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-rw-r--r--kernel/rcutorture.c113
1 files changed, 68 insertions, 45 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 1cff28d..7c4142a 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -136,29 +136,47 @@ static int stutter_pause_test = 0;
#endif
int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
-#define FULLSTOP_SHUTDOWN 1 /* Bail due to system shutdown/panic. */
-#define FULLSTOP_CLEANUP 2 /* Orderly shutdown. */
-static int fullstop; /* stop generating callbacks at test end. */
-DEFINE_MUTEX(fullstop_mutex); /* protect fullstop transitions and */
- /* spawning of kthreads. */
+/* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */
+
+#define FULLSTOP_DONTSTOP 0 /* Normal operation. */
+#define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */
+#define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */
+static int fullstop = FULLSTOP_RMMOD;
+DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */
+ /* of kthreads. */
/*
- * Detect and respond to a signal-based shutdown.
+ * Detect and respond to a system shutdown.
*/
static int
rcutorture_shutdown_notify(struct notifier_block *unused1,
unsigned long unused2, void *unused3)
{
- if (fullstop)
- return NOTIFY_DONE;
mutex_lock(&fullstop_mutex);
- if (!fullstop)
+ if (fullstop == FULLSTOP_DONTSTOP)
fullstop = FULLSTOP_SHUTDOWN;
+ else
+ printk(KERN_WARNING /* but going down anyway, so... */
+ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
mutex_unlock(&fullstop_mutex);
return NOTIFY_DONE;
}
/*
+ * Absorb kthreads into a kernel function that won't return, so that
+ * they won't ever access module text or data again.
+ */
+static void rcutorture_shutdown_absorb(char *title)
+{
+ if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) {
+ printk(KERN_NOTICE
+ "rcutorture thread %s parking due to system shutdown\n",
+ title);
+ schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT);
+ }
+}
+
+/*
* Allocate an element from the rcu_tortures pool.
*/
static struct rcu_torture *
@@ -219,13 +237,14 @@ rcu_random(struct rcu_random_state *rrsp)
}
static void
-rcu_stutter_wait(void)
+rcu_stutter_wait(char *title)
{
- while ((stutter_pause_test || !rcutorture_runnable) && !fullstop) {
+ while (stutter_pause_test || !rcutorture_runnable) {
if (rcutorture_runnable)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
+ rcutorture_shutdown_absorb(title);
}
}
@@ -287,7 +306,7 @@ rcu_torture_cb(struct rcu_head *p)
int i;
struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
- if (fullstop) {
+ if (fullstop != FULLSTOP_DONTSTOP) {
/* Test is ending, just drop callbacks on the floor. */
/* The next initialization will pick up the pieces. */
return;
@@ -619,10 +638,11 @@ rcu_torture_writer(void *arg)
}
rcu_torture_current_version++;
oldbatch = cur_ops->completed();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_writer");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ rcutorture_shutdown_absorb("rcu_torture_writer");
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -643,11 +663,12 @@ rcu_torture_fakewriter(void *arg)
schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
udelay(rcu_random(&rand) & 0x3ff);
cur_ops->sync();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_fakewriter");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ rcutorture_shutdown_absorb("rcu_torture_fakewriter");
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -752,12 +773,13 @@ rcu_torture_reader(void *arg)
preempt_enable();
cur_ops->readunlock(idx);
schedule();
- rcu_stutter_wait();
- } while (!kthread_should_stop() && !fullstop);
+ rcu_stutter_wait("rcu_torture_reader");
+ } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP);
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
+ rcutorture_shutdown_absorb("rcu_torture_reader");
if (irqreader && cur_ops->irqcapable)
del_timer_sync(&t);
- while (!kthread_should_stop() && fullstop != FULLSTOP_SHUTDOWN)
+ while (!kthread_should_stop())
schedule_timeout_uninterruptible(1);
return 0;
}
@@ -854,7 +876,8 @@ rcu_torture_stats(void *arg)
do {
schedule_timeout_interruptible(stat_interval * HZ);
rcu_torture_stats_print();
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_stats");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
return 0;
}
@@ -866,52 +889,49 @@ static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
*/
static void rcu_torture_shuffle_tasks(void)
{
- cpumask_var_t tmp_mask;
+ cpumask_t tmp_mask;
int i;
- if (!alloc_cpumask_var(&tmp_mask, GFP_KERNEL))
- BUG();
-
- cpumask_setall(tmp_mask);
+ cpus_setall(tmp_mask);
get_online_cpus();
/* No point in shuffling if there is only one online CPU (ex: UP) */
- if (num_online_cpus() == 1)
- goto out;
+ if (num_online_cpus() == 1) {
+ put_online_cpus();
+ return;
+ }
if (rcu_idle_cpu != -1)
- cpumask_clear_cpu(rcu_idle_cpu, tmp_mask);
+ cpu_clear(rcu_idle_cpu, tmp_mask);
- set_cpus_allowed_ptr(current, tmp_mask);
+ set_cpus_allowed_ptr(current, &tmp_mask);
if (reader_tasks) {
for (i = 0; i < nrealreaders; i++)
if (reader_tasks[i])
set_cpus_allowed_ptr(reader_tasks[i],
- tmp_mask);
+ &tmp_mask);
}
if (fakewriter_tasks) {
for (i = 0; i < nfakewriters; i++)
if (fakewriter_tasks[i])
set_cpus_allowed_ptr(fakewriter_tasks[i],
- tmp_mask);
+ &tmp_mask);
}
if (writer_task)
- set_cpus_allowed_ptr(writer_task, tmp_mask);
+ set_cpus_allowed_ptr(writer_task, &tmp_mask);
if (stats_task)
- set_cpus_allowed_ptr(stats_task, tmp_mask);
+ set_cpus_allowed_ptr(stats_task, &tmp_mask);
if (rcu_idle_cpu == -1)
rcu_idle_cpu = num_online_cpus() - 1;
else
rcu_idle_cpu--;
-out:
put_online_cpus();
- free_cpumask_var(tmp_mask);
}
/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
@@ -925,7 +945,8 @@ rcu_torture_shuffle(void *arg)
do {
schedule_timeout_interruptible(shuffle_interval * HZ);
rcu_torture_shuffle_tasks();
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_shuffle");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
return 0;
}
@@ -940,10 +961,11 @@ rcu_torture_stutter(void *arg)
do {
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 1;
- if (!kthread_should_stop() && !fullstop)
+ if (!kthread_should_stop())
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 0;
- } while (!kthread_should_stop() && !fullstop);
+ rcutorture_shutdown_absorb("rcu_torture_stutter");
+ } while (!kthread_should_stop());
VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping");
return 0;
}
@@ -970,15 +992,16 @@ rcu_torture_cleanup(void)
int i;
mutex_lock(&fullstop_mutex);
- if (!fullstop) {
- /* If being signaled, let it happen, then exit. */
+ if (fullstop == FULLSTOP_SHUTDOWN) {
+ printk(KERN_WARNING /* but going down anyway, so... */
+ "Concurrent 'rmmod rcutorture' and shutdown illegal!\n");
mutex_unlock(&fullstop_mutex);
- schedule_timeout_interruptible(10 * HZ);
+ schedule_timeout_uninterruptible(10);
if (cur_ops->cb_barrier != NULL)
cur_ops->cb_barrier();
return;
}
- fullstop = FULLSTOP_CLEANUP;
+ fullstop = FULLSTOP_RMMOD;
mutex_unlock(&fullstop_mutex);
unregister_reboot_notifier(&rcutorture_nb);
if (stutter_task) {
@@ -1078,7 +1101,7 @@ rcu_torture_init(void)
else
nrealreaders = 2 * num_online_cpus();
rcu_torture_print_module_parms("Start of test");
- fullstop = 0;
+ fullstop = FULLSTOP_DONTSTOP;
/* Set up the freelist. */
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