[PATCH v2] barriers: introduce smp_mb__release_acquire and update documentation

[Will Deacon]

On Fri, Oct 09, 2015 at 01:02:46PM +0200, Peter Zijlstra wrote:
> On Fri, Oct 09, 2015 at 10:40:39AM +0100, Will Deacon wrote:
> > Stepping back a second, I believe that there are three cases:
> > 
> > 
> >  RELEASE X -> ACQUIRE Y (same CPU)
> >    * Needs a barrier on TSO architectures for full ordering
> 	+PPC
> 
> >  UNLOCK X -> LOCK Y (same CPU)
> >    * Needs a barrier on PPC for full ordering
> 
> 
> >  RELEASE X -> ACQUIRE X (different CPUs)
>     * Fully ordered everywhere...
>     * ... but needs a barrier on TSO + PPC to become a full barrier
> 
> >  UNLOCK X -> ACQUIRE X (different CPUs)
> 
> s/ACQUIRE/LOCK/ ?

Yes, sorry.

Will