rcutorture: Verify NUM_ACTIVE_RCU_POLL_OLDSTATE

This commit adds code to the RTWS_POLL_GET case of rcu_torture_writer()
to verify that the value of NUM_ACTIVE_RCU_POLL_OLDSTATE is sufficiently
large

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index b688576..9ad5301 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -357,7 +357,9 @@ struct rcu_torture_ops {
        bool (*poll_gp_state_exp)(unsigned long oldstate);
        void (*cond_sync_exp)(unsigned long oldstate);
        void (*cond_sync_exp_full)(struct rcu_gp_oldstate *rgosp);
+       unsigned long (*get_comp_state)(void);
        void (*get_comp_state_full)(struct rcu_gp_oldstate *rgosp);
+       bool (*same_gp_state)(unsigned long oldstate1, unsigned long oldstate2);
        bool (*same_gp_state_full)(struct rcu_gp_oldstate *rgosp1, struct rcu_gp_oldstate *rgosp2);
        unsigned long (*get_gp_state)(void);
        void (*get_gp_state_full)(struct rcu_gp_oldstate *rgosp);
@@ -537,7 +539,9 @@ static struct rcu_torture_ops rcu_ops = {
        .deferred_free          = rcu_torture_deferred_free,
        .sync                   = synchronize_rcu,
        .exp_sync               = synchronize_rcu_expedited,
+       .same_gp_state          = same_state_synchronize_rcu,
        .same_gp_state_full     = same_state_synchronize_rcu_full,
+       .get_comp_state         = get_completed_synchronize_rcu,
        .get_comp_state_full    = get_completed_synchronize_rcu_full,
        .get_gp_state           = get_state_synchronize_rcu,
        .get_gp_state_full      = get_state_synchronize_rcu_full,
@@ -1262,7 +1266,8 @@ static void rcu_torture_write_types(void)
        } else if (gp_normal && !cur_ops->deferred_free) {
                pr_alert("%s: gp_normal without primitives.\n", __func__);
        }
-       if (gp_poll1 && cur_ops->start_gp_poll && cur_ops->poll_gp_state) {
+       if (gp_poll1 && cur_ops->get_comp_state && cur_ops->same_gp_state &&
+           cur_ops->start_gp_poll && cur_ops->poll_gp_state) {
                synctype[nsynctypes++] = RTWS_POLL_GET;
                pr_info("%s: Testing polling GPs.\n", __func__);
        } else if (gp_poll && (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)) {
@@ -1344,6 +1349,7 @@ rcu_torture_writer(void *arg)
        struct rcu_gp_oldstate cookie_full;
        int expediting = 0;
        unsigned long gp_snap;
+       unsigned long gp_snap1;
        struct rcu_gp_oldstate gp_snap_full;
        struct rcu_gp_oldstate gp_snap1_full;
        int i;
@@ -1354,6 +1360,7 @@ rcu_torture_writer(void *arg)
        struct rcu_torture *old_rp;
        static DEFINE_TORTURE_RANDOM(rand);
        bool stutter_waited;
+       unsigned long ulo[NUM_ACTIVE_RCU_POLL_OLDSTATE];
 
        VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
        if (!can_expedite)
@@ -1470,11 +1477,22 @@ rcu_torture_writer(void *arg)
                                break;
                        case RTWS_POLL_GET:
                                rcu_torture_writer_state = RTWS_POLL_GET;
+                               for (i = 0; i < ARRAY_SIZE(ulo); i++)
+                                       ulo[i] = cur_ops->get_comp_state();
                                gp_snap = cur_ops->start_gp_poll();
                                rcu_torture_writer_state = RTWS_POLL_WAIT;
-                               while (!cur_ops->poll_gp_state(gp_snap))
+                               while (!cur_ops->poll_gp_state(gp_snap)) {
+                                       gp_snap1 = cur_ops->get_gp_state();
+                                       for (i = 0; i < ARRAY_SIZE(ulo); i++)
+                                               if (cur_ops->poll_gp_state(ulo[i]) ||
+                                                   cur_ops->same_gp_state(ulo[i], gp_snap1)) {
+                                                       ulo[i] = gp_snap1;
+                                                       break;
+                                               }
+                                       WARN_ON_ONCE(i >= ARRAY_SIZE(ulo));
                                        torture_hrtimeout_jiffies(torture_random(&rand) % 16,
                                                                  &rand);
+                               }
                                rcu_torture_pipe_update(old_rp);
                                break;
                        case RTWS_POLL_GET_FULL: