Re: [RFC 3/3] tools/memory-model: Add litmus test for RMW + smp_mb__after_atomic()

From: Boqun Feng
Date: Fri Feb 14 2020 - 03:20:49 EST


On Fri, Feb 14, 2020 at 09:18:26AM +0100, Andrea Parri wrote:
> > > @@ -0,0 +1,29 @@
> > > +C Atomic-RMW+mb__after_atomic-is-strong-acquire
> > > +
> > > +(*
> > > + * Result: Never
> > > + *
> > > + * Test of an atomic RMW followed by a smp_mb__after_atomic() is
> > > + * "strong-acquire": both the read and write part of the RMW is ordered before
> > > + * the subsequential memory accesses.
> > > + *)
> > > +
> > > +{
> > > +}
> > > +
> > > +P0(int *x, atomic_t *y)
> > > +{
> > > + r0 = READ_ONCE(*x);
> > > + smp_rmb();
> > > + r1 = atomic_read(y);
>
> IIRC, klitmus7 needs a declaration for these local variables, say
> (trying to keep herd7 happy):
>

Got it. I will add the declaration in the next version. It's just that
herd doesn't need those so I haven't put them in this version ;-)

Thanks!

Regards,
Boqun

> P0(int *x, atomic_t *y)
> {
> int r0;
> int r1;
>
> r0 = READ_ONCE(*x);
> smp_rmb();
> r1 = atomic_read(y);
> }
>
> Thanks,
> Andrea