From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e19.ny.us.ibm.com (e19.ny.us.ibm.com [129.33.205.209]) (using TLSv1.2 with cipher CAMELLIA256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3qmDbf47PHzDq5y for ; Fri, 15 Apr 2016 07:39:58 +1000 (AEST) Received: from localhost by e19.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 14 Apr 2016 17:39:56 -0400 Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id BAB256E8041 for ; Thu, 14 Apr 2016 17:26:41 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id u3ELdqXs32309490 for ; Thu, 14 Apr 2016 21:39:52 GMT Received: from d01av01.pok.ibm.com (localhost [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id u3ELdmBo007590 for ; Thu, 14 Apr 2016 17:39:52 -0400 Date: Thu, 14 Apr 2016 14:40:15 -0700 From: "Paul E. McKenney" To: Peter Zijlstra Cc: 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: <20160414214015.GA31866@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> <20160127083546.GJ6357@twins.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20160127083546.GJ6357@twins.programming.kicks-ass.net> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Jan 27, 2016 at 09:35:46AM +0100, Peter Zijlstra wrote: > On Tue, Jan 26, 2016 at 12:11:43PM -0800, Paul E. McKenney wrote: > > So Peter, would you like to update your patch to include yourself > > and Will as authors? > > Sure, here goes. > > --- > Subject: documentation: Add disclaimer > > It appears people are reading this document as a requirements list for > building hardware. This is not the intent of this document. Nor is it > particularly suited for this purpose. > > The primary purpose of this document is our collective attempt to define > a set of primitives that (hopefully) allow us to write correct code on > the myriad of SMP platforms Linux supports. > > Its a definite work in progress as our understanding of these platforms, > and memory ordering in general, progresses. > > Nor does being mentioned in this document mean we think its a > particularly good idea; the data dependency barrier required by Alpha > being a prime example. Yes we have it, no you're insane to require it > when building new hardware. > > Signed-off-by: Peter Zijlstra (Intel) Rather belatedly queued and pushed to -rcu, apologies for the delay. One minor edit noted below. Thanx, Paul > --- > Documentation/memory-barriers.txt | 18 +++++++++++++++++- > 1 file changed, 17 insertions(+), 1 deletion(-) > > diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt > index a61be39c7b51..98626125f484 100644 > --- a/Documentation/memory-barriers.txt > +++ b/Documentation/memory-barriers.txt > @@ -4,8 +4,24 @@ > > By: David Howells > Paul E. McKenney > + Will Deacon > + Peter Zijlstra > > -Contents: > +========== > +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 s/I/To/ because there is more than one author. > +hardware. > + > +======== > +CONTENTS > +======== > > (*) Abstract memory access model. > >