--- linux-2.6.0-test3-mm1-O14.1/kernel/sched.c	2003-08-12 22:04:13.000000000 +1000
+++ linux-2.6.0-test3-mm1/kernel/sched.c	2003-08-12 22:03:47.000000000 +1000
@@ -620,8 +620,13 @@ repeat_lock_task:
 				__activate_task(p, rq);
 			else {
 				activate_task(p, rq);
-				if (TASK_PREEMPTS_CURR(p, rq))
-					resched_task(rq->curr);
+				/*
+				 * Parents are not allowed to preempt their
+				 * children
+				 */
+				if (TASK_PREEMPTS_CURR(p, rq) &&
+					p != rq->curr->parent)
+						resched_task(rq->curr);
 			}
 			success = 1;
 		}
@@ -1124,7 +1129,7 @@ static inline void pull_task(runqueue_t 
 	 * Note that idle threads have a prio of MAX_PRIO, for this test
 	 * to be always true for them.
 	 */
-	if (TASK_PREEMPTS_CURR(p, this_rq))
+	if (TASK_PREEMPTS_CURR(p, this_rq) && p != this_rq->curr->parent)
 		set_need_resched();
 }
 
@@ -1493,9 +1498,8 @@ need_resched:
 	 * priority bonus
 	 */
 	if (HIGH_CREDIT(prev))
-		run_time /= (MAX_BONUS + 1 -
-			(NS_TO_JIFFIES(prev->sleep_avg) * MAX_BONUS /
-			MAX_SLEEP_AVG));
+		run_time /= ((NS_TO_JIFFIES(prev->sleep_avg) * MAX_BONUS /
+				MAX_SLEEP_AVG) ? : 1);
 
 	spin_lock_irq(&rq->lock);