rcutorture: Add torture tests for RCU-tasks

This commit adds torture tests for RCU-tasks.  It also fixes a bug that
would segfault for an RCU flavor lacking a callback-barrier function.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 54b2ebb203133673d269f54ba6804f6ac000478d..a3123f53a4cec7c90df78144781155e76f2cba55 100644 (file)
--- a/include/linux/rcupdate.h
+++ b/include/linux/rcupdate.h
@@ -55,6 +55,7 @@ enum rcutorture_type {
        RCU_FLAVOR,
        RCU_BH_FLAVOR,
        RCU_SCHED_FLAVOR,
+       RCU_TASKS_FLAVOR,
        SRCU_FLAVOR,
        INVALID_RCU_FLAVOR
 };

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 178716713e110e91b4561ab045366ca65d18ff91..75b1abf78c4880a6749c074a74e31a086d81362e 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -601,6 +601,52 @@ static struct rcu_torture_ops sched_ops = {
        .name           = "sched"
 };
 
+#ifdef CONFIG_TASKS_RCU
+
+/*
+ * Definitions for RCU-tasks torture testing.
+ */
+
+static int tasks_torture_read_lock(void)
+{
+       return 0;
+}
+
+static void tasks_torture_read_unlock(int idx)
+{
+}
+
+static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
+{
+       call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops tasks_ops = {
+       .ttype          = RCU_TASKS_FLAVOR,
+       .init           = rcu_sync_torture_init,
+       .readlock       = tasks_torture_read_lock,
+       .read_delay     = rcu_read_delay,  /* just reuse rcu's version. */
+       .readunlock     = tasks_torture_read_unlock,
+       .completed      = rcu_no_completed,
+       .deferred_free  = rcu_tasks_torture_deferred_free,
+       .sync           = synchronize_rcu_tasks,
+       .exp_sync       = synchronize_rcu_tasks,
+       .call           = call_rcu_tasks,
+       .cb_barrier     = rcu_barrier_tasks,
+       .fqs            = NULL,
+       .stats          = NULL,
+       .irq_capable    = 1,
+       .name           = "tasks"
+};
+
+#define RCUTORTURE_TASKS_OPS &tasks_ops,
+
+#else /* #ifdef CONFIG_TASKS_RCU */
+
+#define RCUTORTURE_TASKS_OPS
+
+#endif /* #else #ifdef CONFIG_TASKS_RCU */
+
 /*
  * RCU torture priority-boost testing.  Runs one real-time thread per
  * CPU for moderate bursts, repeatedly registering RCU callbacks and
@@ -1295,7 +1341,8 @@ static int rcu_torture_barrier_cbs(void *arg)
                if (atomic_dec_and_test(&barrier_cbs_count))
                        wake_up(&barrier_wq);
        } while (!torture_must_stop());
-       cur_ops->cb_barrier();
+       if (cur_ops->cb_barrier != NULL)
+               cur_ops->cb_barrier();
        destroy_rcu_head_on_stack(&rcu);
        torture_kthread_stopping("rcu_torture_barrier_cbs");
        return 0;
@@ -1534,6 +1581,7 @@ rcu_torture_init(void)
        int firsterr = 0;
        static struct rcu_torture_ops *torture_ops[] = {
                &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &sched_ops,
+               RCUTORTURE_TASKS_OPS
        };
 
        if (!torture_init_begin(torture_type, verbose, &rcutorture_runnable))