From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: linux-3.0.18+r8169+ipv4/tcp forwarding = tso/gso weirdness and performance degration Date: Wed, 14 Mar 2012 13:12:45 -0700 Message-ID: <1331755965.6022.55.camel@edumazet-glaptop> References: <20120314190156.622c8cd5@vostro> <1331745314.6022.27.camel@edumazet-glaptop> <20120314192945.65867e9f@vostro> <1331753354.2564.7.camel@bwh-desktop.uk.solarflarecom.com> <20120314215142.655ae607@vostro> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Ben Hutchings , netdev@vger.kernel.org, Francois Romieu To: Timo Teras Return-path: Received: from mail-gx0-f174.google.com ([209.85.161.174]:48328 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030518Ab2CNUMs (ORCPT ); Wed, 14 Mar 2012 16:12:48 -0400 Received: by gghe5 with SMTP id e5so2245070ggh.19 for ; Wed, 14 Mar 2012 13:12:48 -0700 (PDT) In-Reply-To: <20120314215142.655ae607@vostro> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, 2012-03-14 at 21:51 +0200, Timo Teras wrote: > Very good point. I thought gso also enabled gro, but seems that my > ethtool was old. > > And GRO was enabled along with some other stuff. Turning GRO off made > my tcp performance immediately a lot better; jumped from 2MB/s to 8MB/s > or so (not ideal yet, though; but the remainder of the difference could > be related to other issue). > > So something is definitely broke in 3.0.x with GRO enabled, but GSO off. "ifconfig eth2 ; netstat -s" can really help, I suspect tcp stack drops