Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753194AbaBTWww (ORCPT ); Thu, 20 Feb 2014 17:52:52 -0500 Received: from mail-ve0-f173.google.com ([209.85.128.173]:40910 "EHLO mail-ve0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522AbaBTWwr (ORCPT ); Thu, 20 Feb 2014 17:52:47 -0500 MIME-Version: 1.0 In-Reply-To: <20140220221027.GC4250@linux.vnet.ibm.com> References: <1392752867.18779.8120.camel@triegel.csb> <20140220040102.GM4250@linux.vnet.ibm.com> <20140220083032.GN4250@linux.vnet.ibm.com> <20140220181116.GT4250@linux.vnet.ibm.com> <20140220185608.GX4250@linux.vnet.ibm.com> <20140220221027.GC4250@linux.vnet.ibm.com> Date: Thu, 20 Feb 2014 14:52:46 -0800 X-Google-Sender-Auth: _yA53OV7KXWTegAKZAmlxBHHglA Message-ID: Subject: Re: [RFC][PATCH 0/5] arch: atomic rework From: Linus Torvalds To: Paul McKenney Cc: Torvald Riegel , Will Deacon , Peter Zijlstra , Ramana Radhakrishnan , David Howells , "linux-arch@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "akpm@linux-foundation.org" , "mingo@kernel.org" , "gcc@gcc.gnu.org" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 20, 2014 at 2:10 PM, Paul E. McKenney wrote: > > Linus, given that you are calling me out for pushing "legalistic and bad" > things, "syntactic bullshit", and playing "little games", I am forced > to conclude that you have never attended any sort of standards-committee > meeting. ;-) Heh. I have heard people wax poetic about the pleasures of standards committee meetings. Enough that I haven't really ever had the slightest urge to participate ;) > FWIW, the last time I tried excluding things like "f-f", "x%1", "y*0" and > so on, I got a lot of pushback. The reason I didn't argue too much back > (2007 or some such) then was that my view at the time was that I figured > the kernel code wouldn't do things like that anyway, so it didn't matter. Well.. I'd really hope we would never do that. That said, we have certainly used disgusting things that we knew would disable certain optimizations in the compiler before, so I wouldn't put it *entirely* past us to do things like that, but I'd argue that we'd do so in order to confuse the compiler to do what we want, not in order to argue that it's a good thing. I mean, right now we have at least *one* active ugly work-around for a compiler bug (the magic empty inline asm that works around the "asm goto" bug in gcc). So it's not like I would claim that we don't do disgusting things when we need to. But I'm pretty sure that any compiler guy must *hate* that current odd dependency-generation part, and if I was a gcc person, seeing that bugzilla entry Torvald pointed at, I would personally want to dismember somebody with a rusty spoon.. So I suspect there are a number of people who would be *more* than happy with a change to those odd dependency rules. Linus -- 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/