Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761006AbXKDPNR (ORCPT ); Sun, 4 Nov 2007 10:13:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757163AbXKDPNF (ORCPT ); Sun, 4 Nov 2007 10:13:05 -0500 Received: from nf-out-0910.google.com ([64.233.182.186]:64395 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756205AbXKDPNC (ORCPT ); Sun, 4 Nov 2007 10:13:02 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=awfTZoXJWpYDP+KHU4G65d34oTPUIKLZNqn5NLlGpAvsxpsnH8HHE8uuZGKRmPt3KBDOF9If8Uic64AGnq+6mHeu/MPfZNsKWbkSt8FKG9ozQ/tTvp8JfByTXIEjgwltgWp+Hc6ekLE849I2jfgHEcW0o4JTj+o6RwEsg8igrdQ= Message-ID: Date: Sun, 4 Nov 2007 16:13:00 +0100 From: "Bart Van Assche" To: "Andrew Haley" Subject: Re: Is gcc thread-unsafe? Cc: "Linux Kernel Mailing List" , "Linus Torvalds" , "Tomash Brechko" In-Reply-To: <18219.17505.443550.620503@zebedee.pink> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <18210.2314.57767.962503@zebedee.pink> <18215.1394.294830.944162@zebedee.pink> <18219.17505.443550.620503@zebedee.pink> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1607 Lines: 35 On 11/2/07, Andrew Haley wrote: > Bart Van Assche writes: > > On 10/30/07, Andrew Haley wrote: > > > That's what the proposed standard language says, kinda-sorta. There's > > > an informal description at > > > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2338.html. > > > > There is other important information in the cited text. A.o. it is > > explained that register promotion of potentially shared variables > > can introduce data races. Or: register promotion can introduce bugs > > in multithreaded software when compiled with optimization > > enabled. Are there any register promotion transformations > > implemented in gcc that can introduce data races in multithreaded > > software ? > > I expect so. We're going to have to audit this whole enormous code > base to find them all and take them out. > > Note that some of these optimizations have been around since gcc 3.4. Has it already been decided who will do this audit, and when this audit will happen ? Has a target date been set when this audit should be complete, or is the completion of this audit a requirement for the release of a specific gcc version ? And if there would exist register promotion transformations in gcc that can introduce data races, which would be the optimization levels that enable these transformations ? Bart Van Assche. - 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/