From mboxrd@z Thu Jan 1 00:00:00 1970 From: john stultz Date: Mon, 16 May 2005 19:50:55 +0000 Subject: Re: IA64 implementation of timesource for new time of day subsystem Message-Id: <1116273055.13867.5.camel@cog.beaverton.ibm.com> List-Id: 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> <1116264858.26990.39.camel@cog.beaverton.ibm.com> <1116269136.26990.67.camel@cog.beaverton.ibm.com> <17032.62615.750699.18847@napali.hpl.hp.com> In-Reply-To: <17032.62615.750699.18847@napali.hpl.hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Mosberger Cc: Christoph Lameter , lkml , Tim Schmielau , George Anzinger , albert@users.sourceforge.net, Ulrich Windl , Dominik Brodowski , 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 On Mon, 2005-05-16 at 12:29 -0700, David Mosberger wrote: > >>>>> On Mon, 16 May 2005 12:24:08 -0700 (PDT), Christoph Lameter said: > > Christoph> Other IA64 vendors will see that their timer performance > Christoph> drops significantly after the new timer subsystem is > Christoph> in. IBM no longer has IA64 systems that rely on ITC? > > Would that somehow make it ok to break existing and working code? No. I intend to preserve the existing functionality (and performance) of the current code. The current timeofday core should allow for this (as I described in my last mail), so really its just a matter of either me or someone else getting around to properly converting that arch with the help of the arch maintainer. Until the arch is really ready to use the new timeofday core, no changes are necessary. Christoph's patch is just a step in the right direction. That is, a much appreciated step, I haven't yet had the time to implement or test the ia64 timesources. Any notable regressions introduced will need to be resolved before the arch specific patch is finally submitted. What I'm trying to shake out, with Christoph's help, is any major limitations in the core timeofday code that would keep an arch from being able to use it. I feel Christoph's concerns have been addressed, but please let me know if you disagree. thanks -john