--- linux-2.6.2/kernel/sched.c	2004-02-04 17:11:55.637964232 +1100
+++ linux-2.6.2-ck1/kernel/sched.c	2004-02-04 17:23:28.585620176 +1100
@@ -1726,7 +1726,7 @@ need_resched:
 			if (ht_active) {
 				/*
 				 * If a HT sibling task is sleeping due to
-				 * priority reasons wake it up now
+				 * priority or batch reasons wake it up now
 				 */
 				runqueue_t *htrq;
 				htrq = cpu_rq(cpu_sibling_map[(rq->cpu)]);
@@ -1782,7 +1782,7 @@ need_resched:
 		 * cpu's resources.
 		 */
 		if (next->mm && htcurr->mm && !rt_task(next) && 
-			((next->static_prio > 
+			!batch_task(htcurr) && ((next->static_prio > 
 			htcurr->static_prio && htcurr->time_slice > 
 			task_timeslice(next)) || rt_task(htcurr))) {
 				next = rq->idle;
@@ -1790,14 +1790,29 @@ need_resched:
 		}
 		
 		/*
-		 * Reschedule a lower priority task
+		 * Prevent a batch task from running if a user
+		 * non batch task is running on a HT sibling.
+		 */
+		if (unlikely(batch_task(next) && htrq->nr_running > 
+			htrq->nr_batch && htcurr->mm)) {
+				dequeue_task(next, array);
+				enqueue_task(next, rq->batch);
+				next = rq->idle;
+				if (htcurr == htrq->idle)
+					resched_task(htcurr);
+				goto switch_tasks;
+		}
+		
+		/*
+		 * Reschedule a lower priority or batch task
 		 * on the HT sibling, or wake it up if it has been
 		 * put to sleep for priority reasons.
 		 */
 		if ((htcurr != htrq->idle && 
 			htcurr->static_prio > next->static_prio) ||
 			(rt_task(next) && !rt_task(htcurr)) ||
-			(htcurr == htrq->idle && htrq->nr_running))
+			(htcurr == htrq->idle && htrq->nr_running) ||
+			(batch_task(htcurr) && next->mm && !batch_task(next)))
 				resched_task(htcurr);
 
 	}