Commit 094a7c31 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

Merge branch 'pm-cpuidle' 

Merge a menu governor fix for 6.17-rc3

* pm-cpuidle:
  cpuidle: governors: menu: Avoid selecting states with too much latency
parents 2bc1adb0 779b1a1c

drivers/cpuidle/governors/menu.c

+12 −17
Original line number Diff line number Diff line
@@ -287,20 +287,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
		return 0;

	}



	if (tick_nohz_tick_stopped()) {

	/*

		 * If the tick is already stopped, the cost of possible short

		 * idle duration misprediction is much higher, because the CPU

		 * may be stuck in a shallow idle state for a long time as a

		 * result of it.  In that case say we might mispredict and use

		 * the known time till the closest timer event for the idle

		 * state selection.

	 * If the tick is already stopped, the cost of possible short idle

	 * duration misprediction is much higher, because the CPU may be stuck

	 * in a shallow idle state for a long time as a result of it.  In that

	 * case, say we might mispredict and use the known time till the closest

	 * timer event for the idle state selection.

	 */

		if (predicted_ns < TICK_NSEC)

	if (tick_nohz_tick_stopped() && predicted_ns < TICK_NSEC)

		predicted_ns = data->next_timer_ns;

	} else if (latency_req > predicted_ns) {

		latency_req = predicted_ns;

	}



	/*

	 * Find the idle state with the lowest power while satisfying
@@ -316,13 +311,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
		if (idx == -1)

			idx = i; /* first enabled state */



		if (s->exit_latency_ns > latency_req)

			break;



		if (s->target_residency_ns > predicted_ns) {

			/*

			 * Use a physical idle state, not busy polling, unless

			 * a timer is going to trigger soon enough.

			 */

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

			    s->exit_latency_ns <= latency_req &&

			    s->target_residency_ns <= data->next_timer_ns) {

				predicted_ns = s->target_residency_ns;

				idx = i;
@@ -354,8 +351,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev, 


			return idx;

		}

		if (s->exit_latency_ns > latency_req)

			break;



		idx = i;

	}