From owner-freebsd-xen@FreeBSD.ORG Sat Apr 19 12:10:33 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 4A50F758 for ; Sat, 19 Apr 2014 12:10:33 +0000 (UTC) Received: from mail-yh0-x22c.google.com (mail-yh0-x22c.google.com [IPv6:2607:f8b0:4002:c01::22c]) (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 0C46C1C94 for ; Sat, 19 Apr 2014 12:10:32 +0000 (UTC) Received: by mail-yh0-f44.google.com with SMTP id f10so2202091yha.3 for ; Sat, 19 Apr 2014 05:10:32 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=content-type:mime-version:subject:from:in-reply-to:date:cc :content-transfer-encoding:message-id:references:to; bh=Cwh6dymDAdQ3i+yaOwffMSw9BiR/IE7E052p9BTVvKU=; b=ky7GPOY7fBSCjHIiaOTzKuSuU2JNxtAVWrsYIBnY6beBnQlO4sXkrmTcv7Be5eMvTK gl6B+0kLYuPruwejnYp4YTq45WaNcJEeJJYb9fSTGPT029rpmXNr2TGIHeDOnya5dtVu J+M3Rnt3/uT9sadistnGk5mzsjpZBvt9onPHFpzuwdDelAi6P6rKScLv6PJ0HYiZ+NJM cZbfukuQk5062pOnbIpn5Qc8GvgPE2Z/nmt4paiG6XavACOZws+scn4qWUaAsytyeCEx d7K2b3h3Snb0f0+T8s+KYo3cTi8fVdzNqZJaNOYNz0QdInsClZFcTXOZ4+tfBZAO+wIl 6Pow== X-Received: by 10.236.119.99 with SMTP id m63mr9083061yhh.65.1397909432142; Sat, 19 Apr 2014 05:10:32 -0700 (PDT) Received: from [191.14.30.229] ([191.14.30.229]) by mx.google.com with ESMTPSA id c27sm58694994yhm.35.2014.04.19.05.10.29 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sat, 19 Apr 2014 05:10:30 -0700 (PDT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (1.0) Subject: Re: VM in Xen 4.1; poor packet forwarding performance on xn0 From: Tiago Ribeiro X-Mailer: iPhone Mail (11D167) In-Reply-To: Date: Sat, 19 Apr 2014 09:11:59 -0300 Content-Transfer-Encoding: quoted-printable Message-Id: <2C3A747F-DA88-4815-A930-7C5EB1CD6238@gmail.com> References: To: "seanrees@gmail.com" Cc: "freebsd-xen@freebsd.org" 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: Sat, 19 Apr 2014 12:10:33 -0000 > Em 18/04/2014, =C3=A0s 11:57, "seanrees@gmail.com" es= creveu: >=20 > Hi there freebsd-xen, >=20 > I tried first on freebsd-questions@ without success, so I thought to retry= > here. >=20 > I run OpenVPN on a FreeBSD 10.0-Rp1 VM in Xen 4.1 (HVM). I am experiencing= > slow network performance on xn0 that seems to have developed after I > upgraded to FreeBSD 10 (no other changes). I can only achieve about 0.5mbp= s > through this interface when forwarding packets; packets in a single > direction are fine (e.g; downloading to the VPS or pushing from the VPS) > and clock in at many (>10 usually) mbps. >=20 > Interestingly, my identical VM (configuration managed centrally) running o= n > Xen 3.4 (HVM) does *not* have this issue. >=20 > I did a little debugging and here's what I've noticed: > - Not related to OpenVPN, repro'd using ssh -d. > - Slow VM has a very low rate of context switches (~250) while > forwarding, fast VM has a lot more (~2000) sampled over 5 seconds using > systat -v. > - I can't repro a context switch limit (tried a limited fork() bomb). > - Tried with *and* without LRO and TSO on xn0 (and all combinations of > LRO and TSO on/off) >=20 > I started digging into the Xen drivers but I realised I am not equipped to= > debug this. I'm looking for suggestions on what to check. My provider is > offering to move me to an older Xen host but I'd like to see if I can help= > identify a bug either in my configuration or perhaps in FreeBSD's Xen code= . >=20 > Sean > _____________________________________________ Do you use pf?=20=