Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261579AbVEOJMK (ORCPT ); Sun, 15 May 2005 05:12:10 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261574AbVEOJMK (ORCPT ); Sun, 15 May 2005 05:12:10 -0400 Received: from anchor-post-35.mail.demon.net ([194.217.242.85]:57360 "EHLO anchor-post-35.mail.demon.net") by vger.kernel.org with ESMTP id S261570AbVEOJMC (ORCPT ); Sun, 15 May 2005 05:12:02 -0400 Message-ID: <428722E3.6040202@superbug.co.uk> Date: Sun, 15 May 2005 11:22:27 +0100 From: James Courtier-Dutton User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050416) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Christoph Lameter CC: john stultz , lkml , Tim Schmielau , George Anzinger , albert@users.sourceforge.net, Ulrich Windl , Dominik Brodowski , David Mosberger , Andi Kleen , paulus@samba.org, schwidefsky@de.ibm.com, keith maanthey , Chris McDermott , Max Asbock , mahuja@us.ibm.com, Nishanth Aravamudan , Darren Hart , "Darrick J. Wong" , Anton Blanchard , donf@us.ibm.com, mpm@selenic.com, benh@kernel.crashing.org, linux-ia64@vger.kernel.org Subject: Re: IA64 implementation of timesource for new time of day subsystem References: <1116029796.26454.2.camel@cog.beaverton.ibm.com> <1116029872.26454.4.camel@cog.beaverton.ibm.com> <1116029971.26454.7.camel@cog.beaverton.ibm.com> <1116030058.26454.10.camel@cog.beaverton.ibm.com> <1116030139.26454.13.camel@cog.beaverton.ibm.com> In-Reply-To: X-Enigmail-Version: 0.86.1.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1501 Lines: 40 Christoph Lameter wrote: > On Fri, 13 May 2005, john stultz wrote: > > >>I look forward to your comments and feedback. > > > Here is the implementation of the IA64 timesources for the new time of > day subsystem. > > This is quite straighforward. Thanks John. However, the ITC > interpolator can no longer use MMIO in SMP situations since there is no > provision for jitter compensation in the new time of day subsystem. I have > implemented that via a function now which will slow down clock access > for non SGI IA64 hardware significantly since it will not be able to use > the fastcall anymore. > > I am working on the fastcall but I would need a couple of changes > to the core code to make the following symbols non-static since they > will need to be accessed from the fast syscall handler: > > timesource > system_time > wall_time_offset > offset_base > Will this mean that Linux will have a monotonic time source? For media players we need a timesource that does not change under any circumstances. e.g. User changes the clock time, the monotonic time source should not change. The monotonic time source should just start at 0 at power on, and continually increase accurately over time. I.e. A very accurate "uptime" measurement. James - 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/