From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rick Jones Subject: Re: e1000 performance issue in 4 simultaneous links Date: Thu, 10 Jan 2008 10:26:04 -0800 Message-ID: <4786633C.6000308@hp.com> References: <1199981839.8931.35.camel@cafe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: Breno Leitao Return-path: Received: from g5t0007.atlanta.hp.com ([15.192.0.44]:15951 "EHLO g5t0007.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754671AbYAJS0H (ORCPT ); Thu, 10 Jan 2008 13:26:07 -0500 In-Reply-To: <1199981839.8931.35.camel@cafe> Sender: netdev-owner@vger.kernel.org List-ID: Many many things to check when running netperf :) *) Are the cards on the same or separate PCImumble bus, and what sort of bus *) is the two interface performance two interfaces on the same four-port card, or an interface from each of the two four-port cards? *) is there a dreaded (IMO) irqbalance daemon running? one of the very first things I do when running netperf is terminate the irqbalance daemon with as extreme a predjudice as I can. *) what is the distribution of interrupts from the interfaces to the CPUs? if you've tried to set that manually, the dreaded irqbalance daemon will come along shortly thereafter and ruin everything. *) what does netperf say about the overall CPU utilization of the system(s) when the tests are running? *) what does top say about the utilization of any single CPU in the system(s) when the tests are running? *) are you using the global -T option to spread the netperf/netserver processes across the CPUs, or leaving that all up to the stack/scheduler/etc? I suspect there could be more but that is what comes to mind thusfar as far as things I often check when running netperf. rick jones