From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933850AbZHGUaE (ORCPT ); Fri, 7 Aug 2009 16:30:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933754AbZHGUaD (ORCPT ); Fri, 7 Aug 2009 16:30:03 -0400 Received: from e2.ny.us.ibm.com ([32.97.182.142]:39329 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932721AbZHGUaA (ORCPT ); Fri, 7 Aug 2009 16:30:00 -0400 Subject: Re: [GIT pull] timers fixes for 2.6.31 From: john stultz To: Martin Schwidefsky Cc: Ingo Molnar , Linus Torvalds , Thomas Gleixner , Andrew Morton , LKML In-Reply-To: <20090807101847.2ee08c76@skybase> References: <20090731123711.GA5421@elte.hu> <1f1b08da0908061536o57cebeb6r2f522cb3c5419e1@mail.gmail.com> <20090807101847.2ee08c76@skybase> Content-Type: text/plain Date: Fri, 07 Aug 2009 13:28:55 -0700 Message-Id: <1249676935.7185.4.camel@localhost.localdomain> Mime-Version: 1.0 X-Mailer: Evolution 2.24.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2009-08-07 at 10:18 +0200, Martin Schwidefsky wrote: > On Thu, 6 Aug 2009 15:36:36 -0700 > john stultz wrote: > > > Splitting this up has been on my list for awhile, but I've never > > gotten to it. However, Martin Schwidefsky has been doing a great job > > with his latest patches cleaning up some of uglier parts of the > > timekeeping/clocksource interactions. There is still lots of changes > > I'd like to see, but they will take time as we still haven't gotten > > all the arches over to GENERIC_TIME, so some cruft has to stick > > around. But Martin's patches are a great big step towards it and > > hopefully his patches will be ready for .32. > > The question what we do with the mult_orig on clocksource > enable/disable is one of the remaining open issues with my patch set. > With the NTP adjusted multiplicator in the struct timekeeper we don't > have a convenient place to keep the NTP adjusted multiplier while a > clocksource is disabled. My initial thought was: why do we store the > old multiplier at all? Its not that the clocksource changes all the > time and NTP will catch up again if it is changed. Just start from > scratch with the initial multiplicator. Indeed, we don't need to store the adjusted multiplier while a clocksource is not in use. We just have to make sure every time it is used, we start with the same original multiplier, so we have a constant base from which the NTP freq adjustment can be made upon. I think you're approach (keeping the clocksource mult untouched, and keeping the adjusted mult in the timekeeper structure)is fine. thanks -john