[RTEMS Project] #3700: Add rtems_rate_monotonic_deadline()

[RTEMS trac]

#3700: Add rtems_rate_monotonic_deadline()
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 Reporter:  Sebastian Huber  |       Owner:  Sebastian Huber
     Type:  enhancement      |      Status:  assigned
 Priority:  normal           |   Milestone:  6.1
Component:  rtems            |     Version:  5
 Severity:  normal           |  Resolution:
 Keywords:                   |  Blocked By:
 Blocking:                   |
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Comment (by Jonathan Walsh):

 We are seeing a behavior with EDF enabled in SMP mode that we see a hang
 under load. The test stimulus that we have isolated this to is now very
 simple.

 for(uint32_t j = 0; j < test_iterations; j++)
 {
         sc = pthread_mutex_lock(&mx);
         rtems_test_assert(sc == RTEMS_SUCCESSFUL);
         NOP;
         sc = pthread_mutex_unlock(&mtx);
         rtems_test_assert(sc == RTEMS_SUCCESSFUL);
 }

 When we run this pretty much basic unit test all OK. Then we run more and
 more threads in parallel and we see RTEMS lock up. When we go to the
 simple round-robin scheduler we can run these loops forever with as many
 threads as we want and don't see a lock-up.

 Apologies if I am posting the question in the wrong place - I want to
 avoid creating spam. Sebastian seems to be the expert on EDF and we are
 wondering if this is a known issue with a lock-up under load with EDF
 enabled.

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Ticket URL: <http://devel.rtems.org/ticket/3700#comment:4>
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