Commit 03dba278 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

cpuidle: menu: Replace data->predicted_us with local variable 



The predicted_us field in struct menu_device is only accessed in
menu_select(), so replace it with a local variable in that function.

With that, stop using expected_interval instead of predicted_us to
store the new predicted idle duration value if it is set to the
selected state's target residency which is quite confusing.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: default avatarDaniel Lezcano <daniel.lezcano@linaro.org>
parent 7037b43e

drivers/cpuidle/governors/menu.c

+11 −12
Original line number Diff line number Diff line
@@ -124,7 +124,6 @@ struct menu_device { 
	int             tick_wakeup;



	unsigned int	next_timer_us;

	unsigned int	predicted_us;

	unsigned int	bucket;

	unsigned int	correction_factor[BUCKETS];

	unsigned int	intervals[INTERVALS];
@@ -290,6 +289,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
	int idx;

	unsigned int interactivity_req;

	unsigned int expected_interval;

	unsigned int predicted_us;

	unsigned long nr_iowaiters, cpu_load;

	ktime_t delta_next;
@@ -315,7 +315,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
	 * operands are 32 bits.

	 * Make sure to round up for half microseconds.

	 */

	data->predicted_us = DIV_ROUND_CLOSEST_ULL((uint64_t)data->next_timer_us *

	predicted_us = DIV_ROUND_CLOSEST_ULL((uint64_t)data->next_timer_us *

					 data->correction_factor[data->bucket],

					 RESOLUTION * DECAY);
@@ -341,7 +341,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
	/*

	 * Use the lowest expected idle interval to pick the idle state.

	 */

	data->predicted_us = min(data->predicted_us, expected_interval);

	predicted_us = min(predicted_us, expected_interval);



	if (tick_nohz_tick_stopped()) {

		/*
@@ -352,19 +352,18 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
		 * the known time till the closest timer event for the idle

		 * state selection.

		 */

		if (data->predicted_us < TICK_USEC)

			data->predicted_us = ktime_to_us(delta_next);

		if (predicted_us < TICK_USEC)

			predicted_us = ktime_to_us(delta_next);

	} else {

		/*

		 * Use the performance multiplier and the user-configurable

		 * latency_req to determine the maximum exit latency.

		 */

		interactivity_req = data->predicted_us / performance_multiplier(nr_iowaiters, cpu_load);

		interactivity_req = predicted_us / performance_multiplier(nr_iowaiters, cpu_load);

		if (latency_req > interactivity_req)

			latency_req = interactivity_req;

	}



	expected_interval = data->predicted_us;

	/*

	 * Find the idle state with the lowest power while satisfying

	 * our constraints.
@@ -378,8 +377,8 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
			continue;

		if (idx == -1)

			idx = i; /* first enabled state */

		if (s->target_residency > data->predicted_us) {

			if (data->predicted_us < TICK_USEC)

		if (s->target_residency > predicted_us) {

			if (predicted_us < TICK_USEC)

				break;



			if (!tick_nohz_tick_stopped()) {
@@ -389,7 +388,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
				 * tick in that case and let the governor run

				 * again in the next iteration of the loop.

				 */

				expected_interval = drv->states[idx].target_residency;

				predicted_us = drv->states[idx].target_residency;

				break;

			}
@@ -412,7 +411,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
			 * expected idle duration so that the tick is retained

			 * as long as that target residency is low enough.

			 */

			expected_interval = drv->states[idx].target_residency;

			predicted_us = drv->states[idx].target_residency;

			break;

		}

		idx = i;
@@ -426,7 +425,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
	 * expected idle duration is shorter than the tick period length.

	 */

	if (((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) ||

	     expected_interval < TICK_USEC) && !tick_nohz_tick_stopped()) {

	     predicted_us < TICK_USEC) && !tick_nohz_tick_stopped()) {

		unsigned int delta_next_us = ktime_to_us(delta_next);



		*stop_tick = false;