diff -urN oldtree/mm/page-writeback.c newtree/mm/page-writeback.c
--- oldtree/mm/page-writeback.c	2006-09-26 15:30:26.000000000 -0400
+++ newtree/mm/page-writeback.c	2006-09-26 15:30:56.000000000 -0400
@@ -66,33 +66,33 @@
 /*
  * Start background writeback (via pdflush) at this percentage
  */
-int dirty_background_ratio = 10;
+int dirty_background_ratio __read_mostly = 10;
 
 /*
  * The generator of dirty data starts writeback at this percentage
  */
-int vm_dirty_ratio = 40;
+int vm_dirty_ratio __read_mostly;
 
 /*
  * The interval between `kupdate'-style writebacks, in jiffies
  */
-int dirty_writeback_interval = 5 * HZ;
+int dirty_writeback_interval __read_mostly = 5 * HZ;
 
 /*
  * The longest number of jiffies for which data is allowed to remain dirty
  */
-int dirty_expire_interval = 30 * HZ;
+int dirty_expire_interval __read_mostly = 30 * HZ;
 
 /*
  * Flag that makes the machine dump writes/reads and block dirtyings.
  */
-int block_dump;
+int block_dump __read_mostly;
 
 /*
  * Flag that puts the machine in "laptop mode". Doubles as a timeout in jiffies:
  * a full sync is triggered after this time elapses without any disk activity.
  */
-int laptop_mode;
+int laptop_mode __read_mostly;
 
 EXPORT_SYMBOL(laptop_mode);