From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ian Jeffray Subject: Re: sendfile() broken with 2.6.26 + Apache 2 ? Date: Wed, 16 Jul 2008 08:30:16 +0100 Message-ID: <487DA388.3030104@jeffray.co.uk> References: <487CD7A7.2080800@jeffray.co.uk> <487D893A.5080207@cosmosbay.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: linux-kernel@vger.kernel.org, Linux Netdev List To: Eric Dumazet Return-path: Received: from smtp-out5.blueyonder.co.uk ([195.188.213.8]:52035 "EHLO smtp-out5.blueyonder.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751618AbYGPHaV convert rfc822-to-8bit (ORCPT ); Wed, 16 Jul 2008 03:30:21 -0400 In-Reply-To: <487D893A.5080207@cosmosbay.com> Sender: netdev-owner@vger.kernel.org List-ID: Hi Eric, Thanks for directing me to a better list. =46urther responses below: Eric Dumazet wrote: > CC to netdev where this report might find better answers >=20 > Ian Jeffray a =E9crit : >> All, >> >> I moved from kernel 2.6.25.4 to 2.6.26 yesterday and observed that >> large files sent via Apache2 are partially corrupt. >> >> This appears to be linked to sendfile() -- disabling the use of >> sendfile in the apache config (EnableSendfile Off) allows it to >> function as normal. >> >> My system is a simple Core2Duo running Debian lenny/sid; nothing >> special, and I have never observed problems like this before. >> >> The problem feels certainly related to sendfile() since the data >> reads correctly from disc in other programs, and via CIFS etc. >> >> The corruption happens part-way in to the file... I've no exact >> figure but it would seem like maybe 32KB -- I'm seeing broken >> PNGs served from Apache, where the top few dozen lines decode >> correctly, and the rest is garbage. >> >> I've made basically no configuration changes between 2.6.25.4 and >> 2.6.26 and have explicitly tried both enabling and disabling the >> new PAT support to no effect. >> >> This is completely repeatable and reproducible. >> >> Is anyone else seeing this broken behaviour? >> >=20 >=20 > What kind of network adapter are you using ? (lspci | grep -i ether) 02:00.0 Ethernet controller: Attansic Technology Corp. L1 Gigabit=20 Ethernet Adapter (rev b0) > If you disable TCP segmentation offload on this NIC (ethtool -K eth0 = tso=20 > off) , is this problem still present ? Wow. That 'solves' the problem! Great. Does this therefore point to an attansic driver issue? Ian.