Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932643AbWLMJyJ (ORCPT ); Wed, 13 Dec 2006 04:54:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932644AbWLMJyJ (ORCPT ); Wed, 13 Dec 2006 04:54:09 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:39652 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932643AbWLMJyH (ORCPT ); Wed, 13 Dec 2006 04:54:07 -0500 Date: Wed, 13 Dec 2006 10:51:33 +0100 From: Ingo Molnar To: john stultz Cc: Roman Zippel , Thomas Gleixner , Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: [RFC] HZ free ntp Message-ID: <20061213095132.GA22280@elte.hu> References: <20061204204024.2401148d.akpm@osdl.org> <20061205203013.7073cb38.akpm@osdl.org> <1165393929.24604.222.camel@localhost.localdomain> <20061206131155.GA8558@elte.hu> <1165956021.20229.10.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1165956021.20229.10.camel@localhost> User-Agent: Mutt/1.4.2.2i X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -5.9 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-5.9 required=5.9 tests=ALL_TRUSTED,BAYES_00 autolearn=no SpamAssassin version=3.0.3 -3.3 ALL_TRUSTED Did not pass through any untrusted hosts -2.6 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1436 Lines: 33 * john stultz wrote: > On Wed, 2006-12-06 at 15:33 +0100, Roman Zippel wrote: > > On Wed, 6 Dec 2006, Ingo Molnar wrote: > > > i disagree with you and it's pretty low-impact anyway. There's still > > > quite many HZ/tick assumptions all around the time code (NTP being one > > > example), we'll deal with those via other patches. > > > > Why do you pick on the NTP code? That's actually one of the places where > > assumptions about HZ are largely gone. NTP state is updated incrementally > > and this won't change, but the update frequency can now be easily > > disconnected from HZ. > > Hey Roman, > Here's my rough first attempt at doing so. I'd not call it easy, but > maybe you have some suggestions for a simpler way? > > Basically INTERVAL_LENGTH_NSEC defines the NTP interval length that > the time code will use to accumulate with. In this patch I've pushed > it out to a full second, but it could be set via config > (NSEC_PER_SEC/HZ for regular systems, something larger for systems > using dynticks). cool! I'll give this one a go in -rt, combined with the exponential second-overflow patch. (that one is now algorithmically safe, right?) Ingo - 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/