From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753423Ab3GORjF (ORCPT ); Mon, 15 Jul 2013 13:39:05 -0400 Received: from mx1.redhat.com ([209.132.183.28]:58381 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752283Ab3GORjD (ORCPT ); Mon, 15 Jul 2013 13:39:03 -0400 Date: Mon, 15 Jul 2013 13:38:48 -0400 From: Dave Jones To: Frederic Weisbecker , Linux Kernel Mailing List , rostedt@goodmis.org Subject: Re: nohz: Warn if the machine can not perform nohz_full Message-ID: <20130715173848.GA1066@redhat.com> Mail-Followup-To: Dave Jones , Frederic Weisbecker , Linux Kernel Mailing List , rostedt@goodmis.org References: <20130715170859.GA25570@redhat.com> <20130715171800.GD6442@somewhere> <20130715172423.GA27745@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20130715172423.GA27745@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 15, 2013 at 01:24:23PM -0400, Dave Jones wrote: > On Mon, Jul 15, 2013 at 07:18:02PM +0200, Frederic Weisbecker wrote: > > > > So I guess you guys never want this to be enabled on distro kernels ? > > > If that's the case, can you add something to that effect in Kconfig ? > > > > I believe we want it to be enabled on distros in the long term. But right now it would > > be a bad idea until the off case (nohz_full= parameter empty) is carefully optimized. > > I'm currently working on that. > > > > Now for the unstable tsc, which is what it's about on the above code block, we need > > the tick to be there to leverage the sched clock madness. May be there could be some > > other solution that could work along full dynticks but for now we chose the easy path. > > > > Are broken TSCs that common? > > I just hit one apparently. http://paste.fedoraproject.org/25421/73907845/raw/ > That's a fairly recent Atom board, so I suspect it's not uncommon on that platform. And here's a Core Duo from circa 2008. http://paste.fedoraproject.org/25429/13739098/raw Two for two so far. I get the feeling you guys are going to get a ton of these reports. Dave