From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: forcedeth driver hangs under heavy load Date: Tue, 13 Apr 2010 14:43:40 -0700 (PDT) Message-ID: <20100413.144340.138717714.davem@davemloft.net> References: <1271160298.2098.0.camel@achroite.uk.solarflarecom.com> <4BC47F38.5040509@gmail.com> <1271169741.16881.437.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: smulcahy@gmail.com, bhutchings@solarflare.com, netdev@vger.kernel.org, ben@decadent.org.uk, aabdulla@nvidia.com, 572201@bugs.debian.org To: eric.dumazet@gmail.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:45605 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752353Ab0DMVni convert rfc822-to-8bit (ORCPT ); Tue, 13 Apr 2010 17:43:38 -0400 In-Reply-To: <1271169741.16881.437.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: =46rom: Eric Dumazet Date: Tue, 13 Apr 2010 16:42:21 +0200 > Le mardi 13 avril 2010 =E0 15:27 +0100, stephen mulcahy a =E9crit : >> Ok, I've tried both of the following with my reproducer >>=20 >> 1. ethtool -K eth0 tso off >>=20 >> RESULT: reproducer causes multiple hosts to be come unresponsive on=20 >> first run. >>=20 >> 2. ethtool -K eth0 tx off >>=20 >> RESULT: reproducer runs three times without any hosts becoming unres= ponsive. >>=20 >> -stephen >=20 > Thanks Stephen ! >=20 > Now some brave fouls to check the 6410 lines of this driver ? ;) >=20 > Question of the day : Why TSO is broken in forcedeth ? > Is it generically broken or is it broken for specific NICS ? Do you really come to the conclusion that TSO is broken with the above test results? I would conclude that there is a TX checksumming issue, since merely turning TSO off does not fix the problem whereas turning TX checksumming off does.