From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753399AbaKLUnw (ORCPT ); Wed, 12 Nov 2014 15:43:52 -0500 Received: from shards.monkeyblade.net ([149.20.54.216]:46451 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753248AbaKLUnu (ORCPT ); Wed, 12 Nov 2014 15:43:50 -0500 Date: Wed, 12 Nov 2014 15:43:41 -0500 (EST) Message-Id: <20141112.154341.1705628294274955796.davem@davemloft.net> To: alexander.h.duyck@redhat.com Cc: will.deacon@arm.com, alexander.duyck@gmail.com, linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, mikey@neuling.org, tony.luck@intel.com, mathieu.desnoyers@polymtl.ca, peterz@infradead.org, benh@kernel.crashing.org, heiko.carstens@de.ibm.com, oleg@redhat.com, michael@ellerman.id.au, geert@linux-m68k.org, fweisbec@gmail.com, schwidefsky@de.ibm.com, linux@arm.linux.org.uk, paulmck@linux.vnet.ibm.com, torvalds@linux-foundation.org, mingo@kernel.org Subject: Re: [PATCH] arch: Introduce read_acquire() From: David Miller In-Reply-To: <54627BC0.4020705@redhat.com> References: <20141111185510.2181.75347.stgit@ahduyck-workstation.home> <20141111194734.GL16265@arm.com> <54627BC0.4020705@redhat.com> X-Mailer: Mew version 6.5 on Emacs 24.1 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.7 (shards.monkeyblade.net [149.20.54.216]); Wed, 12 Nov 2014 12:43:48 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Duyck Date: Tue, 11 Nov 2014 13:12:32 -0800 > The architectures I need to sort out are arm, x86, sparc, ia64, and > s390 as they are the only ones that tried to make use of the > smp_load_acquire logic. On sparc64, you don't have to worry about anything really. Only mb() does anything. The cpus execute in a reasonably strict memory ordering mode, and that's why rmb/wmb and friends are simply nops with a compiler barrier.