cpuidle: governors: teo: Refine tick_intercepts vs total events check

Use 2/3 as the proportion coefficient in the check comparing
cpu_data->tick_intercepts with cpu_data->total because it is close
enough to the current one (5/8) and it allows of more straightforward
interpretation (on average, intercepts within the tick period length
are twice as frequent as other events).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Christian Loehle <christian.loehle@arm.com>
Link: https://patch.msgid.link/10793374.nUPlyArG6x@rafael.j.wysocki

Author: rafaeljw

drivers/cpuidle/governors/teo.c

@@ -485,7 +485,7 @@ static int teo_select(struct cpuidle_driver *drv, struct cpuidle_device *dev,
 	 * total wakeup events, do not stop the tick.
 	 */
 	if (drv->states[idx].target_residency_ns < TICK_NSEC &&
-	    cpu_data->tick_intercepts > cpu_data->total / 2 + cpu_data->total / 8)
+	    3 * cpu_data->tick_intercepts >= 2 * cpu_data->total)
 		duration_ns = TICK_NSEC / 2;
 
 end: