From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753699AbXDRSOc (ORCPT ); Wed, 18 Apr 2007 14:14:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753674AbXDRSOc (ORCPT ); Wed, 18 Apr 2007 14:14:32 -0400 Received: from squawk.glines.org ([72.36.206.66]:51721 "EHLO squawk.glines.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753371AbXDRSOc (ORCPT ); Wed, 18 Apr 2007 14:14:32 -0400 X-Greylist: delayed 1572 seconds by postgrey-1.27 at vger.kernel.org; Wed, 18 Apr 2007 14:14:31 EDT Date: Wed, 18 Apr 2007 10:48:14 -0700 From: Mark Glines To: Linus Torvalds Cc: Matt Mackall , Nick Piggin , Bill Huey , Mike Galbraith , Peter Williams , William Lee Irwin III , linux-kernel@vger.kernel.org, ck list , Thomas Gleixner , Andrew Morton , Arjan van de Ven Subject: Re: [ck] Re: [Announce] [patch] Modular Scheduler Core and Completely Fair Scheduler [CFS] Message-ID: <20070418104814.2c6fdda7@chirp> In-Reply-To: References: <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> <20070418152355.GU11115@waste.org> Organization: Glines.org X-Mailer: Claws Mail 2.8.0 (GTK+ 2.10.11; i686-pc-linux-gnu) X-Useless-Header: yay! Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, 18 Apr 2007 10:22:59 -0700 (PDT) Linus Torvalds wrote: > So if you have 2 users on a machine running CPU hogs, you should > *first* try to be fair among users. If one user then runs 5 programs, > and the other one runs just 1, then the *one* program should get 50% > of the CPU time (the users fair share), and the five programs should > get 10% of CPU time each. And if one of them uses two threads, each > thread should get 5%. This sounds great, to me. One minor question: is it even possible to be completely fair on SMP? For instance, if you have a 2-way SMP box running 3 applications, one of which has 2 threads, will the threaded app have an advantage here? (The current system seems to try to keep each thread on a specific CPU, to reduce cache thrashing, which means threads and processes alike each get 50% of the CPU.) Mark