--- linux-2.6.0-test1-mm1/kernel/sched.c	2003-07-17 19:59:16.000000000 +1000
+++ linux-2.6.0-testck1/kernel/sched.c	2003-07-19 01:56:41.000000000 +1000
@@ -76,7 +76,6 @@
 #define MIN_SLEEP_AVG		(HZ)
 #define MAX_SLEEP_AVG		(10*HZ)
 #define STARVATION_LIMIT	(10*HZ)
-#define SLEEP_BUFFER		(HZ/100)
 #define NODE_THRESHOLD		125
 #define MAX_BONUS		(MAX_USER_PRIO * PRIO_BONUS_RATIO / 100)
 
@@ -391,11 +390,11 @@ static inline void activate_task(task_t 
 
 	if (sleep_time > 0) {
 		/*
-		 * Tasks that sleep a long time are categorised as idle and
+		 * User tasks that sleep a long time are categorised as idle and
 		 * will get just under interactive status with a small runtime
 		 * to allow them to become interactive or non-interactive rapidly
 		 */
-		if (sleep_time > MIN_SLEEP_AVG){
+		if (sleep_time > MIN_SLEEP_AVG && p->mm){
 			p->avg_start = jiffies - MIN_SLEEP_AVG;
 			p->sleep_avg = MIN_SLEEP_AVG * (MAX_BONUS - INTERACTIVE_DELTA - 2) /
 				MAX_BONUS;
@@ -421,13 +420,8 @@ static inline void activate_task(task_t 
 			 */
 			p->sleep_avg = (p->sleep_avg * MAX_BONUS / runtime + 1) * runtime / MAX_BONUS;
 
-			/*
-			 * Keep a small buffer of SLEEP_BUFFER sleep_avg to
-			 * prevent fully interactive tasks from becoming
-			 * lower priority with small bursts of cpu usage.
-			 */
-			if (p->sleep_avg > (MAX_SLEEP_AVG + SLEEP_BUFFER))
-				p->sleep_avg = MAX_SLEEP_AVG + SLEEP_BUFFER;
+			if (p->sleep_avg > MAX_SLEEP_AVG)
+				p->sleep_avg = MAX_SLEEP_AVG;
 		}
 
 		if (unlikely(p->avg_start > jiffies)){
@@ -1310,10 +1304,12 @@ void scheduler_tick(int user_ticks, int 
 			enqueue_task(p, rq->expired);
 		} else
 			enqueue_task(p, rq->active);
-	} else if (p->prio < effective_prio(p)){
+	} else if (p->mm && !((task_timeslice(p) - p->time_slice) %
+		 (MIN_TIMESLICE * (MAX_BONUS + 1 - p->sleep_avg * MAX_BONUS / MAX_SLEEP_AVG)))){
 		/*
-		 * Tasks that have lowered their priority are put to the end
-		 * of the active array with their remaining timeslice
+		 * Running user tasks get requeued with their remaining timeslice
+		 * after a period proportional to how cpu intensive they are to
+		 * minimise the duration one interactive task can starve another
 		 */
 		dequeue_task(p, rq->active);
 		set_tsk_need_resched(p);