From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752172AbZDEQoc (ORCPT ); Sun, 5 Apr 2009 12:44:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751417AbZDEQoX (ORCPT ); Sun, 5 Apr 2009 12:44:23 -0400 Received: from e3.ny.us.ibm.com ([32.97.182.143]:58763 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751331AbZDEQoW (ORCPT ); Sun, 5 Apr 2009 12:44:22 -0400 Date: Sun, 5 Apr 2009 09:44:20 -0700 From: "Paul E. McKenney" To: Ingo Molnar Cc: Josh Boyer , linux-kernel@vger.kernel.org, akpm@linux-foundation.org, dipankar@in.ibm.com, niv@us.ibm.com, manfred@colorfullife.com, peterz@infradead.org, lethal@linux-sh.org, kernel@wantstofly.org, andi@firstfloor.org, kyle@mcmartin.ca, deller@gmx.de, davem@davemloft.net, ralf@linux-mips.org, jes@sgi.com, benh@kernel.crashing.org, paulus@samba.org, anton@samba.org Subject: Re: [PATCH -tip] Convert CONFIG_SMP=y powerpc defconfigs to TREE_RCU. Message-ID: <20090405164420.GI6893@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <3181463559098978317@unknownmsgid> <625fc13d0904040621g7b89cd2cq9681ce80635a65c4@mail.gmail.com> <20090404163149.GC6893@linux.vnet.ibm.com> <20090405101756.GA10490@elte.hu> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="MGYHOYXEY6WxJCY8" Content-Disposition: inline In-Reply-To: <20090405101756.GA10490@elte.hu> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --MGYHOYXEY6WxJCY8 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Sun, Apr 05, 2009 at 12:17:56PM +0200, Ingo Molnar wrote: > > * Paul E. McKenney wrote: > > > On Sat, Apr 04, 2009 at 09:21:58AM -0400, Josh Boyer wrote: > > > On Fri, Apr 3, 2009 at 8:27 PM, Paul E. McKenney > > > wrote: > > > > From: Paul E. McKenney > > > > > > Why would one want to do this? The commit log doesn't explain the > > > switch and why it's great. Mostly because the commit log doesn't > > > exist. (I'll stop channeling Andrew now) > > > > Indeed, I am sure that I will get the hang the relevant git > > commands at some point, but clearly am not yet there. > > > > The thing that is great about this patch is that it is a step on > > the way to retiring Classic RCU entirely. > > I'd suggest you dont do these dozens of defconfig updates at all - > arch maintainers can do this themselves, once the core kernel > default has been flipped. I am of course personally quite happy with this approach in the short term, as I would only need to worry about one patch. My one concern would be that we cannot retire Classic RCU until all the arch maintainers remove CONFIG_CLASSIC_RCU=y from their defconfig files. However, given that the attached script suffices, I am not too worried about that. Of course, none of this matters unless people agree that Tree RCU has proven reliable enough to be made default. So, any objections to such a change at this point? Thanx, Paul --MGYHOYXEY6WxJCY8 Content-Type: application/x-sh Content-Description: 2rcutree.sh Content-Disposition: attachment; filename="2rcutree.sh" Content-Transfer-Encoding: quoted-printable #!/bin/sh=0A#=0A# Switches the roles of CONFIG_CLASSIC_RCU and CONFIG_TREE_= RCU in the=0A# specified defconfig files. The old version of the file is r= etained=0A# with a .orig extension. The .orig is created even if no change= s were=0A# made, but git figures out the difference just fine.=0A#=0A# Peop= le wishing fully automatic operation can do the following:=0A#=0A# sh 2rcut= ree.sh `grep -l CONFIG_SMP=3Dy *defconfig`=0A#=0A# This program is free sof= tware; you can redistribute it and/or modify=0A# it under the terms of the = GNU General Public License as published by=0A# the Free Software Foundation= ; either version 2 of the License, or=0A# (at your option) any later versio= n.=0A#=0A# This program is distributed in the hope that it will be useful,= =0A# but WITHOUT ANY WARRANTY; without even the implied warranty of=0A# MER= CHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the=0A# GNU General = Public License for more details.=0A#=0A# You should have received a copy of= the GNU General Public License=0A# along with this program; if not, write = to the Free Software=0A# Foundation, Inc., 59 Temple Place - Suite 330, Bos= ton, MA 02111-1307, USA.=0A#=0A# Copyright (C) IBM Corporation, 2009=0A#=0A= # Authors: Paul E. McKenney =0A=0Afor i in "$@"= =0Ado=0A mv $i $i.orig=0A sed -e 's/CONFIG_CLASSIC_RCU\([=3D ]\)/CONFIG_@@@= \1/' \=0A -e 's/TREE_RCU\([=3D ]\)/CLASSIC_RCU\1/' \=0A -e 's/CONFI= G_@@@\([=3D ]\)/CONFIG_TREE_RCU\1/' \=0A < $i.orig > $i=0Adone=0A --MGYHOYXEY6WxJCY8--