rcutorture: Test srcu_expedite_current()

This commit adds a ->exp_current member to the rcu_torture_ops structure
to test the srcu_expedite_current() function.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <bpf@vger.kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>

Author: paulmckrcu

kernel/rcu/rcutorture.c

@@ -389,6 +389,7 @@ struct rcu_torture_ops {
 	void (*deferred_free)(struct rcu_torture *p);
 	void (*sync)(void);
 	void (*exp_sync)(void);
+	void (*exp_current)(void);
 	unsigned long (*get_gp_state_exp)(void);
 	unsigned long (*start_gp_poll_exp)(void);
 	void (*start_gp_poll_exp_full)(struct rcu_gp_oldstate *rgosp);
@@ -857,6 +858,11 @@ static void srcu_torture_synchronize_expedited(void)
 	synchronize_srcu_expedited(srcu_ctlp);
 }
 
+static void srcu_torture_expedite_current(void)
+{
+	srcu_expedite_current(srcu_ctlp);
+}
+
 static struct rcu_torture_ops srcu_ops = {
 	.ttype		= SRCU_FLAVOR,
 	.init		= rcu_sync_torture_init,
@@ -871,6 +877,7 @@ static struct rcu_torture_ops srcu_ops = {
 	.deferred_free	= srcu_torture_deferred_free,
 	.sync		= srcu_torture_synchronize,
 	.exp_sync	= srcu_torture_synchronize_expedited,
+	.exp_current	= srcu_torture_expedite_current,
 	.same_gp_state	= same_state_synchronize_srcu,
 	.get_comp_state = get_completed_synchronize_srcu,
 	.get_gp_state	= srcu_torture_get_gp_state,
@@ -919,6 +926,7 @@ static struct rcu_torture_ops srcud_ops = {
 	.deferred_free	= srcu_torture_deferred_free,
 	.sync		= srcu_torture_synchronize,
 	.exp_sync	= srcu_torture_synchronize_expedited,
+	.exp_current	= srcu_torture_expedite_current,
 	.same_gp_state	= same_state_synchronize_srcu,
 	.get_comp_state = get_completed_synchronize_srcu,
 	.get_gp_state	= srcu_torture_get_gp_state,
@@ -1700,6 +1708,8 @@ rcu_torture_writer(void *arg)
 					ulo[i] = cur_ops->get_comp_state();
 				gp_snap = cur_ops->start_gp_poll();
 				rcu_torture_writer_state = RTWS_POLL_WAIT;
+				if (cur_ops->exp_current && !torture_random(&rand) % 0xff)
+					cur_ops->exp_current();
 				while (!cur_ops->poll_gp_state(gp_snap)) {
 					gp_snap1 = cur_ops->get_gp_state();
 					for (i = 0; i < ulo_size; i++)
@@ -1720,6 +1730,8 @@ rcu_torture_writer(void *arg)
 					cur_ops->get_comp_state_full(&rgo[i]);
 				cur_ops->start_gp_poll_full(&gp_snap_full);
 				rcu_torture_writer_state = RTWS_POLL_WAIT_FULL;
+				if (cur_ops->exp_current && !torture_random(&rand) % 0xff)
+					cur_ops->exp_current();
 				while (!cur_ops->poll_gp_state_full(&gp_snap_full)) {
 					cur_ops->get_gp_state_full(&gp_snap1_full);
 					for (i = 0; i < rgo_size; i++)