blob: af9463b39b4a5daacd517d7e552f49ac963f1206 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
|
C R+fencembonceonces
(*
* Result: Never
*
* This is the fully ordered (via smp_mb()) version of one of the classic
* counterintuitive litmus tests that illustrates the effects of store
* propagation delays. Note that weakening either of the barriers would
* cause the resulting test to be allowed.
*)
{
int x;
int y;
}
P0(int *x, int *y)
{
WRITE_ONCE(*x, 1);
smp_mb();
WRITE_ONCE(*y, 1);
}
P1(int *x, int *y)
{
int r0;
WRITE_ONCE(*y, 2);
smp_mb();
r0 = READ_ONCE(*x);
}
exists (y=2 /\ 1:r0=0)
|
