2 * Read-Copy Update module-based torture test facility
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 * Copyright (C) IBM Corporation, 2005, 2006
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Josh Triplett <josh@freedesktop.org>
23 * See also: Documentation/RCU/torture.txt
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/kthread.h>
30 #include <linux/err.h>
31 #include <linux/spinlock.h>
32 #include <linux/smp.h>
33 #include <linux/rcupdate.h>
34 #include <linux/interrupt.h>
35 #include <linux/sched.h>
36 #include <asm/atomic.h>
37 #include <linux/bitops.h>
38 #include <linux/module.h>
39 #include <linux/completion.h>
40 #include <linux/moduleparam.h>
41 #include <linux/percpu.h>
42 #include <linux/notifier.h>
43 #include <linux/cpu.h>
44 #include <linux/random.h>
45 #include <linux/delay.h>
46 #include <linux/byteorder/swabb.h>
47 #include <linux/stat.h>
48 #include <linux/srcu.h>
50 MODULE_LICENSE("GPL");
51 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and "
52 "Josh Triplett <josh@freedesktop.org>");
54 static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */
55 static int nfakewriters = 4; /* # fake writer threads */
56 static int stat_interval; /* Interval between stats, in seconds. */
57 /* Defaults to "only at end of test". */
58 static int verbose; /* Print more debug info. */
59 static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
60 static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/
61 static char *torture_type = "rcu"; /* What RCU implementation to torture. */
63 module_param(nreaders, int, 0);
64 MODULE_PARM_DESC(nreaders, "Number of RCU reader threads");
65 module_param(nfakewriters, int, 0);
66 MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads");
67 module_param(stat_interval, int, 0);
68 MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s");
69 module_param(verbose, bool, 0);
70 MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s");
71 module_param(test_no_idle_hz, bool, 0);
72 MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs");
73 module_param(shuffle_interval, int, 0);
74 MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles");
75 module_param(torture_type, charp, 0);
76 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)");
78 #define TORTURE_FLAG "-torture:"
79 #define PRINTK_STRING(s) \
80 do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
81 #define VERBOSE_PRINTK_STRING(s) \
82 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0)
83 #define VERBOSE_PRINTK_ERRSTRING(s) \
84 do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
86 static char printk_buf[4096];
88 static int nrealreaders;
89 static struct task_struct *writer_task;
90 static struct task_struct **fakewriter_tasks;
91 static struct task_struct **reader_tasks;
92 static struct task_struct *stats_task;
93 static struct task_struct *shuffler_task;
95 #define RCU_TORTURE_PIPE_LEN 10
98 struct rcu_head rtort_rcu;
100 struct list_head rtort_free;
104 static int fullstop = 0; /* stop generating callbacks at test end. */
105 static LIST_HEAD(rcu_torture_freelist);
106 static struct rcu_torture *rcu_torture_current = NULL;
107 static long rcu_torture_current_version = 0;
108 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
109 static DEFINE_SPINLOCK(rcu_torture_lock);
110 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) =
112 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) =
114 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
115 static atomic_t n_rcu_torture_alloc;
116 static atomic_t n_rcu_torture_alloc_fail;
117 static atomic_t n_rcu_torture_free;
118 static atomic_t n_rcu_torture_mberror;
119 static atomic_t n_rcu_torture_error;
120 static struct list_head rcu_torture_removed;
123 * Allocate an element from the rcu_tortures pool.
125 static struct rcu_torture *
126 rcu_torture_alloc(void)
130 spin_lock_bh(&rcu_torture_lock);
131 if (list_empty(&rcu_torture_freelist)) {
132 atomic_inc(&n_rcu_torture_alloc_fail);
133 spin_unlock_bh(&rcu_torture_lock);
136 atomic_inc(&n_rcu_torture_alloc);
137 p = rcu_torture_freelist.next;
139 spin_unlock_bh(&rcu_torture_lock);
140 return container_of(p, struct rcu_torture, rtort_free);
144 * Free an element to the rcu_tortures pool.
147 rcu_torture_free(struct rcu_torture *p)
149 atomic_inc(&n_rcu_torture_free);
150 spin_lock_bh(&rcu_torture_lock);
151 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
152 spin_unlock_bh(&rcu_torture_lock);
155 struct rcu_random_state {
156 unsigned long rrs_state;
160 #define RCU_RANDOM_MULT 39916801 /* prime */
161 #define RCU_RANDOM_ADD 479001701 /* prime */
162 #define RCU_RANDOM_REFRESH 10000
164 #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 }
167 * Crude but fast random-number generator. Uses a linear congruential
168 * generator, with occasional help from get_random_bytes().
171 rcu_random(struct rcu_random_state *rrsp)
175 if (--rrsp->rrs_count < 0) {
176 get_random_bytes(&refresh, sizeof(refresh));
177 rrsp->rrs_state += refresh;
178 rrsp->rrs_count = RCU_RANDOM_REFRESH;
180 rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD;
181 return swahw32(rrsp->rrs_state);
185 * Operations vector for selecting different types of tests.
188 struct rcu_torture_ops {
190 void (*cleanup)(void);
191 int (*readlock)(void);
192 void (*readdelay)(struct rcu_random_state *rrsp);
193 void (*readunlock)(int idx);
194 int (*completed)(void);
195 void (*deferredfree)(struct rcu_torture *p);
197 int (*stats)(char *page);
200 static struct rcu_torture_ops *cur_ops = NULL;
203 * Definitions for rcu torture testing.
206 static int rcu_torture_read_lock(void) __acquires(RCU)
212 static void rcu_read_delay(struct rcu_random_state *rrsp)
215 const long longdelay = 200;
217 /* We want there to be long-running readers, but not all the time. */
219 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay);
224 static void rcu_torture_read_unlock(int idx) __releases(RCU)
229 static int rcu_torture_completed(void)
231 return rcu_batches_completed();
235 rcu_torture_cb(struct rcu_head *p)
238 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
241 /* Test is ending, just drop callbacks on the floor. */
242 /* The next initialization will pick up the pieces. */
245 i = rp->rtort_pipe_count;
246 if (i > RCU_TORTURE_PIPE_LEN)
247 i = RCU_TORTURE_PIPE_LEN;
248 atomic_inc(&rcu_torture_wcount[i]);
249 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
250 rp->rtort_mbtest = 0;
251 rcu_torture_free(rp);
253 cur_ops->deferredfree(rp);
256 static void rcu_torture_deferred_free(struct rcu_torture *p)
258 call_rcu(&p->rtort_rcu, rcu_torture_cb);
261 static struct rcu_torture_ops rcu_ops = {
264 .readlock = rcu_torture_read_lock,
265 .readdelay = rcu_read_delay,
266 .readunlock = rcu_torture_read_unlock,
267 .completed = rcu_torture_completed,
268 .deferredfree = rcu_torture_deferred_free,
269 .sync = synchronize_rcu,
274 static void rcu_sync_torture_deferred_free(struct rcu_torture *p)
277 struct rcu_torture *rp;
278 struct rcu_torture *rp1;
281 list_add(&p->rtort_free, &rcu_torture_removed);
282 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
283 i = rp->rtort_pipe_count;
284 if (i > RCU_TORTURE_PIPE_LEN)
285 i = RCU_TORTURE_PIPE_LEN;
286 atomic_inc(&rcu_torture_wcount[i]);
287 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
288 rp->rtort_mbtest = 0;
289 list_del(&rp->rtort_free);
290 rcu_torture_free(rp);
295 static void rcu_sync_torture_init(void)
297 INIT_LIST_HEAD(&rcu_torture_removed);
300 static struct rcu_torture_ops rcu_sync_ops = {
301 .init = rcu_sync_torture_init,
303 .readlock = rcu_torture_read_lock,
304 .readdelay = rcu_read_delay,
305 .readunlock = rcu_torture_read_unlock,
306 .completed = rcu_torture_completed,
307 .deferredfree = rcu_sync_torture_deferred_free,
308 .sync = synchronize_rcu,
314 * Definitions for rcu_bh torture testing.
317 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
323 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
325 rcu_read_unlock_bh();
328 static int rcu_bh_torture_completed(void)
330 return rcu_batches_completed_bh();
333 static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
335 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
338 struct rcu_bh_torture_synchronize {
339 struct rcu_head head;
340 struct completion completion;
343 static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head)
345 struct rcu_bh_torture_synchronize *rcu;
347 rcu = container_of(head, struct rcu_bh_torture_synchronize, head);
348 complete(&rcu->completion);
351 static void rcu_bh_torture_synchronize(void)
353 struct rcu_bh_torture_synchronize rcu;
355 init_completion(&rcu.completion);
356 call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb);
357 wait_for_completion(&rcu.completion);
360 static struct rcu_torture_ops rcu_bh_ops = {
363 .readlock = rcu_bh_torture_read_lock,
364 .readdelay = rcu_read_delay, /* just reuse rcu's version. */
365 .readunlock = rcu_bh_torture_read_unlock,
366 .completed = rcu_bh_torture_completed,
367 .deferredfree = rcu_bh_torture_deferred_free,
368 .sync = rcu_bh_torture_synchronize,
374 * Definitions for srcu torture testing.
377 static struct srcu_struct srcu_ctl;
379 static void srcu_torture_init(void)
381 init_srcu_struct(&srcu_ctl);
382 rcu_sync_torture_init();
385 static void srcu_torture_cleanup(void)
387 synchronize_srcu(&srcu_ctl);
388 cleanup_srcu_struct(&srcu_ctl);
391 static int srcu_torture_read_lock(void)
393 return srcu_read_lock(&srcu_ctl);
396 static void srcu_read_delay(struct rcu_random_state *rrsp)
399 const long uspertick = 1000000 / HZ;
400 const long longdelay = 10;
402 /* We want there to be long-running readers, but not all the time. */
404 delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick);
406 schedule_timeout_interruptible(longdelay);
409 static void srcu_torture_read_unlock(int idx)
411 srcu_read_unlock(&srcu_ctl, idx);
414 static int srcu_torture_completed(void)
416 return srcu_batches_completed(&srcu_ctl);
419 static void srcu_torture_synchronize(void)
421 synchronize_srcu(&srcu_ctl);
424 static int srcu_torture_stats(char *page)
428 int idx = srcu_ctl.completed & 0x1;
430 cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):",
431 torture_type, TORTURE_FLAG, idx);
432 for_each_possible_cpu(cpu) {
433 cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu,
434 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx],
435 per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]);
437 cnt += sprintf(&page[cnt], "\n");
441 static struct rcu_torture_ops srcu_ops = {
442 .init = srcu_torture_init,
443 .cleanup = srcu_torture_cleanup,
444 .readlock = srcu_torture_read_lock,
445 .readdelay = srcu_read_delay,
446 .readunlock = srcu_torture_read_unlock,
447 .completed = srcu_torture_completed,
448 .deferredfree = rcu_sync_torture_deferred_free,
449 .sync = srcu_torture_synchronize,
450 .stats = srcu_torture_stats,
454 static struct rcu_torture_ops *torture_ops[] =
455 { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &srcu_ops, NULL };
458 * RCU torture writer kthread. Repeatedly substitutes a new structure
459 * for that pointed to by rcu_torture_current, freeing the old structure
460 * after a series of grace periods (the "pipeline").
463 rcu_torture_writer(void *arg)
466 long oldbatch = rcu_batches_completed();
467 struct rcu_torture *rp;
468 struct rcu_torture *old_rp;
469 static DEFINE_RCU_RANDOM(rand);
471 VERBOSE_PRINTK_STRING("rcu_torture_writer task started");
472 set_user_nice(current, 19);
475 schedule_timeout_uninterruptible(1);
476 if ((rp = rcu_torture_alloc()) == NULL)
478 rp->rtort_pipe_count = 0;
479 udelay(rcu_random(&rand) & 0x3ff);
480 old_rp = rcu_torture_current;
481 rp->rtort_mbtest = 1;
482 rcu_assign_pointer(rcu_torture_current, rp);
484 if (old_rp != NULL) {
485 i = old_rp->rtort_pipe_count;
486 if (i > RCU_TORTURE_PIPE_LEN)
487 i = RCU_TORTURE_PIPE_LEN;
488 atomic_inc(&rcu_torture_wcount[i]);
489 old_rp->rtort_pipe_count++;
490 cur_ops->deferredfree(old_rp);
492 rcu_torture_current_version++;
493 oldbatch = cur_ops->completed();
494 } while (!kthread_should_stop() && !fullstop);
495 VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping");
496 while (!kthread_should_stop())
497 schedule_timeout_uninterruptible(1);
502 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
503 * delay between calls.
506 rcu_torture_fakewriter(void *arg)
508 DEFINE_RCU_RANDOM(rand);
510 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started");
511 set_user_nice(current, 19);
514 schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10);
515 udelay(rcu_random(&rand) & 0x3ff);
517 } while (!kthread_should_stop() && !fullstop);
519 VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping");
520 while (!kthread_should_stop())
521 schedule_timeout_uninterruptible(1);
526 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
527 * incrementing the corresponding element of the pipeline array. The
528 * counter in the element should never be greater than 1, otherwise, the
529 * RCU implementation is broken.
532 rcu_torture_reader(void *arg)
536 DEFINE_RCU_RANDOM(rand);
537 struct rcu_torture *p;
540 VERBOSE_PRINTK_STRING("rcu_torture_reader task started");
541 set_user_nice(current, 19);
544 idx = cur_ops->readlock();
545 completed = cur_ops->completed();
546 p = rcu_dereference(rcu_torture_current);
548 /* Wait for rcu_torture_writer to get underway */
549 cur_ops->readunlock(idx);
550 schedule_timeout_interruptible(HZ);
553 if (p->rtort_mbtest == 0)
554 atomic_inc(&n_rcu_torture_mberror);
555 cur_ops->readdelay(&rand);
557 pipe_count = p->rtort_pipe_count;
558 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
559 /* Should not happen, but... */
560 pipe_count = RCU_TORTURE_PIPE_LEN;
562 ++__get_cpu_var(rcu_torture_count)[pipe_count];
563 completed = cur_ops->completed() - completed;
564 if (completed > RCU_TORTURE_PIPE_LEN) {
565 /* Should not happen, but... */
566 completed = RCU_TORTURE_PIPE_LEN;
568 ++__get_cpu_var(rcu_torture_batch)[completed];
570 cur_ops->readunlock(idx);
572 } while (!kthread_should_stop() && !fullstop);
573 VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping");
574 while (!kthread_should_stop())
575 schedule_timeout_uninterruptible(1);
580 * Create an RCU-torture statistics message in the specified buffer.
583 rcu_torture_printk(char *page)
588 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
589 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
591 for_each_possible_cpu(cpu) {
592 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
593 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
594 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
597 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
598 if (pipesummary[i] != 0)
601 cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG);
602 cnt += sprintf(&page[cnt],
603 "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d "
606 rcu_torture_current_version,
607 list_empty(&rcu_torture_freelist),
608 atomic_read(&n_rcu_torture_alloc),
609 atomic_read(&n_rcu_torture_alloc_fail),
610 atomic_read(&n_rcu_torture_free),
611 atomic_read(&n_rcu_torture_mberror));
612 if (atomic_read(&n_rcu_torture_mberror) != 0)
613 cnt += sprintf(&page[cnt], " !!!");
614 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
616 cnt += sprintf(&page[cnt], "!!! ");
617 atomic_inc(&n_rcu_torture_error);
619 cnt += sprintf(&page[cnt], "Reader Pipe: ");
620 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
621 cnt += sprintf(&page[cnt], " %ld", pipesummary[i]);
622 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
623 cnt += sprintf(&page[cnt], "Reader Batch: ");
624 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
625 cnt += sprintf(&page[cnt], " %ld", batchsummary[i]);
626 cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG);
627 cnt += sprintf(&page[cnt], "Free-Block Circulation: ");
628 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
629 cnt += sprintf(&page[cnt], " %d",
630 atomic_read(&rcu_torture_wcount[i]));
632 cnt += sprintf(&page[cnt], "\n");
633 if (cur_ops->stats != NULL)
634 cnt += cur_ops->stats(&page[cnt]);
639 * Print torture statistics. Caller must ensure that there is only
640 * one call to this function at a given time!!! This is normally
641 * accomplished by relying on the module system to only have one copy
642 * of the module loaded, and then by giving the rcu_torture_stats
643 * kthread full control (or the init/cleanup functions when rcu_torture_stats
644 * thread is not running).
647 rcu_torture_stats_print(void)
651 cnt = rcu_torture_printk(printk_buf);
652 printk(KERN_ALERT "%s", printk_buf);
656 * Periodically prints torture statistics, if periodic statistics printing
657 * was specified via the stat_interval module parameter.
659 * No need to worry about fullstop here, since this one doesn't reference
660 * volatile state or register callbacks.
663 rcu_torture_stats(void *arg)
665 VERBOSE_PRINTK_STRING("rcu_torture_stats task started");
667 schedule_timeout_interruptible(stat_interval * HZ);
668 rcu_torture_stats_print();
669 } while (!kthread_should_stop());
670 VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping");
674 static int rcu_idle_cpu; /* Force all torture tasks off this CPU */
676 /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case
677 * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs.
679 static void rcu_torture_shuffle_tasks(void)
681 cpumask_t tmp_mask = CPU_MASK_ALL;
686 /* No point in shuffling if there is only one online CPU (ex: UP) */
687 if (num_online_cpus() == 1) {
688 unlock_cpu_hotplug();
692 if (rcu_idle_cpu != -1)
693 cpu_clear(rcu_idle_cpu, tmp_mask);
695 set_cpus_allowed(current, tmp_mask);
697 if (reader_tasks != NULL) {
698 for (i = 0; i < nrealreaders; i++)
700 set_cpus_allowed(reader_tasks[i], tmp_mask);
703 if (fakewriter_tasks != NULL) {
704 for (i = 0; i < nfakewriters; i++)
705 if (fakewriter_tasks[i])
706 set_cpus_allowed(fakewriter_tasks[i], tmp_mask);
710 set_cpus_allowed(writer_task, tmp_mask);
713 set_cpus_allowed(stats_task, tmp_mask);
715 if (rcu_idle_cpu == -1)
716 rcu_idle_cpu = num_online_cpus() - 1;
720 unlock_cpu_hotplug();
723 /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the
724 * system to become idle at a time and cut off its timer ticks. This is meant
725 * to test the support for such tickless idle CPU in RCU.
728 rcu_torture_shuffle(void *arg)
730 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started");
732 schedule_timeout_interruptible(shuffle_interval * HZ);
733 rcu_torture_shuffle_tasks();
734 } while (!kthread_should_stop());
735 VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping");
740 rcu_torture_print_module_parms(char *tag)
742 printk(KERN_ALERT "%s" TORTURE_FLAG
743 "--- %s: nreaders=%d nfakewriters=%d "
744 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
745 "shuffle_interval = %d\n",
746 torture_type, tag, nrealreaders, nfakewriters,
747 stat_interval, verbose, test_no_idle_hz, shuffle_interval);
751 rcu_torture_cleanup(void)
756 if (shuffler_task != NULL) {
757 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
758 kthread_stop(shuffler_task);
760 shuffler_task = NULL;
762 if (writer_task != NULL) {
763 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
764 kthread_stop(writer_task);
768 if (reader_tasks != NULL) {
769 for (i = 0; i < nrealreaders; i++) {
770 if (reader_tasks[i] != NULL) {
771 VERBOSE_PRINTK_STRING(
772 "Stopping rcu_torture_reader task");
773 kthread_stop(reader_tasks[i]);
775 reader_tasks[i] = NULL;
780 rcu_torture_current = NULL;
782 if (fakewriter_tasks != NULL) {
783 for (i = 0; i < nfakewriters; i++) {
784 if (fakewriter_tasks[i] != NULL) {
785 VERBOSE_PRINTK_STRING(
786 "Stopping rcu_torture_fakewriter task");
787 kthread_stop(fakewriter_tasks[i]);
789 fakewriter_tasks[i] = NULL;
791 kfree(fakewriter_tasks);
792 fakewriter_tasks = NULL;
795 if (stats_task != NULL) {
796 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
797 kthread_stop(stats_task);
801 /* Wait for all RCU callbacks to fire. */
804 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
806 if (cur_ops->cleanup != NULL)
808 if (atomic_read(&n_rcu_torture_error))
809 rcu_torture_print_module_parms("End of test: FAILURE");
811 rcu_torture_print_module_parms("End of test: SUCCESS");
815 rcu_torture_init(void)
821 /* Process args and tell the world that the torturer is on the job. */
823 for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) {
824 cur_ops = torture_ops[i];
825 if (strcmp(torture_type, cur_ops->name) == 0) {
829 if (cur_ops == NULL) {
830 printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n",
834 if (cur_ops->init != NULL)
835 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
838 nrealreaders = nreaders;
840 nrealreaders = 2 * num_online_cpus();
841 rcu_torture_print_module_parms("Start of test");
844 /* Set up the freelist. */
846 INIT_LIST_HEAD(&rcu_torture_freelist);
847 for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) {
848 rcu_tortures[i].rtort_mbtest = 0;
849 list_add_tail(&rcu_tortures[i].rtort_free,
850 &rcu_torture_freelist);
853 /* Initialize the statistics so that each run gets its own numbers. */
855 rcu_torture_current = NULL;
856 rcu_torture_current_version = 0;
857 atomic_set(&n_rcu_torture_alloc, 0);
858 atomic_set(&n_rcu_torture_alloc_fail, 0);
859 atomic_set(&n_rcu_torture_free, 0);
860 atomic_set(&n_rcu_torture_mberror, 0);
861 atomic_set(&n_rcu_torture_error, 0);
862 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
863 atomic_set(&rcu_torture_wcount[i], 0);
864 for_each_possible_cpu(cpu) {
865 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
866 per_cpu(rcu_torture_count, cpu)[i] = 0;
867 per_cpu(rcu_torture_batch, cpu)[i] = 0;
871 /* Start up the kthreads. */
873 VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task");
874 writer_task = kthread_run(rcu_torture_writer, NULL,
875 "rcu_torture_writer");
876 if (IS_ERR(writer_task)) {
877 firsterr = PTR_ERR(writer_task);
878 VERBOSE_PRINTK_ERRSTRING("Failed to create writer");
882 fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
884 if (fakewriter_tasks == NULL) {
885 VERBOSE_PRINTK_ERRSTRING("out of memory");
889 for (i = 0; i < nfakewriters; i++) {
890 VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task");
891 fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
892 "rcu_torture_fakewriter");
893 if (IS_ERR(fakewriter_tasks[i])) {
894 firsterr = PTR_ERR(fakewriter_tasks[i]);
895 VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter");
896 fakewriter_tasks[i] = NULL;
900 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
902 if (reader_tasks == NULL) {
903 VERBOSE_PRINTK_ERRSTRING("out of memory");
907 for (i = 0; i < nrealreaders; i++) {
908 VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task");
909 reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
910 "rcu_torture_reader");
911 if (IS_ERR(reader_tasks[i])) {
912 firsterr = PTR_ERR(reader_tasks[i]);
913 VERBOSE_PRINTK_ERRSTRING("Failed to create reader");
914 reader_tasks[i] = NULL;
918 if (stat_interval > 0) {
919 VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task");
920 stats_task = kthread_run(rcu_torture_stats, NULL,
921 "rcu_torture_stats");
922 if (IS_ERR(stats_task)) {
923 firsterr = PTR_ERR(stats_task);
924 VERBOSE_PRINTK_ERRSTRING("Failed to create stats");
929 if (test_no_idle_hz) {
930 rcu_idle_cpu = num_online_cpus() - 1;
931 /* Create the shuffler thread */
932 shuffler_task = kthread_run(rcu_torture_shuffle, NULL,
933 "rcu_torture_shuffle");
934 if (IS_ERR(shuffler_task)) {
935 firsterr = PTR_ERR(shuffler_task);
936 VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler");
937 shuffler_task = NULL;
944 rcu_torture_cleanup();
948 module_init(rcu_torture_init);
949 module_exit(rcu_torture_cleanup);