From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756115Ab3B0VoJ (ORCPT ); Wed, 27 Feb 2013 16:44:09 -0500 Received: from mail.candelatech.com ([208.74.158.172]:49717 "EHLO ns3.lanforge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752587Ab3B0VoI (ORCPT ); Wed, 27 Feb 2013 16:44:08 -0500 Message-ID: <512E7DD1.1010209@candelatech.com> Date: Wed, 27 Feb 2013 13:42:41 -0800 From: Ben Greear Organization: Candela Technologies User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130219 Thunderbird/17.0.3 MIME-Version: 1.0 To: Eliezer Tamir CC: Rick Jones , Eliezer Tamir , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Dave Miller , Jesse Brandeburg , e1000-devel@lists.sourceforge.net, Willem de Bruijn , Andi Kleen , HPA , Eliezer Tamir Subject: Re: [RFC PATCH 0/5] net: low latency Ethernet device polling References: <20130227175549.10611.82188.stgit@gitlad.jf.intel.com> <512E654A.2010209@hp.com> <512E6F23.3090003@linux.intel.com> In-Reply-To: <512E6F23.3090003@linux.intel.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/27/2013 12:40 PM, Eliezer Tamir wrote: > On 27/02/2013 21:58, Rick Jones wrote: >> On 02/27/2013 09:55 AM, Eliezer Tamir wrote: >>> >>> Performance numbers: >>> Kernel Config C3/6 rx-usecs TCP UDP >>> 3.8rc6 typical off adaptive 37k 40k >>> 3.8rc6 typical off 0* 50k 56k >>> 3.8rc6 optimized off 0* 61k 67k >>> 3.8rc6 optimized on adaptive 26k 29k >>> patched typical off adaptive 70k 78k >>> patched optimized off adaptive 79k 88k >>> patched optimized off 100 84k 92k >>> patched optimized on adaptive 83k 91k >>> *rx-usecs=0 is usually not useful in a production environment. >> >> I would think that latency-sensitive folks would be using rx-usecs=0 in >> production - at least if the NIC in use didn't have low enough latency >> with its default interrupt coalescing/avoidance heuristics. > > It will only work well if you have no bulk traffic on the same port as the low latency traffic at all. Have you done any tests for bulk throughput with busy-poll? Yes, it will eat a core, but that might be worth it in some cases if there was significant throughput increase... Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com