Add a proc tunable of /proc/sys/kernel/interactive which is set to 1 by default
and allows users to choose between prioritising latency or throughput.

-ck

---
 kernel/sched/bfs.c |   21 +++++++++++++++------
 kernel/sysctl.c    |   10 ++++++++++
 2 files changed, 25 insertions(+), 6 deletions(-)

Index: linux-4.3-ck3/kernel/sched/bfs.c
===================================================================
--- linux-4.3-ck3.orig/kernel/sched/bfs.c	2015-12-15 17:01:01.885962087 +1100
+++ linux-4.3-ck3/kernel/sched/bfs.c	2015-12-15 17:01:01.883962099 +1100
@@ -135,7 +135,7 @@
 
 void print_scheduler_version(void)
 {
-	printk(KERN_INFO "BFS CPU scheduler v0.466 by Con Kolivas.\n");
+	printk(KERN_INFO "BFS CPU scheduler v0.467 by Con Kolivas.\n");
 }
 
 /*
@@ -145,6 +145,11 @@ void print_scheduler_version(void)
  */
 int rr_interval __read_mostly = 6;
 
+/* Tunable to choose whether to prioritise latency or throughput, simple
+ * binary yes or no */
+
+int sched_interactive __read_mostly = 1;
+
 /*
  * sched_iso_cpu - sysctl which determines the cpu percentage SCHED_ISO tasks
  * are allowed to run five seconds as real time tasks. This is the total over
@@ -3188,7 +3193,6 @@ task_struct *earliest_deadline_task(stru
 		 */
 		earliest_deadline = ~0ULL;
 		list_for_each_entry(p, queue, run_list) {
-			int tcpu;
 			u64 dl;
 
 			/* Make sure cpu affinity is ok */
@@ -3206,10 +3210,15 @@ task_struct *earliest_deadline_task(stru
 			 * against its deadline when not, based on cpu cache
 			 * locality.
 			 */
-			tcpu = task_cpu(p);
-			if (tcpu != cpu && task_sticky(p) && scaling_rq(rq))
-				continue;
-			dl = p->deadline << locality_diff(tcpu, rq);
+			if (sched_interactive)
+				dl = p->deadline;
+			else {
+				int tcpu = task_cpu(p);
+
+				if (tcpu != cpu && task_sticky(p) && scaling_rq(rq))
+					continue;
+				dl = p->deadline << locality_diff(tcpu, rq);
+			}
 
 			if (deadline_before(dl, earliest_deadline)) {
 				earliest_deadline = dl;
Index: linux-4.3-ck3/kernel/sysctl.c
===================================================================
--- linux-4.3-ck3.orig/kernel/sysctl.c	2015-12-15 17:01:01.885962087 +1100
+++ linux-4.3-ck3/kernel/sysctl.c	2015-12-15 17:01:01.883962099 +1100
@@ -127,6 +127,7 @@ static unsigned long one_ul = 1;
 static int __maybe_unused one_hundred = 100;
 #ifdef CONFIG_SCHED_BFS
 extern int rr_interval;
+extern int sched_interactive;
 extern int sched_iso_cpu;
 static int __read_mostly one_thousand = 1000;
 #endif
@@ -988,6 +989,15 @@ static struct ctl_table kern_table[] = {
 		.extra2		= &one_thousand,
 	},
 	{
+		.procname	= "interactive",
+		.data		= &sched_interactive,
+		.maxlen		= sizeof(int),
+		.mode		= 0644,
+		.proc_handler	= &proc_dointvec_minmax,
+		.extra1		= &zero,
+		.extra2		= &one,
+	},
+	{
 		.procname	= "iso_cpu",
 		.data		= &sched_iso_cpu,
 		.maxlen		= sizeof (int),