1C MP+unlocklockonceonce+fencermbonceonce
 2
 3(*
 4 * Result: Never
 5 *
 6 * If two locked critical sections execute on the same CPU, stores in the
 7 * first must propagate to each CPU before stores in the second do, even if
 8 * the critical sections are protected by different locks.
 9 *)
10
11{}
12
13P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
14{
15	spin_lock(s);
16	WRITE_ONCE(*x, 1);
17	spin_unlock(s);
18	spin_lock(t);
19	WRITE_ONCE(*y, 1);
20	spin_unlock(t);
21}
22
23P1(int *x, int *y)
24{
25	int r1;
26	int r2;
27
28	r1 = READ_ONCE(*y);
29	smp_rmb();
30	r2 = READ_ONCE(*x);
31}
32
33exists (1:r1=1 /\ 1:r2=0)

 1C MP+unlocklockonceonce+fencermbonceonce
 2
 3(*
 4 * Result: Never
 5 *
 6 * If two locked critical sections execute on the same CPU, stores in the
 7 * first must propagate to each CPU before stores in the second do, even if
 8 * the critical sections are protected by different locks.
 9 *)
10
11{}
12
13P0(spinlock_t *s, spinlock_t *t, int *x, int *y)
14{
15	spin_lock(s);
16	WRITE_ONCE(*x, 1);
17	spin_unlock(s);
18	spin_lock(t);
19	WRITE_ONCE(*y, 1);
20	spin_unlock(t);
21}
22
23P1(int *x, int *y)
24{
25	int r1;
26	int r2;
27
28	r1 = READ_ONCE(*y);
29	smp_rmb();
30	r2 = READ_ONCE(*x);
31}
32
33exists (1:r1=1 /\ 1:r2=0)