From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: Re: Regression: too many packets with incorrect checksum Date: Wed, 08 May 2013 20:22:23 +0800 Message-ID: <1368015743.3115.12.camel@cr0> References: <1368013888.3115.9.camel@cr0> <518A41CA.3030804@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, "David S. Miller" To: PJ Waskiewicz Return-path: Received: from mx1.redhat.com ([209.132.183.28]:2037 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754312Ab3EHMWa (ORCPT ); Wed, 8 May 2013 08:22:30 -0400 In-Reply-To: <518A41CA.3030804@linux.intel.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2013-05-08 at 05:15 -0700, PJ Waskiewicz wrote: > On 5/8/2013 4:51 AM, Cong Wang wrote: > > Hi, all > > > > The latest -net tree has some regression, I saw too many packets with > > incorrect checksum from tcpdump inside a KVM guest, see the bottom. > > (firewall is turned off on both sides.) > > > > It seems this is not related with drivers, I tried virtio and e1000, > > both have the same problem. And UDP has the problem too. But turning off > > tx-checksum by `ethtool -K eth0 tx off` makes the problem disappear > > (just turning off TSO or GSO doesn't make any difference). > > > > I can provide other information if you need. > > Reproduce on bare metal, non-KVM? > Sorry that I don't have env or time to test it on non-KVM, because my kernel config is specific to KVM and kicks out all modules.