diff options
Diffstat (limited to 'Documentation')
5 files changed, 143 insertions, 0 deletions
diff --git a/Documentation/litmus-tests/README b/Documentation/litmus-tests/README index 26ca56df0212..6c666f3422ea 100644 --- a/Documentation/litmus-tests/README +++ b/Documentation/litmus-tests/README @@ -21,6 +21,22 @@ Atomic-RMW-ops-are-atomic-WRT-atomic_set.litmus Test that atomic_set() cannot break the atomicity of atomic RMWs. NOTE: Require herd7 7.56 or later which supports "(void)expr". +cmpxchg-fail-ordered-1.litmus + Demonstrate that a failing cmpxchg() operation acts as a full barrier + when followed by smp_mb__after_atomic(). + +cmpxchg-fail-ordered-2.litmus + Demonstrate that a failing cmpxchg() operation acts as an acquire + operation when followed by smp_mb__after_atomic(). + +cmpxchg-fail-unordered-1.litmus + Demonstrate that a failing cmpxchg() operation does not act as a + full barrier. + +cmpxchg-fail-unordered-2.litmus + Demonstrate that a failing cmpxchg() operation does not act as an + acquire operation. + locking (/locking directory) ---------------------------- 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 000000000000..3df1d140b189 --- /dev/null +++ b/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-1.litmus @@ -0,0 +1,34 @@ +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; + + 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) diff --git a/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-2.litmus b/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-2.litmus new file mode 100644 index 000000000000..54146044a16f --- /dev/null +++ b/Documentation/litmus-tests/atomic/cmpxchg-fail-ordered-2.litmus @@ -0,0 +1,30 @@ +C cmpxchg-fail-ordered-2 + +(* + * Result: Never + * + * Demonstrate use of smp_mb__after_atomic() to make a failing cmpxchg + * operation have acquire ordering. + *) + +{} + +P0(int *x, int *y) +{ + int r0; + int r1; + + WRITE_ONCE(*x, 1); + r1 = cmpxchg(y, 0, 1); +} + +P1(int *x, int *y) +{ + int r0; + + r1 = cmpxchg(y, 0, 1); + smp_mb__after_atomic(); + r2 = READ_ONCE(*x); +} + +exists (0:r1=0 /\ 1:r1=1 /\ 1:r2=0) diff --git a/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-1.litmus b/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-1.litmus new file mode 100644 index 000000000000..a727ce23b1a6 --- /dev/null +++ b/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-1.litmus @@ -0,0 +1,33 @@ +C cmpxchg-fail-unordered-1 + +(* + * Result: Sometimes + * + * Demonstrate that a failing cmpxchg() operation does not act as a + * full barrier. (In contrast, a successful cmpxchg() does act as a + * full barrier.) + *) + +{} + +P0(int *x, int *y, int *z) +{ + int r0; + int r1; + + WRITE_ONCE(*x, 1); + r1 = cmpxchg(z, 1, 0); + r0 = READ_ONCE(*y); +} + +P1(int *x, int *y, int *z) +{ + int r0; + + WRITE_ONCE(*y, 1); + r1 = cmpxchg(z, 1, 0); + r0 = READ_ONCE(*x); +} + +locations[0:r1;1:r1] +exists (0:r0=0 /\ 1:r0=0) diff --git a/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-2.litmus b/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-2.litmus new file mode 100644 index 000000000000..a245bac55b57 --- /dev/null +++ b/Documentation/litmus-tests/atomic/cmpxchg-fail-unordered-2.litmus @@ -0,0 +1,30 @@ +C cmpxchg-fail-unordered-2 + +(* + * Result: Sometimes + * + * Demonstrate that a failing cmpxchg() operation does not act as either + * an acquire release operation. (In contrast, a successful cmpxchg() + * does act as both an acquire and a release operation.) + *) + +{} + +P0(int *x, int *y) +{ + int r0; + int r1; + + WRITE_ONCE(*x, 1); + r1 = cmpxchg(y, 0, 1); +} + +P1(int *x, int *y) +{ + int r0; + + r1 = cmpxchg(y, 0, 1); + r2 = READ_ONCE(*x); +} + +exists (0:r1=0 /\ 1:r1=1 /\ 1:r2=0) |