Index: linux-2.6.20-rc6/mm/page-writeback.c
===================================================================
--- linux-2.6.20-rc6.orig/mm/page-writeback.c	2007-01-26 08:05:12.000000000 -0800
+++ linux-2.6.20-rc6/mm/page-writeback.c	2007-01-26 08:05:21.000000000 -0800
@@ -139,7 +139,7 @@ static unsigned long determine_available
 
 			x -= zone_page_state(z, NR_FREE_PAGES)
 				+ zone_page_state(z, NR_INACTIVE)
-				+ zone_page_state(z, NR_INACTIVE);
+				+ zone_page_state(z, NR_ACTIVE);
 		}
 	}