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Diffstat (limited to 'Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus')
| -rw-r--r-- | Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus b/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus new file mode 100644 index 0000000000..c0f93dc071 --- /dev/null +++ b/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus @@ -0,0 +1,35 @@ +C cmpxchg-fail-ordered-1 + +(* + * Result: Never + * + * Demonstrate that a failing cmpxchg() operation will act as a full + * barrier when followed by smp_mb__after_atomic(). + *) + +{} + +P0(int *x, int *y, int *z) +{ + int r0; + int r1; + + WRITE_ONCE(*x, 1); + r1 = cmpxchg(z, 1, 0); + smp_mb__after_atomic(); + r0 = READ_ONCE(*y); +} + +P1(int *x, int *y, int *z) +{ + int r0; + int r1; + + WRITE_ONCE(*y, 1); + r1 = cmpxchg(z, 1, 0); + smp_mb__after_atomic(); + r0 = READ_ONCE(*x); +} + +locations[0:r1;1:r1] +exists (0:r0=0 /\ 1:r0=0) |