From owner-freebsd-current@FreeBSD.ORG Fri Sep 5 21:36:07 2014 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 60E3FBAD; Fri, 5 Sep 2014 21:36:07 +0000 (UTC) Received: from bigwig.baldwin.cx (bigwig.baldwin.cx [IPv6:2001:470:1f11:75::1]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 1CB8A1120; Fri, 5 Sep 2014 21:36:07 +0000 (UTC) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 0C2C2B97B; Fri, 5 Sep 2014 17:36:06 -0400 (EDT) From: John Baldwin To: Peter Wemm Subject: Re: ddb_enable="YES" by default? Date: Fri, 5 Sep 2014 17:35:49 -0400 User-Agent: KMail/1.13.5 (FreeBSD/8.4-CBSD-20140415; KDE/4.5.5; amd64; ; ) References: <1690616.oBzWaFvmny@overcee.wemm.org> In-Reply-To: <1690616.oBzWaFvmny@overcee.wemm.org> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-15" Content-Transfer-Encoding: 7bit Message-Id: <201409051735.49577.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.7 (bigwig.baldwin.cx); Fri, 05 Sep 2014 17:36:06 -0400 (EDT) Cc: Craig Rodrigues , freebsd-current@freebsd.org, Brooks Davis X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 05 Sep 2014 21:36:07 -0000 On Friday, September 05, 2014 5:08:07 pm Peter Wemm wrote: > On Friday 05 September 2014 13:51:24 Craig Rodrigues wrote: > > On Fri, Sep 5, 2014 at 7:54 AM, John Baldwin wrote: > > > Probably at least 50% of the time when I work with a user on a bug report, > > > I ask them to go into kgdb and run specific commands to extract more > > > detailed info (print some struct, etc.). > > > > Sure, I understand, but you are not working with every user who > > encounters a kernel panic in FreeBSD. For the average or casual > > FreeBSD user, such as desktop > > users of FreeBSD or PC-BSD, wouldn't it be better > > to have ddb_enable="YES" be the default in FreeBSD? The ddb script > > there does a fairly reasonable > > job of gathering some useful info which can be analyzed later, and > > then rebooting the box. > > > > For more expert users, or people developing products, they can set > > ddb_enable="NO" > > and do more advanced debugging. Or hook into /etc/rc.d/ddb and define > > a different > > ddb script which doesn't do textdumps on kernel panic. > > I think what John was saying was at that point it's too late. The loss of the > crash dump means the one shot at getting more information is gone. > > For reproducable crashes, yes, an end user could just flip the bit. But for a > one-off, it's too late. Also, crashinfo is already enabled by default. If a user enables crash dumps in the installer, they will have a nice /var/crash/core.txt.N that they can post to the mailing lists just as easily as the text dump you envision. And in fact, I've seen our users already doing this. (Have you looked at a /var/crash/core.txt.N file yet?) -- John Baldwin