Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932458AbWBOTar (ORCPT ); Wed, 15 Feb 2006 14:30:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932460AbWBOTaq (ORCPT ); Wed, 15 Feb 2006 14:30:46 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:50118 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S932458AbWBOTaq (ORCPT ); Wed, 15 Feb 2006 14:30:46 -0500 Subject: Re: [patch] hrtimer: round up relative start time on low-res arches From: john stultz To: Roman Zippel Cc: Ingo Molnar , Andrew Morton , Thomas Gleixner , linux-kernel@vger.kernel.org In-Reply-To: References: <1139827927.4932.17.camel@localhost.localdomain> <20060214074151.GA29426@elte.hu> <20060214122031.GA30983@elte.hu> <20060215091959.GB1376@elte.hu> Content-Type: text/plain Date: Wed, 15 Feb 2006 12:43:54 -0800 Message-Id: <1140036234.27720.8.camel@leatherman> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1668 Lines: 37 On Wed, 2006-02-15 at 13:26 +0100, Roman Zippel wrote: > Hi, > > On Wed, 15 Feb 2006, Ingo Molnar wrote: > > > yeah, agreed. That will be accurately fixed via GTOD's per-hwclock > > resolution values. It will have another advantage as well: e.g. the > > whole of m68k wont be penalized via CONFIG_TIME_LOW_RES for having a > > handful of sub-arches (Apollo, Sun3x, Q40) that dont have a higher > > resolution timer - every clock can define its own resolution. You could > > help that effort by porting m68k to use GTOD ;-) > > I'll do that as soon as the perfomance is equal or better than what we > have right now and expensive 64bit math in the fast path, where it's > provably a waste, is not exactly encouraging. I already provided all the > math and code to keep it cheap and (relatively) simple, but I don't have > the time to work constantly on it, so if you'd help to integrate it into > John's work it would go a lot faster. Hey Roman, I just wanted to make sure you know I'm not ignoring your suggestions. I do appreciate the time you have spent, and I have been continuing to work on implementing your idea. Unfortunately the code is not trivial and very much hurts the readability. I expect thats a sacrifice that will be necessary, but hopefully after some review cycles we'll be able to come to something we both like. I'm hoping to have a first pass patch I can mail this week. thanks -john - 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/