Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932144AbWEGM4V (ORCPT ); Sun, 7 May 2006 08:56:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932145AbWEGM4V (ORCPT ); Sun, 7 May 2006 08:56:21 -0400 Received: from smtp110.mail.mud.yahoo.com ([209.191.85.220]:19790 "HELO smtp110.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S932144AbWEGM4V (ORCPT ); Sun, 7 May 2006 08:56:21 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=clxqJlU2HUXEvmPkQrmCHbvYc3mjCWRoOYMQgNcqfl0XFW0LGJAEHxJXdYB/d9uDTJ2N4cnc5LEVDy5vAT27kJadkV35MTwxVKqvk5Ae2ngqSGYcckpi1QgQBmH3PDqMq9X/Vcg/z+GQb4c1L3jT3ptReJuuj17b38SVKDx6LpY= ; Message-ID: <445DEE70.10807@yahoo.com.au> Date: Sun, 07 May 2006 22:56:16 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Russell King CC: Mike Galbraith , Andi Kleen , Christopher Friesen , linux-kernel@vger.kernel.org Subject: Re: sched_clock() uses are broken References: <20060502132953.GA30146@flint.arm.linux.org.uk> <44578EB9.8050402@nortel.com> <200605021859.18948.ak@suse.de> <445791D3.9060306@yahoo.com.au> <1146640155.7526.27.camel@homer> <445DE925.9010006@yahoo.com.au> <20060507124307.GA20443@flint.arm.linux.org.uk> In-Reply-To: <20060507124307.GA20443@flint.arm.linux.org.uk> 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 Content-Length: 1217 Lines: 29 Russell King wrote: > On Sun, May 07, 2006 at 10:33:41PM +1000, Nick Piggin wrote: > >>No, sched_clock is fine to be used in CPU scheduling choices, which are >>heuristic anyway (although strictly speaking, even using it for timeslicing >>within a single CPU could cause slight unfairness). > > > Except maybe if it rolls over every 178 seconds, which is my original > point. Maybe someone could comment on my initial patch sent 5 days > ago? Well yes that's true. I meant the "sched_clock interface as defined". Now there are obviously issues (including the one you raised) that makes the sched_clock interface unreasonable to implement. I stand by my first reply to your comment WRT the API. Seems like most of the rest of the debate was unrelated or concerning implementation details. kernel/sched.c patches implementing the new API would get an ack from me. -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/