diff --git a/tools/memory-model/linux-kernel.cat b/tools/memory-model/linux-kernel.cat
index ab9de9c1234b..b8e6197f05af 100644
--- a/tools/memory-model/linux-kernel.cat
+++ b/tools/memory-model/linux-kernel.cat
@@ -91,32 +91,37 @@ acyclic pb as propagation
 (*******)
 
 (*
- * Effect of read-side critical section proceeds from the rcu_read_lock()
- * onward on the one hand and from the rcu_read_unlock() backwards on the
+ * Effects of read-side critical sections proceed from the rcu_read_unlock()
+ * backwards on the one hand, and from the rcu_read_lock() forwards on the
  * other hand.
+ *
+ * In the definition of rcu-fence below, the po term at the left-hand side
+ * of each disjunct and the po? term at the right-hand end have been factored
+ * out.  They have been moved into the definitions of rcu-link and rb.
  *)
-let rcu-rscsi = po ; rcu-rscs^-1 ; po?
+let rcu-gp = [Sync-rcu]		(* Compare with gp *)
+let rcu-rscsi = rcu-rscs^-1
 
 (*
  * The synchronize_rcu() strong fence is special in that it can order not
  * one but two non-rf relations, but only in conjunction with an RCU
  * read-side critical section.
  *)
-let rcu-link = hb* ; pb* ; prop
+let rcu-link = po? ; hb* ; pb* ; prop ; po
 
 (*
  * Any sequence containing at least as many grace periods as RCU read-side
  * critical sections (joined by rcu-link) acts as a generalized strong fence.
  *)
-let rec rcu-fence = gp |
-	(gp ; rcu-link ; rcu-rscsi) |
-	(rcu-rscsi ; rcu-link ; gp) |
-	(gp ; rcu-link ; rcu-fence ; rcu-link ; rcu-rscsi) |
-	(rcu-rscsi ; rcu-link ; rcu-fence ; rcu-link ; gp) |
+let rec rcu-fence = rcu-gp |
+	(rcu-gp ; rcu-link ; rcu-rscsi) |
+	(rcu-rscsi ; rcu-link ; rcu-gp) |
+	(rcu-gp ; rcu-link ; rcu-fence ; rcu-link ; rcu-rscsi) |
+	(rcu-rscsi ; rcu-link ; rcu-fence ; rcu-link ; rcu-gp) |
 	(rcu-fence ; rcu-link ; rcu-fence)
 
 (* rb orders instructions just as pb does *)
-let rb = prop ; rcu-fence ; hb* ; pb*
+let rb = prop ; po ; rcu-fence ; po? ; hb* ; pb*
 
 irreflexive rb as rcu