1 C 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
12 P0(int *x, int *y)
13 {
14 int r1;
15
16 WRITE_ONCE(*x, 1);
17 r1 = cmpxchg(y, 0, 1);
18 }
19
20 P1(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
30 exists (0:r1=0 /\ 1:r1=1 /\ 1:r2=0)
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