From mboxrd@z Thu Jan 1 00:00:00 1970 From: Changli Gao Subject: Re: rps perfomance WAS(Re: rps: question Date: Thu, 15 Apr 2010 06:51:29 +0800 Message-ID: References: <1265568122.3688.36.camel@bigi> <1271245986.3943.55.camel@bigi> <1271268242.16881.1719.camel@edumazet-laptop> <1271271222.4567.51.camel@bigi> <20100414124426.6aee95c3@nehalam> <1271276568.4567.59.camel@bigi> <1271276855.16881.1756.camel@edumazet-laptop> <1271278661.16881.1761.camel@edumazet-laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Tom Herbert , hadi@cyberus.ca, Stephen Hemminger , netdev@vger.kernel.org, robert@herjulf.net, David Miller , Andi Kleen To: Eric Dumazet Return-path: Received: from mail-gy0-f174.google.com ([209.85.160.174]:57537 "EHLO mail-gy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757035Ab0DNWvu convert rfc822-to-8bit (ORCPT ); Wed, 14 Apr 2010 18:51:50 -0400 Received: by gyg13 with SMTP id 13so333359gyg.19 for ; Wed, 14 Apr 2010 15:51:49 -0700 (PDT) In-Reply-To: <1271278661.16881.1761.camel@edumazet-laptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Apr 15, 2010 at 4:57 AM, Eric Dumazet = wrote: > > RPS can be tuned (Changli wants a finer tuning...), it would be > intereting to tune multiqueue devices too. I dont know if its possibl= e > right now. > > On my Nehalem machine (16 logical cpus), its NetXtreme II BCM57711E > 10Gigabit has 16 queues. It might be good to use less queues accordin= g > to your results on some workloads, and eventually use RPS on a second > layering. My idear is: run a daemon in userland to monitor the softnet statistics, and tun the RPS setting if necessary. It seems that the current softnet statistics data isn't correct. Long time ago, I did a test, and the conclution was call_function_single IPI was more expensive than resched IPI, so I moved to kernel thread from softirq for packet processing. I'll redo the test later. --=20 Regards=EF=BC=8C Changli Gao(xiaosuo@gmail.com)