From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Date: Wed, 27 Jan 2016 23:35:04 +0000 Subject: Re: [PATCH] documentation: Add disclaimer Message-Id: <20160127233504.GP4503@linux.vnet.ibm.com> List-Id: 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> In-Reply-To: <15882.1453906627@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Howells Cc: linux-mips@linux-mips.org, linux-ia64@vger.kernel.org, "Michael S. Tsirkin" , Peter Zijlstra , Will Deacon , virtualization@lists.linux-foundation.org, "H. Peter Anvin" , sparclinux@vger.kernel.org, Ingo Molnar , linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, Russell King - ARM Linux , user-mode-linux-devel@lists.sourceforge.net, linux-sh@vger.kernel.org, Michael Ellerman , x86@kernel.org, xen-devel@lists.xenproject.org, Ingo Molnar , linux-xtensa@linux-xtensa.org, james.hogan@imgtec.com, Arnd Bergmann , Stefano Stabellini , adi-buildroot-devel@lists.sourceforge.net, Leonid Yegoshin , ddaney.cavm@gmail.com, Thomas Gleixner 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