From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <linux-kernel-owner@vger.kernel.org>
Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand
	id S934378Ab3BSVnA (ORCPT <rfc822;w@1wt.eu>);
	Tue, 19 Feb 2013 16:43:00 -0500
Received: from mail.linuxfoundation.org ([140.211.169.12]:58409 "EHLO
	mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S933545Ab3BSVm7 (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Tue, 19 Feb 2013 16:42:59 -0500
Date: Tue, 19 Feb 2013 13:42:56 -0800
From: Andrew Morton <akpm@linux-foundation.org>
To: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>, Michal Marek <mmarek@suse.cz>,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        ebiederm@xmission.com, xemul@parallels.com,
        Andrey Vagin <avagin@openvz.org>,
        KOSAKI Motohiro <kosaki.motohiro@gmail.com>,
        Ingo Molnar <mingo@elte.hu>, Thomas Gleixner <tglx@linutronix.de>,
        Glauber Costa <glommer@parallels.com>,
        Andi Kleen <andi@firstfloor.org>, Tejun Heo <tj@kernel.org>,
        Matt Helsley <matthltc@us.ibm.com>, Pekka Enberg <penberg@kernel.org>,
        Eric Dumazet <eric.dumazet@gmail.com>,
        Vasiliy Kulikov <segoon@openwall.com>,
        Alexey Dobriyan <adobriyan@gmail.com>,
        Frederic Weisbecker <fweisbec@gmail.com>
Subject: Re: [patch 1/2] kcmp: Make it to depend on CONFIG_KCMP
Message-Id: <20130219134256.f4cedf44.akpm@linux-foundation.org>
In-Reply-To: <20130219182838.GL20312@moon>
References: <20130219064800.719149796@openvz.org>
	<20130219065210.030802820@openvz.org>
	<5123444D.6000806@suse.cz>
	<20130219093154.GF20312@moon>
	<5123BC2B.6000304@zytor.com>
	<20130219182838.GL20312@moon>
X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu)
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Tue, 19 Feb 2013 22:28:38 +0400
Cyrill Gorcunov <gorcunov@openvz.org> wrote:

> Since kcmp syscall has been implemented (initially on
> x86 architecture) a number of other archs wire it up
> as well: xtensa, sparc, sh, s390, mips, microblaze,
> m68k (not taking into account those who uses
> <asm-generic/unistd.h> for syscall numbers
> definitions).
> 
> But the Makefile, which turns kcmp.o generation on
> still depends on former config-x86. Thus get rid
> of this limitation and make kcmp.o depend on CONFIG_KCMP
> option.
> 
> ...
>
> --- linux-2.6.git.orig/init/Kconfig
> +++ linux-2.6.git/init/Kconfig
> @@ -279,6 +279,15 @@ config FHANDLE
>  	  get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
>  	  syscalls.
>  
> +config KCMP
> +	bool "kcmp syscall"
> +	default CHECKPOINT_RESTORE
> +	help
> +	  If you say Y here, a user level program will be able to use
> +	  kcmp(2) syscall.
> +
> +	  If unsure, say Y.
> +
>  config AUDIT
>  	bool "Auditing support"
>  	depends on NET
> Index: linux-2.6.git/kernel/Makefile
> ===================================================================
> --- linux-2.6.git.orig/kernel/Makefile
> +++ linux-2.6.git/kernel/Makefile
> @@ -25,9 +25,7 @@ endif
>  obj-y += sched/
>  obj-y += power/
>  
> -ifeq ($(CONFIG_CHECKPOINT_RESTORE),y)
> -obj-$(CONFIG_X86) += kcmp.o
> -endif
> +obj-$(CONFIG_KCMP) += kcmp.o
>  obj-$(CONFIG_FREEZER) += freezer.o
>  obj-$(CONFIG_PROFILING) += profile.o
>  obj-$(CONFIG_STACKTRACE) += stacktrace.o

This permits people to select kcmp with CONFIG_CHECKPOINT_RESTORE=n. 
Is there any point in doing that?

What would be wrong with just doing

	obj-$(CONFIG_CHECKPOINT_RESTORE) += kcmp.o

?