1C cmpxchg-fail-ordered-2
 2
 3(*
 4 * Result: Never
 5 *
 6 * Demonstrate use of smp_mb__after_atomic() to make a failing cmpxchg
 7 * operation have acquire ordering.
 8 *)
 9
10{}
11
12P0(int *x, int *y)
13{
14	int r1;
15
16	WRITE_ONCE(*x, 1);
17	r1 = cmpxchg(y, 0, 1);
18}
19
20P1(int *x, int *y)
21{
22	int r1;
23	int r2;
24
25	r1 = cmpxchg(y, 0, 1);
26	smp_mb__after_atomic();
27	r2 = READ_ONCE(*x);
28}
29
30exists (0:r1=0 /\ 1:r1=1 /\ 1:r2=0)