[PATCH] Add node to zone for the NUMA case

Add the node in order to optimize zone_to_nid.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Acked-by: Paul Jackson <pj@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 7477fb5..8e433bb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -446,7 +446,11 @@
 
 static inline unsigned long zone_to_nid(struct zone *zone)
 {
-	return zone->zone_pgdat->node_id;
+#ifdef CONFIG_NUMA
+	return zone->node;
+#else
+	return 0;
+#endif
 }
 
 static inline unsigned long page_to_nid(struct page *page)