Re: [Sched-tools] [PATCH 03/13] rt-app: add a t_zero to which every tasks has to refer

On 11 November 2016 at 10:17, Juri Lelli juri.lelli@arm.com wrote:

Also a barrier is added so that execution starts at the same instant for everybody.

Signed-off-by: Juri Lelli juri.lelli@arm.com

src/rt-app.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/src/rt-app.c b/src/rt-app.c index 211dd77da98f..51aadf480a3f 100644 --- a/src/rt-app.c +++ b/src/rt-app.c @@ -35,6 +35,8 @@ static int nthreads; static volatile sig_atomic_t running_threads; static int p_load; rtapp_options_t opts; +static struct timespec t_zero; +static pthread_barrier_t threads_barrier;

static ftrace_data_t ft_data = { .debugfs = "/sys/kernel/debug", @@ -217,7 +219,8 @@ static void memload(unsigned long count, struct _rtapp_iomem_buf *iomem) }

static int run_event(event_data_t *event, int dry_run,

•           unsigned long *perf, unsigned long *duration, rtapp_resource_t *resources)
  

•           unsigned long *perf, unsigned long *duration, rtapp_resource_t *resources,
  

•           struct timespec *t_first)
  

{ rtapp_resource_t *rdata = &(resources[event->res]); rtapp_resource_t *ddata = &(resources[event->dep]); @@ -303,7 +306,7 @@ static int run_event(event_data_t *event, int dry_run,

                    if (rdata->res.timer.init == 0) {
                            rdata->res.timer.init = 1;

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

•                           rdata->res.timer.t_next = *t_first;
                    }
  
                    rdata->res.timer.t_next = timespec_add(&rdata->res.timer.t_next, &t_period);
  

@@ -348,7 +351,8 @@ static int run_event(event_data_t *event, int dry_run, }

int run(int ind, phase_data_t *pdata, unsigned long *duration,

•           rtapp_resource_t *resources)
  

•           rtapp_resource_t *resources,
  

•           struct timespec *t_first)
  

{ event_data_t *events = pdata->events; int nbevents = pdata->nbevents; @@ -365,7 +369,7 @@ int run(int ind, phase_data_t *pdata, unsigned long *duration, log_ftrace(ft_data.marker_fd, "[%d] executing %d", ind, i);

•           lock += run_event(&events[i], !continue_running, &perf, duration, resources);
  

•           lock += run_event(&events[i], !continue_running, &perf, duration, resources, t_first);
    }
  
    return perf;
  

@@ -411,7 +415,7 @@ void *thread_body(void *arg) thread_data_t *data = (thread_data_t*) arg; phase_data_t *pdata; struct sched_param param;

•   struct timespec t_start, t_end;
  

•   struct timespec t_start, t_end, t_first;
    unsigned long t_start_usec;
    unsigned long perf, duration;
    timing_point_t *curr_timing;
  

@@ -536,6 +540,17 @@ void *thread_body(void *arg) } }

•   if (data->ind == 0) {
  

•           clock_gettime(CLOCK_MONOTONIC, &t_zero);
  

•           if (opts.ftrace)
  

•                   log_ftrace(ft_data.marker_fd,
  

•                           "[%d] sets zero time",
  

•                           data->ind);
  

•   }
  

Only the 1st thread (data->ind == 0) is going to set t_zero. It's worth adding a comment explaining the mecanism that 1st thread set t_zero and other thread sync with this timestamp

•   pthread_barrier_wait(&threads_barrier);
  

•   t_first = t_zero;
  

•   log_notice("[%d] starting thread ...\n", data->ind);
  
    fprintf(data->log_handler, "#idx\tperf\trun\tperiod\tstart\t\tend\t\trel_st\n");
  

@@ -571,7 +586,7 @@ void *thread_body(void *arg)

            duration = 0;
            clock_gettime(CLOCK_MONOTONIC, &t_start);

•           perf = run(data->ind, pdata, &duration, *(data->resources));
  

•           perf = run(data->ind, pdata, &duration, *(data->resources), &t_first);
            clock_gettime(CLOCK_MONOTONIC, &t_end);
  
            if (timings)
  

@@ -660,7 +675,7 @@ int main(int argc, char* argv[]) /* allocated threads */ nthreads = opts.nthreads; threads = malloc(nthreads * sizeof(pthread_t));

•   running_threads = 0;
  

•   pthread_barrier_init(&threads_barrier, NULL, nthreads);
  
    /* install a signal handler for proper shutdown */
    signal(SIGQUIT, shutdown);
  

-- 2.10.0