---
 kernel/sched_bfs.c |   25 +++++++++++++++++++++++++
 kernel/sysctl.c    |   10 ++++++++++
 2 files changed, 35 insertions(+)

Index: linux-2.6.35.5-ck1/kernel/sched_bfs.c
===================================================================
--- linux-2.6.35.5-ck1.orig/kernel/sched_bfs.c	2010-10-04 20:32:39.968671850 +1100
+++ linux-2.6.35.5-ck1/kernel/sched_bfs.c	2010-10-04 21:02:08.689577993 +1100
@@ -137,6 +137,14 @@ int rr_interval __read_mostly = 6;
 int sched_iso_cpu __read_mostly = 70;
 
 /*
+ * latency_bias is used to determine whether we should sacrifice throughput
+ * as load increases to try and keep latencies bound to rr_interval. It does
+ * not change the fairness, so heavy CPU users will still run slow (slower
+ * since throughput decreases dramatically the higher this is set to).
+ */
+int latency_bias __read_mostly = 2;
+
+/*
  * The relative length of deadline for each priority(nice) level.
  */
 static int prio_ratios[PRIO_RANGE] __read_mostly;
@@ -2062,6 +2070,23 @@ update_cpu_clock(struct rq *rq, struct t
 		s64 time_diff = rq->clock - rq->rq_last_ran;
 
 		niffy_diff(&time_diff, 1);
+		/*
+		 * If we are overloaded, then shorten the effective timeslices
+		 * to ensure latencies are kept as small as is possible by
+		 * making them expire at a rate proportional to load/CPUs. Use
+		 * latency_bias to determine the upper limit for how much to
+		 * shorten the effective timeslice.
+		 */
+		if (latency_bias) {
+			int nr = nr_running(), nol = num_online_cpus();
+
+			if (nr > nol) {
+				time_diff /= nol;
+				if (nr > latency_bias * nol)
+					nr = latency_bias * nol;
+				time_diff *= nr;
+			}
+		}
 		rq->rq_time_slice -= NS_TO_US(time_diff);
 	}
 	rq->rq_last_ran = rq->timekeep_clock = rq->clock;
Index: linux-2.6.35.5-ck1/kernel/sysctl.c
===================================================================
--- linux-2.6.35.5-ck1.orig/kernel/sysctl.c	2010-10-04 20:32:39.977671481 +1100
+++ linux-2.6.35.5-ck1/kernel/sysctl.c	2010-10-04 20:32:48.030341034 +1100
@@ -119,6 +119,7 @@ static int __maybe_unused one_hundred =
 #ifdef CONFIG_SCHED_BFS
 extern int rr_interval;
 extern int sched_iso_cpu;
+extern int latency_bias;
 static int __read_mostly one_thousand = 1000;
 #endif
 #ifdef CONFIG_PRINTK
@@ -802,6 +803,15 @@ static struct ctl_table kern_table[] = {
 		.maxlen		= sizeof (int),
 		.mode		= 0644,
 		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one_hundred,
+	},
+	{
+		.procname	= "latency_bias",
+		.data		= &latency_bias,
+		.maxlen		= sizeof (int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
 		.extra1		= &zero,
 		.extra2		= &one_hundred,
 	},