From owner-freebsd-arch@FreeBSD.ORG Sun Jan 18 14:09:27 2009 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 0B890106564A for ; Sun, 18 Jan 2009 14:09:27 +0000 (UTC) (envelope-from pho@holm.cc) Received: from relay03.pair.com (relay03.pair.com [209.68.5.17]) by mx1.freebsd.org (Postfix) with SMTP id B61998FC08 for ; Sun, 18 Jan 2009 14:09:26 +0000 (UTC) (envelope-from pho@holm.cc) Received: (qmail 87351 invoked from network); 18 Jan 2009 14:09:25 -0000 Received: from 87.58.145.190 (HELO x2.osted.lan) (87.58.145.190) by relay03.pair.com with SMTP; 18 Jan 2009 14:09:25 -0000 X-pair-Authenticated: 87.58.145.190 Received: from x2.osted.lan (localhost.osted.lan [127.0.0.1]) by x2.osted.lan (8.14.2/8.14.2) with ESMTP id n0IE9O6x027944; Sun, 18 Jan 2009 15:09:24 +0100 (CET) (envelope-from pho@x2.osted.lan) Received: (from pho@localhost) by x2.osted.lan (8.14.2/8.14.2/Submit) id n0IE9OpG027943; Sun, 18 Jan 2009 15:09:24 +0100 (CET) (envelope-from pho) Date: Sun, 18 Jan 2009 15:09:24 +0100 From: Peter Holm To: Kostik Belousov Message-ID: <20090118140924.GA27264@x2.osted.lan> References: <20090118082145.GA18067@x2.osted.lan> <86iqocstjm.fsf@ds4.des.no> <20090118131028.GA26179@x2.osted.lan> <20090118132819.GS48057@deviant.kiev.zoral.com.ua> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090118132819.GS48057@deviant.kiev.zoral.com.ua> User-Agent: Mutt/1.4.2.3i Cc: Dag-Erling Sm?rgrav , freebsd-arch@freebsd.org Subject: Re: stress2 is now in projects X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 18 Jan 2009 14:09:27 -0000 On Sun, Jan 18, 2009 at 03:28:19PM +0200, Kostik Belousov wrote: > On Sun, Jan 18, 2009 at 02:10:28PM +0100, Peter Holm wrote: > > On Sun, Jan 18, 2009 at 01:11:25PM +0100, Dag-Erling Sm?rgrav wrote: > > > Peter Holm 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. > > > > > > > Yes, by design. > > > > > You should at the very least allow the user to specify the random seed. > > > > > > > Yes, it would be interesting to see if this is enough to reproduce a > > problem in a deterministic way. I'll look into this. > > I shall state from my experience using it (or, rather, inspecting bug > reports generated by stress2), that in fact it is quite repeatable. > I.e., when looking into one area, you almost always get _that_ problem, > together with 2-3 related issues. > > Due to the nature of the tests and kernel undeterministic operations, > I think that use of the same random seed gains nothing in regard with > repeatability of the tests. It is an old issue that has come up many times: It would be so great if it was possible to some how record the exact sequence that lead up to a panic and play it back. But on the other hand, as you say, it *is* repeatable. The only issue is that it may take 5 minutes or 5 hours. But I'm still game to see if it is possible at all (in single user mode with no network activity etc.) - Peter