From owner-freebsd-arm@FreeBSD.ORG Wed Mar 11 20:27:51 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 B5570193 for ; Wed, 11 Mar 2015 20:27:51 +0000 (UTC) Received: from mail-pa0-f54.google.com (mail-pa0-f54.google.com [209.85.220.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 81D308E0 for ; Wed, 11 Mar 2015 20:27:51 +0000 (UTC) Received: by pabli10 with SMTP id li10so14098125pab.13 for ; Wed, 11 Mar 2015 13:27:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:sender:subject:mime-version:content-type:from :in-reply-to:date:cc:message-id:references:to; bh=Vh5h8N9m+7Fu4lCHiICszzygwobNzcaaaMjiQ9ptupY=; b=Ey6ojaAgnC1un4g27E5d4IyS1K8ExQ/elGNzydCJcxAcIn5XBbrqsl+yiG2Thr9Gdo R0/D2mzsJJhGudcTJ521FEhJkPBgSQdlMYj8qrty+wt/M3UNUcQTgD7bbD6/wL/kPkpd gqE/VOGmU4zq0XM4Pt0444jVHwTS5XeSEyGM0YdmLbM0V6CIt5tydHeQYCvQFTFMzJfm 5jLJKJ+9cO49WgSxUOuZltQ0qmSYQDNA36yEeqXP67FkqDPqAEskGTwXZxWYuzXm/aa4 BJAUGvxtSsqIt/gwmDAEOVo2R0ysDxcAt0P+3BshTdp/jILzsgVbr9tRdaR5eo1giXDL wexg== X-Gm-Message-State: ALoCoQnLwRP2bio/jw0iECp2nI/2ifnabDucYjMHSuR6+qiX6cSvhcyMvHLEynu4eLYiUw9XKaRA X-Received: by 10.66.121.161 with SMTP id ll1mr45500031pab.131.1426105664739; Wed, 11 Mar 2015 13:27:44 -0700 (PDT) Received: from [192.168.18.6] (221x253x176x170.ap221.ftth.ucom.ne.jp. [221.253.176.170]) by mx.google.com with ESMTPSA id hk6sm7324589pdb.83.2015.03.11.13.27.42 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 11 Mar 2015 13:27:43 -0700 (PDT) Sender: Warner Losh Subject: Re: BBB freebsd-current backtrace. why? Mime-Version: 1.0 (Mac OS X Mail 8.2 \(2070.6\)) Content-Type: multipart/signed; boundary="Apple-Mail=_CB08C7FF-B9EA-4A6B-BCB5-B5D9C0755ECF"; protocol="application/pgp-signature"; micalg=pgp-sha512 X-Pgp-Agent: GPGMail 2.5b5 From: Warner Losh In-Reply-To: <1426083066.33324.34.camel@freebsd.org> Date: Thu, 12 Mar 2015 05:27:40 +0900 Message-Id: <5C9C39FF-CB6D-45B8-A957-06AC5BF5ED91@bsdimp.com> References: <1426083066.33324.34.camel@freebsd.org> To: Ian Lepore X-Mailer: Apple Mail (2.2070.6) 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 20:27:51 -0000 --Apple-Mail=_CB08C7FF-B9EA-4A6B-BCB5-B5D9C0755ECF Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Mar 11, 2015, at 11:11 PM, Ian Lepore wrote: >=20 > On Tue, 2015-03-10 at 21:09 -0700, 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. >=20 > The point is that those LORs are harmless. They were declared = harmless > by the gurus who understand them, years ago, and apparently just by > issuing that proclamation, it's a closed subject and we all just have = to > live with the spewage. Except that=E2=80=99s not entirely true. There are some that are known = to be harmless, but others that aren=E2=80=99t. Sadly, there=E2=80=99s no way to mark = the harmless ones in the source. Some LoRs are harmless, others lead to deadlock. Warner --Apple-Mail=_CB08C7FF-B9EA-4A6B-BCB5-B5D9C0755ECF Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP using GPGMail -----BEGIN PGP SIGNATURE----- Comment: GPGTools - https://gpgtools.org iQIcBAEBCgAGBQJVAKU9AAoJEGwc0Sh9sBEAgEwP/3ACP6oINMsOgVTrLuv+5nR1 vEuoTxH6cVg8KW/hhC1PvCU8PHQMfiLMNqqzB0oJ3xyDL5PWcEcLy5B9gs5li8RU m3CRvCwzuy0VF+I6yVt3NWZqh2VBiwlFzTTjw8AjjA86PN4leT+8YR6Kp7znT7iu 7M84/pkz9FiK8ujt26g8GEULGes1msFNVARrPexqKrWdAMIJjm8ZLpyPYQ717RRr 5WAC+yFVYJ38njsws0vaw9SmXG2q/uu2ouj8VpLXEYl5j68Fz41yjm6Ne+IRULpv CZmJtmhCHODOmK3VqOyVVJNHf24NrPPjfWLoHt1H2hj7NhHVShIZZ3Fx9zq8u9Pj ImUU2fdGpm73FqkALuwjBYjsf91VPLJ1EpNhu9yhk1T6wJg3C81Mwvdusm0YQxgP uV6LM5WIGHbgv0xPbZfCduLKfwZgLKRls9/Cb+/aDyuGywMZexlof/PcpURavMVR RJfAhe/ZegUTqY7iJS403mBPq5w+Gzn3Px5EOJiN+kZQqXn0jGN/VuGYEEePI627 weaKFy37Exbf+Iah+OwJIdMT4at10VMBCs8BCBHv0SjMdhQonVJAX3cPi0oEax6A NqRGkkNSNNh+UOjwLQa6PS6b8i2gnOGTugNYm2Q7HIx69BgddIy9cZKOx68YesaG Rjw8fO0c2wkmPx59kA15 =b6yD -----END PGP SIGNATURE----- --Apple-Mail=_CB08C7FF-B9EA-4A6B-BCB5-B5D9C0755ECF--