From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: rps perfomance WAS(Re: rps: question Date: Thu, 15 Apr 2010 01:50:05 -0700 (PDT) Message-ID: <20100415.015005.156280476.davem@davemloft.net> References: <1271268242.16881.1719.camel@edumazet-laptop> <1271271222.4567.51.camel@bigi> <20100414124426.6aee95c3@nehalam> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: hadi@cyberus.ca, eric.dumazet@gmail.com, therbert@google.com, netdev@vger.kernel.org, robert@herjulf.net, xiaosuo@gmail.com, andi@firstfloor.org To: shemminger@vyatta.com Return-path: Received: from 74-93-104-97-Washington.hfc.comcastbusiness.net ([74.93.104.97]:49424 "EHLO sunset.davemloft.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757513Ab0DOIuA (ORCPT ); Thu, 15 Apr 2010 04:50:00 -0400 In-Reply-To: <20100414124426.6aee95c3@nehalam> Sender: netdev-owner@vger.kernel.org List-ID: From: Stephen Hemminger Date: Wed, 14 Apr 2010 12:44:26 -0700 > On Wed, 14 Apr 2010 14:53:42 -0400 > jamal wrote: > >> Agreed. So to enumerate, the benefits come in if: >> a) you have many processors >> b) you have single-queue nic >> c) at sub-threshold traffic you dont care about a little latency > > There probably needs to be better autotuning for this, there is no reason > that RPS to be steering packets unless the queue is getting backed up. I disagree, if the goal is to migrate the bulk of packet processing to where the app will actually sink and process the data then it should forward to RPS marked cpus regardless of local queue levels.