From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e33.co.us.ibm.com (e33.co.us.ibm.com [32.97.110.151]) (using TLSv1 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id F2D7B1A0054 for ; Thu, 28 Jan 2016 11:40:43 +1100 (AEDT) Received: from localhost by e33.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 27 Jan 2016 17:40:42 -0700 Received: from b03cxnp07029.gho.boulder.ibm.com (b03cxnp07029.gho.boulder.ibm.com [9.17.130.16]) by d03dlp02.boulder.ibm.com (Postfix) with ESMTP id 16D793E4003F for ; Wed, 27 Jan 2016 17:40:39 -0700 (MST) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp07029.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u0S0ed9t25559058 for ; Wed, 27 Jan 2016 17:40:39 -0700 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u0S0eTnv026779 for ; Wed, 27 Jan 2016 17:40:38 -0700 Date: Wed, 27 Jan 2016 15:35:04 -0800 From: "Paul E. McKenney" To: David Howells Cc: Peter Zijlstra , Will Deacon , Leonid Yegoshin , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, Arnd Bergmann , linux-arch@vger.kernel.org, Andrew Cooper , Russell King - ARM Linux , virtualization@lists.linux-foundation.org, Stefano Stabellini , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Joe Perches , David Miller , linux-ia64@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-metag@vger.kernel.org, linux-mips@linux-mips.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, adi-buildroot-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, linux-xtensa@linux-xtensa.org, xen-devel@lists.xenproject.org, Ralf Baechle , Ingo Molnar , ddaney.cavm@gmail.com, james.hogan@imgtec.com, Michael Ellerman Subject: Re: [PATCH] documentation: Add disclaimer Message-ID: <20160127233504.GP4503@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <20160114120445.GB15828@arm.com> <56980145.5030901@imgtec.com> <20160114204827.GE3818@linux.vnet.ibm.com> <56981212.7050301@imgtec.com> <20160114222046.GH3818@linux.vnet.ibm.com> <20160126102402.GE6357@twins.programming.kicks-ass.net> <20160126103200.GI6375@twins.programming.kicks-ass.net> <20160126110053.GA21553@arm.com> <20160126201143.GV4503@linux.vnet.ibm.com> <15882.1453906627@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <15882.1453906627@warthog.procyon.org.uk> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jan 27, 2016 at 02:57:07PM +0000, David Howells wrote: > Peter Zijlstra wrote: > > > +========== > > +DISCLAIMER > > +========== > > + > > +This document is not a specification; it is intentionally (for the sake of > > +brevity) and unintentionally (due to being human) incomplete. This document is > > +meant as a guide to using the various memory barriers provided by Linux, but > > +in case of any doubt (and there are many) please ask. > > + > > +I repeat, this document is not a specification of what Linux expects from > > +hardware. > > The purpose of this document is twofold: > > (1) to specify the minimum functionality that one can rely on for any > particular barrier, and > > (2) to provide a guide as to how to use the barriers that are available. > > Note that an architecture can provide more than the minimum requirement for > any particular barrier, but if the barrier provides less than that, it is > incorrect. > > Note also that it is possible that a barrier may be a no-op for an > architecture because the way that arch works renders an explicit barrier > unnecessary in that case. > > > + > > Can you bung an extra blank line in here if you have to redo this at all? > > > +======== > > +CONTENTS > > +======== > > > > (*) Abstract memory access model. Good point! Would you be willing to add a Signed-off-by so I can take the combined change, assuming Peter and Will are good with it? Thanx, Paul