Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

[linux.git] / kernel / rcu / rcutorture.c

diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 049b3735dba834483d76342f71135ca36489b612..c596c6f1e45717af99da5139d3c5078782deafbe 100644 (file)
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -169,7 +169,7 @@ static long n_rcu_torture_boost_failure;
 static long n_rcu_torture_boosts;
 static atomic_long_t n_rcu_torture_timers;
 static long n_barrier_attempts;
-static long n_barrier_successes;
+static long n_barrier_successes; /* did rcu_barrier test succeed? */
 static atomic_long_t n_cbfloods;
 static struct list_head rcu_torture_removed;
 
@@ -1539,7 +1539,7 @@ rcu_torture_stats(void *arg)
        return 0;
 }
 
-static inline void
+static void
 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
 {
        pr_alert("%s" TORTURE_FLAG
@@ -1723,8 +1723,9 @@ static int rcu_torture_barrier(void *arg)
                               atomic_read(&barrier_cbs_invoked),
                               n_barrier_cbs);
                        WARN_ON_ONCE(1);
+               } else {
+                       n_barrier_successes++;
                }
-               n_barrier_successes++;
                schedule_timeout_interruptible(HZ / 10);
        } while (!torture_must_stop());
        torture_kthread_stopping("rcu_torture_barrier");
@@ -1787,6 +1788,30 @@ static void rcu_torture_barrier_cleanup(void)
        }
 }
 
+static bool rcu_torture_can_boost(void)
+{
+       static int boost_warn_once;
+       int prio;
+
+       if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2)
+               return false;
+
+       prio = rcu_get_gp_kthreads_prio();
+       if (!prio)
+               return false;
+
+       if (prio < 2) {
+               if (boost_warn_once  == 1)
+                       return false;
+
+               pr_alert("%s: WARN: RCU kthread priority too low to test boosting.  Skipping RCU boost test. Try passing rcutree.kthread_prio > 1 on the kernel command line.\n", KBUILD_MODNAME);
+               boost_warn_once = 1;
+               return false;
+       }
+
+       return true;
+}
+
 static enum cpuhp_state rcutor_hp;
 
 static void
@@ -1831,8 +1856,7 @@ rcu_torture_cleanup(void)
        torture_stop_kthread(rcu_torture_fqs, fqs_task);
        for (i = 0; i < ncbflooders; i++)
                torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
-       if ((test_boost == 1 && cur_ops->can_boost) ||
-           test_boost == 2)
+       if (rcu_torture_can_boost())
                cpuhp_remove_state(rcutor_hp);
 
        /*
@@ -1937,8 +1961,8 @@ rcu_torture_init(void)
                         torture_type);
                pr_alert("rcu-torture types:");
                for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
-                       pr_alert(" %s", torture_ops[i]->name);
-               pr_alert("\n");
+                       pr_cont(" %s", torture_ops[i]->name);
+               pr_cont("\n");
                firsterr = -EINVAL;
                goto unwind;
        }
@@ -2056,8 +2080,7 @@ rcu_torture_init(void)
                test_boost_interval = 1;
        if (test_boost_duration < 2)
                test_boost_duration = 2;
-       if ((test_boost == 1 && cur_ops->can_boost) ||
-           test_boost == 2) {
+       if (rcu_torture_can_boost()) {
 
                boost_starttime = jiffies + test_boost_interval * HZ;