cpuidle: menu: Move the latency_req == 0 special case check
authorRafael J. Wysocki <rafael.j.wysocki@intel.com>
Tue, 2 Oct 2018 21:47:43 +0000 (23:47 +0200)
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>
Thu, 4 Oct 2018 17:27:27 +0000 (19:27 +0200)
It is better to always update data->bucket before returning from
menu_select() to avoid updating the correction factor for a stale
bucket, so combine the latency_req == 0 special check with the more
general check below.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
drivers/cpuidle/governors/menu.c

index 667606c..b754296 100644 (file)
@@ -297,19 +297,13 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
                data->needs_update = 0;
        }
 
-       /* Special case when user has set very strict latency requirement */
-       if (unlikely(latency_req == 0)) {
-               *stop_tick = false;
-               return 0;
-       }
-
        /* determine the expected residency time, round up */
        data->next_timer_us = ktime_to_us(tick_nohz_get_sleep_length(&delta_next));
 
        get_iowait_load(&nr_iowaiters, &cpu_load);
        data->bucket = which_bucket(data->next_timer_us, nr_iowaiters);
 
-       if (unlikely(drv->state_count <= 1) ||
+       if (unlikely(drv->state_count <= 1 || latency_req == 0) ||
            ((data->next_timer_us < drv->states[1].target_residency ||
              latency_req < drv->states[1].exit_latency) &&
             !drv->states[0].disabled && !dev->states_usage[0].disable)) {