/*
- * Read-Copy Update /proc-based torture test facility
+ * Read-Copy Update module-based torture test facility
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
#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)*/
+static char *torture_type = "rcu"; /* What to torture. */
-MODULE_PARM(nreaders, "i");
+module_param(nreaders, int, 0);
MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
-MODULE_PARM(stat_interval, "i");
+module_param(stat_interval, int, 0);
MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
-MODULE_PARM(verbose, "i");
+module_param(verbose, bool, 0);
MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
-#define TORTURE_FLAG "rcutorture: "
+module_param(test_no_idle_hz, bool, 0);
+MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
+module_param(shuffle_interval, int, 0);
+MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
+module_param(torture_type, charp, 0);
+MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh)");
+
+#define TORTURE_FLAG "-torture:"
#define PRINTK_STRING(s) \
- do { printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0)
+ do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
#define VERBOSE_PRINTK_STRING(s) \
- do { if (verbose) printk(KERN_ALERT TORTURE_FLAG s "\n"); } while (0)
+ do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
#define VERBOSE_PRINTK_ERRSTRING(s) \
- do { if (verbose) printk(KERN_ALERT TORTURE_FLAG "!!! " s "\n"); } while (0)
+ do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
static char printk_buf[4096];
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
/*
* Allocate an element from the rcu_tortures pool.
*/
-struct rcu_torture *
+static struct rcu_torture *
rcu_torture_alloc(void)
{
struct list_head *p;
- spin_lock(&rcu_torture_lock);
+ spin_lock_bh(&rcu_torture_lock);
if (list_empty(&rcu_torture_freelist)) {
atomic_inc(&n_rcu_torture_alloc_fail);
- spin_unlock(&rcu_torture_lock);
+ spin_unlock_bh(&rcu_torture_lock);
return NULL;
}
atomic_inc(&n_rcu_torture_alloc);
p = rcu_torture_freelist.next;
list_del_init(p);
- spin_unlock(&rcu_torture_lock);
+ spin_unlock_bh(&rcu_torture_lock);
return container_of(p, struct rcu_torture, rtort_free);
}
rcu_torture_free(struct rcu_torture *p)
{
atomic_inc(&n_rcu_torture_free);
- spin_lock(&rcu_torture_lock);
+ spin_lock_bh(&rcu_torture_lock);
list_add_tail(&p->rtort_free, &rcu_torture_freelist);
- spin_unlock(&rcu_torture_lock);
-}
-
-static void
-rcu_torture_cb(struct rcu_head *p)
-{
- int i;
- struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
-
- if (fullstop) {
- /* Test is ending, just drop callbacks on the floor. */
- /* The next initialization will pick up the pieces. */
- return;
- }
- i = rp->rtort_pipe_count;
- 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) {
- rp->rtort_mbtest = 0;
- rcu_torture_free(rp);
- } else
- call_rcu(p, rcu_torture_cb);
+ spin_unlock_bh(&rcu_torture_lock);
}
struct rcu_random_state {
}
/*
+ * Operations vector for selecting different types of tests.
+ */
+
+struct rcu_torture_ops {
+ void (*init)(void);
+ void (*cleanup)(void);
+ int (*readlock)(void);
+ void (*readunlock)(int idx);
+ int (*completed)(void);
+ void (*deferredfree)(struct rcu_torture *p);
+ int (*stats)(char *page);
+ char *name;
+};
+static struct rcu_torture_ops *cur_ops = NULL;
+
+/*
+ * Definitions for rcu torture testing.
+ */
+
+static int rcu_torture_read_lock(void)
+{
+ rcu_read_lock();
+ return 0;
+}
+
+static void rcu_torture_read_unlock(int idx)
+{
+ rcu_read_unlock();
+}
+
+static int rcu_torture_completed(void)
+{
+ return rcu_batches_completed();
+}
+
+static void
+rcu_torture_cb(struct rcu_head *p)
+{
+ int i;
+ struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
+
+ if (fullstop) {
+ /* Test is ending, just drop callbacks on the floor. */
+ /* The next initialization will pick up the pieces. */
+ return;
+ }
+ i = rp->rtort_pipe_count;
+ 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) {
+ rp->rtort_mbtest = 0;
+ rcu_torture_free(rp);
+ } else
+ cur_ops->deferredfree(rp);
+}
+
+static void rcu_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops rcu_ops = {
+ .init = NULL,
+ .cleanup = NULL,
+ .readlock = rcu_torture_read_lock,
+ .readunlock = rcu_torture_read_unlock,
+ .completed = rcu_torture_completed,
+ .deferredfree = rcu_torture_deferred_free,
+ .stats = NULL,
+ .name = "rcu"
+};
+
+/*
+ * Definitions for rcu_bh torture testing.
+ */
+
+static int rcu_bh_torture_read_lock(void)
+{
+ rcu_read_lock_bh();
+ return 0;
+}
+
+static void rcu_bh_torture_read_unlock(int idx)
+{
+ rcu_read_unlock_bh();
+}
+
+static int rcu_bh_torture_completed(void)
+{
+ return rcu_batches_completed_bh();
+}
+
+static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
+{
+ call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
+}
+
+static struct rcu_torture_ops rcu_bh_ops = {
+ .init = NULL,
+ .cleanup = NULL,
+ .readlock = rcu_bh_torture_read_lock,
+ .readunlock = rcu_bh_torture_read_unlock,
+ .completed = rcu_bh_torture_completed,
+ .deferredfree = rcu_bh_torture_deferred_free,
+ .stats = NULL,
+ .name = "rcu_bh"
+};
+
+static struct rcu_torture_ops *torture_ops[] =
+ { &rcu_ops, &rcu_bh_ops, NULL };
+
+/*
* RCU torture writer kthread. Repeatedly substitutes a new structure
* for that pointed to by rcu_torture_current, freeing the old structure
* after a series of grace periods (the "pipeline").
do {
schedule_timeout_uninterruptible(1);
- if (rcu_batches_completed() == oldbatch)
- continue;
if ((rp = rcu_torture_alloc()) == NULL)
continue;
rp->rtort_pipe_count = 0;
i = RCU_TORTURE_PIPE_LEN;
atomic_inc(&rcu_torture_wcount[i]);
old_rp->rtort_pipe_count++;
- call_rcu(&old_rp->rtort_rcu, rcu_torture_cb);
+ cur_ops->deferredfree(old_rp);
}
rcu_torture_current_version++;
- oldbatch = rcu_batches_completed();
+ oldbatch = cur_ops->completed();
} while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
while (!kthread_should_stop())
rcu_torture_reader(void *arg)
{
int completed;
+ int idx;
DEFINE_RCU_RANDOM(rand);
struct rcu_torture *p;
int pipe_count;
set_user_nice(current, 19);
do {
- rcu_read_lock();
- completed = rcu_batches_completed();
+ idx = cur_ops->readlock();
+ completed = cur_ops->completed();
p = rcu_dereference(rcu_torture_current);
if (p == NULL) {
/* Wait for rcu_torture_writer to get underway */
- rcu_read_unlock();
+ cur_ops->readunlock(idx);
schedule_timeout_interruptible(HZ);
continue;
}
pipe_count = RCU_TORTURE_PIPE_LEN;
}
++__get_cpu_var(rcu_torture_count)[pipe_count];
- completed = rcu_batches_completed() - completed;
+ completed = cur_ops->completed() - completed;
if (completed > RCU_TORTURE_PIPE_LEN) {
/* Should not happen, but... */
completed = RCU_TORTURE_PIPE_LEN;
}
++__get_cpu_var(rcu_torture_batch)[completed];
preempt_enable();
- rcu_read_unlock();
+ cur_ops->readunlock(idx);
schedule();
} while (!kthread_should_stop() && !fullstop);
VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
- for_each_cpu(cpu) {
+ for_each_possible_cpu(cpu) {
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
if (pipesummary[i] != 0)
break;
}
- cnt += sprintf(&page[cnt], "rcutorture: ");
+ cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
cnt += sprintf(&page[cnt],
"rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
"rtmbe: %d",
atomic_read(&n_rcu_torture_mberror));
if (atomic_read(&n_rcu_torture_mberror) != 0)
cnt += sprintf(&page[cnt], " !!!");
- cnt += sprintf(&page[cnt], "\nrcutorture: ");
+ cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
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]);
- cnt += sprintf(&page[cnt], "\nrcutorture: ");
+ cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
cnt += sprintf(&page[cnt], "Reader Batch: ");
- for (i = 0; i < RCU_TORTURE_PIPE_LEN; i++)
+ for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
cnt += sprintf(&page[cnt], " %ld", batchsummary[i]);
- cnt += sprintf(&page[cnt], "\nrcutorture: ");
+ cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
cnt += sprintf(&page[cnt], "Free-Block Circulation: ");
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
cnt += sprintf(&page[cnt], " %d",
atomic_read(&rcu_torture_wcount[i]));
}
cnt += sprintf(&page[cnt], "\n");
+ if (cur_ops->stats != NULL)
+ cnt += cur_ops->stats(&page[cnt]);
return cnt;
}
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 inline void
+rcu_torture_print_module_parms(char *tag)
+{
+ printk(KERN_ALERT "%s" TORTURE_FLAG "--- %s: nreaders=%d "
+ "stat_interval=%d verbose=%d test_no_idle_hz=%d "
+ "shuffle_interval = %d\n",
+ torture_type, tag, nrealreaders, stat_interval, verbose,
+ test_no_idle_hz, shuffle_interval);
+}
+
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);
rcu_barrier();
rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
- printk(KERN_ALERT TORTURE_FLAG
- "--- End of test: %s\n",
- atomic_read(&n_rcu_torture_error) == 0 ? "SUCCESS" : "FAILURE");
+
+ if (cur_ops->cleanup != NULL)
+ cur_ops->cleanup();
+ if (atomic_read(&n_rcu_torture_error))
+ rcu_torture_print_module_parms("End of test: FAILURE");
+ else
+ rcu_torture_print_module_parms("End of test: SUCCESS");
}
static int
/* Process args and tell the world that the torturer is on the job. */
+ for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) {
+ cur_ops = torture_ops[i];
+ if (strcmp(torture_type, cur_ops->name) == 0) {
+ break;
+ }
+ }
+ if (cur_ops == NULL) {
+ printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
+ torture_type);
+ return (-EINVAL);
+ }
+ if (cur_ops->init != NULL)
+ cur_ops->init(); /* no "goto unwind" prior to this point!!! */
+
if (nreaders >= 0)
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);
+ rcu_torture_print_module_parms("Start of test");
fullstop = 0;
/* Set up the freelist. */
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) {
+ for_each_possible_cpu(cpu) {
for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
per_cpu(rcu_torture_count, cpu)[i] = 0;
per_cpu(rcu_torture_batch, cpu)[i] = 0;
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:
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff