From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755533Ab2IQKAz (ORCPT ); Mon, 17 Sep 2012 06:00:55 -0400 Received: from mail-bk0-f46.google.com ([209.85.214.46]:63925 "EHLO mail-bk0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754580Ab2IQKAw (ORCPT ); Mon, 17 Sep 2012 06:00:52 -0400 Date: Mon, 17 Sep 2012 12:00:46 +0200 From: Ingo Molnar To: Jan Beulich Cc: tglx@linutronix.de, torvalds@linux-foundation.org, linux-kernel@vger.kernel.org, hpa@zytor.com Subject: Re: [tip:x86/asm] x86: Prefer TZCNT over BFS Message-ID: <20120917100046.GA32463@gmail.com> References: <504DEA1B020000780009A277@nat28.tlf.novell.com> <5056F04B020000780009BAF9@nat28.tlf.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5056F04B020000780009BAF9@nat28.tlf.novell.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Jan Beulich wrote: > >>> On 14.09.12 at 23:14, Linus Torvalds wrote: > > On Thu, Sep 13, 2012 at 11:23 PM, tip-bot for Jan Beulich > > wrote: > >> > >> x86: Prefer TZCNT over BFS > > > > This patch is insane. > > I'm not going to defend this simple and strait forward a patch > to such a reply, so Ingo, just drop it to please Linus, even > though I can't see what's _this_ bad about it. Well, the problem is the complication of the dependencies, which obscures the logic and makes it hard to maintain going forward. Linus's suggestion is to introduce CONFIG_X86_TZCNT as an add-on patch that cleans up and documents what this is all about. Would you be willing to do such a patch? Thanks, Ingo