From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752257AbXDQHd2 (ORCPT ); Tue, 17 Apr 2007 03:33:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752259AbXDQHd2 (ORCPT ); Tue, 17 Apr 2007 03:33:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:52356 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752237AbXDQHd1 (ORCPT ); Tue, 17 Apr 2007 03:33:27 -0400 Date: Tue, 17 Apr 2007 09:33:12 +0200 From: Nick Piggin To: Davide Libenzi Cc: William Lee Irwin III , Peter Williams , Mike Galbraith , Con Kolivas , Ingo Molnar , ck list , Bill Huey , Linux Kernel Mailing List , Linus Torvalds , Andrew Morton , Arjan van de Ven , Thomas Gleixner Subject: Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS] Message-ID: <20070417073312.GA20026@wotan.suse.de> References: <46240F98.3020800@bigpond.net.au> <1176776941.6222.21.camel@Homer.simpson.net> <20070417034050.GD25513@wotan.suse.de> <46244A52.4000403@bigpond.net.au> <20070417042954.GG25513@wotan.suse.de> <20070417060955.GO8915@holomorphy.com> <20070417061503.GC1057@wotan.suse.de> <20070417070949.GR8915@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 17, 2007 at 12:27:28AM -0700, Davide Libenzi wrote: > On Tue, 17 Apr 2007, William Lee Irwin III wrote: > > > On Mon, Apr 16, 2007 at 11:50:03PM -0700, Davide Libenzi wrote: > > > I would suggest to thoroughly test all your alternatives before deciding. > > > Some code and design may look very good and small at the beginning, but > > > when you start patching it to cover all the dark spots, you effectively > > > end up with another thing (in both design and code footprint). > > > About O(1), I never thought it was a must (besides a good marketing > > > material), and O(log(N)) *may* be just fine (to be verified, of course). > > > > The trouble with thorough testing right now is that no one agrees on > > what the tests should be and a number of the testcases are not in great > > shape. An agreed-upon set of testcases for basic correctness should be > > devised and the implementations of those testcases need to be > > maintainable code and the tests set up for automated testing and > > changing their parameters without recompiling via command-line options. > > > > Once there's a standard regression test suite for correctness, one > > needs to be devised for performance, including interactive performance. > > The primary difficulty I see along these lines is finding a way to > > automate tests of graphics and input device response performance. Others, > > like how deterministically priorities are respected over progressively > > smaller time intervals and noninteractive workload performance are > > nowhere near as difficult to arrange and in many cases already exist. > > Just reuse SDET, AIM7/AIM9, OAST, contest, interbench, et al. > > What I meant was, that the rules (requirements and associated test cases) > for this new Scheduler Amazing Race should be set forward, and not kept a > moving target to fit&follow one or the other implementation. Exactly. Well I don't mind if it is a moving target as such, just as long as the decisions are rational (no "blah is more important because I say so").