From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267514AbUHDXp6 (ORCPT ); Wed, 4 Aug 2004 19:45:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267518AbUHDXpQ (ORCPT ); Wed, 4 Aug 2004 19:45:16 -0400 Received: from gizmo03ps.bigpond.com ([144.140.71.13]:47007 "HELO gizmo03ps.bigpond.com") by vger.kernel.org with SMTP id S267514AbUHDXoK (ORCPT ); Wed, 4 Aug 2004 19:44:10 -0400 Message-ID: <411174C6.2020109@bigpond.net.au> Date: Thu, 05 Aug 2004 09:44:06 +1000 From: Peter Williams User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030624 Netscape/7.1 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Andrew Morton CC: "Martin J. Bligh" , kernel@kolivas.org, linux-kernel@vger.kernel.org, Ingo Molnar Subject: Re: 2.6.8-rc2-mm2 performance improvements (scheduler?) References: <6560000.1091632215@[10.10.2.4]> <7480000.1091632378@[10.10.2.4]> <20040804122414.4f8649df.akpm@osdl.org> In-Reply-To: <20040804122414.4f8649df.akpm@osdl.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > "Martin J. Bligh" wrote: > >>SDET 8 (see disclaimer) >> Throughput Std. Dev >> 2.6.7 100.0% 0.2% >> 2.6.8-rc2 100.2% 1.0% >> 2.6.8-rc2-mm2 117.4% 0.9% >> >> SDET 16 (see disclaimer) >> Throughput Std. Dev >> 2.6.7 100.0% 0.3% >> 2.6.8-rc2 99.5% 0.3% >> 2.6.8-rc2-mm2 118.5% 0.6% > > > hum, interesting. Can Con's changes affect the inter-node and inter-cpu > balancing decisions, or is this all due to caching effects, reduced context > switching etc? One candidate for the cause of this improvement is the replacement of the active/expired array mechanism with a single array. I believe that one of the short comings of the active/expired array mechanism is that it can lead to excessive queuing (possibly even starvation) of tasks that aren't considered "interactive". > > I don't expect we'll be merging a new CPU scheduler into mainline any time > soon, but we should work to understand where this improvement came from, > and see if we can get the mainline scheduler to catch up. Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce