[RTEMS Project] #4019: Potential issue with SMP EDF scheduler and priority inheritance

[RTEMS trac]

#4019: Potential issue with SMP EDF scheduler and priority inheritance
------------------------------+-----------------------------
  Reporter:  Sebastian Huber  |      Owner:  Sebastian Huber
      Type:  defect           |     Status:  assigned
  Priority:  normal           |  Milestone:  6.1
 Component:  score            |    Version:
  Severity:  normal           |   Keywords:
Blocked By:                   |   Blocking:
------------------------------+-----------------------------
 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.

--
Ticket URL: <http://devel.rtems.org/ticket/4019>
RTEMS Project <http://www.rtems.org/>
RTEMS Project