diff -urN oldtree/include/linux/mm.h newtree/include/linux/mm.h
--- oldtree/include/linux/mm.h	2006-09-24 17:03:56.000000000 -0400
+++ newtree/include/linux/mm.h	2006-09-27 14:05:05.000000000 -0400
@@ -421,7 +421,7 @@
 #else
 #define ZONEID_SHIFT		(NODES_SHIFT + ZONES_SHIFT)
 #endif
-#define ZONEID_PGSHIFT		ZONES_PGOFF
+#define ZONEID_PGSHIFT		ZONES_PGSHIFT
 
 #if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED
 #error SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH > FLAGS_RESERVED