1C ISA2+pooncelock+pooncelock+pombonce.litmus
2
3(*
4 * Result: Sometimes
5 *
6 * This test shows that the ordering provided by a lock-protected S
7 * litmus test (P0() and P1()) are not visible to external process P2().
8 * This is likely to change soon.
9 *)
10
11{}
12
13P0(int *x, int *y, spinlock_t *mylock)
14{
15	spin_lock(mylock);
16	WRITE_ONCE(*x, 1);
17	WRITE_ONCE(*y, 1);
18	spin_unlock(mylock);
19}
20
21P1(int *y, int *z, spinlock_t *mylock)
22{
23	int r0;
24
25	spin_lock(mylock);
26	r0 = READ_ONCE(*y);
27	WRITE_ONCE(*z, 1);
28	spin_unlock(mylock);
29}
30
31P2(int *x, int *z)
32{
33	int r1;
34	int r2;
35
36	r2 = READ_ONCE(*z);
37	smp_mb();
38	r1 = READ_ONCE(*x);
39}
40
41exists (1:r0=1 /\ 2:r2=1 /\ 2:r1=0)
42