Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932592AbVLBA6M (ORCPT ); Thu, 1 Dec 2005 19:58:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932593AbVLBA6M (ORCPT ); Thu, 1 Dec 2005 19:58:12 -0500 Received: from e34.co.us.ibm.com ([32.97.110.152]:8636 "EHLO e34.co.us.ibm.com") by vger.kernel.org with ESMTP id S932592AbVLBA6K (ORCPT ); Thu, 1 Dec 2005 19:58:10 -0500 Subject: Re: [patch 00/43] ktimer reworked From: john stultz To: Kyle Moffett Cc: Roman Zippel , Steven Rostedt , george@mvista.com, mingo@elte.hu, akpm@osdl.org, linux-kernel@vger.kernel.org, Thomas Gleixner , ray-gmail@madrabbit.org, Russell King In-Reply-To: <91D50CB6-A9B0-4501-AAD2-7D80948E7367@mac.com> References: <1133395019.32542.443.camel@tglx.tec.linutronix.de> <23CA09D3-4C11-4A4B-A5C6-3C38FA9C203D@mac.com> <2c0942db0512010822x1ae20622obf224ce9728e83f8@mail.gmail.com> <20051201165144.GC31551@flint.arm.linux.org.uk> <1133464097.7130.15.camel@localhost.localdomain> <91D50CB6-A9B0-4501-AAD2-7D80948E7367@mac.com> Content-Type: text/plain Date: Thu, 01 Dec 2005 16:58:06 -0800 Message-Id: <1133485086.7605.9.camel@cog.beaverton.ibm.com> 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: 1178 Lines: 29 On Thu, 2005-12-01 at 19:41 -0500, Kyle Moffett wrote: > On Dec 01, 2005, at 19:29, Roman Zippel wrote: > > Hi, > > > >> As for portablility, I believe John Stultz has some nice plugins > >> coming to what timer source you want to use, so if there's a > >> better way to get a time, these should make things easy to add. > > > > These plugins can do no magic, if the hardware timer is slow, the > > whole thing gets slow. > > The point is that you could switch both the timer and timeout > implementations to jiffies if you wanted to, at the expense of the > accuracy that a lot of people care about. While I'm not challenging the possibility of doing this, my timekeeping work does not provide quite this level of flexibility you imply. Indeed one could use jiffies as a clocksource, limiting all time users (including ktimers) to jiffies resolution, but I would consider that to be abusing the interface. 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/