Re: [RFC] [rt-tests] change to cyclictest behavior

Carsten Emde
2010-01-07T15:00:28Z

On 01/07/2010 03:47 PM, Clark Williams wrote:
> On Thu, 07 Jan 2010 08:23:52 +0100
> Carsten Emde <Carsten.Emde@osadl.org> wrote:
>>>> -S --smp Standard SMP testing (equals -a -t -n -d0),
>>>> same priority on all threads.
>> After having done some tests with a quickly hacked cyclictest version, I
>> have found an issue with including -d0. Apparently, small numbers make
>> life especially difficult for the scheduler; this is why we often used
>> -d1. Specifying -d0 seems a special case where all threads are in sync.
>> Maybe, we may miss some important latency constellations, if we do not
>> let the tasks slightly interfere. In any case, I would like to be able
>> to specify a distance _in addition_ to -S.
>> [..]
> I don't have a problem not having -d in the -S option. I was looking at
> the possibility of synchronous sampling as well so it's probably a good
> idea to keep it separate.
> The main things we want are implied -t, -a and -n.
Yes, let's do it this way.