Fix build...
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7eeb062..8266fdc 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -3400,7 +3400,7 @@
 	/*
 	 * Tune reconstruction:
 	 */
-	window = vm_max_readahead*(PAGE_SIZE/512);
+	window = MAX_READAHEAD*(PAGE_SIZE/512);
 	printk(KERN_INFO "md: using %dk window, over a total of %d blocks.\n",
 	       window/2,max_sectors/2);