--- linux-2.6.1/include/linux/sched.h	2004-01-27 17:05:54.108844000 +1100
+++ linux-2.6.1-ck1/include/linux/sched.h	2004-01-27 17:07:51.949929432 +1100
@@ -127,9 +127,10 @@ extern unsigned long nr_iowait(void);
 #define SCHED_FIFO		1
 #define SCHED_RR		2
 #define SCHED_BATCH		3
+#define SCHED_ISO		4
 
 #define SCHED_MIN		0
-#define SCHED_MAX		3
+#define SCHED_MAX		4
 
 #define SCHED_RANGE(policy)	((policy) >= SCHED_MIN && \
 					(policy) <= SCHED_MAX)
@@ -294,6 +295,7 @@ struct signal_struct {
 
 #define rt_task(p)		((p)->prio < MAX_RT_PRIO)
 #define batch_task(p)		((p)->policy == SCHED_BATCH)
+#define iso_task(p)		((p)->policy == SCHED_ISO)
 
 /*
  * Some day this will be a full-fledged user tracking system..
--- linux-2.6.1/kernel/sched.c	2004-01-27 17:18:54.620188240 +1100
+++ linux-2.6.1-ck1/kernel/sched.c	2004-01-27 17:24:18.313979304 +1100
@@ -1498,9 +1498,31 @@ void scheduler_tick(int user_ticks, int 
 			enqueue_task(p, rq->batch);
 		else {
 			if (!TASK_INTERACTIVE(p) || EXPIRED_STARVING(rq)) {
-				enqueue_task(p, rq->expired);
-				if (p->static_prio < rq->best_expired_prio)
-					rq->best_expired_prio = p->static_prio;
+				if (iso_task(p)) {
+					/*
+					 * If a SCHED_ISO task should expire
+					 * a task from the expired list is
+					 * pulled to active list instead.
+					 */
+					prio_array_t *array;
+					array = rq->expired;
+					if (array->nr_active) {
+						task_t *reactivate;
+						struct list_head *queue;
+						int idx;
+
+						idx = sched_find_first_bit(array->bitmap);
+						queue = array->queue + idx;
+						reactivate = list_entry(queue->next, task_t, run_list);
+						dequeue_task(reactivate, array);
+						enqueue_task(reactivate, rq->active);
+					}
+					enqueue_task(p, rq->active);
+				} else {
+					enqueue_task(p, rq->expired);
+					if (p->static_prio < rq->best_expired_prio)
+						rq->best_expired_prio = p->static_prio;
+				}
 			} else
 				enqueue_task(p, rq->active);
 		}
@@ -2186,8 +2208,13 @@ static int setscheduler(pid_t pid, int p
 			goto out_unlock;
 
 	retval = -EPERM;
-	if (SCHED_RT(policy) && !capable(CAP_SYS_NICE))
-		goto out_unlock;
+	if (SCHED_RT(policy) && !capable(CAP_SYS_NICE)) 
+		/*
+		 * If the caller requested an RT policy without having the
+		 * necessary rights, we downgrade the policy to SCHED_ISO.
+		 */
+		policy = SCHED_ISO;
+	
 	if ((current->euid != p->euid) && (current->euid != p->uid) &&
 	    !capable(CAP_SYS_NICE))
 		goto out_unlock;
@@ -2220,6 +2247,13 @@ static int setscheduler(pid_t pid, int p
 		} else if (TASK_PREEMPTS_CURR(p, rq))
 			resched_task(rq->curr);
 	}
+	if (policy == SCHED_ISO) {
+		/*
+		 * SCHED_ISO tasks get maximum interactivity.
+		 */
+		p->sleep_avg = NS_MAX_SLEEP_AVG;
+		p->interactive_credit = CREDIT_LIMIT + 1;
+	}
 
 out_unlock:
 	task_rq_unlock(rq, &flags);
@@ -2512,6 +2546,7 @@ asmlinkage long sys_sched_get_priority_m
 		break;
 	case SCHED_NORMAL:
 	case SCHED_BATCH:
+	case SCHED_ISO:
 		ret = 0;
 		break;
 	}
@@ -2536,6 +2571,7 @@ asmlinkage long sys_sched_get_priority_m
 		break;
 	case SCHED_NORMAL:
 	case SCHED_BATCH:
+	case SCHED_ISO:
 		ret = 0;
 	}
 	return ret;