diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/litmus-tests/README | 11 | ||||
| -rw-r--r-- | Documentation/litmus-tests/rcu/RCU+sync+read.litmus | 37 |
2 files changed, 48 insertions, 0 deletions
diff --git a/Documentation/litmus-tests/README b/Documentation/litmus-tests/README new file mode 100644 index 000000000000..c4307ea9f996 --- /dev/null +++ b/Documentation/litmus-tests/README @@ -0,0 +1,11 @@ +============ +LITMUS TESTS +============ + +RCU (/rcu directory) +-------------------- + +RCU+sync+read.litmus +RCU+sync+free.litmus + Both the above litmus tests demonstrate the RCU grace period guarantee + that an RCU read-side critical section can never span a grace period. diff --git a/Documentation/litmus-tests/rcu/RCU+sync+read.litmus b/Documentation/litmus-tests/rcu/RCU+sync+read.litmus new file mode 100644 index 000000000000..f34176720231 --- /dev/null +++ b/Documentation/litmus-tests/rcu/RCU+sync+read.litmus @@ -0,0 +1,37 @@ +C RCU+sync+read + +(* + * Result: Never + * + * This litmus test demonstrates that after a grace period, an RCU updater always + * sees all stores done in prior RCU read-side critical sections. Such + * read-side critical sections would have ended before the grace period ended. + * + * This is one implication of the RCU grace-period guarantee, which says (among + * other things) that an RCU read-side critical section cannot span a grace period. + *) + +{ +int x = 0; +int y = 0; +} + +P0(int *x, int *y) +{ + rcu_read_lock(); + WRITE_ONCE(*x, 1); + WRITE_ONCE(*y, 1); + rcu_read_unlock(); +} + +P1(int *x, int *y) +{ + int r0; + int r1; + + r0 = READ_ONCE(*x); + synchronize_rcu(); + r1 = READ_ONCE(*y); +} + +exists (1:r0=1 /\ 1:r1=0) |