aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/rcu/rcutorture.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-04 12:58:33 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-04 12:58:33 -0700
commit28e92f990337b8b4c5fdec47667f8b96089c503e (patch)
tree0dc55280883e7262d831ad24deb3a4fd2a56031a /kernel/rcu/rcutorture.c
parentda803f82faa5ceeff34aa56c08ceba5384e44e47 (diff)
parent641faf1b9064c270a476a424e60063bb05df3ee9 (diff)
Merge branch 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU updates from Paul McKenney: - Bitmap parsing support for "all" as an alias for all bits - Documentation updates - Miscellaneous fixes, including some that overlap into mm and lockdep - kvfree_rcu() updates - mem_dump_obj() updates, with acks from one of the slab-allocator maintainers - RCU NOCB CPU updates, including limited deoffloading - SRCU updates - Tasks-RCU updates - Torture-test updates * 'core-rcu-2021.07.04' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: (78 commits) tasks-rcu: Make show_rcu_tasks_gp_kthreads() be static inline rcu-tasks: Make ksoftirqd provide RCU Tasks quiescent states rcu: Add missing __releases() annotation rcu: Remove obsolete rcu_read_unlock() deadlock commentary rcu: Improve comments describing RCU read-side critical sections rcu: Create an unrcu_pointer() to remove __rcu from a pointer srcu: Early test SRCU polling start rcu: Fix various typos in comments rcu/nocb: Unify timers rcu/nocb: Prepare for fine-grained deferred wakeup rcu/nocb: Only cancel nocb timer if not polling rcu/nocb: Delete bypass_timer upon nocb_gp wakeup rcu/nocb: Cancel nocb_timer upon nocb_gp wakeup rcu/nocb: Allow de-offloading rdp leader rcu/nocb: Directly call __wake_nocb_gp() from bypass timer rcu: Don't penalize priority boosting when there is nothing to boost rcu: Point to documentation of ordering guarantees rcu: Make rcu_gp_cleanup() be noinline for tracing rcu: Restrict RCU_STRICT_GRACE_PERIOD to at most four CPUs rcu: Make show_rcu_gp_kthreads() dump rcu_node structures blocking GP ...
Diffstat (limited to 'kernel/rcu/rcutorture.c')
-rw-r--r--kernel/rcu/rcutorture.c315
1 files changed, 170 insertions, 145 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index 194b9c145c40..40ef5417d954 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -245,12 +245,6 @@ static const char *rcu_torture_writer_state_getname(void)
return rcu_torture_writer_state_names[i];
}
-#if defined(CONFIG_RCU_BOOST) && defined(CONFIG_PREEMPT_RT)
-# define rcu_can_boost() 1
-#else
-# define rcu_can_boost() 0
-#endif
-
#ifdef CONFIG_RCU_TRACE
static u64 notrace rcu_trace_clock_local(void)
{
@@ -331,6 +325,7 @@ struct rcu_torture_ops {
void (*read_delay)(struct torture_random_state *rrsp,
struct rt_read_seg *rtrsp);
void (*readunlock)(int idx);
+ int (*readlock_held)(void);
unsigned long (*get_gp_seq)(void);
unsigned long (*gp_diff)(unsigned long new, unsigned long old);
void (*deferred_free)(struct rcu_torture *p);
@@ -345,6 +340,7 @@ struct rcu_torture_ops {
void (*fqs)(void);
void (*stats)(void);
void (*gp_kthread_dbg)(void);
+ bool (*check_boost_failed)(unsigned long gp_state, int *cpup);
int (*stall_dur)(void);
int irq_capable;
int can_boost;
@@ -359,6 +355,11 @@ static struct rcu_torture_ops *cur_ops;
* Definitions for rcu torture testing.
*/
+static int torture_readlock_not_held(void)
+{
+ return rcu_read_lock_bh_held() || rcu_read_lock_sched_held();
+}
+
static int rcu_torture_read_lock(void) __acquires(RCU)
{
rcu_read_lock();
@@ -483,30 +484,32 @@ static void rcu_sync_torture_init(void)
}
static struct rcu_torture_ops rcu_ops = {
- .ttype = RCU_FLAVOR,
- .init = rcu_sync_torture_init,
- .readlock = rcu_torture_read_lock,
- .read_delay = rcu_read_delay,
- .readunlock = rcu_torture_read_unlock,
- .get_gp_seq = rcu_get_gp_seq,
- .gp_diff = rcu_seq_diff,
- .deferred_free = rcu_torture_deferred_free,
- .sync = synchronize_rcu,
- .exp_sync = synchronize_rcu_expedited,
- .get_gp_state = get_state_synchronize_rcu,
- .start_gp_poll = start_poll_synchronize_rcu,
- .poll_gp_state = poll_state_synchronize_rcu,
- .cond_sync = cond_synchronize_rcu,
- .call = call_rcu,
- .cb_barrier = rcu_barrier,
- .fqs = rcu_force_quiescent_state,
- .stats = NULL,
- .gp_kthread_dbg = show_rcu_gp_kthreads,
- .stall_dur = rcu_jiffies_till_stall_check,
- .irq_capable = 1,
- .can_boost = rcu_can_boost(),
- .extendables = RCUTORTURE_MAX_EXTEND,
- .name = "rcu"
+ .ttype = RCU_FLAVOR,
+ .init = rcu_sync_torture_init,
+ .readlock = rcu_torture_read_lock,
+ .read_delay = rcu_read_delay,
+ .readunlock = rcu_torture_read_unlock,
+ .readlock_held = torture_readlock_not_held,
+ .get_gp_seq = rcu_get_gp_seq,
+ .gp_diff = rcu_seq_diff,
+ .deferred_free = rcu_torture_deferred_free,
+ .sync = synchronize_rcu,
+ .exp_sync = synchronize_rcu_expedited,
+ .get_gp_state = get_state_synchronize_rcu,
+ .start_gp_poll = start_poll_synchronize_rcu,
+ .poll_gp_state = poll_state_synchronize_rcu,
+ .cond_sync = cond_synchronize_rcu,
+ .call = call_rcu,
+ .cb_barrier = rcu_barrier,
+ .fqs = rcu_force_quiescent_state,
+ .stats = NULL,
+ .gp_kthread_dbg = show_rcu_gp_kthreads,
+ .check_boost_failed = rcu_check_boost_fail,
+ .stall_dur = rcu_jiffies_till_stall_check,
+ .irq_capable = 1,
+ .can_boost = IS_ENABLED(CONFIG_RCU_BOOST),
+ .extendables = RCUTORTURE_MAX_EXTEND,
+ .name = "rcu"
};
/*
@@ -540,6 +543,7 @@ static struct rcu_torture_ops rcu_busted_ops = {
.readlock = rcu_torture_read_lock,
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
.readunlock = rcu_torture_read_unlock,
+ .readlock_held = torture_readlock_not_held,
.get_gp_seq = rcu_no_completed,
.deferred_free = rcu_busted_torture_deferred_free,
.sync = synchronize_rcu_busted,
@@ -589,6 +593,11 @@ static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
srcu_read_unlock(srcu_ctlp, idx);
}
+static int torture_srcu_read_lock_held(void)
+{
+ return srcu_read_lock_held(srcu_ctlp);
+}
+
static unsigned long srcu_torture_completed(void)
{
return srcu_batches_completed(srcu_ctlp);
@@ -646,6 +655,7 @@ static struct rcu_torture_ops srcu_ops = {
.readlock = srcu_torture_read_lock,
.read_delay = srcu_read_delay,
.readunlock = srcu_torture_read_unlock,
+ .readlock_held = torture_srcu_read_lock_held,
.get_gp_seq = srcu_torture_completed,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
@@ -681,6 +691,7 @@ static struct rcu_torture_ops srcud_ops = {
.readlock = srcu_torture_read_lock,
.read_delay = srcu_read_delay,
.readunlock = srcu_torture_read_unlock,
+ .readlock_held = torture_srcu_read_lock_held,
.get_gp_seq = srcu_torture_completed,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
@@ -700,6 +711,7 @@ static struct rcu_torture_ops busted_srcud_ops = {
.readlock = srcu_torture_read_lock,
.read_delay = rcu_read_delay,
.readunlock = srcu_torture_read_unlock,
+ .readlock_held = torture_srcu_read_lock_held,
.get_gp_seq = srcu_torture_completed,
.deferred_free = srcu_torture_deferred_free,
.sync = srcu_torture_synchronize,
@@ -787,6 +799,7 @@ static struct rcu_torture_ops trivial_ops = {
.readlock = rcu_torture_read_lock_trivial,
.read_delay = rcu_read_delay, /* just reuse rcu's version. */
.readunlock = rcu_torture_read_unlock_trivial,
+ .readlock_held = torture_readlock_not_held,
.get_gp_seq = rcu_no_completed,
.sync = synchronize_rcu_trivial,
.exp_sync = synchronize_rcu_trivial,
@@ -850,6 +863,7 @@ static struct rcu_torture_ops tasks_tracing_ops = {
.readlock = tasks_tracing_torture_read_lock,
.read_delay = srcu_read_delay, /* just reuse srcu's version. */
.readunlock = tasks_tracing_torture_read_unlock,
+ .readlock_held = rcu_read_lock_trace_held,
.get_gp_seq = rcu_no_completed,
.deferred_free = rcu_tasks_tracing_torture_deferred_free,
.sync = synchronize_rcu_tasks_trace,
@@ -871,32 +885,13 @@ static unsigned long rcutorture_seq_diff(unsigned long new, unsigned long old)
return cur_ops->gp_diff(new, old);
}
-static bool __maybe_unused torturing_tasks(void)
-{
- return cur_ops == &tasks_ops || cur_ops == &tasks_rude_ops;
-}
-
/*
* RCU torture priority-boost testing. Runs one real-time thread per
- * CPU for moderate bursts, repeatedly registering RCU callbacks and
- * spinning waiting for them to be invoked. If a given callback takes
- * too long to be invoked, we assume that priority inversion has occurred.
+ * CPU for moderate bursts, repeatedly starting grace periods and waiting
+ * for them to complete. If a given grace period takes too long, we assume
+ * that priority inversion has occurred.
*/
-struct rcu_boost_inflight {
- struct rcu_head rcu;
- int inflight;
-};
-
-static void rcu_torture_boost_cb(struct rcu_head *head)
-{
- struct rcu_boost_inflight *rbip =
- container_of(head, struct rcu_boost_inflight, rcu);
-
- /* Ensure RCU-core accesses precede clearing ->inflight */
- smp_store_release(&rbip->inflight, 0);
-}
-
static int old_rt_runtime = -1;
static void rcu_torture_disable_rt_throttle(void)
@@ -923,49 +918,68 @@ static void rcu_torture_enable_rt_throttle(void)
old_rt_runtime = -1;
}
-static bool rcu_torture_boost_failed(unsigned long start, unsigned long end)
+static bool rcu_torture_boost_failed(unsigned long gp_state, unsigned long *start)
{
+ int cpu;
static int dbg_done;
-
- if (end - start > test_boost_duration * HZ - HZ / 2) {
+ unsigned long end = jiffies;
+ bool gp_done;
+ unsigned long j;
+ static unsigned long last_persist;
+ unsigned long lp;
+ unsigned long mininterval = test_boost_duration * HZ - HZ / 2;
+
+ if (end - *start > mininterval) {
+ // Recheck after checking time to avoid false positives.
+ smp_mb(); // Time check before grace-period check.
+ if (cur_ops->poll_gp_state(gp_state))
+ return false; // passed, though perhaps just barely
+ if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, &cpu)) {
+ // At most one persisted message per boost test.
+ j = jiffies;
+ lp = READ_ONCE(last_persist);
+ if (time_after(j, lp + mininterval) && cmpxchg(&last_persist, lp, j) == lp)
+ pr_info("Boost inversion persisted: No QS from CPU %d\n", cpu);
+ return false; // passed on a technicality
+ }
VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
n_rcu_torture_boost_failure++;
- if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg)
+ if (!xchg(&dbg_done, 1) && cur_ops->gp_kthread_dbg) {
+ pr_info("Boost inversion thread ->rt_priority %u gp_state %lu jiffies %lu\n",
+ current->rt_priority, gp_state, end - *start);
cur_ops->gp_kthread_dbg();
+ // Recheck after print to flag grace period ending during splat.
+ gp_done = cur_ops->poll_gp_state(gp_state);
+ pr_info("Boost inversion: GP %lu %s.\n", gp_state,
+ gp_done ? "ended already" : "still pending");
- return true; /* failed */
+ }
+
+ return true; // failed
+ } else if (cur_ops->check_boost_failed && !cur_ops->check_boost_failed(gp_state, NULL)) {
+ *start = jiffies;
}
- return false; /* passed */
+ return false; // passed
}
static int rcu_torture_boost(void *arg)
{
- unsigned long call_rcu_time;
unsigned long endtime;
+ unsigned long gp_state;
+ unsigned long gp_state_time;
unsigned long oldstarttime;
- struct rcu_boost_inflight rbi = { .inflight = 0 };
VERBOSE_TOROUT_STRING("rcu_torture_boost started");
/* Set real-time priority. */
sched_set_fifo_low(current);
- init_rcu_head_on_stack(&rbi.rcu);
/* Each pass through the following loop does one boost-test cycle. */
do {
bool failed = false; // Test failed already in this test interval
- bool firsttime = true;
+ bool gp_initiated = 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;
@@ -979,33 +993,33 @@ static int rcu_torture_boost(void *arg)
goto checkwait;
}
- /* Do one boost-test interval. */
+ // Do one boost-test interval.
endtime = oldstarttime + test_boost_duration * HZ;
while (time_before(jiffies, endtime)) {
- /* If we don't have a callback in flight, post one. */
- if (!smp_load_acquire(&rbi.inflight)) {
- /* RCU core before ->inflight = 1. */
- smp_store_release(&rbi.inflight, 1);
- cur_ops->call(&rbi.rcu, rcu_torture_boost_cb);
- /* Check if the boost test failed */
- if (!firsttime && !failed)
- failed = rcu_torture_boost_failed(call_rcu_time, jiffies);
- call_rcu_time = jiffies;
- firsttime = false;
+ // Has current GP gone too long?
+ if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state))
+ failed = rcu_torture_boost_failed(gp_state, &gp_state_time);
+ // If we don't have a grace period in flight, start one.
+ if (!gp_initiated || cur_ops->poll_gp_state(gp_state)) {
+ gp_state = cur_ops->start_gp_poll();
+ gp_initiated = true;
+ gp_state_time = jiffies;
}
- if (stutter_wait("rcu_torture_boost"))
+ if (stutter_wait("rcu_torture_boost")) {
sched_set_fifo_low(current);
+ // If the grace period already ended,
+ // we don't know when that happened, so
+ // start over.
+ if (cur_ops->poll_gp_state(gp_state))
+ gp_initiated = false;
+ }
if (torture_must_stop())
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 (!firsttime && !failed && smp_load_acquire(&rbi.inflight))
- rcu_torture_boost_failed(call_rcu_time, jiffies);
+ // In case the grace period extended beyond the end of the loop.
+ if (gp_initiated && !failed && !cur_ops->poll_gp_state(gp_state))
+ rcu_torture_boost_failed(gp_state, &gp_state_time);
/*
* Set the start time of the next test interval.
@@ -1014,11 +1028,12 @@ static int rcu_torture_boost(void *arg)
* interval. Besides, we are running at RT priority,
* so delays should be relatively rare.
*/
- while (oldstarttime == boost_starttime &&
- !kthread_should_stop()) {
+ while (oldstarttime == boost_starttime && !kthread_should_stop()) {
if (mutex_trylock(&boost_mutex)) {
- boost_starttime = jiffies +
- test_boost_interval * HZ;
+ if (oldstarttime == boost_starttime) {
+ boost_starttime = jiffies + test_boost_interval * HZ;
+ n_rcu_torture_boosts++;
+ }
mutex_unlock(&boost_mutex);
break;
}
@@ -1030,15 +1045,11 @@ checkwait: if (stutter_wait("rcu_torture_boost"))
sched_set_fifo_low(current);
} while (!torture_must_stop());
- while (smp_load_acquire(&rbi.inflight))
- schedule_timeout_uninterruptible(1); // rcu_barrier() deadlocks.
-
/* Clean up and exit. */
- while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
+ while (!kthread_should_stop()) {
torture_shutdown_absorb("rcu_torture_boost");
schedule_timeout_uninterruptible(1);
}
- destroy_rcu_head_on_stack(&rbi.rcu);
torture_kthread_stopping("rcu_torture_boost");
return 0;
}
@@ -1553,11 +1564,7 @@ static bool rcu_torture_one_read(struct torture_random_state *trsp, long myid)
started = cur_ops->get_gp_seq();
ts = rcu_trace_clock_local();
p = rcu_dereference_check(rcu_torture_current,
- rcu_read_lock_bh_held() ||
- rcu_read_lock_sched_held() ||
- srcu_read_lock_held(srcu_ctlp) ||
- rcu_read_lock_trace_held() ||
- torturing_tasks());
+ !cur_ops->readlock_held || cur_ops->readlock_held());
if (p == NULL) {
/* Wait for rcu_torture_writer to get underway */
rcutorture_one_extend(&readstate, 0, trsp, rtrsp);
@@ -1861,48 +1868,49 @@ rcu_torture_stats(void *arg)
torture_shutdown_absorb("rcu_torture_stats");
} while (!torture_must_stop());
torture_kthread_stopping("rcu_torture_stats");
-
- {
- struct rcu_head *rhp;
- struct kmem_cache *kcp;
- static int z;
-
- kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL);
- rhp = kmem_cache_alloc(kcp, GFP_KERNEL);
- pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z);
- pr_alert("mem_dump_obj(ZERO_SIZE_PTR):");
- mem_dump_obj(ZERO_SIZE_PTR);
- pr_alert("mem_dump_obj(NULL):");
- mem_dump_obj(NULL);
- pr_alert("mem_dump_obj(%px):", &rhp);
- mem_dump_obj(&rhp);
- pr_alert("mem_dump_obj(%px):", rhp);
- mem_dump_obj(rhp);
- pr_alert("mem_dump_obj(%px):", &rhp->func);
- mem_dump_obj(&rhp->func);
- pr_alert("mem_dump_obj(%px):", &z);
- mem_dump_obj(&z);
- kmem_cache_free(kcp, rhp);
- kmem_cache_destroy(kcp);
- rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
- pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
- pr_alert("mem_dump_obj(kmalloc %px):", rhp);
- mem_dump_obj(rhp);
- pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func);
- mem_dump_obj(&rhp->func);
- kfree(rhp);
- rhp = vmalloc(4096);
- pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
- pr_alert("mem_dump_obj(vmalloc %px):", rhp);
- mem_dump_obj(rhp);
- pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func);
- mem_dump_obj(&rhp->func);
- vfree(rhp);
- }
-
return 0;
}
+/* Test mem_dump_obj() and friends. */
+static void rcu_torture_mem_dump_obj(void)
+{
+ struct rcu_head *rhp;
+ struct kmem_cache *kcp;
+ static int z;
+
+ kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL);
+ rhp = kmem_cache_alloc(kcp, GFP_KERNEL);
+ pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z);
+ pr_alert("mem_dump_obj(ZERO_SIZE_PTR):");
+ mem_dump_obj(ZERO_SIZE_PTR);
+ pr_alert("mem_dump_obj(NULL):");
+ mem_dump_obj(NULL);
+ pr_alert("mem_dump_obj(%px):", &rhp);
+ mem_dump_obj(&rhp);
+ pr_alert("mem_dump_obj(%px):", rhp);
+ mem_dump_obj(rhp);
+ pr_alert("mem_dump_obj(%px):", &rhp->func);
+ mem_dump_obj(&rhp->func);
+ pr_alert("mem_dump_obj(%px):", &z);
+ mem_dump_obj(&z);
+ kmem_cache_free(kcp, rhp);
+ kmem_cache_destroy(kcp);
+ rhp = kmalloc(sizeof(*rhp), GFP_KERNEL);
+ pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
+ pr_alert("mem_dump_obj(kmalloc %px):", rhp);
+ mem_dump_obj(rhp);
+ pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func);
+ mem_dump_obj(&rhp->func);
+ kfree(rhp);
+ rhp = vmalloc(4096);
+ pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp);
+ pr_alert("mem_dump_obj(vmalloc %px):", rhp);
+ mem_dump_obj(rhp);
+ pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func);
+ mem_dump_obj(&rhp->func);
+ vfree(rhp);
+}
+
static void
rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
{
@@ -2634,7 +2642,7 @@ static bool rcu_torture_can_boost(void)
if (!(test_boost == 1 && cur_ops->can_boost) && test_boost != 2)
return false;
- if (!cur_ops->call)
+ if (!cur_ops->start_gp_poll || !cur_ops->poll_gp_state)
return false;
prio = rcu_get_gp_kthreads_prio();
@@ -2642,7 +2650,7 @@ static bool rcu_torture_can_boost(void)
return false;
if (prio < 2) {
- if (boost_warn_once == 1)
+ 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);
@@ -2818,6 +2826,8 @@ rcu_torture_cleanup(void)
if (cur_ops->cleanup != NULL)
cur_ops->cleanup();
+ rcu_torture_mem_dump_obj();
+
rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
if (err_segs_recorded) {
@@ -3120,6 +3130,21 @@ rcu_torture_init(void)
if (firsterr < 0)
goto unwind;
rcutor_hp = firsterr;
+
+ // Testing RCU priority boosting requires rcutorture do
+ // some serious abuse. Counter this by running ksoftirqd
+ // at higher priority.
+ if (IS_BUILTIN(CONFIG_RCU_TORTURE_TEST)) {
+ for_each_online_cpu(cpu) {
+ struct sched_param sp;
+ struct task_struct *t;
+
+ t = per_cpu(ksoftirqd, cpu);
+ WARN_ON_ONCE(!t);
+ sp.sched_priority = 2;
+ sched_setscheduler_nocheck(t, SCHED_FIFO, &sp);
+ }
+ }
}
shutdown_jiffies = jiffies + shutdown_secs * HZ;
firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);

Privacy Policy