From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030225AbVHZTeD (ORCPT ); Fri, 26 Aug 2005 15:34:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1030216AbVHZTeB (ORCPT ); Fri, 26 Aug 2005 15:34:01 -0400 Received: from omx1-ext.sgi.com ([192.48.179.11]:22744 "EHLO omx1.americas.sgi.com") by vger.kernel.org with ESMTP id S1030225AbVHZTeA (ORCPT ); Fri, 26 Aug 2005 15:34:00 -0400 Date: Fri, 26 Aug 2005 12:33:23 -0700 (PDT) From: Christoph Lameter To: Alex Williamson cc: george@mvista.com, john stultz , linux-kernel@vger.kernel.org Subject: Re: Need better is_better_time_interpolator() algorithm In-Reply-To: <1125084417.5182.58.camel@tdi> Message-ID: References: <1124988269.5331.49.camel@tdi> <1124991406.20820.188.camel@cog.beaverton.ibm.com> <1124995405.5331.90.camel@tdi> <1125073089.5182.30.camel@tdi> <430F6A7E.203@mvista.com> <1125084417.5182.58.camel@tdi> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 26 Aug 2005, Alex Williamson wrote: > Would we ever want to favor a frequency shifting timer over anything > else in the system? If it was noticeable perhaps we'd just need a > callback to re-evaluate the frequency and rescan for the best timer. If > it happens without notice, a flag that statically assigns it the lowest > priority will due. Or maybe if the driver factored the frequency > shifting into the drift it would make the timer undesirable without > resorting to flags. Thanks, Timers are usually constant. AFAIK Frequency shifts only occur through power management. In that case we usually have some notifiers running before the change. These notifiers need to switch to a different time source if the timer frequency will be shifting or the timer will become unavailable.