Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755476AbaBTSpN (ORCPT ); Thu, 20 Feb 2014 13:45:13 -0500 Received: from mx1.redhat.com ([209.132.183.28]:19151 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754244AbaBTSpI (ORCPT ); Thu, 20 Feb 2014 13:45:08 -0500 Subject: Re: [RFC][PATCH 0/5] arch: atomic rework From: Torvald Riegel To: paulmck@linux.vnet.ibm.com Cc: Linus Torvalds , 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" In-Reply-To: <20140220181116.GT4250@linux.vnet.ibm.com> References: <1392740258.18779.7732.camel@triegel.csb> <1392752867.18779.8120.camel@triegel.csb> <20140220040102.GM4250@linux.vnet.ibm.com> <20140220083032.GN4250@linux.vnet.ibm.com> <20140220181116.GT4250@linux.vnet.ibm.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 20 Feb 2014 19:44:32 +0100 Message-ID: <1392921872.18779.10287.camel@triegel.csb> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2014-02-20 at 10:11 -0800, Paul E. McKenney wrote: > But yes, the compiler guys would be extremely happy to simply drop > memory_order_consume from the standard, as it is the memory order > that they most love to hate. > > Getting them to agree to any sort of peep-hole optimization semantics > for memory_order_consume is likely problematic. I wouldn't be so pessimistic about that. If the transformations can be shown to be always correct in terms of the semantics specified in the standard, and if the performance win is sufficiently large, why not? Of course, somebody has to volunteer to actually implement it :) -- 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/