Index: linux-2.6.12-rc6-ck2/include/linux/ioprio.h
===================================================================
--- linux-2.6.12-rc6-ck2.orig/include/linux/ioprio.h	2005-06-11 22:21:05.000000000 +1000
+++ linux-2.6.12-rc6-ck2/include/linux/ioprio.h	2005-06-11 22:21:40.000000000 +1000
@@ -55,7 +55,13 @@ static inline int task_ioprio(struct tas
 
 static inline int task_nice_ioprio(struct task_struct *task)
 {
-	return (task_nice(task) + 20) / 5;
+	int effective_nice = task_nice(task);
+
+	if (batch_task(task))
+		effective_nice = 19;
+	else if (iso_task(task))
+		effective_nice = -20;
+	return (effective_nice + 20) / 5;
 }
 
 /*