From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: rps testing questions Date: Mon, 17 Jan 2011 10:53:14 +0100 Message-ID: <1295257994.3335.6.camel@edumazet-laptop> 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 mail-ew0-f46.google.com ([209.85.215.46]:55510 "EHLO mail-ew0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751878Ab1AQJxT (ORCPT ); Mon, 17 Jan 2011 04:53:19 -0500 Received: by ewy5 with SMTP id 5so2427538ewy.19 for ; Mon, 17 Jan 2011 01:53:18 -0800 (PST) In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: Le lundi 17 janvier 2011 =C3=A0 17:43 +0800, mi wake a =C3=A9crit : > 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 bnx2x with one queue only ? > 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. Really ? that seems unlikely with your one flow test, unless you _also_ have hardware IRQS hitting all your cpus. (That would be very bad) >=20 > is there something wrong with my test=EF=BC=9F > -- If you test with one flow, RPS brings nothing at all. Better handle the packet directly from the cpu handling the hardware IRQ (and NAPI) You better make sure hardware IRQ are on one cpu, instead of many cpus.