From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 28487 invoked by alias); 26 Jul 2013 21:13:52 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 28476 invoked by uid 89); 26 Jul 2013 21:13:51 -0000 X-Spam-SWARE-Status: No, score=-3.5 required=5.0 tests=AWL,BAYES_50,KHOP_RCVD_UNTRUST,RCVD_IN_HOSTKARMA_W,RCVD_IN_HOSTKARMA_WL,RDNS_NONE autolearn=no version=3.3.1 Received: from Unknown (HELO mga14.intel.com) (143.182.124.37) by sourceware.org (qpsmtpd/0.84/v0.84-167-ge50287c) with ESMTP; Fri, 26 Jul 2013 21:13:51 +0000 Received: from azsmga001.ch.intel.com ([10.2.17.19]) by azsmga102.ch.intel.com with ESMTP; 26 Jul 2013 14:13:40 -0700 X-ExtLoop1: 1 Received: from tassilo.jf.intel.com (HELO tassilo.localdomain) ([10.7.201.78]) by azsmga001.ch.intel.com with ESMTP; 26 Jul 2013 14:13:40 -0700 Received: by tassilo.localdomain (Postfix, from userid 1000) id E5B5A301150; Fri, 26 Jul 2013 14:13:39 -0700 (PDT) From: Andi Kleen To: Andrew MacLeod Cc: gcc-patches , hp@bitrange.com Subject: Re: [PATCH] Add atomic type qualifier References: <51F2AEB1.60408@redhat.com> <87ob9pm9gt.fsf@tassilo.jf.intel.com> <51F2CEFB.1040000@redhat.com> Date: Fri, 26 Jul 2013 21:14:00 -0000 In-Reply-To: <51F2CEFB.1040000@redhat.com> (Andrew MacLeod's message of "Fri, 26 Jul 2013 15:33:15 -0400") Message-ID: <87fvv1m3cs.fsf@tassilo.jf.intel.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-SW-Source: 2013-07/txt/msg01292.txt.bz2 Andrew MacLeod writes: >> > The way the standard is defined, any implicit operation like that is > seq_cst. If you want something other than seq-cst, you have to > explicitly call atomic_store (&x, 0, model). Thanks. This doesn't sound like a good default for x86. seq_cst requires somewhat expensive extra barriers that most people most likely don't need. -Andi -- ak@linux.intel.com -- Speaking for myself only