--- /dev/null
+C LB+unlocklockonceonce+poacquireonce
+
+(*
+ * Result: Never
+ *
+ * If two locked critical sections execute on the same CPU, all accesses
+ * in the first must execute before any accesses in the second, even if the
+ * critical sections are protected by different locks. Note: Even when a
+ * write executes before a read, their memory effects can be reordered from
+ * the viewpoint of another CPU (the kind of reordering allowed by TSO).
+ *)
+
+{}
+
+P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
+{
+ int r1;
+
+ spin_lock(s);
+ r1 = READ_ONCE(*x);
+ spin_unlock(s);
+ spin_lock(t);
+ WRITE_ONCE(*y, 1);
+ spin_unlock(t);
+}
+
+P1(int *x, int *y)
+{
+ int r2;
+
+ r2 = smp_load_acquire(y);
+ WRITE_ONCE(*x, 1);
+}
+
+exists (0:r1=1 /\ 1:r2=1)
--- /dev/null
+C MP+unlocklockonceonce+fencermbonceonce
+
+(*
+ * Result: Never
+ *
+ * If two locked critical sections execute on the same CPU, stores in the
+ * first must propagate to each CPU before stores in the second do, even if
+ * the critical sections are protected by different locks.
+ *)
+
+{}
+
+P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
+{
+ spin_lock(s);
+ WRITE_ONCE(*x, 1);
+ spin_unlock(s);
+ spin_lock(t);
+ WRITE_ONCE(*y, 1);
+ spin_unlock(t);
+}
+
+P1(int *x, int *y)
+{
+ int r1;
+ int r2;
+
+ r1 = READ_ONCE(*y);
+ smp_rmb();
+ r2 = READ_ONCE(*x);
+}
+
+exists (1:r1=1 /\ 1:r2=0)
As above, but with store-release replaced with WRITE_ONCE()
and load-acquire replaced with READ_ONCE().
+LB+unlocklockonceonce+poacquireonce.litmus
+ Does a unlock+lock pair provides ordering guarantee between a
+ load and a store?
+
MP+onceassign+derefonce.litmus
As below, but with rcu_assign_pointer() and an rcu_dereference().
As below, but with the first access of the writer process
and the second access of reader process protected by a lock.
+MP+unlocklockonceonce+fencermbonceonce.litmus
+ Does a unlock+lock pair provides ordering guarantee between a
+ store and another store?
+
MP+fencewmbonceonce+fencermbonceonce.litmus
Does a smp_wmb() (between the stores) and an smp_rmb() (between
the loads) suffice for the message-passing litmus test, where one