[RTEMS Project] #2795: Overrun Handling for general real-time models

[RTEMS trac]

#2795: Overrun Handling for general real-time models
-------------------------------------------------+-------------------------
 Reporter:  khchen                               |       Owner:
     Type:  enhancement                          |      Status:  new
 Priority:  high                                 |   Milestone:  4.11.1
Component:  cpukit                               |     Version:  4.11
 Severity:  critical                             |  Resolution:
 Keywords:  Overrun, RMS, SP, Scheduler,         |
  Periodicity                                    |
-------------------------------------------------+-------------------------

Comment (by sebastian.huber):

 In RTEMS the behaviour of the rate-monotonic periods depends on the
 scheduler. We have a fix-priority scheduler (default scheduler) and a job-
 level fixed-priority scheduler (EDF).

 In your test case you have 6000/10000 + 1000/2000 = 110% processor
 utilization, so your task set is not schedulable.

 In case of the default scheduler, the priority assignment is not according
 to the rules:

 https://docs.rtems.org/doc-current/share/rtems/html/c_user/Rate-Monotonic-
 Manager-Rate-Monotonic-Scheduling-Algorithm.html#Rate-Monotonic-Manager-
 Rate-Monotonic-Scheduling-Algorithm

 Task 2 has a shorter period compared to task 1, so it must have a higher
 priority.

 What changes your patch? You automatically restart the watchdog in case of
 a timeout and count the number of timeouts?

--
Ticket URL: <http://devel.rtems.org/ticket/2795#comment:2>
RTEMS Project <http://www.rtems.org/>
RTEMS Project