From mboxrd@z Thu Jan 1 00:00:00 1970 From: "juice" Subject: Re: Using ethernet device as efficient small packet generator Date: Wed, 22 Dec 2010 09:30:39 +0200 Message-ID: Reply-To: juice@swagman.org Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT To: "Stephen Hemminger" , netdev@vger.kernel.org Return-path: Received: from www.liukuma.net ([62.220.235.15]:56585 "EHLO www.liukuma.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752401Ab0LVHaq (ORCPT ); Wed, 22 Dec 2010 02:30:46 -0500 Sender: netdev-owner@vger.kernel.org List-ID: > On Tue, 21 Dec 2010 11:56:42 +0200 shemminger wrote: > I regularly get full 1G line rate of 64 byte packets using old Opteron box and pktgen. It does require some tuning of IRQ's and interrupt mitigation but > no patches. Did you remember to do the basic stuff like setting IRQ affinity > and not enabling debugging or tracing in the kernel? This is on sky2, but > also using e1000 and tg3. Others have reported 7M packets per second over > 10G cards. > The r8169 hardware is low end consumer hardware and doesn't work as well. > It is possible to get close to 1G line rate forwarding with a single core > with current > generation processors. Actual rate depends on hardware and configuration (size of route > table, firewalling, etc). Much better performance with multi-queue hardware to spread load > over multiple cores. I did my testing on two kinds of boxes we use in our lab, an older Pomi Supermicro with e1000 and a newer Dell T3500 with tg3 and r8169. Both computers have dual-core 2.4G Xeon Cpus, but with somewhat different model and stepping. Both boxes are running the same OS, Ubuntu 2.6.32-26-generic #48. Could you share some information on the required interrupt tuning? It would certainly be easiest if the full line rate can be achieved without any patching of drivers or hindering normal eth/ip interface operation. Yours, Jussi Ohenoja