Index: sched_ule.c
===================================================================
RCS file: /home/ncvs/src/sys/kern/sched_ule.c,v
retrieving revision 1.206
diff -u -r1.206 sched_ule.c
--- sched_ule.c	17 Sep 2007 05:27:20 -0000	1.206
+++ sched_ule.c	21 Sep 2007 04:56:11 -0000
@@ -407,7 +407,7 @@
 				pri = (unsigned char)(pri - 1) % RQ_NQS;
 		} else
 			pri = tdq->tdq_ridx;
-		runq_add_pri(ts->ts_runq, ts, pri, flags);
+		runq_add_pri(ts->ts_runq, ts, pri, flags|SRQ_PREEMPTED);
 	} else
 		runq_add(ts->ts_runq, ts, flags);
 }
@@ -639,6 +639,11 @@
 		move = min(move, transferable);
 		for (i = 0; i < move; i++)
 			tdq_move(high, low);
+		/*
+		 * IPI the target cpu to force it to reschedule with the new
+		 * workload.
+		 */
+		ipi_selected(1 << TDQ_ID(low), IPI_PREEMPT);
 	}
 	TDQ_UNLOCK(high);
 	TDQ_UNLOCK(low);
@@ -686,7 +691,6 @@
 	ts->ts_cpu = cpu;
 	td->td_lock = TDQ_LOCKPTR(to);
 	tdq_add(to, td, SRQ_YIELDING);
-	tdq_notify(ts);
 }
 
 /*
@@ -1402,8 +1406,12 @@
 	 * Scores greater than this are placed on the normal timeshare queue
 	 * where the priority is partially decided by the most recent cpu
 	 * utilization and the rest is decided by nice value.
+	 *
+	 * The nice value of the process has a linear effect on the calculated
+	 * score.  Negative nice values make it easier for a thread to be
+	 * considered interactive.
 	 */
-	score = sched_interact_score(td);
+	score = sched_interact_score(td) - td->td_proc->p_nice;
 	if (score < sched_interact) {
 		pri = PRI_MIN_REALTIME;
 		pri += ((PRI_MAX_REALTIME - PRI_MIN_REALTIME) / sched_interact)