From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eli Cooper Subject: Re: Large performance regression with 6in4 tunnel (sit) Date: Fri, 25 Nov 2016 14:05:04 +0800 Message-ID: References: <20161125120947.142c3af5@canb.auug.org.au> <20161125134520.68ca0969@canb.auug.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Stephen Rothwell Return-path: Received: from mout.gmx.net ([212.227.17.21]:55636 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751645AbcKYGF5 (ORCPT ); Fri, 25 Nov 2016 01:05:57 -0500 In-Reply-To: <20161125134520.68ca0969@canb.auug.org.au> Sender: netdev-owner@vger.kernel.org List-ID: Hi Stephen, On 2016/11/25 10:45, Stephen Rothwell wrote: > Hi Eli, > > On Fri, 25 Nov 2016 10:18:12 +0800 Eli Cooper wrote: >> Sounds like TSO/GSO packets are not properly segmented and therefore >> dropped. >> >> Could you first try turning off segmentation offloading for the tunnel >> interface? >> ethtool -K sit0 tso off gso off > On Thu, 24 Nov 2016 18:30:14 -0800 Eric Dumazet >> You also could try to disable TSO and see if this makes a difference >> >> ethtool -K sixtofour0 tso off > So turning off tso brings performance up to IPv4 levels ... > > Thanks for that, it solves my immediate problem. I think this is similar to the bug I fixed in commit ae148b085876 ("ip6_tunnel: Update skb->protocol to ETH_P_IPV6 in ip6_tnl_xmit()"). I can reproduce a similar problem by applying xfrm to sit traffic. TSO/GSO packets are dropped when IPSec is enabled, and IPv6 throughput drops to 10s of Kbps. I am not sure if this is the same issue you experienced, but I wrote a patch that fixed at least the issue I had. Could you test the patch I sent to the mailing list just now? Thanks, Eli