From owner-freebsd-current@FreeBSD.ORG Fri Nov 21 14:24:50 2014 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 660AB969 for ; Fri, 21 Nov 2014 14:24:50 +0000 (UTC) Received: from mail-qa0-x229.google.com (mail-qa0-x229.google.com [IPv6:2607:f8b0:400d:c00::229]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 0C51E80F for ; Fri, 21 Nov 2014 14:24:50 +0000 (UTC) Received: by mail-qa0-f41.google.com with SMTP id f12so3510392qad.0 for ; Fri, 21 Nov 2014 06:24:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=message-id:date:from:user-agent:mime-version:to:cc:subject :references:in-reply-to:content-type:content-transfer-encoding; bh=LYxSYIJZMrvyXfuDWF7cDEKc53e9hQ11QoY4Ew0I7M0=; b=TaamU6xaZenLTp36vakEXNaAMIIWFeyXgjyRy3LTCkoeMUEdIj1wnbVhBa0CiirAA8 mO7iTLUmzZWh7SVlgTSaeYMlTXLIjbr/0++DUKMBAvF1AtPMiIfj5PmGpr/jBCdbu+NK m79Sr2cht/oQb4EBmuwJ2kyw5XRX2AVa3+x12VDzCAxsfPzKyfciYsdB122Qu56mNicO 11PZQwHchBQ3jQPFf4SW0FoGV7LOX8aYgYsJlQNfycdlnOW0bSY9Se6LQgSU+7ohYyWH EKdFUW+8cNu0tv1LiiuUYRgZHpro0m7uzsLTG4LzO2GFiwkdAN0ZG48Tgix+9IiU3IG6 tw2Q== X-Received: by 10.224.80.6 with SMTP id r6mr6796662qak.5.1416579888418; Fri, 21 Nov 2014 06:24:48 -0800 (PST) Received: from [10.7.1.109] (moist.vrt.sourcefire.com. [198.148.79.134]) by mx.google.com with ESMTPSA id h10sm4771791qge.16.2014.11.21.06.24.47 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 21 Nov 2014 06:24:47 -0800 (PST) Message-ID: <546F4B2F.6050608@gmail.com> Date: Fri, 21 Nov 2014 09:24:47 -0500 From: Shawn Webb User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: "Bjoern A. Zeeb" Subject: Re: Kernel Panic in frag6_slowtimeo References: <1E9CD103-709F-4AAE-B975-14429138293F@gmail.com> <54F837A5-1301-4253-BA87-317C01311BA6@lists.zabbadoz.net> In-Reply-To: <54F837A5-1301-4253-BA87-317C01311BA6@lists.zabbadoz.net> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Cc: freebsd-current@freebsd.org 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, 21 Nov 2014 14:24:50 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =20 On 11/21/2014 5:53 AM, Bjoern A. Zeeb wrote: > > On 21 Nov 2014, at 06:10 , Shawn Webb wrote: > >> Looks like I=92m getting a kernel panic on heavy work loads (poudriere= run with 10 build slaves on an Intel Core i7 box). Below is a link to an imgur album of screenshots I took with my phone. >> >> I can reproduce this quite easily simply by spinning up a new poudriere run. Should I file a bug report or is reporting here all that=92s needed? >> >> Link to screenshots: http://imgur.com/a/h64uB > > > Which exact revision/version of FreeBSD is this (SVN revision in case of non-release)? I'm at r274745. The code in question was written in 2003. I've narrowed down the behavior to OpenVPN with IPv6 causing this kernel panic. My OpenVPN server dishes out IPv6 as well as IPv4 in routing mode and is configured to use UDP (which is the default). OpenVPN's default keepalive is 120 seconds. If the tunnel goes down within that 120 seconds and OpenVPN doesn't notice, the tun device is still active but packages are simply queued rather then delivered. Eventually OpenVPN re-establishes the tunnel while keeping the tun device open, reusing it rather than destroying/recreating it. The kernel panic is happening either while the tunnel is down (yet tun device still is open) or when the tunnel is being brought back up. If I set the keepalive to a really small value (I currently have it at two seconds), then the kernel panic doesn't happen. Really interesting behavior. Thanks, Shawn -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (MingW32) =20 iQIcBAEBAgAGBQJUb0svAAoJEGqEZY9SRW7uXAsP/AzM3wfkDUQrBXtm2M3UdhLc Y0EI+eqj58wIQ3UvwuRTLKg6T+Zpz5+yTBIzysPGCtgoR9UzYePVkqLyE2qD0bHT FSPDpOKGzhZBOdElsTGZziw/tHK+jL/JIqVLS98T8uUpzb6YHJWMD6uT9ZjLkS3+ tvIoyL1R7BtVhpnu73HCH4aGrshEgn9Tmtq3FSczAOMysYwtGc0oVFiSXpPy0wBg n2zW56jIHOFl/h6NkGD6HYFaDainkSf4yH+BbyMT82OiGSxOW2boz6IdGiopf5qI lTEpbdUQQ0R0YhMIaDNwawC7VhsGFSAe8kkrs/ma8Ut/X2D1yGhhpD2tTnYUMf0l g3sn2K27WHldGqK/YQ1KUDk1vqnynB7aTqfD7lTx2h//kYZbhVdLUiTS1VwzOuZU Qgz4Y/SJycx/qE19OnZ7L41XtyIICNpqYkI1HoFZBPqNePn6j2oZ9sUp92Rmui6S wvYZ0WP3FYZVsPUiFrZfKFb/RJ7woMyklBiRs09D4V5oO3Fxk3uxbQE5sSnr1mhn cN0izfazAXePMcSE3zMgARv+M/GT2LgySlurOb+7xAs47YecN2IT33m+Ffd+rF7X /jEaGMHGObZtQCl20GGPDcfy/KQrwHN8BdGJ81+T61NYfN+F1MImWve3YdzEOF1N Y6jill9bzaksguJ5WYev =3DAiXD -----END PGP SIGNATURE-----