From mboxrd@z Thu Jan 1 00:00:00 1970 From: Troy Wilson Subject: Re: Early SPECWeb99 results on 2.5.33 with TSO on e1000 Date: Thu, 5 Sep 2002 17:11:15 -0500 (CDT) Sender: netdev-bounce@oss.sgi.com Message-ID: <200209052211.g85MBFdm099387@tempest.prismnet.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, netdev@oss.sgi.com Return-path: In-Reply-To: "from jamal at Sep 5, 2002 04:59:47 pm" To: jamal Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org > So if i understood correctly (looking at the intel site) the main value > add of this feature is probably in having the CPU avoid reassembling and > retransmitting. Quoting David S. Miller: dsm> The performance improvement comes from the fact that the card dsm> is given huge 64K packets, then the card (using the given ip/tcp dsm> headers as a template) spits out 1500 byte mtu sized packets. dsm> dsm> Less data DMA'd to the device per normal-mtu packet and less dsm> per-packet data structure work by the cpu is where the improvement dsm> comes from. > Do you have any stats from the hardware that could show > retransmits etc; I'll gather netstat -s after runs with and without TSO enabled. Anything else you'd like to see? > have you tested this with zero copy as well (sendfile) Yes. My webserver is Apache 2.0.36, which uses sendfile for anything over 8k in size. But, iirc, Apache sends the http headers using writev. Thanks, - Troy