On 20-01-17, 16:27, Philipp Miedl wrote:

This is not my issue. The code I'm referring to can be found in
cpufreq_governor.c:
<-->
if (unlikely(wall_time > (2 * sampling_rate) &&
       j_cdbs->prev_load)) {

This only confirms that the CPU was idle for sometime.

  load = j_cdbs->prev_load;

  /*
   * Perform a destructive copy, to ensure that we copy
   * the previous load only once, upon the first wake-up
   * from idle.
   */
  j_cdbs->prev_load = 0;
} else {
  load = 100 * (wall_time - idle_time) / wall_time;
  j_cdbs->prev_load = load;
}
<-->

How can it happen that "unlikely(wall_time > (2 * sampling_rate)" is true
although the CPU utilization was 5%?

I am not sure how your test works, etc. Maybe try to generate traces for your
CPUs to see if they are going into idle or not. Maybe you are having a hard time
because of SMP platform ?

-- 
viresh