Re: [Sched-tools] [PATCH v2 04/14] rt-app: add wake-up latency to the log metrics

On 21/11/16 10:33, Vincent Guittot wrote:

On 21 November 2016 at 10:28, Vincent Guittot vincent.guittot@linaro.org wrote:

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On 17 November 2016 at 17:34, Juri Lelli juri.lelli@arm.com wrote:

[...]

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    case rtapp_timer:
            {

•                   struct timespec t_period, t_now;
  

•                   struct timespec t_period, t_now, t_wu;
                    log_debug("timer %d ", event->duration);
  
                    t_period = usec_to_timespec(event->duration);
  

@@ -311,10 +311,15 @@ static int run_event(event_data_t *event, int dry_run,

                    rdata->res.timer.t_next = timespec_add(&rdata->res.timer.t_next, &t_period);
                    clock_gettime(CLOCK_MONOTONIC, &t_now);

•                   if (timespec_lower(&t_now, &rdata->res.timer.t_next))
  

•                   if (timespec_lower(&t_now, &rdata->res.timer.t_next)) {
                            clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &rdata->res.timer.t_next, NULL);
  

•                   else
  

•                           clock_gettime(CLOCK_MONOTONIC, &t_now);
  

•                           t_wu = timespec_sub(&t_now, &rdata->res.timer.t_next);
  

•                           *wu_latency = timespec_to_usec(&t_wu);
  

You should add the same wake up latency metric for the sleep event

OK, will look into it.

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•                   } else {
                            clock_gettime(CLOCK_MONOTONIC, &rdata->res.timer.t_next);
  

•                           *wu_latency = 0UL;
  

•                   }
            }
            break;
  

[...]

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@@ -608,6 +616,7 @@ void *thread_body(void *arg) curr_timing->period = timespec_to_usec(&t_diff); curr_timing->duration = duration; curr_timing->perf = perf;

•           curr_timing->wu_latency = wu_latency;
  

What happen if we have several timer in one phase ? we will only get the last wake up latency, isn't it ?

Not sure I get where the problem is. Can you give me an example (and intended usage) of a phase with multiple timers? I don't seem to understand how that is supposed to work. :)