[PATCH] documentation: Add disclaimer

[Paul E. McKenney]

On Wed, Jan 27, 2016 at 02:57:07PM +0000, David Howells wrote:
> Peter Zijlstra <peterz at infradead.org> 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