From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: rps testing questions Date: Mon, 17 Jan 2011 13:08:33 +0000 Message-ID: <1295269713.3700.5.camel@localhost> References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: netdev@vger.kernel.org To: mi wake Return-path: Received: from exchange.solarflare.com ([216.237.3.220]:36720 "EHLO exchange.solarflare.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752395Ab1AQNIz convert rfc822-to-8bit (ORCPT ); Mon, 17 Jan 2011 08:08:55 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: On Mon, 2011-01-17 at 17:43 +0800, mi wake wrote: > I do a rps(Receive Packet Steering) testing on centos 5.5 with kerne= l 2.6.37. > cpu: 8 core Intel. > ethernet adapter: bnx2x >=20 > Problem statement: > enable rps with: > echo "ff" > /sys/class/net/eth2/queues/rx-0/rps_cpus. >=20 > running 1 instances of netperf TCP_RR: netperf -t TCP_RR -H 192.168.= 0.1 -c -C > without rps: 9963.48(Trans Rate per sec) > with rps: 9387.59(Trans Rate per sec) >=20 > I do ab and tbench testing also find there is less tps with enable > rps.but,there is more cpu using when with enable rps.when with enable > rps =EF=BC=8Csoftirqs is blanced on cpus. >=20 > is there something wrong with my test=EF=BC=9F In addition to what Eric said, check the interrupt moderation settings (ethtool -c/-C options). One-way latency for a single request/response test will be at least the interrupt moderation value. I haven't tested RPS by itself (Solarflare NICs have plenty of hardware queues) so I don't know whether it can improve latency. However, RFS certainly does when there are many flows. Ben. --=20 Ben Hutchings, Senior Software Engineer, Solarflare Communications Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.