Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753855AbaBQXNH (ORCPT ); Mon, 17 Feb 2014 18:13:07 -0500 Received: from relay1.mentorg.com ([192.94.38.131]:61969 "EHLO relay1.mentorg.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752843AbaBQXND (ORCPT ); Mon, 17 Feb 2014 18:13:03 -0500 Date: Mon, 17 Feb 2014 23:12:54 +0000 From: "Joseph S. Myers" X-X-Sender: jsm28@digraph.polyomino.org.uk To: Torvald Riegel CC: Linus Torvalds , Paul McKenney , 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" Subject: Re: [RFC][PATCH 0/5] arch: atomic rework In-Reply-To: <1392666096.18779.6810.camel@triegel.csb> Message-ID: References: <1392183564.18779.2187.camel@triegel.csb> <20140212180739.GB4250@linux.vnet.ibm.com> <20140213002355.GI4250@linux.vnet.ibm.com> <1392321837.18779.3249.camel@triegel.csb> <20140214020144.GO4250@linux.vnet.ibm.com> <1392352981.18779.3800.camel@triegel.csb> <20140214172920.GQ4250@linux.vnet.ibm.com> <20140215020815.GS4250@linux.vnet.ibm.com> <1392487627.18779.6535.camel@triegel.csb> <1392666096.18779.6810.camel@triegel.csb> MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" X-OriginalArrivalTime: 17 Feb 2014 23:12:58.0134 (UTC) FILETIME=[CBD02B60:01CF2C35] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 17 Feb 2014, Torvald Riegel wrote: > On Mon, 2014-02-17 at 18:59 +0000, Joseph S. Myers wrote: > > On Sat, 15 Feb 2014, Torvald Riegel wrote: > > > > > glibc is a counterexample that comes to mind, although it's a smaller > > > code base. (It's currently not using C11 atomics, but transitioning > > > there makes sense, and some thing I want to get to eventually.) > > > > glibc is using C11 atomics (GCC builtins rather than _Atomic / > > , but using __atomic_* with explicitly specified memory model > > rather than the older __sync_*) on AArch64, plus in certain cases on ARM > > and MIPS. > > I think the major steps remaining is moving the other architectures > over, and rechecking concurrent code (e.g., for the code that I have I don't think we'll be ready to require GCC >= 4.7 to build glibc for another year or two, although probably we could move the requirement up from 4.4 to 4.6. (And some platforms only had the C11 atomics optimized later than 4.7.) -- Joseph S. Myers joseph@codesourcery.com -- 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/