summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt6
-rw-r--r--kernel/rcu/rcutorture.c114
2 files changed, 91 insertions, 29 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 9725c546a0d4..ba60da85d1c8 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4603,8 +4603,12 @@
in seconds.
rcutorture.fwd_progress= [KNL]
- Enable RCU grace-period forward-progress testing
+ Specifies the number of kthreads to be used
+ for RCU grace-period forward-progress testing
for the types of RCU supporting this notion.
+ Defaults to 1 kthread, values less than zero or
+ greater than the number of CPUs cause the number
+ of CPUs to be used.
rcutorture.fwd_progress_div= [KNL]
Specify the fraction of a CPU-stall-warning
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index bc854f935548..9390f867ba6c 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -79,7 +79,7 @@ torture_param(int, fqs_duration, 0,
"Duration of fqs bursts (us), 0 to disable");
torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
-torture_param(bool, fwd_progress, 1, "Test grace-period forward progress");
+torture_param(int, fwd_progress, 1, "Test grace-period forward progress");
torture_param(int, fwd_progress_div, 4, "Fraction of CPU stall to wait");
torture_param(int, fwd_progress_holdoff, 60,
"Time between forward-progress tests (s)");
@@ -146,7 +146,7 @@ static struct task_struct *stats_task;
static struct task_struct *fqs_task;
static struct task_struct *boost_tasks[NR_CPUS];
static struct task_struct *stall_task;
-static struct task_struct *fwd_prog_task;
+static struct task_struct **fwd_prog_tasks;
static struct task_struct **barrier_cbs_tasks;
static struct task_struct *barrier_task;
static struct task_struct *read_exit_task;
@@ -2161,10 +2161,12 @@ struct rcu_fwd {
unsigned long rcu_fwd_startat;
struct rcu_launder_hist n_launders_hist[N_LAUNDERS_HIST];
unsigned long rcu_launder_gp_seq_start;
+ int rcu_fwd_id;
};
static DEFINE_MUTEX(rcu_fwd_mutex);
static struct rcu_fwd *rcu_fwds;
+static unsigned long rcu_fwd_seq;
static bool rcu_fwd_emergency_stop;
static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
@@ -2177,8 +2179,9 @@ static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
for (i = ARRAY_SIZE(rfp->n_launders_hist) - 1; i > 0; i--)
if (rfp->n_launders_hist[i].n_launders > 0)
break;
- pr_alert("%s: Callback-invocation histogram (duration %lu jiffies):",
- __func__, jiffies - rfp->rcu_fwd_startat);
+ mutex_lock(&rcu_fwd_mutex); // Serialize histograms.
+ pr_alert("%s: Callback-invocation histogram %d (duration %lu jiffies):",
+ __func__, rfp->rcu_fwd_id, jiffies - rfp->rcu_fwd_startat);
gps_old = rfp->rcu_launder_gp_seq_start;
for (j = 0; j <= i; j++) {
gps = rfp->n_launders_hist[j].launder_gp_seq;
@@ -2189,6 +2192,7 @@ static void rcu_torture_fwd_cb_hist(struct rcu_fwd *rfp)
gps_old = gps;
}
pr_cont("\n");
+ mutex_unlock(&rcu_fwd_mutex);
}
/* Callback function for continuous-flood RCU callbacks. */
@@ -2314,7 +2318,8 @@ static void rcu_torture_fwd_prog_nr(struct rcu_fwd *rfp,
cver = READ_ONCE(rcu_torture_current_version) - cver;
gps = rcutorture_seq_diff(cur_ops->get_gp_seq(), gps);
WARN_ON(!cver && gps < 2);
- pr_alert("%s: Duration %ld cver %ld gps %ld\n", __func__, dur, cver, gps);
+ pr_alert("%s: %d Duration %ld cver %ld gps %ld\n", __func__,
+ rfp->rcu_fwd_id, dur, cver, gps);
}
if (selfpropcb) {
WRITE_ONCE(fcs.stop, 1);
@@ -2432,6 +2437,8 @@ static void rcu_torture_fwd_prog_cr(struct rcu_fwd *rfp)
static int rcutorture_oom_notify(struct notifier_block *self,
unsigned long notused, void *nfreed)
{
+ int i;
+ long ncbs;
struct rcu_fwd *rfp;
mutex_lock(&rcu_fwd_mutex);
@@ -2442,18 +2449,26 @@ static int rcutorture_oom_notify(struct notifier_block *self,
}
WARN(1, "%s invoked upon OOM during forward-progress testing.\n",
__func__);
- rcu_torture_fwd_cb_hist(rfp);
- rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp->rcu_fwd_startat)) / 2);
+ for (i = 0; i < fwd_progress; i++) {
+ rcu_torture_fwd_cb_hist(&rfp[i]);
+ rcu_fwd_progress_check(1 + (jiffies - READ_ONCE(rfp[i].rcu_fwd_startat)) / 2);
+ }
WRITE_ONCE(rcu_fwd_emergency_stop, true);
smp_mb(); /* Emergency stop before free and wait to avoid hangs. */
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
+ ncbs = 0;
+ for (i = 0; i < fwd_progress; i++)
+ ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
+ pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
rcu_barrier();
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
+ ncbs = 0;
+ for (i = 0; i < fwd_progress; i++)
+ ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
+ pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
rcu_barrier();
- pr_info("%s: Freed %lu RCU callbacks.\n",
- __func__, rcu_torture_fwd_prog_cbfree(rfp));
+ ncbs = 0;
+ for (i = 0; i < fwd_progress; i++)
+ ncbs += rcu_torture_fwd_prog_cbfree(&rfp[i]);
+ pr_info("%s: Freed %lu RCU callbacks.\n", __func__, ncbs);
smp_mb(); /* Frees before return to avoid redoing OOM. */
(*(unsigned long *)nfreed)++; /* Forward progress CBs freed! */
pr_info("%s returning after OOM processing.\n", __func__);
@@ -2469,6 +2484,7 @@ static struct notifier_block rcutorture_oom_nb = {
static int rcu_torture_fwd_prog(void *args)
{
int oldnice = task_nice(current);
+ unsigned long oldseq = READ_ONCE(rcu_fwd_seq);
struct rcu_fwd *rfp = args;
int tested = 0;
int tested_tries = 0;
@@ -2478,21 +2494,31 @@ static int rcu_torture_fwd_prog(void *args)
if (!IS_ENABLED(CONFIG_SMP) || !IS_ENABLED(CONFIG_RCU_BOOST))
set_user_nice(current, MAX_NICE);
do {
- schedule_timeout_interruptible(fwd_progress_holdoff * HZ);
- WRITE_ONCE(rcu_fwd_emergency_stop, false);
+ if (!rfp->rcu_fwd_id) {
+ schedule_timeout_interruptible(fwd_progress_holdoff * HZ);
+ WRITE_ONCE(rcu_fwd_emergency_stop, false);
+ WRITE_ONCE(rcu_fwd_seq, rcu_fwd_seq + 1);
+ } else {
+ while (READ_ONCE(rcu_fwd_seq) == oldseq)
+ schedule_timeout_interruptible(1);
+ oldseq = READ_ONCE(rcu_fwd_seq);
+ }
+ pr_alert("%s: Starting forward-progress test %d\n", __func__, rfp->rcu_fwd_id);
+ if (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id)
+ rcu_torture_fwd_prog_cr(rfp);
if (!IS_ENABLED(CONFIG_TINY_RCU) ||
- rcu_inkernel_boot_has_ended())
+ (rcu_inkernel_boot_has_ended() && torture_num_online_cpus() > rfp->rcu_fwd_id))
rcu_torture_fwd_prog_nr(rfp, &tested, &tested_tries);
- if (rcu_inkernel_boot_has_ended())
- rcu_torture_fwd_prog_cr(rfp);
/* Avoid slow periods, better to test when busy. */
if (stutter_wait("rcu_torture_fwd_prog"))
sched_set_normal(current, oldnice);
} while (!torture_must_stop());
/* Short runs might not contain a valid forward-progress attempt. */
- WARN_ON(!tested && tested_tries >= 5);
- pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries);
+ if (!rfp->rcu_fwd_id) {
+ WARN_ON(!tested && tested_tries >= 5);
+ pr_alert("%s: tested %d tested_tries %d\n", __func__, tested, tested_tries);
+ }
torture_kthread_stopping("rcu_torture_fwd_prog");
return 0;
}
@@ -2500,17 +2526,27 @@ static int rcu_torture_fwd_prog(void *args)
/* If forward-progress checking is requested and feasible, spawn the thread. */
static int __init rcu_torture_fwd_prog_init(void)
{
+ int i;
+ int ret = 0;
struct rcu_fwd *rfp;
if (!fwd_progress)
return 0; /* Not requested, so don't do it. */
+ if (fwd_progress >= nr_cpu_ids) {
+ VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Limiting fwd_progress to # CPUs.\n");
+ fwd_progress = nr_cpu_ids;
+ } else if (fwd_progress < 0) {
+ fwd_progress = nr_cpu_ids;
+ }
if ((!cur_ops->sync && !cur_ops->call) ||
!cur_ops->stall_dur || cur_ops->stall_dur() <= 0 || cur_ops == &rcu_busted_ops) {
VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, unsupported by RCU flavor under test");
+ fwd_progress = 0;
return 0;
}
if (stall_cpu > 0) {
VERBOSE_TOROUT_STRING("rcu_torture_fwd_prog_init: Disabled, conflicts with CPU-stall testing");
+ fwd_progress = 0;
if (IS_MODULE(CONFIG_RCU_TORTURE_TEST))
return -EINVAL; /* In module, can fail back to user. */
WARN_ON(1); /* Make sure rcutorture notices conflict. */
@@ -2520,29 +2556,51 @@ static int __init rcu_torture_fwd_prog_init(void)
fwd_progress_holdoff = 1;
if (fwd_progress_div <= 0)
fwd_progress_div = 4;
- rfp = kzalloc(sizeof(*rfp), GFP_KERNEL);
- if (!rfp)
+ rfp = kcalloc(fwd_progress, sizeof(*rfp), GFP_KERNEL);
+ fwd_prog_tasks = kcalloc(fwd_progress, sizeof(*fwd_prog_tasks), GFP_KERNEL);
+ if (!rfp || !fwd_prog_tasks) {
+ kfree(rfp);
+ kfree(fwd_prog_tasks);
+ fwd_prog_tasks = NULL;
+ fwd_progress = 0;
return -ENOMEM;
- spin_lock_init(&rfp->rcu_fwd_lock);
- rfp->rcu_fwd_cb_tail = &rfp->rcu_fwd_cb_head;
+ }
+ for (i = 0; i < fwd_progress; i++) {
+ spin_lock_init(&rfp[i].rcu_fwd_lock);
+ rfp[i].rcu_fwd_cb_tail = &rfp[i].rcu_fwd_cb_head;
+ rfp[i].rcu_fwd_id = i;
+ }
mutex_lock(&rcu_fwd_mutex);
rcu_fwds = rfp;
mutex_unlock(&rcu_fwd_mutex);
register_oom_notifier(&rcutorture_oom_nb);
- return torture_create_kthread(rcu_torture_fwd_prog, rfp, fwd_prog_task);
+ for (i = 0; i < fwd_progress; i++) {
+ ret = torture_create_kthread(rcu_torture_fwd_prog, &rcu_fwds[i], fwd_prog_tasks[i]);
+ if (ret) {
+ fwd_progress = i;
+ return ret;
+ }
+ }
+ return 0;
}
static void rcu_torture_fwd_prog_cleanup(void)
{
+ int i;
struct rcu_fwd *rfp;
- torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_task);
- rfp = rcu_fwds;
+ if (!rcu_fwds || !fwd_prog_tasks)
+ return;
+ for (i = 0; i < fwd_progress; i++)
+ torture_stop_kthread(rcu_torture_fwd_prog, fwd_prog_tasks[i]);
+ unregister_oom_notifier(&rcutorture_oom_nb);
mutex_lock(&rcu_fwd_mutex);
+ rfp = rcu_fwds;
rcu_fwds = NULL;
mutex_unlock(&rcu_fwd_mutex);
- unregister_oom_notifier(&rcutorture_oom_nb);
kfree(rfp);
+ kfree(fwd_prog_tasks);
+ fwd_prog_tasks = NULL;
}
/* Callback function for RCU barrier testing. */
generated by cgit v1.2.3 (git 2.39.1) at 2024-09-06 06:27:10 +0000