Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S269624AbUICKIs (ORCPT ); Fri, 3 Sep 2004 06:08:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S269658AbUICKHb (ORCPT ); Fri, 3 Sep 2004 06:07:31 -0400 Received: from natnoddy.rzone.de ([81.169.145.166]:35579 "EHLO natnoddy.rzone.de") by vger.kernel.org with ESMTP id S269624AbUICKGY (ORCPT ); Fri, 3 Sep 2004 06:06:24 -0400 Date: Fri, 3 Sep 2004 11:54:35 +0200 From: Dominik Brodowski To: john stultz Cc: lkml , tim@physik3.uni-rostock.de, george@mvista.com, albert@users.sourceforge.net, Ulrich.Windl@rz.uni-regensburg.de, clameter@sgi.com, len.brown@intel.com, davidm@hpl.hp.com, ak@suse.de, paulus@samba.org, schwidefsky@de.ibm.com, jimix@us.ibm.com, keith maanthey , greg kh , Patricia Gaughen , Chris McDermott Subject: Re: [RFC] New Time of day proposal (updated 9/2/04) Message-ID: <20040903095435.GA11572@dominikbrodowski.de> Mail-Followup-To: Dominik Brodowski , john stultz , lkml , tim@physik3.uni-rostock.de, george@mvista.com, albert@users.sourceforge.net, Ulrich.Windl@rz.uni-regensburg.de, clameter@sgi.com, len.brown@intel.com, davidm@hpl.hp.com, ak@suse.de, paulus@samba.org, schwidefsky@de.ibm.com, jimix@us.ibm.com, keith maanthey , greg kh , Patricia Gaughen , Chris McDermott References: <1094159238.14662.318.camel@cog.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1094159238.14662.318.camel@cog.beaverton.ibm.com> User-Agent: Mutt/1.5.6i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1378 Lines: 31 Hi John, Thanks for this exciting code. A few questions: - Where do you intend to put the "delay" code to? Generalize it as well? - cpufreq hooks to tsc.c and i386_tsc.c[*] can easily be added. For them to work _better_ than current code: can timeofday_hook() be called (with IRQs disabled) _anywhen_ from kernel context? [*] actually, only one of them needs the notifier, AFAICS... - what about keeping lower-priority timesources still "active" in some sort to a) enable loading _and_ unloading timsources (even modularizing them becoms possible which should make testing easier...), b) call them every couple of seconds to verify the currently used timesource is still sane (and if not, call cpufreq_delayed_get() for example or disable the timesource). This would mean that e.g. pmtmr and pit can be used to "verify" and "backup" tsc, or otherwise... The "clock=tsc" override would only affect the priority of the timesource then, making it so large that no other timesource can "preempt" it, but doesn't avoid making other timesources available for backup and verification purposes. Thanks, Dominik - 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/