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>

include/linux/gfp.h

@@ -173,11 +173,24 @@ static inline void arch_free_page(struct page *page, int order) { }
 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);
+
+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);
+}
 
-extern struct page *
-__alloc_pages_nodemask(gfp_t, unsigned int,
-				struct zonelist *, nodemask_t *nodemask);
 
 static inline struct page *alloc_pages_node(int nid, gfp_t gfp_mask,
 						unsigned int order)

mm/page_alloc.c

@@ -1429,7 +1429,7 @@ try_next_zone:
 /*
  * This is the 'heart' of the zoned buddy allocator.
  */
-static struct page *
+struct page *
 __alloc_pages_internal(gfp_t gfp_mask, unsigned int order,
 			struct zonelist *zonelist, nodemask_t *nodemask)
 {
@@ -1632,22 +1632,7 @@ nopage:
 got_pg:
 	return page;
 }
-
-struct page *
-__alloc_pages(gfp_t gfp_mask, unsigned int order,
-		struct zonelist *zonelist)
-{
-	return __alloc_pages_internal(gfp_mask, order, zonelist, NULL);
-}
-
-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);
-}
-
-EXPORT_SYMBOL(__alloc_pages);
+EXPORT_SYMBOL(__alloc_pages_internal);
 
 /*
  * Common helper functions.