1 files changed, 16 insertions, 15 deletions

diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 4d9aa5ce31f0..64d6f7a1c776 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -188,20 +188,17 @@ again:
 	 *
 	 * This can deal with workloads that have long pauses interspersed
 	 * with sporadic activity with a bunch of short pauses.
+	 *
+	 * However, if the number of remaining samples is too small to exclude
+	 * any more outliers, allow the deepest available idle state to be
+	 * selected because there are systems where the time spent by CPUs in
+	 * deep idle states is correlated to the maximum frequency the CPUs
+	 * can get to.  On those systems, shallow idle states should be avoided
+	 * unless there is a clear indication that the given CPU is most likley
+	 * going to be woken up shortly.
 	 */
-	if (divisor * 4 <= INTERVALS * 3) {
-		/*
-		 * If there are sufficiently many data points still under
-		 * consideration after the outliers have been eliminated,
-		 * returning without a prediction would be a mistake because it
-		 * is likely that the next interval will not exceed the current
-		 * maximum, so return the latter in that case.
-		 */
-		if (divisor >= INTERVALS / 2)
-			return max;
-
+	if (divisor * 4 <= INTERVALS * 3)
 		return UINT_MAX;
-	}
 
 	/* Update the thresholds for the next round. */
 	if (avg - min > max - avg)
@@ -320,11 +317,15 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 		}
 
 		/*
-		 * Use a physical idle state, not busy polling, unless a timer
-		 * is going to trigger soon enough.
+		 * Use a physical idle state instead of busy polling so long as
+		 * its target residency is below the residency threshold, its
+		 * exit latency is not greater than the predicted idle duration,
+		 * and the next timer doesn't expire soon.
 		 */
 		if ((drv->states[idx].flags & CPUIDLE_FLAG_POLLING) &&
-		    s->target_residency_ns <= data->next_timer_ns) {
+		    s->target_residency_ns < RESIDENCY_THRESHOLD_NS &&
+		    s->target_residency_ns <= data->next_timer_ns &&
+		    s->exit_latency_ns <= predicted_ns) {
 			predicted_ns = s->target_residency_ns;
 			idx = i;
 			break;