rcu/rcutorture: Use call_rcu_flush() where needed

call_rcu() changes to save power will change the behavior of rcutorture
tests. Use the call_rcu_flush() API instead which reverts to the old
behavior.

Reported-by: Paul E. McKenney <[email protected]>
Signed-off-by: Joel Fernandes (Google) <[email protected]>
Signed-off-by: Paul E. McKenney <[email protected]>

Author: joelagnel

kernel/rcu/rcutorture.c

@@ -510,7 +510,7 @@ static unsigned long rcu_no_completed(void)
 
 static void rcu_torture_deferred_free(struct rcu_torture *p)
 {
-	call_rcu(&p->rtort_rcu, rcu_torture_cb);
+	call_rcu_flush(&p->rtort_rcu, rcu_torture_cb);
 }
 
 static void rcu_sync_torture_init(void)
@@ -551,7 +551,7 @@ static struct rcu_torture_ops rcu_ops = {
 	.start_gp_poll_exp_full	= start_poll_synchronize_rcu_expedited_full,
 	.poll_gp_state_exp	= poll_state_synchronize_rcu,
 	.cond_sync_exp		= cond_synchronize_rcu_expedited,
-	.call			= call_rcu,
+	.call			= call_rcu_flush,
 	.cb_barrier		= rcu_barrier,
 	.fqs			= rcu_force_quiescent_state,
 	.stats			= NULL,
@@ -848,7 +848,7 @@ static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
 
 static void synchronize_rcu_mult_test(void)
 {
-	synchronize_rcu_mult(call_rcu_tasks, call_rcu);
+	synchronize_rcu_mult(call_rcu_tasks, call_rcu_flush);
 }
 
 static struct rcu_torture_ops tasks_ops = {
@@ -3388,13 +3388,13 @@ static void rcu_test_debug_objects(void)
 	/* Try to queue the rh2 pair of callbacks for the same grace period. */
 	preempt_disable(); /* Prevent preemption from interrupting test. */
 	rcu_read_lock(); /* Make it impossible to finish a grace period. */
-	call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
+	call_rcu_flush(&rh1, rcu_torture_leak_cb); /* Start grace period. */
 	local_irq_disable(); /* Make it harder to start a new grace period. */
-	call_rcu(&rh2, rcu_torture_leak_cb);
-	call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
+	call_rcu_flush(&rh2, rcu_torture_leak_cb);
+	call_rcu_flush(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
 	if (rhp) {
-		call_rcu(rhp, rcu_torture_leak_cb);
-		call_rcu(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
+		call_rcu_flush(rhp, rcu_torture_leak_cb);
+		call_rcu_flush(rhp, rcu_torture_err_cb); /* Another duplicate callback. */
 	}
 	local_irq_enable();
 	rcu_read_unlock();