bfs: Add zen-tune tweaks

init/Kconfig

@@ -44,14 +44,19 @@ config ZEN_INTERACTIVE
 	    NCQ Queue Depth................:  31    ->   8
 	    Block Layer Queue Depth........: 128    ->  16
 
-	  --- CPU Scheduler --------------------------------------
+	  --- CPU Scheduler (CFS) --------------------------------
 
 	    Scheduling latency.............:   6    ->   3    ms
 	    Minimal granularity............:   0.75 ->   0.3  ms
 	    Wakeup granularity.............:   1    ->   0.5  ms
 	    CPU migration cost.............:   0.5  ->   0.25 ms
 	    Bandwidth slice size...........:   5    ->   3    ms
 
+	  --- CPU Scheduler (BFS) --------------------------------
+
+	    Scheduling interval............:   6    ->   3    ms
+	    ISO task max realtime use......:  70 %  ->  25 %
+
 	  --- CPU Frequency Scaling ------------------------------
 
 	    Ondemand down scaling factor...:   1    ->  10

kernel/sched/bfs.c

@@ -144,7 +144,11 @@ void print_scheduler_version(void)
  * Value is in ms and set to a minimum of 6ms. Scales with number of cpus.
  * Tunable via /proc interface.
  */
+#ifdef CONFIG_ZEN_INTERACTIVE
+int rr_interval __read_mostly = 3;
+#else
 int rr_interval __read_mostly = 6;
+#endif
 
 /* Tunable to choose whether to prioritise latency or throughput, simple
  * binary yes or no */
@@ -156,7 +160,11 @@ int sched_interactive __read_mostly = 1;
  * are allowed to run five seconds as real time tasks. This is the total over
  * all online cpus.
  */
+#ifdef CONFIG_ZEN_INTERACTIVE
+int sched_iso_cpu __read_mostly = 25;
+#else
 int sched_iso_cpu __read_mostly = 70;
+#endif
 
 /*
  * The relative length of deadline for each priority(nice) level.