Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758264AbYHZQRH (ORCPT ); Tue, 26 Aug 2008 12:17:07 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753751AbYHZQQz (ORCPT ); Tue, 26 Aug 2008 12:16:55 -0400 Received: from one.firstfloor.org ([213.235.205.2]:51284 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753661AbYHZQQy (ORCPT ); Tue, 26 Aug 2008 12:16:54 -0400 To: "Maciej W. Rozycki" Cc: Avi Kivity , Alan Cox , Pavel Machek , Ingo Molnar , "Eric W. Biederman" , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [PATCH] x86: default to reboot via ACPI From: Andi Kleen References: <1219659087-17536-1-git-send-email-avi@qumranet.com> <20080826095032.GA309@elf.ucw.cz> <48B3D579.40502@qumranet.com> <20080826113317.520cbab1@lxorguk.ukuu.org.uk> <48B3F3A9.8030709@qumranet.com> Date: Tue, 26 Aug 2008 18:16:42 +0200 In-Reply-To: (Maciej W. Rozycki's message of "Tue, 26 Aug 2008 14:24:20 +0100 (BST)") Message-ID: <87fxorsqdx.fsf@basil.nowhere.org> User-Agent: Gnus/5.1008 (Gnus v5.10.8) Emacs/21.3 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1545 Lines: 34 "Maciej W. Rozycki" writes: > On Tue, 26 Aug 2008, Avi Kivity wrote: > >> Most machines are recent machines. > > This is a bold statement I would say. Any numbers to back it up? You can do the math. Reasonable assumptions are ~10% growth rate in year-by-year units shipment (that's conservative, usually it is higher) and that most systems are only used for 4-5 years (on commercial servers it's typically 4 years, on privately used systems perhaps a bit more, laptops certainly less because they tend to break earlier). That is the average, of course there are systems which are used much longer (or much shorter), but I would expect them to be the minority. Also laptops are growing more and more compared to desktops (iirc the cross over of more laptops than desktops shipping happened recently) and if the assumption that they break earlier is true (it is definitely in my experience) so it's likely that the average system live time shrinks in the future. With that it's reasonably easy to show that most systems are recent, if you define recent as 1-3 years. The "ACPI is the standard validated mode of operation" window is more like 7-8 years by now. With that I would expect the systems with very poor ACPI implementation to be a small minority by now. -Andi -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/