[PATCH v3 tip/core/rcu 5/9] rcutorture: Add torture tests for RCU-tasks

Paul E. McKenney
2014-07-31T21:55:22Z

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

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>
---
include/linux/rcupdate.h | 1 +
kernel/rcu/rcutorture.c | 40 +++++++++++++++++++++++++++++++++++++++-
2 files changed, 40 insertions(+), 1 deletion(-)

diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h
index 1f073af940a5..f9d314bbc7b6 100644
--- 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 febe07062ac5..6d12ab6675bc 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -602,6 +602,42 @@ static struct rcu_torture_ops sched_ops = {
};

/*
+ * 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"
+};
+
+/*
* RCU torture priority-boost testing. Runs one real-time thread per
* CPU for moderate bursts, repeatedly registering RCU callbacks and
* spinning waiting for them to be invoked. If a given callback takes
@@ -1295,7 +1331,8 @@ 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 +1571,7 @@ 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,
+ &tasks_ops,
};

if (!torture_init_begin(torture_type, verbose, &rcutorture_runnable))
--
1.8.1.5