#include <linux/torture.h>
#include <linux/vmalloc.h>
#include <linux/sched/debug.h>
+#include <linux/sched/sysctl.h>
#include "rcu.h"
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;
smp_store_release(&rbip->inflight, 0);
}
+static int old_rt_runtime = -1;
+
+static void rcu_torture_disable_rt_throttle(void)
+{
+ /*
+ * Disable RT throttling so that rcutorture's boost threads don't get
+ * throttled. Only possible if rcutorture is built-in otherwise the
+ * user should manually do this by setting the sched_rt_period_us and
+ * sched_rt_runtime sysctls.
+ */
+ if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime != -1)
+ return;
+
+ old_rt_runtime = sysctl_sched_rt_runtime;
+ sysctl_sched_rt_runtime = -1;
+}
+
+static void rcu_torture_enable_rt_throttle(void)
+{
+ if (!IS_BUILTIN(CONFIG_RCU_TORTURE_TEST) || old_rt_runtime == -1)
+ return;
+
+ sysctl_sched_rt_runtime = old_rt_runtime;
+ old_rt_runtime = -1;
+}
+
+static bool rcu_torture_boost_failed(unsigned long start, unsigned long end)
+{
+ if (end - start > test_boost_duration * HZ - HZ / 2) {
+ VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
+ n_rcu_torture_boost_failure++;
+
+ return true; /* failed */
+ }
+
+ return false; /* passed */
+}
+
static int rcu_torture_boost(void *arg)
{
unsigned long call_rcu_time;
init_rcu_head_on_stack(&rbi.rcu);
/* Each pass through the following loop does one boost-test cycle. */
do {
+ /* Track if the test failed already in this test interval? */
+ bool failed = false;
+
+ /* Increment n_rcu_torture_boosts once per boost-test */
+ while (!kthread_should_stop()) {
+ if (mutex_trylock(&boost_mutex)) {
+ n_rcu_torture_boosts++;
+ mutex_unlock(&boost_mutex);
+ break;
+ }
+ schedule_timeout_uninterruptible(1);
+ }
+ if (kthread_should_stop())
+ goto checkwait;
+
/* Wait for the next test interval. */
oldstarttime = boost_starttime;
while (ULONG_CMP_LT(jiffies, oldstarttime)) {
/* RCU core before ->inflight = 1. */
smp_store_release(&rbi.inflight, 1);
call_rcu(&rbi.rcu, rcu_torture_boost_cb);
- if (jiffies - call_rcu_time >
- test_boost_duration * HZ - HZ / 2) {
- VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
- n_rcu_torture_boost_failure++;
- }
+ /* Check if the boost test failed */
+ failed = failed ||
+ rcu_torture_boost_failed(call_rcu_time,
+ jiffies);
call_rcu_time = jiffies;
}
stutter_wait("rcu_torture_boost");
goto checkwait;
}
+ /*
+ * If boost never happened, then inflight will always be 1, in
+ * this case the boost check would never happen in the above
+ * loop so do another one here.
+ */
+ if (!failed && smp_load_acquire(&rbi.inflight))
+ rcu_torture_boost_failed(call_rcu_time, jiffies);
+
/*
* Set the start time of the next test interval.
* Yes, this is vulnerable to long delays, but such
if (mutex_trylock(&boost_mutex)) {
boost_starttime = jiffies +
test_boost_interval * HZ;
- n_rcu_torture_boosts++;
mutex_unlock(&boost_mutex);
break;
}
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
mutex_lock(&boost_mutex);
t = boost_tasks[cpu];
boost_tasks[cpu] = NULL;
+ rcu_torture_enable_rt_throttle();
mutex_unlock(&boost_mutex);
/* This must be outside of the mutex, otherwise deadlock! */
/* Don't allow time recalculation while creating a new task. */
mutex_lock(&boost_mutex);
+ rcu_torture_disable_rt_throttle();
VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
cpu_to_node(cpu),
VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
}
if (!kthread_should_stop()) {
- stop_at = get_seconds() + stall_cpu;
+ stop_at = ktime_get_seconds() + stall_cpu;
/* RCU CPU stall is expected behavior in following code. */
rcu_read_lock();
if (stall_cpu_irqsoff)
preempt_disable();
pr_alert("rcu_torture_stall start on CPU %d.\n",
smp_processor_id());
- while (ULONG_CMP_LT(get_seconds(), stop_at))
+ while (ULONG_CMP_LT((unsigned long)ktime_get_seconds(),
+ stop_at))
continue; /* Induce RCU CPU stall warning. */
if (stall_cpu_irqsoff)
local_irq_enable();
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");
}
}
+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
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);
/*
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;
}
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;
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