From owner-freebsd-arm@FreeBSD.ORG Wed Mar 11 14:29:16 2015 Return-Path: Delivered-To: freebsd-arm@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 95B26D3F for ; Wed, 11 Mar 2015 14:29:16 +0000 (UTC) Received: from gromit.dlib.vt.edu (gromit.dlib.vt.edu [128.173.126.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "gromit.dlib.vt.edu", Issuer "Chumby Certificate Authority" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id 6970037E for ; Wed, 11 Mar 2015 14:29:16 +0000 (UTC) Received: from pmather.lib.vt.edu (pmather.lib.vt.edu [128.173.126.193]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by gromit.dlib.vt.edu (Postfix) with ESMTPSA id 214D0152; Wed, 11 Mar 2015 10:29:15 -0400 (EDT) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Subject: Re: BBB freebsd-current backtrace. why? From: Paul Mather In-Reply-To: Date: Wed, 11 Mar 2015 10:29:14 -0400 Content-Transfer-Encoding: quoted-printable Message-Id: <85F7C686-B0D3-4A48-9180-C0BA9C7DD651@gromit.dlib.vt.edu> References: To: jungle Boogie X-Mailer: Apple Mail (2.1878.6) Cc: "freebsd-arm@freebsd.org" X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Mar 2015 14:29:16 -0000 On Mar 11, 2015, at 12:09 AM, jungle Boogie = wrote: > Hi Jason, > On 10 March 2015 at 19:05, Jason Birch wrote: >>=20 >> They're lock order reversals, as enabled by the WITNESS kernel = option. You >> probably don't need to worry, but it's helpful to check if they've = been >> reported and, if not, report them. >>=20 >> You might be running into this one: >> http://sources.zabbadoz.net/freebsd/lor/261.html >>=20 >> Quick Googling turns up these resources: >>=20 >> lock order reversals - what do they mean?: >> = https://lists.freebsd.org/pipermail/freebsd-current/2003-December/016617.h= tml >> Glossary of Kernel Options for Debugging: >> = https://www.freebsd.org/doc/en/books/developers-handbook/kerneldebug-optio= ns.html >> FreeBSD LOR(lock order reversal)s seen and comments: >> http://sources.zabbadoz.net/freebsd/lor.html >=20 > Based on what Ian says, I hope these BT don't continue. Those threads > are very likely before the BBB was made...much less had freeBSD > running, so hopefully some progress has been made with freeBSD. Related to what Ian said (re: the LOR list not being actively maintained = any more), for a while now I have been using this kernel config file = with my Beaglebone Black: =3D=3D=3D=3D=3D8<=3D=3D=3D=3D=3D include BEAGLEBONE ident BEAGLEBONE-NO_WITNESS nooption WITNESS nooption WITNESS_SKIPSPIN =3D=3D=3D=3D=3D>8=3D=3D=3D=3D=3D I did this when the stability of FreeBSD/arm was rather shaky (it's = improved immensely, now), and I'd often confuse the LOR output for = panics at first glance. :-) Cheers, Paul.=