From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: [ofa-general] Re: [PATCH 0/9 Rev3] Implement batching skb API and support in IPoIB Date: Fri, 24 Aug 2007 11:46:26 -0700 Message-ID: <46CF2782.6060006@hp.com> References: <20070821.212229.82050253.davem@davemloft.net> <46CC6DD1.5020105@hp.com> <20070822.132145.90824527.davem@davemloft.net> <1187906650.4279.16.camel@localhost> <1187907903.4279.28.camel@localhost> <46CE0BA1.60206@hp.com> <20070823231820.2ae52cc0.billfink@mindspring.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: jagana@us.ibm.com, herbert@gondor.apana.org.au, gaagaan@gmail.com, Robert.Olsson@data.slu.se, mcarlson@broadcom.com, rdreier@cisco.com, peter.p.waskiewicz.jr@intel.com, hadi@cyberus.ca, kaber@trash.net, jeff@garzik.org, general@lists.openfabrics.org, mchan@broadcom.com, tgraf@suug.ch, netdev@vger.kernel.org, johnpol@2ka.mipt.ru, shemminger@linux-foundation.org, David Miller , sri@us.ibm.com To: Bill Fink Return-path: In-Reply-To: <20070823231820.2ae52cc0.billfink@mindspring.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: general-bounces@lists.openfabrics.org Errors-To: general-bounces@lists.openfabrics.org List-Id: netdev.vger.kernel.org Bill Fink wrote: > On Thu, 23 Aug 2007, Rick Jones wrote: > > >>jamal wrote: >> >>>[TSO already passed - iirc, it has been >>>demostranted to really not add much to throughput (cant improve much >>>over closeness to wire speed) but improve CPU utilization]. >> >>In the one gig space sure, but in the 10 Gig space, TSO on/off does make a >>difference for throughput. > > > Not too much. > > TSO enabled: > > [root@lang2 ~]# ethtool -k eth2 > Offload parameters for eth2: > rx-checksumming: on > tx-checksumming: on > scatter-gather: on > tcp segmentation offload: on > > [root@lang2 ~]# nuttcp -w10m 192.168.88.16 > 11813.4375 MB / 10.00 sec = 9906.1644 Mbps 99 %TX 80 %RX > > TSO disabled: > > [root@lang2 ~]# ethtool -K eth2 tso off > [root@lang2 ~]# ethtool -k eth2 > Offload parameters for eth2: > rx-checksumming: on > tx-checksumming: on > scatter-gather: on > tcp segmentation offload: off > > [root@lang2 ~]# nuttcp -w10m 192.168.88.16 > 11818.2500 MB / 10.00 sec = 9910.0176 Mbps 100 %TX 78 %RX > > Pretty negligible difference it seems. Leaves one wondering how often more than one segment was sent to the card in the 9000 byte case :) rick jones