From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030619AbXDUNlY (ORCPT ); Sat, 21 Apr 2007 09:41:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031030AbXDUNlY (ORCPT ); Sat, 21 Apr 2007 09:41:24 -0400 Received: from mail.tmr.com ([64.65.253.246]:44242 "EHLO gaimboi.tmr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030619AbXDUNlY (ORCPT ); Sat, 21 Apr 2007 09:41:24 -0400 Message-ID: <462A144B.9000400@tmr.com> Date: Sat, 21 Apr 2007 09:40:27 -0400 From: Bill Davidsen User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.8) Gecko/20061105 SeaMonkey/1.0.6 MIME-Version: 1.0 To: Linus Torvalds CC: Matt Mackall , Nick Piggin , William Lee Irwin III , Peter Williams , Mike Galbraith , Con Kolivas , Ingo Molnar , ck list , Bill Huey , linux-kernel@vger.kernel.org, Andrew Morton , Arjan van de Ven , Thomas Gleixner Subject: Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS] References: <46244A52.4000403@bigpond.net.au> <20070417042954.GG25513@wotan.suse.de> <20070417060955.GO8915@holomorphy.com> <20070417061503.GC1057@wotan.suse.de> <20070417062621.GL2986@holomorphy.com> <20070417070155.GF1057@wotan.suse.de> <20070417213954.GE11166@waste.org> <20070418031511.GA18452@wotan.suse.de> <20070418043831.GR11115@waste.org> <20070418050024.GF18452@wotan.suse.de> <20070418055525.GS11115@waste.org> In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds wrote: > > On Wed, 18 Apr 2007, Matt Mackall wrote: >> Why is X special? Because it does work on behalf of other processes? >> Lots of things do this. Perhaps a scheduler should focus entirely on >> the implicit and directed wakeup matrix and optimizing that >> instead[1]. > > I 100% agree - the perfect scheduler would indeed take into account where > the wakeups come from, and try to "weigh" processes that help other > processes make progress more. That would naturally give server processes > more CPU power, because they help others > > I don't believe for a second that "fairness" means "give everybody the > same amount of CPU". That's a totally illogical measure of fairness. All > processes are _not_ created equal. > > That said, even trying to do "fairness by effective user ID" would > probably already do a lot. In a desktop environment, X would get as much > CPU time as the user processes, simply because it's in a different > protection domain (and that's really what "effective user ID" means: it's > not about "users", it's really about "protection domains"). > > And "fairness by euid" is probably a hell of a lot easier to do than > trying to figure out the wakeup matrix. > You probably want to consider the controlling terminal as well... do you want to have people starting 'at' jobs competing on equal footing with people typing at a terminal? I'm not offering an answer, just raising the question. And for some database applications, everyone in a group may connect with the same login-id, then do sub authorization to the database application. euid may be an issue there as well. -- Bill Davidsen "We have more to fear from the bungling of the incompetent than from the machinations of the wicked." - from Slashdot