Index: linux-2.6.15/include/linux/sched.h
===================================================================
--- linux-2.6.15.orig/include/linux/sched.h
+++ linux-2.6.15/include/linux/sched.h
@@ -683,6 +683,13 @@ static inline void prefetch_stack(struct
 struct audit_context;		/* See audit.c */
 struct mempolicy;
 
+enum sleep_type {
+	SLEEP_NORMAL,
+	SLEEP_NONINTERACTIVE,
+	SLEEP_INTERACTIVE,
+	SLEEP_INTERRUPTED,
+};
+
 struct task_struct {
 	volatile long state;	/* -1 unrunnable, 0 runnable, >0 stopped */
 	struct thread_info *thread_info;
@@ -704,7 +711,7 @@ struct task_struct {
 	unsigned long sleep_avg;
 	unsigned long long timestamp, last_ran;
 	unsigned long long sched_time; /* sched_clock time spent running */
-	int activated;
+	enum sleep_type sleep_type;
 
 	unsigned long policy;
 	cpumask_t cpus_allowed;
Index: linux-2.6.15/kernel/sched.c
===================================================================
--- linux-2.6.15.orig/kernel/sched.c
+++ linux-2.6.15/kernel/sched.c
@@ -747,35 +747,30 @@ static int recalc_task_prio(task_t *p, u
 	if (likely(sleep_time > 0)) {
 		/*
 		 * User tasks that sleep a long time are categorised as
-		 * idle and will get just interactive status to stay active &
-		 * prevent them suddenly becoming cpu hogs and starving
-		 * other processes.
+		 * idle. They will only have their sleep_avg increased to a
+		 * level that makes them just interactive priority to stay
+		 * active yet prevent them suddenly becoming cpu hogs and
+		 * starving other processes.
 		 */
-		if (p->mm && p->activated != -1 &&
-			sleep_time > INTERACTIVE_SLEEP(p)) {
-				p->sleep_avg = JIFFIES_TO_NS(MAX_SLEEP_AVG -
-						DEF_TIMESLICE);
+		if (p->mm && sleep_time > INTERACTIVE_SLEEP(p)) {
+				unsigned long ceiling;
+
+				ceiling = JIFFIES_TO_NS(MAX_SLEEP_AVG -
+					DEF_TIMESLICE);
+				if (p->sleep_avg < ceiling)
+					p->sleep_avg = ceiling;
 		} else {
+
 			/*
 			 * The lower the sleep avg a task has the more
-			 * rapidly it will rise with sleep time.
+			 * rapidly it will rise with sleep time. This enables
+			 * tasks to rapidly recover to a low latency priority.
+			 * If a task was sleeping with the noninteractive
+			 * label do not apply this non-linear boost
 			 */
-			sleep_time *= (MAX_BONUS - CURRENT_BONUS(p)) ? : 1;
-
-			/*
-			 * Tasks waking from uninterruptible sleep are
-			 * limited in their sleep_avg rise as they
-			 * are likely to be waiting on I/O
-			 */
-			if (p->activated == -1 && p->mm) {
-				if (p->sleep_avg >= INTERACTIVE_SLEEP(p))
-					sleep_time = 0;
-				else if (p->sleep_avg + sleep_time >=
-						INTERACTIVE_SLEEP(p)) {
-					p->sleep_avg = INTERACTIVE_SLEEP(p);
-					sleep_time = 0;
-				}
-			}
+			if (p->sleep_type != SLEEP_NONINTERACTIVE || !p->mm)
+				sleep_time *=
+					(MAX_BONUS - CURRENT_BONUS(p)) ? : 1;
 
 			/*
 			 * This code gives a bonus to interactive tasks.
@@ -818,11 +813,7 @@ static void activate_task(task_t *p, run
 	if (!rt_task(p))
 		p->prio = recalc_task_prio(p, now);
 
-	/*
-	 * This checks to make sure it's not an uninterruptible task
-	 * that is now waking up.
-	 */
-	if (!p->activated) {
+	if (p->sleep_type != SLEEP_NONINTERACTIVE) {
 		/*
 		 * Tasks which were woken up by interrupts (ie. hw events)
 		 * are most likely of interactive nature. So we give them
@@ -831,13 +822,13 @@ static void activate_task(task_t *p, run
 		 * on a CPU, first time around:
 		 */
 		if (in_interrupt())
-			p->activated = 2;
+			p->sleep_type = SLEEP_INTERRUPTED;
 		else {
 			/*
 			 * Normal first-time wakeups get a credit too for
 			 * on-runqueue time, but it will be weighted down:
 			 */
-			p->activated = 1;
+			p->sleep_type = SLEEP_INTERACTIVE;
 		}
 	}
 	p->timestamp = now;
@@ -1356,22 +1347,23 @@ out_activate:
 	if (old_state == TASK_UNINTERRUPTIBLE) {
 		rq->nr_uninterruptible--;
 		/*
-		 * Tasks on involuntary sleep don't earn
-		 * sleep_avg beyond just interactive state.
+		 * Tasks waking from uninterruptible sleep are likely
+		 * to be sleeping involuntarily on I/O and are otherwise
+		 * cpu bound so label them as noninteractive.
 		 */
-		p->activated = -1;
-	}
+		p->sleep_type = SLEEP_NONINTERACTIVE;
+	} else
 
 	/*
 	 * Tasks that have marked their sleep as noninteractive get
-	 * woken up without updating their sleep average. (i.e. their
-	 * sleep is handled in a priority-neutral manner, no priority
-	 * boost and no penalty.)
+	 * woken up with their sleep average not weighted in an
+	 * interactive way.
 	 */
-	if (old_state & TASK_NONINTERACTIVE)
-		__activate_task(p, rq);
-	else
-		activate_task(p, rq, cpu == this_cpu);
+		if (old_state & TASK_NONINTERACTIVE)
+			p->sleep_type = SLEEP_NONINTERACTIVE;
+
+
+	activate_task(p, rq, cpu == this_cpu);
 	/*
 	 * Sync wakeups (i.e. those types of wakeups where the waker
 	 * has indicated that it will leave the CPU in short order)
@@ -2938,6 +2930,12 @@ EXPORT_SYMBOL(sub_preempt_count);
 
 #endif
 
+static inline int interactive_sleep(enum sleep_type sleep_type)
+{
+	return (sleep_type == SLEEP_INTERACTIVE ||
+		sleep_type == SLEEP_INTERRUPTED);
+}
+
 /*
  * schedule() is the main scheduler function.
  */
@@ -3063,12 +3061,12 @@ go_idle:
 	queue = array->queue + idx;
 	next = list_entry(queue->next, task_t, run_list);
 
-	if (!rt_task(next) && next->activated > 0) {
+	if (!rt_task(next) && interactive_sleep(next->sleep_type)) {
 		unsigned long long delta = now - next->timestamp;
 		if (unlikely((long long)(now - next->timestamp) < 0))
 			delta = 0;
 
-		if (next->activated == 1)
+		if (next->sleep_type == SLEEP_INTERACTIVE)
 			delta = delta * (ON_RUNQUEUE_WEIGHT * 128 / 100) / 128;
 
 		array = next->array;
@@ -3081,7 +3079,7 @@ go_idle:
 		} else
 			requeue_task(next, array);
 	}
-	next->activated = 0;
+	next->sleep_type = SLEEP_NORMAL;
 switch_tasks:
 	if (next == rq->idle)
 		schedstat_inc(rq, sched_goidle);