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-rw-r--r--drivers/cpuidle/governors/menu.c29
1 files changed, 22 insertions, 7 deletions
diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
index 267982e471e0..1bfe03ceb236 100644
--- a/drivers/cpuidle/governors/menu.c
+++ b/drivers/cpuidle/governors/menu.c
@@ -352,13 +352,28 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
*/
data->predicted_us = min(data->predicted_us, expected_interval);
- /*
- * 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);
- if (latency_req > interactivity_req)
- latency_req = interactivity_req;
+ 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 try
+ * to force the CPU into a state for which we would have stopped
+ * the tick, unless a timer is going to expire really soon
+ * anyway.
+ */
+ if (data->predicted_us < TICK_USEC)
+ data->predicted_us = min_t(unsigned int, TICK_USEC,
+ 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);
+ if (latency_req > interactivity_req)
+ latency_req = interactivity_req;
+ }
expected_interval = data->predicted_us;
/*