#include <linux/moduleparam.h>
#include <linux/percpu.h>
#include <linux/notifier.h>
-#include <linux/rcuref.h>
#include <linux/cpu.h>
#include <linux/random.h>
#include <linux/delay.h>
MODULE_LICENSE("GPL");
static int nreaders = -1; /* # reader threads, defaults to 4*ncpus */
-static int stat_interval = 0; /* Interval between stats, in seconds. */
+static int stat_interval; /* Interval between stats, in seconds. */
/* Defaults to "only at end of test". */
-static int verbose = 0; /* Print more debug info. */
+static int verbose; /* Print more debug info. */
+static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
+static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
MODULE_PARM(nreaders, "i");
MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
MODULE_PARM(verbose, "i");
MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
+MODULE_PARM(test_no_idle_hz, "i");
+MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+MODULE_PARM(shuffle_interval, "i");
+MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
#define TORTURE_FLAG "rcutorture: "
#define PRINTK_STRING(s) \
do { printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0)
static struct task_struct *writer_task;
static struct task_struct **reader_tasks;
static struct task_struct *stats_task;
+static struct task_struct *shuffler_task;
#define RCU_TORTURE_PIPE_LEN 10
struct rcu_head rtort_rcu;
int rtort_pipe_count;
struct list_head rtort_free;
+ int rtort_mbtest;
};
static int fullstop = 0; /* stop generating callbacks at test end. */
atomic_t n_rcu_torture_alloc;
atomic_t n_rcu_torture_alloc_fail;
atomic_t n_rcu_torture_free;
+atomic_t n_rcu_torture_mberror;
+atomic_t n_rcu_torture_error;
/*
* Allocate an element from the rcu_tortures pool.
*/
-struct rcu_torture *
+static struct rcu_torture *
rcu_torture_alloc(void)
{
struct list_head *p;
if (i > RCU_TORTURE_PIPE_LEN)
i = RCU_TORTURE_PIPE_LEN;
atomic_inc(&rcu_torture_wcount[i]);
- if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN)
+ if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
+ rp->rtort_mbtest = 0;
rcu_torture_free(rp);
- else
+ } else
call_rcu(p, rcu_torture_cb);
}
rp->rtort_pipe_count = 0;
udelay(rcu_random(&rand) & 0x3ff);
old_rp = rcu_torture_current;
+ rp->rtort_mbtest = 1;
rcu_assign_pointer(rcu_torture_current, rp);
smp_wmb();
if (old_rp != NULL) {
schedule_timeout_interruptible(HZ);
continue;
}
+ if (p->rtort_mbtest == 0)
+ atomic_inc(&n_rcu_torture_mberror);
udelay(rcu_random(&rand) & 0x7f);
preempt_disable();
pipe_count = p->rtort_pipe_count;
}
cnt += sprintf(&page[cnt], "rcutorture: ");
cnt += sprintf(&page[cnt],
- "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d",
+ "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
+ "rtmbe: %d",
rcu_torture_current,
rcu_torture_current_version,
list_empty(&rcu_torture_freelist),
atomic_read(&n_rcu_torture_alloc),
atomic_read(&n_rcu_torture_alloc_fail),
- atomic_read(&n_rcu_torture_free));
+ atomic_read(&n_rcu_torture_free),
+ atomic_read(&n_rcu_torture_mberror));
+ if (atomic_read(&n_rcu_torture_mberror) != 0)
+ cnt += sprintf(&page[cnt], " !!!");
cnt += sprintf(&page[cnt], "\nrcutorture: ");
- if (i > 1)
+ if (i > 1) {
cnt += sprintf(&page[cnt], "!!! ");
+ atomic_inc(&n_rcu_torture_error);
+ }
cnt += sprintf(&page[cnt], "Reader Pipe: ");
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
return 0;
}
+static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
+
+/* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
+ * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
+ */
+void rcu_torture_shuffle_tasks(void)
+{
+ cpumask_t tmp_mask = CPU_MASK_ALL;
+ int i;
+
+ lock_cpu_hotplug();
+
+ /* No point in shuffling if there is only one online CPU (ex: UP) */
+ if (num_online_cpus() == 1) {
+ unlock_cpu_hotplug();
+ return;
+ }
+
+ if (rcu_idle_cpu != -1)
+ cpu_clear(rcu_idle_cpu, tmp_mask);
+
+ set_cpus_allowed(current, tmp_mask);
+
+ if (reader_tasks != NULL) {
+ for (i = 0; i < nrealreaders; i++)
+ if (reader_tasks[i])
+ set_cpus_allowed(reader_tasks[i], tmp_mask);
+ }
+
+ if (writer_task)
+ set_cpus_allowed(writer_task, tmp_mask);
+
+ if (stats_task)
+ set_cpus_allowed(stats_task, tmp_mask);
+
+ if (rcu_idle_cpu == -1)
+ rcu_idle_cpu = num_online_cpus() - 1;
+ else
+ rcu_idle_cpu--;
+
+ unlock_cpu_hotplug();
+}
+
+/* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
+ * system to become idle at a time and cut off its timer ticks. This is meant
+ * to test the support for such tickless idle CPU in RCU.
+ */
+static int
+rcu_torture_shuffle(void *arg)
+{
+ VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
+ do {
+ schedule_timeout_interruptible(shuffle_interval * HZ);
+ rcu_torture_shuffle_tasks();
+ } while (!kthread_should_stop());
+ VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
+ return 0;
+}
+
static void
rcu_torture_cleanup(void)
{
int i;
fullstop = 1;
+ if (shuffler_task != NULL) {
+ VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
+ kthread_stop(shuffler_task);
+ }
+ shuffler_task = NULL;
+
if (writer_task != NULL) {
VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
kthread_stop(writer_task);
stats_task = NULL;
/* Wait for all RCU callbacks to fire. */
+ rcu_barrier();
- for (i = 0; i < RCU_TORTURE_PIPE_LEN; i++)
- synchronize_rcu();
rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
- PRINTK_STRING("--- End of test");
+ printk(KERN_ALERT TORTURE_FLAG
+ "--- End of test: %s\n",
+ atomic_read(&n_rcu_torture_error) == 0 ? "SUCCESS" : "FAILURE");
}
static int
nrealreaders = nreaders;
else
nrealreaders = 2 * num_online_cpus();
- printk(KERN_ALERT TORTURE_FLAG
- "--- Start of test: nreaders=%d stat_interval=%d verbose=%d\n",
- nrealreaders, stat_interval, verbose);
+ printk(KERN_ALERT TORTURE_FLAG "--- Start of test: nreaders=%d "
+ "stat_interval=%d verbose=%d test_no_idle_hz=%d "
+ "shuffle_interval = %d\n",
+ nrealreaders, stat_interval, verbose, test_no_idle_hz,
+ shuffle_interval);
fullstop = 0;
/* Set up the freelist. */
INIT_LIST_HEAD(&rcu_torture_freelist);
for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) {
+ rcu_tortures[i].rtort_mbtest = 0;
list_add_tail(&rcu_tortures[i].rtort_free,
&rcu_torture_freelist);
}
atomic_set(&n_rcu_torture_alloc, 0);
atomic_set(&n_rcu_torture_alloc_fail, 0);
atomic_set(&n_rcu_torture_free, 0);
+ atomic_set(&n_rcu_torture_mberror, 0);
+ atomic_set(&n_rcu_torture_error, 0);
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
atomic_set(&rcu_torture_wcount[i], 0);
for_each_cpu(cpu) {
goto unwind;
}
}
+ if (test_no_idle_hz) {
+ rcu_idle_cpu = num_online_cpus() - 1;
+ /* Create the shuffler thread */
+ shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
+ "rcu_torture_shuffle");
+ if (IS_ERR(shuffler_task)) {
+ firsterr = PTR_ERR(shuffler_task);
+ VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
+ shuffler_task = NULL;
+ goto unwind;
+ }
+ }
return 0;
unwind: