From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael Chan" Subject: Re: TG3 network data corruption regression 2.6.24/2.6.23.4 Date: Tue, 19 Feb 2008 15:52:43 -0800 Message-ID: <1203465163.13495.102.camel@dell> References: <47BA0984.2070306@cybernetics.com> <1203381120.13495.78.camel@dell> <20080218.163554.74130592.davem@davemloft.net> <1203383046.13495.87.camel@dell> <47BB00EC.3010607@cybernetics.com> <1203448265.13495.95.camel@dell> <47BB54C2.6090501@cybernetics.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: "David Miller" , herbert@gondor.apana.org.au, netdev , gregkh@suse.de, linux-kernel@vger.kernel.org To: "Tony Battersby" Return-path: Received: from mms1.broadcom.com ([216.31.210.17]:4104 "EHLO mms1.broadcom.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751703AbYBSXuQ (ORCPT ); Tue, 19 Feb 2008 18:50:16 -0500 In-Reply-To: <47BB54C2.6090501@cybernetics.com> Sender: netdev-owner@vger.kernel.org List-ID: On Tue, 2008-02-19 at 17:14 -0500, Tony Battersby wrote: > > Update: when I revert Herbert's patch in addition to applying your > patch, the iSCSI performance goes back up to 115 MB/s again in both > directions. So it looks like turning off SG for TX didn't itself cause > the performance drop, but rather that the performance drop is just > another manifestation of whatever bug is causing the data corruption. > > I do not regularly use wireshark or look at network packet dumps, so I > am not really sure what to look for. Given the above information, do > you still believe that there is value in examining the packet dump? > Can you confirm whether you're getting TCP checksum errors on the other side that is receiving packets from the 5701? You can just check statistics using netstat -s. I suspect that after we turn off SG, checksum is no longer offloaded and we are getting lots of TCP checksum errors instead that are slowing the performance.