From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265792AbUHGBpN (ORCPT ); Fri, 6 Aug 2004 21:45:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267900AbUHGBpN (ORCPT ); Fri, 6 Aug 2004 21:45:13 -0400 Received: from gizmo09ps.bigpond.com ([144.140.71.19]:27280 "HELO gizmo09ps.bigpond.com") by vger.kernel.org with SMTP id S265792AbUHGBpE (ORCPT ); Fri, 6 Aug 2004 21:45:04 -0400 Message-ID: <41143419.6000407@bigpond.net.au> Date: Sat, 07 Aug 2004 11:44:57 +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: Linux Kernel Mailing List CC: Michal Kaczmarski Subject: [PATCH] V-3.0 Single Priority Array O(1) CPU Scheduler Evaluation 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 Version 3.1 of the various single priority array scheduler patches for 2.6.7, 2.6.8-rc2 and 2.6.8-rc3 kernels are now available for evaluation. This is a bug fix release to fix a problem caused by sched_clock() not being monotonic. This meant that when measuring small time intervals by taking the difference between successive calls to sched_clock() there is a possibility of obtaining a negative value (or, as unsigned long longs are being used, a very big one). One unfortunate consequence of this is that adding to non zero intervals together could lead to a zero result and possible divide by zero problems. 1. [ZAPHOD] Runtime selectable choice between a priority based or entitlement based O(1) scheduler with active/expired arrays replaced by a single array and an O(1) promotion mechanism plus scheduling statistics with new interactive bonus mechanism and throughput bonus mechanism: 2.6.7 2.6.8-rc2 2.6.8-rc3 2. Slightly modified version of Con Kolivas's staircase O(1) scheduler with active/expired arrays replaced by a single array and an O(1) promotion mechanism: 2.6.7 2.6.8-rc2 2.6.8-rc3 3. [HYDRA] Runtime selection between staircase, priority based and entitlement based O(1) schedulers: 2.6.7 2.6.8-rc2 2.6.8-rc3 Other schedulers are also available from So as not to interfere with the staircase scheduler's evaluation I do not propose to release patches for rc3-mm kernels unless requested. I'm in the process of simplifying my schedulers (I got carried away with the theory) in order to reduce their overhead and hope to release a new slimmer version early next week. Also on the "to do" list are CPU rate caps. Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce