Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760692AbYB2Mtr (ORCPT ); Fri, 29 Feb 2008 07:49:47 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759442AbYB2Mt1 (ORCPT ); Fri, 29 Feb 2008 07:49:27 -0500 Received: from scrub.xs4all.nl ([194.109.195.176]:33865 "EHLO scrub.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758649AbYB2MtZ (ORCPT ); Fri, 29 Feb 2008 07:49:25 -0500 Date: Fri, 29 Feb 2008 13:38:15 +0100 (CET) From: Roman Zippel X-X-Sender: roman@scrub.home To: "Paul E. McKenney" cc: ego@in.ibm.com, linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org, Ingo Molnar , Steven Rostedt , Dipankar Sarma , Ted Tso , dvhltc@us.ibm.com, Oleg Nesterov , Andrew Morton , bunk@kernel.org, Josh Triplett , Thomas Gleixner , Peter Zijlstra Subject: Re: [RFC PATCH 4/6] Preempt-RCU: Implementation In-Reply-To: <20080229045328.GA18687@linux.vnet.ibm.com> Message-ID: References: <20071213170348.GA25981@in.ibm.com> <20071213171658.GE25981@in.ibm.com> <200802290534.57040.zippel@linux-m68k.org> <20080229045328.GA18687@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1486 Lines: 45 Hi On Thu, 28 Feb 2008, Paul E. McKenney wrote: > > Why got this moved into init/Kconfig? > > Because there are some arches that don't have kernel/Kconfig.preempt, > its earlier home. Therefore, putting it into kernel/Kconfig.preempt > broke those arches' builds by supplying neither PREEMPT_RCU nor > CLASSIC_RCU. > > > Now it's somewhere in the root menu, not really belonging to anything. > > Do you have a suggested location? > > > Also why is this a choice? Are more RCU types planned? > > I don't expect additional drop-in replacements for RCU, though people > are certainly free to experiment if they wish. It is a choice because > this gives people a very clear idea of the two options and because > it makes the implementation a bit cleaner. I'd suggest to move PREEMPT_RCU back to Kconfig.preempt and if you really need the second symbol leave this behind (maybe with a comment): config CLASSIC_RCU def_bool !PREEMPT_RCU Once there are more options, we can still look for a better place... Also could you please add a proper dependency to RCU_TRACE on PREEMPT_RCU, so that this condition isn't needed anymore: ifeq ($(CONFIG_PREEMPT_RCU),y) obj-$(CONFIG_RCU_TRACE) += rcupreempt_trace.o endif Thanks. bye, Roman -- 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/