rcutorture: Use rcu_gp_slow_register/unregister() only for rcutype test

The rcu_gp_slow_register/unregister() is only useful in tests where
torture_type=rcu, so this commit therefore generates ->gp_slow_register()
and ->gp_slow_unregister() function pointers in the rcu_torture_ops
structure, and slows grace periods only when these function pointers
exist.

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 8654e99bd4a3418c39112d8ab992f5fc571a3cf5..807fbf6123a779062e0f4039e591d159752949a6 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -382,6 +382,8 @@ struct rcu_torture_ops {
        bool (*check_boost_failed)(unsigned long gp_state, int *cpup);
        int (*stall_dur)(void);
        void (*get_gp_data)(int *flags, unsigned long *gp_seq);
+       void (*gp_slow_register)(atomic_t *rgssp);
+       void (*gp_slow_unregister)(atomic_t *rgssp);
        long cbflood_max;
        int irq_capable;
        int can_boost;
@@ -570,6 +572,8 @@ static struct rcu_torture_ops rcu_ops = {
        .check_boost_failed     = rcu_check_boost_fail,
        .stall_dur              = rcu_jiffies_till_stall_check,
        .get_gp_data            = rcutorture_get_gp_data,
+       .gp_slow_register       = rcu_gp_slow_register,
+       .gp_slow_unregister     = rcu_gp_slow_unregister,
        .irq_capable            = 1,
        .can_boost              = IS_ENABLED(CONFIG_RCU_BOOST),
        .extendables            = RCUTORTURE_MAX_EXTEND,
@@ -3343,12 +3347,12 @@ rcu_torture_cleanup(void)
                        pr_info("%s: Invoking %pS().\n", __func__, cur_ops->cb_barrier);
                        cur_ops->cb_barrier();
                }
-               rcu_gp_slow_unregister(NULL);
+               if (cur_ops->gp_slow_unregister)
+                       cur_ops->gp_slow_unregister(NULL);
                return;
        }
        if (!cur_ops) {
                torture_cleanup_end();
-               rcu_gp_slow_unregister(NULL);
                return;
        }
 
@@ -3447,7 +3451,8 @@ rcu_torture_cleanup(void)
        else
                rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
        torture_cleanup_end();
-       rcu_gp_slow_unregister(&rcu_fwd_cb_nodelay);
+       if (cur_ops->gp_slow_unregister)
+               cur_ops->gp_slow_unregister(NULL);
 }
 
 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
@@ -3929,7 +3934,8 @@ rcu_torture_init(void)
        if (object_debug)
                rcu_test_debug_objects();
        torture_init_end();
-       rcu_gp_slow_register(&rcu_fwd_cb_nodelay);
+       if (cur_ops->gp_slow_register && !WARN_ON_ONCE(!cur_ops->gp_slow_unregister))
+               cur_ops->gp_slow_register(&rcu_fwd_cb_nodelay);
        return 0;
 
 unwind: