Re: [PATCH 1/2] do-not-allow-prio-less-than-one-in-cyclictest.patch

[John Kacur <jkacur@redhat.com>]

On Sun, Mar 7, 2010 at 9:39 PM, Carsten Emde <C.Emde@osadl.org> wrote:
> If not in SMP testing mode, the priority may go below 1, if the specified
> priority is lower than the number of threads, e.g.
> # cyclictest -p2 -t3
> T: 0 (21970) P: 2 [..]
> T: 1 (21971) P: 1 [..]
> T: 2 (21972) P: 0 [..]
>
> Do not allow priority to go below 1.
>
> Signed-off-by: Carsten Emde <C.Emde@osadl.org>
>
> Index: rt-tests/src/cyclictest/cyclictest.c
> ===================================================================
> --- rt-tests.orig/src/cyclictest/cyclictest.c
> +++ rt-tests/src/cyclictest/cyclictest.c
> @@ -1304,7 +1304,7 @@ int main(int argc, char **argv)
>                }
>
>                par->prio = priority;
> -               if (!sameprio)
> +               if (priority > 1 && !sameprio)
>                        priority--;
>                 if      (priority && policy <= 1) par->policy = SCHED_FIFO;
>                 else if (priority && policy == 2) par->policy = SCHED_RR;
>
> --

I'm not sure about this, why not allow a priority below 1? The code
below properly sets the third thead to SCHED_OTHER.
I could imagine wanting to test that too. If you don't want to go
below 1 then just set a higher prio, p3 in the scenario you
showed.

Thanks.
John
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