On Wed, 14 Feb 2018, Paul E. McKenney wrote:
> Let's see, examining the Z6 litmus tests and running on herd7 version 7.48:
>
> Z6.0+pooncelock+pooncelock+pombonce Sometimes 1 7
> Z6.0+pooncelock+poonceLock+pombonce Never 0 7
> Z6.0+pooncerelease+poacquirerelease+mbonceonce Sometimes 1 7
>
> But Alan stated that the result of the test would be changed by one of
> the patches in our "pending" list. I ran with all the patches currently
> applied, so I am guessing that Alan was refering to one of the changes
> that we have discussed but not yet created.
>
> Alan, enlightenment?
Here's the relevant patch. It may need some manual adjustment, because
it was not made against the files currently in the repository.
Alan
diff --git a/linux-kernel-hardware.cat b/linux-kernel-hardware.cat
Index: memory-model/linux-kernel-hardware.cat
===================================================================
--- memory-model.orig/linux-kernel-hardware.cat
+++ memory-model/linux-kernel-hardware.cat
@@ -31,7 +31,7 @@ let strong-fence = mb | gp
(* Release Acquire *)
let acq-po = [Acquire] ; po ; [M]
let po-rel = [M] ; po ; [Release]
-let rfi-rel-acq = [Release] ; rfi ; [Acquire]
+let rel-rf-acq-po = [Release] ; rf ; [Acquire] ; po
(**********************************)
(* Fundamental coherence ordering *)
@@ -57,13 +57,13 @@ let to-w = rwdep | addrpo | (overwrite &
let rdw = po-loc & (fre ; rfe)
let detour = po-loc & (coe ; rfe)
let rrdep = addr | (dep ; rfi)
-let to-r = rrdep | rfi-rel-acq
-let fence = strong-fence | wmb | po-rel | rmb | acq-po
+let to-r = rrdep
+let fence = strong-fence | wmb | po-rel | rmb | acq-po | (rel-rf-acq-po & int)
let ppo = to-r | to-w | fence | rdw | detour
(* Happens Before *)
let A-cumul(r) = rfe? ; r
-let cumul-fence = A-cumul(strong-fence | po-rel) | wmb
+let cumul-fence = A-cumul(strong-fence | po-rel) | wmb | rel-rf-acq-po
let rec prop = (overwrite & ext)? ; cumul-fence ; hb*
and hb = ppo | rfe | ((hb* ; prop) & int)
Index: memory-model/linux-kernel.cat
===================================================================
--- memory-model.orig/linux-kernel.cat
+++ memory-model/linux-kernel.cat
@@ -31,7 +31,7 @@ let strong-fence = mb | gp
(* Release Acquire *)
let acq-po = [Acquire] ; po ; [M]
let po-rel = [M] ; po ; [Release]
-let rfi-rel-acq = [Release] ; rfi ; [Acquire]
+let rel-rf-acq-po = [Release] ; rf ; [Acquire] ; po
(**********************************)
(* Fundamental coherence ordering *)
@@ -54,13 +54,13 @@ let rwdep = (dep | ctrl) ; [W]
let overwrite = co | fr
let to-w = rwdep | (overwrite & int)
let rrdep = addr | (dep ; rfi)
-let to-r = rrdep | rfi-rel-acq
-let fence = strong-fence | wmb | po-rel | rmb | acq-po
+let to-r = rrdep
+let fence = strong-fence | wmb | po-rel | rmb | acq-po | (rel-rf-acq-po & int)
let ppo = to-r | to-w | fence
(* Propagation: Ordering from release operations and strong fences. *)
let A-cumul(r) = rfe? ; r
-let cumul-fence = A-cumul(strong-fence | po-rel) | wmb
+let cumul-fence = A-cumul(strong-fence | po-rel) | wmb | rel-rf-acq-po
let prop = (overwrite & ext)? ; cumul-fence* ; rfe?
(*
