POSIX sporadic server uses unexpected CPU budgets

[Sebastian Huber]

The POSIX sporadic server starts with invalid CPU budget of zero. This leads to an unsigned integer underflow in the next scheduler tick. The first _POSIX_Threads_Sporadic_budget_TSR() fixes the problem.

[Sebastian Huber <sebastian.huber@…>]

In 917884c408708c7634e09563d7cd3ed30a4ab71a/rtems:

posix: Fix poradic server initial CPU budget

Update #2738.

[Sebastian Huber]

*** BEGIN OF TEST PSX 12 ***
Init's ID is 0x0b010001
Init: pthread_attr_init - SUCCESSFUL
Init: pthread_create - EINVAL (invalid scheduling policy)
Init: pthread_attr_init - SUCCESSFUL
Init: set scheduling parameter attributes for sporadic server
Init: pthread_create - EINVAL (replenish < budget)
Init: pthread_create - EINVAL (invalid sched_ss_low_priority)
Init: pthread_create - SUCCESSFUL
Sporadic Server: exitting
[0] H 100ms
[0] L 200ms
[1] H 290ms
[1] L 400ms
[2] H 490ms
[2] L 600ms
*** END OF TEST PSX 12 ***

From the test output we see, that the initial high period differs from the later high periods. The later high periods lack one clock tick of time.

[Sebastian Huber <sebastian.huber@…>]

In 661e0e6377b16cb52c46c87877ed182bcf39ef01/rtems:

psxtests/psx12: Use and print proper rounded ms

Update #2738.

[Joel Sherrill]

I am not wanting to change the status on this. Just wondered from looking at the output if the math isn't adding one tick in the conversion from time to ticks or vice-versa. We had an off by one in that time of math a while back somewhere else I recall.