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Date: Sun, 18 Jan 2009 22:05:33 +0000
From: Kris Kennaway <kris@FreeBSD.org>
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Cc: Dag-Erling Sm??rgrav <des@des.no>, freebsd-arch@freebsd.org
Subject: Re: stress2 is now in projects
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Alfred Perlstein wrote:
> * Kris Kennaway <kris@FreeBSD.org> [090118 05:52] wrote:
>> Dag-Erling Sm??rgrav wrote:
>>> Peter Holm <pho@freebsd.org> writes:
>>>> The key functionality of this test suite is that it runs a random
>>>> number of test programs for a random period, in random incarnations
>>>> and in random sequence.
>>> In other words, it's non-deterministic and non-reproducable.
>>>
>>> You should at the very least allow the user to specify the random seed.
>>>
>>> DES
>> I doubt this will help at all since the test suite is (by design) 
>> massively parallel, so you're at the mercy of small timing changes.
> 
> If the start and stop times of the scripts were recorded one could
> synch with the original potentially between runs, at least on the
> same hardware it ran.
> 
> Basically, replay the suite based on time instead of random.
> 
> -Alfred
> 
> 

Since the goal of the stress test is effectively to exploit race 
conditions, I'm still skeptical there is a way to make that happen 
deterministically.  Anyway as Kostik says, problems discovered by 
stress2 do tend to be reproducible given suitable runtime.

Kris