From owner-freebsd-hackers@FreeBSD.ORG Fri Nov 16 07:19:38 2012 Return-Path: Delivered-To: freebsd-hackers@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 6ADE5E51; Fri, 16 Nov 2012 07:19:38 +0000 (UTC) (envelope-from avg@FreeBSD.org) Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140]) by mx1.freebsd.org (Postfix) with ESMTP id ED4F78FC0C; Fri, 16 Nov 2012 07:19:36 +0000 (UTC) Received: from porto.starpoint.kiev.ua (porto-e.starpoint.kiev.ua [212.40.38.100]) by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id JAA12480; Fri, 16 Nov 2012 09:19:34 +0200 (EET) (envelope-from avg@FreeBSD.org) Received: from localhost ([127.0.0.1]) by porto.starpoint.kiev.ua with esmtp (Exim 4.34 (FreeBSD)) id 1TZGD8-000135-3s; Fri, 16 Nov 2012 09:19:34 +0200 Message-ID: <50A5E904.9040808@FreeBSD.org> Date: Fri, 16 Nov 2012 09:19:32 +0200 From: Andriy Gapon User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:16.0) Gecko/20121030 Thunderbird/16.0.2 MIME-Version: 1.0 To: attilio@FreeBSD.org Subject: Re: [RFQ] make witness panic an option References: <1353001175.1217.153.camel@revolution.hippie.lan> <1353009310.1217.172.camel@revolution.hippie.lan> <50A555BD.1010105@FreeBSD.org> In-Reply-To: X-Enigmail-Version: 1.4.5 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Ian Lepore , Adrian Chadd , freebsd-arch@FreeBSD.org, freebsd-hackers@FreeBSD.org X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 16 Nov 2012 07:19:38 -0000 on 16/11/2012 01:38 Attilio Rao said the following: > On Thu, Nov 15, 2012 at 8:51 PM, Andriy Gapon wrote: >> on 15/11/2012 22:00 Adrian Chadd said the following: >>> But I think my change is invaluable for development, where you want to >>> improve and debug the locking and lock interactions of a subsystem. >> >> My practical experience was that if you mess up one lock in one place, then it >> is a total mess further on. but apparently you've got a different practical >> experience :) >> What would indeed be invaluable to _me_ - if the LOR messages also produced the >> stack(s) where a supposedly correct lock order was learned. > > Please note that the "supposedly correct lock order", as for the > definition that it is correct, can be used in several different > stacks. I don't see the point of saving it somewhere. > The only helpful case would be if the "wrong order" is catched first. > If this is really the case, I suggest you to force the order you > expect in the static table so that the first time the wrong order > happens it yells. Exactly my point - if I am a user of some code, not its developer, and I don't know which one is the correct order I would have had the complete information from the very start instead of having to jump through the hoops. -- Andriy Gapon