Re: [PATCH RFC tools/memory-model] Add s390.{cfg,cat}

Paul E. McKenney
2018-04-03T15:16:42Z

On Tue, Apr 03, 2018 at 09:50:19AM -0400, Alan Stern wrote:
> On Mon, 2 Apr 2018, Paul E. McKenney wrote:
>
> > > > I will look at this more later, reaching end of both battery and useful
> > > > attention span...
> >
> > Like the following, perhaps?
> >
> > Thanx, Paul
> >
> > ------------------------------------------------------------------------
> >
> > s390
> >
> > include "fences.cat"
> > include "cos.cat"
> >
> > (* Fundamental coherence ordering *)
> > let com = rf | co | fr
> > acyclic po-loc | com as coherence
> >
> > (* Atomic *)
> > empty rmw & (fre;coe) as atom
> >
> > (* Fences *)
> > let mb = [M] ; fencerel(Mb) ; [M]
> >
> > (* TSO with multicopy atomicity *)
> > let po-ghb = ([R] ; po ; [M]) | ([M] ; po ; [W])
> > acyclic mb | po-ghb | fr | rf | co as sc
>
> Yes, that should work okay (apart from issues related to ordering of
> atomic accesses).
>
> By the way, what does that last "sc" stand for? Surely not Sequential
> Consistency! You might consider renaming it to "tso-mca".

Good point, fixed.

But it is the closest to SC in commercial computing systems, for whatever
that is worth. ;-)

Thanx, Paul