gfp_mask, unsigned int order,
+		struct zonelist *zonelist)
+{
+	return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
+}
+
+static inline struct page *
+__alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
+		struct zonelist *zonelist, nodemask_t *nodemask)
+{
+	return __alloc_pages_internal(gfp_mask, order, zonelist, nodemask);
+}
+
 
 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 						unsigned int order)