On 23 December 2014 at 10:51, Savolainen, Petri (NSN - FI/Espoo)
<[email protected]> wrote:
>
>
>> -----Original Message-----
>> From: ext Ola Liljedahl [mailto:[email protected]]
>> Sent: Monday, December 22, 2014 4:23 PM
>> To: Savolainen, Petri (NSN - FI/Espoo)
>> Cc: ext Bill Fischofer; Mike Holmes; lng-odp-forward
>> Subject: Re: [lng-odp] [PATCH v2 2/3] example: odp_timer_test: remove use
>> of odp_schdule_one
>>
>> On 22 December 2014 at 14:10, Savolainen, Petri (NSN - FI/Espoo)
>> <[email protected]> wrote:
>> >
>> >
>> > Because the thread will exit the schedule loop, it has to pause first
>> and
>> > then run sched loop until the potential per thread local scheduler cache
>> is
>> > empty (see under).
>> In this specific case, the example terminates when the specified
>> number of timeouts have been received and processed. There is no need
>> to pause the scheduler and drain any prescheduled buffers because when
>> the remain counter reaches zero, all threads are done and should
>> terminate.
>>
>> This is a timer example, not a scheduler example. For a scheduler
>> example, we should demonstrate the proper usage of
>> odp_scheduler_pause() and resume.
>
>
> A throughput optimized scheduler may have pre-scheduled multiple buffers
> (incl tmo notifications) to a thread local cache. Scheduler expects the
> thread to continue process new buffers infinitely. Only way for application
> to tell it's going to take a pause on processing those is
> odp_schedule_pause() call. If application would not do that (and drain any
> remaining buffers) those queues pre-scheduled to the thread would suffer a
> long delay (or even deadlock if the thread exits).
>
> So it's an issue any thread need to handle before exiting the schedule loop.
> Also in the test would hang if one thread exits and fails to process all
> pre-scheduled timeouts. Other threads would wait infinitely those missing
> tmos.
I understand all of this and this is how a proper scheduler example
should work. But this example attempts to be a simplified timer
example. When the specified number of timeouts have been received, the
worker threads and the whole program terminates (and this is
definitively completely artificial from a networking perspective). Yes
we don't don't do this in a way that's nice to the scheduler but this
isn't really the scope of this example IMO.
If the timer example can't just be a simplified timer example perhaps
we should put a bullet in it?
>
>
> -Petri
>
>
>>
>>
>> >
>> >
>> >
>> > -Petri
>> >
>> >
>> >
>> > int done = 0;
>> >
>> >
>> >
>> > while (1) {
>> >
>> > odp_timeout_t tmo;
>> >
>> >
>> >
>> > if (done)
>> >
>> > buf = odp_schedule(&queue, ODP_SCHED_NO_WAIT);
>> >
>> > else
>> >
>> > buf = odp_schedule(&queue,
>> > ODP_SCHED_WAIT);
>> >
>> >
>> >
>> > if (buf == ODP_BUFFER_INVALID)
>> >
>> > break;
>> >
>> >
>> >
>> > tmo = odp_timeout_from_buffer(buf);
>> >
>> > tick = odp_timeout_tick(tmo);
>> >
>> >
>> >
>> > EXAMPLE_DBG(" [%i] timeout, tick
>> > %"PRIu64"\n", thr, tick);
>> >
>> >
>> >
>> > odp_buffer_free(buf);
>> >
>> >
>> >
>> > num--;
>> >
>> >
>> >
>> > if (num == 0) {
>> >
>> > odp_schedule_pause();
>> >
>> > done = 1;
>> >
>> > continue;
>> >
>> > }
>> >
>> >
>> >
>> > tick += period;
>> >
>> >
>> >
>> > odp_timer_absolute_tmo(test_timer, tick,
>> >
>> >
>> queue,
>> > ODP_BUFFER_INVALID);
>> >
>> > }
>> >
>> >
>> >
>> >
>> >
>> > From: [email protected]
>> > [mailto:[email protected]] On Behalf Of ext Bill
>> Fischofer
>> > Sent: Friday, December 19, 2014 10:38 PM
>> > To: Mike Holmes
>> > Cc: lng-odp-forward
>> > Subject: Re: [lng-odp] [PATCH v2 2/3] example: odp_timer_test: remove
>> use of
>> > odp_schdule_one
>> >
>> >
>> >
>> > Typo in the title (odp_schdule_one). Presumably Maxim can fix during
>> merge?
>> >
>> >
>> >
>> > On Fri, Dec 19, 2014 at 2:34 PM, Mike Holmes <[email protected]>
>> wrote:
>> >
>> > Signed-off-by: Mike Holmes <[email protected]>
>> > ---
>> > example/timer/odp_timer_test.c | 2 +-
>> > 1 file changed, 1 insertion(+), 1 deletion(-)
>> >
>> > diff --git a/example/timer/odp_timer_test.c
>> b/example/timer/odp_timer_test.c
>> > index 0d6e31a..6d2609a 100644
>> > --- a/example/timer/odp_timer_test.c
>> > +++ b/example/timer/odp_timer_test.c
>> > @@ -84,7 +84,7 @@ static void test_abs_timeouts(int thr, test_args_t
>> *args)
>> > while (1) {
>> > odp_timeout_t tmo;
>> >
>> > - buf = odp_schedule_one(&queue, ODP_SCHED_WAIT);
>> > + buf = odp_schedule(&queue, ODP_SCHED_WAIT);
>> >
>> > tmo = odp_timeout_from_buffer(buf);
>> > tick = odp_timeout_tick(tmo);
>> > --
>> > 2.1.0
>> >
>> >
>> > _______________________________________________
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>> > [email protected]
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>> >
>> >
>> > _______________________________________________
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>> >
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