---

yaml
---
r: 336726
b: refs/heads/master
c: 69a37be
h: refs/heads/master
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e45a00d679a788217f35ee4214a32d6d1924160b
+refs/heads/master: 69a37beabf1f0a6705c08e879bdd5d82ff6486c4

trunk/drivers/cpuidle/governors/menu.c

@@ -28,6 +28,13 @@
 #define MAX_INTERESTING 50000
 #define STDDEV_THRESH 400
 
+/* 60 * 60 > STDDEV_THRESH * INTERVALS = 400 * 8 */
+#define MAX_DEVIATION 60
+
+static DEFINE_PER_CPU(struct hrtimer, menu_hrtimer);
+static DEFINE_PER_CPU(int, hrtimer_status);
+/* menu hrtimer mode */
+enum {MENU_HRTIMER_STOP, MENU_HRTIMER_REPEAT};
 
 /*
  * Concepts and ideas behind the menu governor
@@ -191,17 +198,42 @@ static u64 div_round64(u64 dividend, u32 divisor)
 	return div_u64(dividend + (divisor / 2), divisor);
 }
 
+/* Cancel the hrtimer if it is not triggered yet */
+void menu_hrtimer_cancel(void)
+{
+	int cpu = smp_processor_id();
+	struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
+
+	/* The timer is still not time out*/
+	if (per_cpu(hrtimer_status, cpu)) {
+		hrtimer_cancel(hrtmr);
+		per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
+	}
+}
+EXPORT_SYMBOL_GPL(menu_hrtimer_cancel);
+
+/* Call back for hrtimer is triggered */
+static enum hrtimer_restart menu_hrtimer_notify(struct hrtimer *hrtimer)
+{
+	int cpu = smp_processor_id();
+
+	per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_STOP;
+
+	return HRTIMER_NORESTART;
+}
+
 /*
  * Try detecting repeating patterns by keeping track of the last 8
  * intervals, and checking if the standard deviation of that set
  * of points is below a threshold. If it is... then use the
  * average of these 8 points as the estimated value.
  */
-static void detect_repeating_patterns(struct menu_device *data)
+static int detect_repeating_patterns(struct menu_device *data)
 {
 	int i;
 	uint64_t avg = 0;
 	uint64_t stddev = 0; /* contains the square of the std deviation */
+	int ret = 0;
 
 	/* first calculate average and standard deviation of the past */
 	for (i = 0; i < INTERVALS; i++)
@@ -210,7 +242,7 @@ static void detect_repeating_patterns(struct menu_device *data)
 
 	/* if the avg is beyond the known next tick, it's worthless */
 	if (avg > data->expected_us)
-		return;
+		return 0;
 
 	for (i = 0; i < INTERVALS; i++)
 		stddev += (data->intervals[i] - avg) *
@@ -223,8 +255,12 @@ static void detect_repeating_patterns(struct menu_device *data)
 	 * repeating pattern and predict we keep doing this.
 	 */
 
-	if (avg && stddev < STDDEV_THRESH)
+	if (avg && stddev < STDDEV_THRESH) {
 		data->predicted_us = avg;
+		ret = 1;
+	}
+
+	return ret;
 }
 
 /**
@@ -240,6 +276,9 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	int i;
 	int multiplier;
 	struct timespec t;
+	int repeat = 0, low_predicted = 0;
+	int cpu = smp_processor_id();
+	struct hrtimer *hrtmr = &per_cpu(menu_hrtimer, cpu);
 
 	if (data->needs_update) {
 		menu_update(drv, dev);
@@ -274,7 +313,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 	data->predicted_us = div_round64(data->expected_us * data->correction_factor[data->bucket],
 					 RESOLUTION * DECAY);
 
-	detect_repeating_patterns(data);
+	repeat = detect_repeating_patterns(data);
 
 	/*
 	 * We want to default to C1 (hlt), not to busy polling
@@ -295,8 +334,10 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 
 		if (s->disabled || su->disable)
 			continue;
-		if (s->target_residency > data->predicted_us)
+		if (s->target_residency > data->predicted_us) {
+			low_predicted = 1;
 			continue;
+		}
 		if (s->exit_latency > latency_req)
 			continue;
 		if (s->exit_latency * multiplier > data->predicted_us)
@@ -309,6 +350,27 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
 		}
 	}
 
+	/* not deepest C-state chosen for low predicted residency */
+	if (low_predicted) {
+		unsigned int timer_us = 0;
+
+		/*
+		 * Set a timer to detect whether this sleep is much
+		 * longer than repeat mode predicted.  If the timer
+		 * triggers, the code will evaluate whether to put
+		 * the CPU into a deeper C-state.
+		 * The timer is cancelled on CPU wakeup.
+		 */
+		timer_us = 2 * (data->predicted_us + MAX_DEVIATION);
+
+		if (repeat && (4 * timer_us < data->expected_us)) {
+			hrtimer_start(hrtmr, ns_to_ktime(1000 * timer_us),
+				HRTIMER_MODE_REL_PINNED);
+			/* In repeat case, menu hrtimer is started */
+			per_cpu(hrtimer_status, cpu) = MENU_HRTIMER_REPEAT;
+		}
+	}
+
 	return data->last_state_idx;
 }
 
@@ -399,6 +461,9 @@ static int menu_enable_device(struct cpuidle_driver *drv,
 				struct cpuidle_device *dev)
 {
 	struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
+	struct hrtimer *t = &per_cpu(menu_hrtimer, dev->cpu);
+	hrtimer_init(t, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+	t->function = menu_hrtimer_notify;
 
 	memset(data, 0, sizeof(struct menu_device));
 

trunk/include/linux/tick.h

@@ -142,4 +142,10 @@ static inline u64 get_cpu_idle_time_us(int cpu, u64 *unused) { return -1; }
 static inline u64 get_cpu_iowait_time_us(int cpu, u64 *unused) { return -1; }
 # endif /* !NO_HZ */
 
+# ifdef CONFIG_CPU_IDLE_GOV_MENU
+extern void menu_hrtimer_cancel(void);
+# else
+static inline void menu_hrtimer_cancel(void) {}
+# endif /* CONFIG_CPU_IDLE_GOV_MENU */
+
 #endif

trunk/kernel/time/tick-sched.c

@@ -526,6 +526,8 @@ void tick_nohz_irq_exit(void)
 	if (!ts->inidle)
 		return;
 
+	/* Cancel the timer because CPU already waken up from the C-states*/
+	menu_hrtimer_cancel();
 	__tick_nohz_idle_enter(ts);
 }
 
@@ -621,6 +623,8 @@ void tick_nohz_idle_exit(void)
 
 	ts->inidle = 0;
 
+	/* Cancel the timer because CPU already waken up from the C-states*/
+	menu_hrtimer_cancel();
 	if (ts->idle_active || ts->tick_stopped)
 		now = ktime_get();