[LITMUS^RT] preparing a new release

[Jonathan Herman]

What is the following line defending against:

litmus/preempt.c:
  31│                 /* Litmus tasks should never be subject to a remote



  32│                  * set_tsk_need_resched(). */
  33│                 BUG_ON(is_realtime(tsk));



  34│                 //TRACE_TASK(tsk, "SUPERBAD"); /* I added this */

I keep hitting this when I test with a full schedule under GSN-EDF. Oddly,
when I debug using gdb and view t->comm it is "rtspin", but this is not the
case in the trace log. If I remove the BUG_ON so that TRACE_TASK is hit, I
git the following lines:
158079 P0 [sched_state_will_schedule at litmus/preempt.c:34]:
(kworker/0:0/0:0) SUPERBAD
158080 P0 [sched_state_will_schedule at litmus/preempt.c:37]:
(kworker/0:0/0:0) set_tsk_need_resched() ret:ffffffff810268d4

Which, as far as I can tell, is only possible if tsk->comm ==
"kworker/0:0". But then why is there no pid? This is on the current staging
of liblitmus and litmus-rt.

I am running on a 4 processor system with the following schedule:
10 20
30 50
9 18
10 20
30 50
9 18
10 20
30 50
9 18
10 20
30 50
9 18

Ideas? I'm assuming race condition, as Glenn suggested, because usually if
it's insane, its a race.


On Tue, Nov 27, 2012 at 2:02 PM, Björn Brandenburg <bbb at mpi-sws.org> wrote:

> Hi everyone,
>
> as discussed at RTLWS, we would like to push out another maintenance
> release before RTSS. To this end, I've merged a bunch of prop/ branches
> into staging. However, I believe there are a couple of recent, as of yet
> unannounced prop/ branches in the repository. I'm not merging those until
> it's clear what's ready.
>
> Two action items:
>
> 1) Everyone, please test the current staging branch.
>
> 2) If you'd like to have another prop/ branch merged, please rebase it on
> top of the current staging tree and reply to this message with the name of
> the branch.
>
> Thanks,
> Björn
>
>
> _______________________________________________
> litmus-dev mailing list
> litmus-dev at lists.litmus-rt.org
> https://lists.litmus-rt.org/listinfo/litmus-dev
>



-- 
Jonathan Herman
Department of Computer Science at UNC Chapel Hill
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