1*4882a593SmuzhiyunC WRC+pooncerelease+fencermbonceonce+Once
2*4882a593Smuzhiyun
3*4882a593Smuzhiyun(*
4*4882a593Smuzhiyun * Result: Never
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * This litmus test is an extension of the message-passing pattern, where
7*4882a593Smuzhiyun * the first write is moved to a separate process.  Because it features
8*4882a593Smuzhiyun * a release and a read memory barrier, it should be forbidden.  More
9*4882a593Smuzhiyun * specifically, this litmus test is forbidden because smp_store_release()
10*4882a593Smuzhiyun * is A-cumulative in LKMM.
11*4882a593Smuzhiyun *)
12*4882a593Smuzhiyun
13*4882a593Smuzhiyun{}
14*4882a593Smuzhiyun
15*4882a593SmuzhiyunP0(int *x)
16*4882a593Smuzhiyun{
17*4882a593Smuzhiyun	WRITE_ONCE(*x, 1);
18*4882a593Smuzhiyun}
19*4882a593Smuzhiyun
20*4882a593SmuzhiyunP1(int *x, int *y)
21*4882a593Smuzhiyun{
22*4882a593Smuzhiyun	int r0;
23*4882a593Smuzhiyun
24*4882a593Smuzhiyun	r0 = READ_ONCE(*x);
25*4882a593Smuzhiyun	smp_store_release(y, 1);
26*4882a593Smuzhiyun}
27*4882a593Smuzhiyun
28*4882a593SmuzhiyunP2(int *x, int *y)
29*4882a593Smuzhiyun{
30*4882a593Smuzhiyun	int r0;
31*4882a593Smuzhiyun	int r1;
32*4882a593Smuzhiyun
33*4882a593Smuzhiyun	r0 = READ_ONCE(*y);
34*4882a593Smuzhiyun	smp_rmb();
35*4882a593Smuzhiyun	r1 = READ_ONCE(*x);
36*4882a593Smuzhiyun}
37*4882a593Smuzhiyun
38*4882a593Smuzhiyunexists (1:r0=1 /\ 2:r0=1 /\ 2:r1=0)
39