Re: [PATCH v8 09/13] perf stat: implement control commands handling

From: Jiri Olsa
Date: Thu Jun 25 2020 - 08:15:04 EST


On Wed, Jun 24, 2020 at 05:10:10PM +0300, Alexey Budankov wrote:
>
> On 23.06.2020 17:54, Jiri Olsa wrote:
> > On Wed, Jun 17, 2020 at 11:41:30AM +0300, Alexey Budankov wrote:
> >
> > SNIP
> >
> >>
> >> while (1) {
> >> if (forks)
> >> @@ -581,8 +617,17 @@ static int dispatch_events(bool forks, int timeout, int interval, int *times, st
> >> if (done || stop || child)
> >> break;
> >>
> >> - nanosleep(ts, NULL);
> >> - stop = process_timeout(timeout, interval, times);
> >> + clock_gettime(CLOCK_MONOTONIC, &time_start);
> >> + if (!(evlist__poll(evsel_list, time_to_sleep) > 0)) { /* poll timeout or EINTR */
> >> + stop = process_timeout(timeout, interval, times);
> >> + time_to_sleep = sleep_time;
> >> + } else { /* fd revent */
> >> + stop = process_evlist(evsel_list, interval, times);
> >> + clock_gettime(CLOCK_MONOTONIC, &time_stop);
> >> + diff_timespec(&time_diff, &time_stop, &time_start);
> >> + time_to_sleep -= time_diff.tv_sec * MSEC_PER_SEC +
> >> + time_diff.tv_nsec / NSEC_PER_MSEC;
> >
> > should we check time_to_sleep > time_diff first?
>
> Probably and if time_diff > time_to_sleep then time_to_sleep = 0 ?

or extra call to process_timeout? if we dont want to call evlist_poll
with 0 timeout

jirka

>
> ~Alexey
>
> >
> > jirka
> >
>