Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756213Ab3C0BXi (ORCPT ); Tue, 26 Mar 2013 21:23:38 -0400 Received: from e35.co.us.ibm.com ([32.97.110.153]:60704 "EHLO e35.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752172Ab3C0BXh (ORCPT ); Tue, 26 Mar 2013 21:23:37 -0400 Date: Tue, 26 Mar 2013 18:23:24 -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: <20130327012323.GX4379@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> <20130325170257.GA24554@linux.vnet.ibm.com> <20130325171844.GA3637@linux.vnet.ibm.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: 13032701-4834-0000-0000-0000052632CB Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3047 Lines: 67 On Wed, Mar 27, 2013 at 12:48:20AM +0100, Frederic Weisbecker wrote: > 2013/3/25 Paul E. McKenney : > > On Mon, Mar 25, 2013 at 06:12:12PM +0100, Frederic Weisbecker wrote: > >> 2013/3/25 Paul E. McKenney : > >> > 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? > >> > >> No that looks right. Now I wonder if I should select > >> CONFIG_RCU_NOCB_CPU_ALL at the same time. Probably. > > > > Sounds like a good initial position to me. If it somehow causes problems, > > we can always change it later. > > Ah "rcu: Provide compile-time control for no-CBs CPUs" is not yet in > -tip so I can't do that yet. Ok for now I'm going to add > CONFIG_NO_HZ_EXTENDED_ALL and will select the matching RCU config once > it's visible upstream. Good point... I expect to be sending a pull request in a day or two. Thanx, Paul -- 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/