Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758710Ab3CYRDj (ORCPT ); Mon, 25 Mar 2013 13:03:39 -0400 Received: from e37.co.us.ibm.com ([32.97.110.158]:32823 "EHLO e37.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758635Ab3CYRDi (ORCPT ); Mon, 25 Mar 2013 13:03:38 -0400 Date: Mon, 25 Mar 2013 10:02:57 -0700 From: "Paul E. McKenney" To: Frederic Weisbecker Cc: Ingo Molnar , LKML , Andrew Morton , Chris Metcalf , Christoph Lameter , Geoff Levand , Gilad Ben Yossef , Hakan Akkan , Kevin Hilman , Li Zhong , Namhyung Kim , Paul Gortmaker , Peter Zijlstra , Steven Rostedt , Thomas Gleixner Subject: Re: [GIT PULL] nohz: Full dynticks base interface Message-ID: <20130325170257.GA24554@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1363879460-21595-1-git-send-email-fweisbec@gmail.com> <20130324081701.GA13328@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13032517-7408-0000-0000-00000E28C9AB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2634 Lines: 67 On Sun, Mar 24, 2013 at 03:46:40PM +0100, Frederic Weisbecker wrote: > 2013/3/24 Ingo Molnar : > > > > * Frederic Weisbecker wrote: > > > >> Hi Ingo, > >> > >> This settles the initial ground to start a special full dynticks tree in -tip > >> that we can iterate incrementally to accelerate the development. > >> It is based on tip:sched/core. > >> > >> I tried to rearrange a bit the naming. We are probably not yet done with > >> that but I guess we can fix it along with the rest. > >> > >> Please pull from: > >> > >> git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git > >> full-dynticks-for-mingo > >> > >> Changes on these commits since they were part of 3.9-rc1-nohz1: > >> > >> * Force a timekeeping CPU over the full dynticks range > >> * Rename CONFIG_NO_HZ_FULL to CONFIG_NO_HZ_EXTENDED > >> * Following *_nohz_extended_* APIs renames > >> * Handle CPU hotplug for timekeeping > >> * Rename full_nohz= kernel parameter to nohz_extended= > > > > Note that boot parameters suck for pretty much any purpose but quirks - > > please also add a (default off!) Kconfig option to easily enable > > nohz_extended for all CPUs. > > > > That way I will be able to test it automatically via randconfig and such. > > Sure, I'm adding such an option. Hmmm... This would be an option to make all but one CPU an adaptive-ticks CPU, right? If so, this leads to the question of whether I should add a matching no-CBs Kconfig option. My guess is "no", because the existing CONFIG_RCU_NOCB_CPU_ALL should work just fine -- there would be a CPU that was not an adaptive-ticks CPU, but does have its RCU callbacks offloaded. Or am I missing something here? Thanx, Paul > > My next question/request after that would be: could we make sure that > > enabling this option does not break any applications or kernel > > functionality, ASAP? Once that is offered, it becomes pushable to v3.10 I > > think. > > So that's already the case. I'm careful that, as we iterate, the > changes aren't supposed to break something in the middle. the final > code that eventually shuts the tick down should be the last one in the > series: once we know it is safe to do so. > > > > > Meanwhile I have pulled your tree into tip:sched/nohz to stage and test > > it, in the hope that it becomes mergable quickly! :-) > > Thanks! :) > -- 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/