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

From: Carsten Emde
Date: Thu Jan 07 2010 - 02:30:32 EST


Clark,

>> -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. This would create a scenario
where

cyclictest -d1 -S

results in a distance of 0, and

cyclictest -S -d1

results in a distance of 1. Would this be acceptable?

Carsten.
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