Free running counter is only 32khz, so ages in cpu time at 200mhz. There is a nanosecond IEEE 1588 unit on the network interface ....
I've identified at least 6 timers going at 10ms, only 1-in-1000 invocations seem take more than a tick to run,.. they are all started in the same second but with randomish-jitter between the rtems_time_server_fire_after() calls,.. rtems would not be aligning them to all run at the same time (on tick boundary) would it ? On Tue, 14 Jan 2020 at 14:02, Joel Sherrill <j...@rtems.org> wrote: > > > On Tue, Jan 14, 2020 at 7:37 AM Matthew J Fletcher <ami...@gmail.com> > wrote: > >> Of course without nanoseconds support in the BSP measuring the timer >> callback duration is difficult as most calls will be less than a tick. >> > > Yeah, you can't use the clock services from rtems in that case since they > don't have a high enough resolution. > > Do you have a free running counter/timer you can read? > > I assume you only have a finite number of timer service routines called > from > the Timer Server thread. Can you benchmark them outside the application? > If this is a straightforward case of a single invocation of a method > running too > long, that would be sufficient to figure it out. Or do you have something > that is > processing a set of things and sometimes the set is large? > > Hmmm... it is possible that if the clock tick configured is larger than > any of > your timer intervals, they are firing in clusters. Say you have a 10 > millisecond > clock tick configured and all your timers fire in less than that. They > will all > fire in 1 tick. Any chance of a degenerate set like this? > > --joel > > >> On Tue, 14 Jan 2020 at 08:41, Matthew J Fletcher <ami...@gmail.com> >> wrote: >> >>> Ok, >>> >>> So first step is to create a wrapper that all timers fire through, then >>> an array to count the number of invocations per timer_id, after that some >>> per timer_id time accounting. >>> >>> Will let you know if its anything outside my application. >>> >>> >>> On Mon, 13 Jan 2020 at 15:01, Joel Sherrill <j...@rtems.org> wrote: >>> >>>> >>>> >>>> On Mon, Jan 13, 2020 at 8:53 AM Matthew J Fletcher <ami...@gmail.com> >>>> wrote: >>>> >>>>> Hi, >>>>> >>>>> My application seems to be using around 1/3rd of its total cpu usage >>>>> in the 'TIME' task,. is this the task created by >>>>> rtems_timer_initiate_server() ? >>>>> >>>> >>>> Yes. >>>> >>>>> >>>>> What would be the best way to get more information,. are there console >>>>> commands that would emit more data, or do i need to instrument my >>>>> application to see usage of all rtems_timer_xx callbacks ? >>>>> >>>> >>>> rtems_timer_server_xx would be the ones going to the TIME Server. >>>> >>>> But 1/3 seems quite excessive. I would assume one of your timer server >>>> routines is doing something unexpectedly heavy CPU-wise. >>>> >>>> I don't think there is any instrumentation in the server which would >>>> help. Measuring the execution time of each invocation is what comes to >>>> mind. My first thought is that this would be a nice debug option for >>>> timers. But I am not sure how good this would be for ISR style. >>>> >>>> --joel >>>> >>>>> >>>>> regards >>>>> --- >>>>> Matthew J Fletcher >>>>> >>>>> _______________________________________________ >>>>> users mailing list >>>>> users@rtems.org >>>>> http://lists.rtems.org/mailman/listinfo/users >>>> >>>> >>> >>> -- >>> >>> regards >>> --- >>> Matthew J Fletcher >>> >>> >> >> -- >> >> regards >> --- >> Matthew J Fletcher >> >> -- regards --- Matthew J Fletcher
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