From mboxrd@z Thu Jan 1 00:00:00 1970 From: Antoine Martin Subject: Re: virtio net regression Date: Mon, 20 Apr 2009 16:09:23 +0100 Message-ID: <49EC9023.6080305@devloop.org.uk> References: <49E63DB4.4090107@devloop.org.uk> <49E66FFB.4080504@nagafix.co.uk> <49EB0F7B.3040802@redhat.com> <1240225922.23407.48.camel@blaa> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: Avi Kivity , "kvm@vger.kernel.org" , Rusty Russell , davem@davemloft.net To: Mark McLoughlin Return-path: Received: from mamba.nagafix.co.uk ([194.145.196.68]:38993 "EHLO mail.nagafix.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754941AbZDTPJ4 (ORCPT ); Mon, 20 Apr 2009 11:09:56 -0400 In-Reply-To: <1240225922.23407.48.camel@blaa> Sender: kvm-owner@vger.kernel.org List-ID: Hi, The bug report below does indeed match everything I have experienced. Upon further inspection, 2.6.28.9 is also affected, just less so. Unfortunately I have applied this patch to 2.6.29.1: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2f181855a0 And if anything, it made things worse... (speed was down to just 6KB/s because of the number of broken packets) Any ideas? Cheers Antoine Mark McLoughlin wrote: > On Sun, 2009-04-19 at 14:48 +0300, Avi Kivity wrote: >> Antoine Martin wrote: >>> -----BEGIN PGP SIGNED MESSAGE----- >>> Hash: SHA512 >>> >>> Wireshark was showing a huge amount of invalid packets (wrong checksum) >>> - - that was the cause of the slowdown. >>> Simply rebooting the host into 2.6.28.9 fixed *everything*, regardless >>> of whether the guests use virtio or ne2k_pci/etc. >>> The guests are still running 2.6.29.1, but I am not likely to try that >>> release again on the host anytime soon! Ouch! >>> >> >> Strange, no significant tun changes between .28 and .29. > > Sounds to me like it's this: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=2f181855a0 > > davem said he was queueing up for stable, but it's not in yet: > > http://kerneltrap.org/mailarchive/linux-netdev/2009/3/30/5337934 > > I'll check that it's in the queue. > > Cheers, > Mark. >