From owner-freebsd-xen@FreeBSD.ORG Wed Feb 12 09:13:10 2014 Return-Path: Delivered-To: freebsd-xen@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 50D48B04 for ; Wed, 12 Feb 2014 09:13:10 +0000 (UTC) Received: from cu01176b.smtpx.saremail.com (cu01176b.smtpx.saremail.com [195.16.151.151]) by mx1.freebsd.org (Postfix) with ESMTP id E19A9195B for ; Wed, 12 Feb 2014 09:13:09 +0000 (UTC) Received: from [172.16.2.46] (izaro.sarenet.es [192.148.167.11]) by proxypop04.sare.net (Postfix) with ESMTPSA id D397D9DD379 for ; Wed, 12 Feb 2014 10:05:48 +0100 (CET) From: Egoitz Aurrekoetxea Subject: About XenHVM network driver and mbuf tagging Message-Id: <68058FAE-C913-463E-A20C-67239C1220AE@sarenet.es> Date: Wed, 12 Feb 2014 10:05:46 +0100 To: freebsd-xen@freebsd.org Mime-Version: 1.0 (Mac OS X Mail 7.1 \(1827\)) X-Mailer: Apple Mail (2.1827) Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.17 X-BeenThere: freebsd-xen@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: Discussion of the freebsd port to xen - implementation and usage List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 12 Feb 2014 09:13:10 -0000 Hi all, If you=92re running FreeBSD 9.1 or greater (release versions tested = only) under Xen 4.1 in HVM mode (xen-detect is saying "Running in HVM = context on Xen v4.1.=94) AND if you use some (in combination of both, = and trying to see if with any other network drivers not involving = virtualization and using too the LRO piece of code of the FreeBSD = kernel) kind of software involving mbuf tagging too (Mac Framework, vlan = tagging, ipsec=85.) AND you move an important amount of traffic with = that driver (the net hvm driver in this case) you will see wired memory = starts increasing pretty fast and never being released. This seems to be = due to a problem with the LRO code of the FreeBSD kernel which causes = mbuf_tags not being properly released after the own mbuf chains have = been properly released. So as a temporary workaround (and really as = valid workaround without involving any kind of limitation) you can just = disable LRO flag in you interfaces running this driver (ifconfig = xn0-1-2=85. -lro) and you=92re done. This is a message for just trying to avoid people to waste time in = trying to find some workaround for the issue. For more info, I=92m = moving this topic at freebsd-hackers list with egoitz(at)ramattack.net = email address and with thread subject "mbuf_tag memory freeing issues = with LRO enabled on the XENHVM driver=94. Best regards, Egoitz Aurrekoetxea Departamento de sistemas 944 209 470 Parque Tecnol=F3gico. Edificio 103 48170 Zamudio (Bizkaia) egoitz@sarenet.es www.sarenet.es Antes de imprimir este correo electr=F3nico piense si es necesario = hacerlo.