RTEMS tasks timesliced instead of running to completion. TIMESLICE flag is not active!

[Thanassis Tsiodras (external)]

> Polled vs interrupt console drivers?

I don't see how...  With tasks spawned with RTEMS_DEFAULT_MODES and 
CONFIGURE_MAXIMUM_PROCESSORS set to 1, Task 2 should not be allowed to run 
until Task 1 completes - so the output of "Starting" ( in "task_begin" of 
Task 2) should not be able to precede the output of "Computed" at the end 
of Task1 - the relevant print should not have happened yet. 

I can understand how console output can become garbled in tasks that are 
running concurrently - but in this case, I would expect them to run in 
sequence.
The only way for this

[TASK 0] Starting...
[TASK 0] Computed the correct floating point result.
[TASK 1] Starting...
[TASK 1] Computed the correct integer result.
[TASK 2] Starting...
[TASK 2] Computed the correct floating point result.
[TASK 3] Starting...
[TASK 3] Computed the correct integer result.

to turn into this

The expected result:
[TASK 0] Starting...
[TASK 1] Starting...
[TASK 2] Starting...
[TASK 3] Starting...
[TASK 0] Computed the correct floating point result.
[TASK 1] Computed the correct integer result.
[TASK 2] Computed the correct floating point result.
[TASK 3] Computed the correct integer result.

...is if indeed, the tasks are running concurrently with the ZynQ BSP.

So the question is:

Given the task spawning parameters ("RTEMS_DEFAULT_MODES") and 
CONFIGURE_MAXIMUM_PROCESSORS set to 1, is it right to experience 
timeslicing on the ZynQ ZC706?

Thanassis Tsiodras
Real-time Embedded Software Engineer 
System, Software and Technology Department

ESTEC
Keplerlaan 1, PO Box 299
NL-2200 AG Noordwijk, The Netherlands
Thanassis.Tsiodras at esa.int | www.esa.int
T +31 71 565 5332



From:   "Chris Johns" <chrisj at rtems.org>
To:     "Thanassis Tsiodras (external)" <Thanassis.Tsiodras at esa.int>
Cc:     "Gedare Bloom" <gedare at rtems.org>, "rtems-users at rtems.org" 
<users at rtems.org>, "Fernando Domínguez Pousa" <fdpousa at gmv.com>
Date:   01/05/2020 09:46
Subject:        Re: RTEMS tasks timesliced instead of running to 
completion. TIMESLICE flag is not active!



On 1/5/20 5:08 pm, Thanassis Tsiodras (external) wrote:
> Note that this test (complete code in 
> 
https://gitrepos.estec.esa.int/ttsiodras/RTEMS-build-workflows/-/tree/master/OAR
) 
> creates the proper - non-interleaved - output when compiled and executed 

> for the GR712RC and GR740 boards... but creates the interleaved output 
> in a ZynQ ZC706 board.

Polled vs interrupt console drivers?

Chris




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