From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751320AbVHWCD4 (ORCPT ); Mon, 22 Aug 2005 22:03:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751323AbVHWCDz (ORCPT ); Mon, 22 Aug 2005 22:03:55 -0400 Received: from omta04ps.mx.bigpond.com ([144.140.83.156]:21859 "EHLO omta04ps.mx.bigpond.com") by vger.kernel.org with ESMTP id S1751320AbVHWCDz (ORCPT ); Mon, 22 Aug 2005 22:03:55 -0400 Message-ID: <430A8408.4040101@bigpond.net.au> Date: Tue, 23 Aug 2005 12:03:52 +1000 From: Peter Williams User-Agent: Mozilla Thunderbird 1.0.6-1.1.fc4 (X11/20050720) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Linux Kernel Mailing List CC: Chris Han , Con Kolivas , William Lee Irwin III , Jake Moilanen Subject: [ANNOUNCE][RFC] PlugSched-6.0 for 2.6.12 and 2.6.13-rc6 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Authentication-Info: Submitted using SMTP AUTH PLAIN at omta04ps.mx.bigpond.com from [147.10.133.38] using ID pwil3058@bigpond.net.au at Tue, 23 Aug 2005 02:03:52 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This version contains the following changes: 1. upgrade the staircase scheduler to version 11.6, 2. major reorganization of the spa_no_frills and zaphod code to clean up the mechanism by which they share code. This includes the definition of a simple interface which can be used to extend spa_no_frills to create new schedulers relatively easily, and 3. a new scheduler, spa_ws, which is an extension of spa_no_frills intended for use on work stations. The spa_ws aspires to provide good interactive responsiveness and glitch free audio/video playing by giving tasks that are forking or waking from a sleep a "latency bonus". The latency bonus is composed of a small fixed bonus plus a component based on the tasks sleepiness. Certain tasks (e.g. those with a "nice" value greater than zero or tagged with the TASK_NONINTERACTIVE flag do not receive any bonus as it is assumed that latency is not an issue for these tasks). This scheduler tries to identify audio/video tasks based on the regularity of their wake intervals and their length (currently between 10 and 100 milliseconds) and if it does so gives them a bonus one greater than the maximum that could be attained for other tasks subject to their cpu usage rate being less than a specified minimum. The mechanisms involved are very simple in an attempt to not degrade the compute performance of the scheduler. A patch for 2.6.12 is available at: and for 2.6.13-rc6 at: Very Brief Documentation: You can select a default scheduler at kernel build time. If you wish to boot with a scheduler other than the default it can be selected at boot time by adding: cpusched= to the boot command line where is one of: ingosched, nicksched, staircase, spa_no_frills, spa_ws or zaphod. If you don't change the default when you build the kernel the default scheduler will be ingosched (which is the normal scheduler). The scheduler in force on a running system can be determined by the contents of: /proc/scheduler Control parameters for the scheduler can be read/set via files in: /sys/cpusched// Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce