From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian King Subject: Re: [PATCH 1/4] ibmveth: Enable TCP checksum offload Date: Thu, 19 Jul 2007 08:35:14 -0500 Message-ID: <469F6892.2020908@linux.vnet.ibm.com> References: <11846854701127-patch-mail.ibm.com> <469E9510.7060703@garzik.org> Reply-To: brking@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linuxppc-dev@ozlabs.org, rcjenn@linux.vnet.ibm.com, santil@linux.vnet.ibm.com, netdev@vger.kernel.org To: Jeff Garzik Return-path: Received: from e1.ny.us.ibm.com ([32.97.182.141]:49997 "EHLO e1.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757624AbXGSNfR (ORCPT ); Thu, 19 Jul 2007 09:35:17 -0400 Received: from d01relay04.pok.ibm.com (d01relay04.pok.ibm.com [9.56.227.236]) by e1.ny.us.ibm.com (8.13.8/8.13.8) with ESMTP id l6JDZGW2012157 for ; Thu, 19 Jul 2007 09:35:16 -0400 Received: from d01av02.pok.ibm.com (d01av02.pok.ibm.com [9.56.224.216]) by d01relay04.pok.ibm.com (8.13.8/8.13.8/NCO v8.4) with ESMTP id l6JDZG2g535876 for ; Thu, 19 Jul 2007 09:35:16 -0400 Received: from d01av02.pok.ibm.com (loopback [127.0.0.1]) by d01av02.pok.ibm.com (8.12.11.20060308/8.13.3) with ESMTP id l6JDZFu8026120 for ; Thu, 19 Jul 2007 09:35:16 -0400 In-Reply-To: <469E9510.7060703@garzik.org> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Jeff Garzik wrote: > Brian King wrote: >> This patchset enables TCP checksum offload support for IPV4 >> on ibmveth. This completely eliminates the generation and checking of >> the checksum for packets that are completely virtual and never >> touch a physical network. A simple TCP_STREAM netperf run on >> a virtual network with maximum mtu set yielded a ~30% increase >> in throughput. This feature is enabled by default on systems that >> support it, but can be disabled with a module option. >> >> Signed-off-by: Brian King > > this should be controllable purely via ethtool... I'll remove the module parameter and resend. >> struct ibmveth_rx_q_entry { >> u16 toggle : 1; >> u16 valid : 1; >> - u16 reserved : 14; >> + u16 reserved : 4; >> + u16 no_csum : 1; >> + u16 csum_good : 1; >> + u16 reserved2 : 8; >> u16 offset; > > As a general rule, it would be nice to start moving away from bitfields > in this driver I'll take a look at that for a future cleanup patch. Thanks, Brian -- Brian King Linux on Power Virtualization IBM Linux Technology Center