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 S1752104AbaBWV4L (ORCPT <rfc822;w@1wt.eu>);
	Sun, 23 Feb 2014 16:56:11 -0500
Received: from relay6-d.mail.gandi.net ([217.70.183.198]:35765 "EHLO
	relay6-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org
	with ESMTP id S1751740AbaBWV4J (ORCPT
	<rfc822;linux-kernel@vger.kernel.org>);
	Sun, 23 Feb 2014 16:56:09 -0500
X-Originating-IP: 50.43.14.201
Date: Sun, 23 Feb 2014 13:55:52 -0800
From: Josh Triplett <josh@joshtriplett.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@suse.de>, Andrew Morton <akpm@linux-foundation.org>,
        Andi Kleen <ak@linux.intel.com>, Feng Tang <feng.tang@intel.com>,
        Ingo Molnar <mingo@redhat.com>, Jacob Shin <jacob.shin@amd.com>,
        Jan Beulich <JBeulich@suse.com>,
        Jussi Kivilinna <jussi.kivilinna@iki.fi>,
        "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
        Paul Gortmaker <paul.gortmaker@windriver.com>,
        Peter Zijlstra <peterz@infradead.org>,
        "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>,
        Rob Landley <rob@landley.net>, Seiji Aguchi <seiji.aguchi@hds.com>,
        Stephane Eranian <eranian@google.com>,
        Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>,
        Thomas Gleixner <tglx@linutronix.de>, linux-kernel@vger.kernel.org,
        x86@kernel.org
Subject: Re: [PATCH v2 2/2] x86: Support compiling out human-friendly
 processor feature names
Message-ID: <20140223215552.GB14411@thin>
References: <296de15c8addece6dada4ddac982b3934d8ff6fa.1393096111.git.josh@joshtriplett.org>
 <4bdaeab748d3b51ef24576ca030b5eb80455aff8.1393098813.git.josh@joshtriplett.org>
 <20140222204936.GA2534@pd.tnic>
 <20140222210038.GA19867@thin>
 <1b6550ce-40bd-4fc4-a3e4-37997da17973@email.android.com>
 <20140222213640.GA3409@thin>
 <530A3668.2090902@zytor.com>
 <20140223213252.GA14411@thin>
 <530A6BB4.2070407@zytor.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <530A6BB4.2070407@zytor.com>
User-Agent: Mutt/1.5.21 (2010-09-15)
Sender: linux-kernel-owner@vger.kernel.org
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

On Sun, Feb 23, 2014 at 01:44:20PM -0800, H. Peter Anvin wrote:
> On 02/23/2014 01:32 PM, Josh Triplett wrote:
> > 
> > Because, in order to un-break the build, v3 wraps an ifdef around that
> > dependency, to prevent building cpustr.h.  Otherwise, the rule for
> > cpustr.h tries and fails to build mkcpustr.
> > 
> 
> Why did it fail to build mkcpustr?  It would seem that mkcpustr is or at
> least ought to be completely agnostic to any of these options.
> 
> The extra build machinery here seems completely pointless.
> 
> I agree that the #ifdef isn't a big deal, but all this extra machinery
> really indicates something is odd.
> 
> Oh, and of course, looking at the v2 patchset, the problem is the ifdef
> around the mkcapflags shell script which really shouldn't be necessary.
>  We may have to add a rule to force capflags.c to be built even if
> capflags.o is not requested, but that is fine.
> 
> That will cut down on the Makefile hacks considerably, and will avoid
> this problem completely.

Why have the build system waste time building several things that won't
be used?  It seems like the Makefiles are exactly where we *should* have
the ifdef machinery, rather than in source.  I'd happily add another
ifdef in the Makefile rule that builds cpustr.h, to generate a stub
cpustr.h header, and then remove one more ifdef in the source.

- Josh Triplett