From owner-freebsd-arch@FreeBSD.ORG Thu Nov 15 17:39:46 2012 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id C439FE05; Thu, 15 Nov 2012 17:39:46 +0000 (UTC) (envelope-from freebsd@damnhippie.dyndns.org) Received: from duck.symmetricom.us (duck.symmetricom.us [206.168.13.214]) by mx1.freebsd.org (Postfix) with ESMTP id 903FB8FC12; Thu, 15 Nov 2012 17:39:46 +0000 (UTC) Received: from damnhippie.dyndns.org (daffy.symmetricom.us [206.168.13.218]) by duck.symmetricom.us (8.14.5/8.14.5) with ESMTP id qAFHdcDt039031; Thu, 15 Nov 2012 10:39:38 -0700 (MST) (envelope-from freebsd@damnhippie.dyndns.org) Received: from [172.22.42.240] (revolution.hippie.lan [172.22.42.240]) by damnhippie.dyndns.org (8.14.3/8.14.3) with ESMTP id qAFHdZMB024995; Thu, 15 Nov 2012 10:39:35 -0700 (MST) (envelope-from freebsd@damnhippie.dyndns.org) Subject: Re: [RFQ] make witness panic an option From: Ian Lepore To: Adrian Chadd In-Reply-To: References: Content-Type: text/plain; charset="us-ascii" Date: Thu, 15 Nov 2012 10:39:35 -0700 Message-ID: <1353001175.1217.153.camel@revolution.hippie.lan> Mime-Version: 1.0 X-Mailer: Evolution 2.32.1 FreeBSD GNOME Team Port Content-Transfer-Encoding: 7bit Cc: freebsd-hackers@freebsd.org, freebsd-arch@freebsd.org X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 15 Nov 2012 17:39:46 -0000 On Wed, 2012-11-14 at 22:15 -0800, Adrian Chadd wrote: > Hi all, > > When debugging and writing wireless drivers/stack code, I like to > sprinkle lots of locking assertions everywhere. However, this does > cause things to panic quite often during active development. > > This patch (against stable/9) makes the actual panic itself > configurable. It still prints the message regardless. > > This has allowed me to sprinkle more locking assertions everywhere to > investigate whether particular paths have been hit or not. I don't > necessarily want those to panic the kernel. > > I'd like everyone to consider this for FreeBSD-HEAD. > > Thanks! I strongly support this, because I'm tired of having to hack it in by hand every time I need it. You can't boot an arm platform right now (on freebsd 8, 9, or 10) without a LOR very early in the boot. Once you get past that, 2 or 3 device drivers I use panic way before we even get to mounting root. Those panics can clearly be ignored, because we've been shipping products for years based on this code. (It's on my to-do list to fix them, but more pressing problems are higher on the list.) When a new problem crops up that isn't harmless, it totally sucks that I can't just turn on witness without first hacking the code to make the known problems non-panicky. -- Ian