From owner-cvs-all@FreeBSD.ORG Wed Jan 21 18:11:32 2004 Return-Path: Delivered-To: cvs-all@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id B4F8216A4CE; Wed, 21 Jan 2004 18:11:32 -0800 (PST) Received: from ozlabs.org (ozlabs.org [203.10.76.45]) by mx1.FreeBSD.org (Postfix) with ESMTP id F3FE943D3F; Wed, 21 Jan 2004 18:11:28 -0800 (PST) (envelope-from grog@lemis.com) Received: from blackwater.lemis.com (blackwater.lemis.com [192.109.197.80]) by ozlabs.org (Postfix) with ESMTP id 0B4B52BD75; Thu, 22 Jan 2004 13:11:27 +1100 (EST) Received: by blackwater.lemis.com (Postfix, from userid 1004) id 11FE751206; Thu, 22 Jan 2004 12:41:25 +1030 (CST) Date: Thu, 22 Jan 2004 12:41:25 +1030 From: Greg 'groggy' Lehey To: Bruce Evans Message-ID: <20040122021124.GH86671@wantadilla.lemis.com> References: <200401210148.aa95501@salmon.maths.tcd.ie> <20040120203001.B99547@root.org> <20040121162731.F7489@gamplex.bde.org> <20040120144505.ccsc4kog4c88sgww@www.sweetdreamsracing.biz> <200401210148.aa95501@salmon.maths.tcd.ie> <20040121235215.GV86671@wantadilla.lemis.com> <20040122123454.V10548@gamplex.bde.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="QN0KHc3254GHvltB" Content-Disposition: inline In-Reply-To: <20040122123454.V10548@gamplex.bde.org> User-Agent: Mutt/1.4.1i Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 9A1B 8202 BCCE B846 F92F 09AC 22E6 F290 507A 4223 cc: Kenneth Culver cc: src-committers@FreeBSD.org cc: Poul-Henning Kamp cc: Nate Lawson cc: cvs-src@FreeBSD.org cc: Ian Dowse cc: Mike Silbersack cc: cvs-all@FreeBSD.org Subject: Re: backtrace() and the console log (was Re: cvs commit: src/sys/alpha...) X-BeenThere: cvs-all@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: CVS commit messages for the entire tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Jan 2004 02:11:32 -0000 --QN0KHc3254GHvltB Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thursday, 22 January 2004 at 12:43:40 +1100, Bruce Evans wrote: > On Thu, 22 Jan 2004, Greg 'groggy' Lehey wrote: > >> On Wednesday, 21 January 2004 at 16:40:46 +1100, Bruce Evans wrote: >>> On Tue, 20 Jan 2004, Nate Lawson wrote: >>> >>>> On Wed, 21 Jan 2004, Ian Dowse wrote: >>>>> I've been using the following patch for a while to get backtrace() >>>>> to output to the kernel message buffer. Sending all ddb output via >>>>> printf might be undesirable for some cases, but I guess having it >>>>> configurable with a `debug.ddb_use_printf' sysctl that defaults to >>>>> the old behaviour would be ok? >>> >>> It's undesireable in almost all cases, since it fills up the message >>> buffer with garbage. >> >> If it's "garbage", why are we ever producing it? Currently I'm >> getting a lot of LORs which don't get reported anywhere. I'd really >> like to catch this "garbage". > > Because it is hard to debug when the debugger doesn't print any output. > In almost all cases, you don't want to record all the false trails that > you followed tracking down a problem, especially since any recording might > cycle more important records out of the message buffer before syslogd(8) > has a chance to run. Ah, OK. You're talking about the complete ddb output. I was talking about automatically generated backtraces. Agreed, you don't want to be reminded of the roundabout way you get to a solution. Greg -- See complete headers for address and phone numbers. --QN0KHc3254GHvltB Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.0 (FreeBSD) iD8DBQFADzFMIubykFB6QiMRAg2oAJ9iwl5sFXZbq87hyabe7Gq9AAHNTQCeLqoK 6iZFN/Vkccng35rJeEOz6lQ= =3/0e -----END PGP SIGNATURE----- --QN0KHc3254GHvltB--