1 // SPDX-License-Identifier: GPL-2.0+
3 * Module-based torture test facility for locking
5 * Copyright (C) IBM Corporation, 2014
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
8 * Davidlohr Bueso <dave@stgolabs.net>
9 * Based on kernel/rcu/torture.c.
12 #define pr_fmt(fmt) fmt
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/kthread.h>
17 #include <linux/sched/rt.h>
18 #include <linux/spinlock.h>
19 #include <linux/mutex.h>
20 #include <linux/rwsem.h>
21 #include <linux/smp.h>
22 #include <linux/interrupt.h>
23 #include <linux/sched.h>
24 #include <uapi/linux/sched/types.h>
25 #include <linux/rtmutex.h>
26 #include <linux/atomic.h>
27 #include <linux/moduleparam.h>
28 #include <linux/delay.h>
29 #include <linux/slab.h>
30 #include <linux/percpu-rwsem.h>
31 #include <linux/torture.h>
33 MODULE_LICENSE("GPL");
34 MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
36 torture_param(int, nwriters_stress, -1,
37 "Number of write-locking stress-test threads");
38 torture_param(int, nreaders_stress, -1,
39 "Number of read-locking stress-test threads");
40 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
41 torture_param(int, onoff_interval, 0,
42 "Time between CPU hotplugs (s), 0=disable");
43 torture_param(int, shuffle_interval, 3,
44 "Number of jiffies between shuffles, 0=disable");
45 torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
46 torture_param(int, stat_interval, 60,
47 "Number of seconds between stats printk()s");
48 torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
49 torture_param(int, verbose, 1,
50 "Enable verbose debugging printk()s");
52 static char *torture_type = "spin_lock";
53 module_param(torture_type, charp, 0444);
54 MODULE_PARM_DESC(torture_type,
55 "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
57 static struct task_struct *stats_task;
58 static struct task_struct **writer_tasks;
59 static struct task_struct **reader_tasks;
61 static bool lock_is_write_held;
62 static bool lock_is_read_held;
64 struct lock_stress_stats {
69 /* Forward reference. */
70 static void lock_torture_cleanup(void);
73 * Operations vector for selecting different types of tests.
75 struct lock_torture_ops {
77 int (*writelock)(void);
78 void (*write_delay)(struct torture_random_state *trsp);
79 void (*task_boost)(struct torture_random_state *trsp);
80 void (*writeunlock)(void);
81 int (*readlock)(void);
82 void (*read_delay)(struct torture_random_state *trsp);
83 void (*readunlock)(void);
85 unsigned long flags; /* for irq spinlocks */
89 struct lock_torture_cxt {
90 int nrealwriters_stress;
91 int nrealreaders_stress;
93 atomic_t n_lock_torture_errors;
94 struct lock_torture_ops *cur_ops;
95 struct lock_stress_stats *lwsa; /* writer statistics */
96 struct lock_stress_stats *lrsa; /* reader statistics */
98 static struct lock_torture_cxt cxt = { 0, 0, false,
102 * Definitions for lock torture testing.
105 static int torture_lock_busted_write_lock(void)
107 return 0; /* BUGGY, do not use in real life!!! */
110 static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
112 const unsigned long longdelay_ms = 100;
114 /* We want a long delay occasionally to force massive contention. */
115 if (!(torture_random(trsp) %
116 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
117 mdelay(longdelay_ms);
118 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
119 torture_preempt_schedule(); /* Allow test to be preempted. */
122 static void torture_lock_busted_write_unlock(void)
124 /* BUGGY, do not use in real life!!! */
127 static void torture_boost_dummy(struct torture_random_state *trsp)
129 /* Only rtmutexes care about priority */
132 static struct lock_torture_ops lock_busted_ops = {
133 .writelock = torture_lock_busted_write_lock,
134 .write_delay = torture_lock_busted_write_delay,
135 .task_boost = torture_boost_dummy,
136 .writeunlock = torture_lock_busted_write_unlock,
140 .name = "lock_busted"
143 static DEFINE_SPINLOCK(torture_spinlock);
145 static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
147 spin_lock(&torture_spinlock);
151 static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
153 const unsigned long shortdelay_us = 2;
154 const unsigned long longdelay_ms = 100;
156 /* We want a short delay mostly to emulate likely code, and
157 * we want a long delay occasionally to force massive contention.
159 if (!(torture_random(trsp) %
160 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
161 mdelay(longdelay_ms);
162 if (!(torture_random(trsp) %
163 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
164 udelay(shortdelay_us);
165 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
166 torture_preempt_schedule(); /* Allow test to be preempted. */
169 static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
171 spin_unlock(&torture_spinlock);
174 static struct lock_torture_ops spin_lock_ops = {
175 .writelock = torture_spin_lock_write_lock,
176 .write_delay = torture_spin_lock_write_delay,
177 .task_boost = torture_boost_dummy,
178 .writeunlock = torture_spin_lock_write_unlock,
185 static int torture_spin_lock_write_lock_irq(void)
186 __acquires(torture_spinlock)
190 spin_lock_irqsave(&torture_spinlock, flags);
191 cxt.cur_ops->flags = flags;
195 static void torture_lock_spin_write_unlock_irq(void)
196 __releases(torture_spinlock)
198 spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
201 static struct lock_torture_ops spin_lock_irq_ops = {
202 .writelock = torture_spin_lock_write_lock_irq,
203 .write_delay = torture_spin_lock_write_delay,
204 .task_boost = torture_boost_dummy,
205 .writeunlock = torture_lock_spin_write_unlock_irq,
209 .name = "spin_lock_irq"
212 static DEFINE_RWLOCK(torture_rwlock);
214 static int torture_rwlock_write_lock(void) __acquires(torture_rwlock)
216 write_lock(&torture_rwlock);
220 static void torture_rwlock_write_delay(struct torture_random_state *trsp)
222 const unsigned long shortdelay_us = 2;
223 const unsigned long longdelay_ms = 100;
225 /* We want a short delay mostly to emulate likely code, and
226 * we want a long delay occasionally to force massive contention.
228 if (!(torture_random(trsp) %
229 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
230 mdelay(longdelay_ms);
232 udelay(shortdelay_us);
235 static void torture_rwlock_write_unlock(void) __releases(torture_rwlock)
237 write_unlock(&torture_rwlock);
240 static int torture_rwlock_read_lock(void) __acquires(torture_rwlock)
242 read_lock(&torture_rwlock);
246 static void torture_rwlock_read_delay(struct torture_random_state *trsp)
248 const unsigned long shortdelay_us = 10;
249 const unsigned long longdelay_ms = 100;
251 /* We want a short delay mostly to emulate likely code, and
252 * we want a long delay occasionally to force massive contention.
254 if (!(torture_random(trsp) %
255 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
256 mdelay(longdelay_ms);
258 udelay(shortdelay_us);
261 static void torture_rwlock_read_unlock(void) __releases(torture_rwlock)
263 read_unlock(&torture_rwlock);
266 static struct lock_torture_ops rw_lock_ops = {
267 .writelock = torture_rwlock_write_lock,
268 .write_delay = torture_rwlock_write_delay,
269 .task_boost = torture_boost_dummy,
270 .writeunlock = torture_rwlock_write_unlock,
271 .readlock = torture_rwlock_read_lock,
272 .read_delay = torture_rwlock_read_delay,
273 .readunlock = torture_rwlock_read_unlock,
277 static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
281 write_lock_irqsave(&torture_rwlock, flags);
282 cxt.cur_ops->flags = flags;
286 static void torture_rwlock_write_unlock_irq(void)
287 __releases(torture_rwlock)
289 write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
292 static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
296 read_lock_irqsave(&torture_rwlock, flags);
297 cxt.cur_ops->flags = flags;
301 static void torture_rwlock_read_unlock_irq(void)
302 __releases(torture_rwlock)
304 read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
307 static struct lock_torture_ops rw_lock_irq_ops = {
308 .writelock = torture_rwlock_write_lock_irq,
309 .write_delay = torture_rwlock_write_delay,
310 .task_boost = torture_boost_dummy,
311 .writeunlock = torture_rwlock_write_unlock_irq,
312 .readlock = torture_rwlock_read_lock_irq,
313 .read_delay = torture_rwlock_read_delay,
314 .readunlock = torture_rwlock_read_unlock_irq,
315 .name = "rw_lock_irq"
318 static DEFINE_MUTEX(torture_mutex);
320 static int torture_mutex_lock(void) __acquires(torture_mutex)
322 mutex_lock(&torture_mutex);
326 static void torture_mutex_delay(struct torture_random_state *trsp)
328 const unsigned long longdelay_ms = 100;
330 /* We want a long delay occasionally to force massive contention. */
331 if (!(torture_random(trsp) %
332 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
333 mdelay(longdelay_ms * 5);
335 mdelay(longdelay_ms / 5);
336 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
337 torture_preempt_schedule(); /* Allow test to be preempted. */
340 static void torture_mutex_unlock(void) __releases(torture_mutex)
342 mutex_unlock(&torture_mutex);
345 static struct lock_torture_ops mutex_lock_ops = {
346 .writelock = torture_mutex_lock,
347 .write_delay = torture_mutex_delay,
348 .task_boost = torture_boost_dummy,
349 .writeunlock = torture_mutex_unlock,
356 #include <linux/ww_mutex.h>
357 static DEFINE_WD_CLASS(torture_ww_class);
358 static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class);
359 static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class);
360 static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class);
362 static int torture_ww_mutex_lock(void)
363 __acquires(torture_ww_mutex_0)
364 __acquires(torture_ww_mutex_1)
365 __acquires(torture_ww_mutex_2)
368 struct reorder_lock {
369 struct list_head link;
370 struct ww_mutex *lock;
371 } locks[3], *ll, *ln;
372 struct ww_acquire_ctx ctx;
374 locks[0].lock = &torture_ww_mutex_0;
375 list_add(&locks[0].link, &list);
377 locks[1].lock = &torture_ww_mutex_1;
378 list_add(&locks[1].link, &list);
380 locks[2].lock = &torture_ww_mutex_2;
381 list_add(&locks[2].link, &list);
383 ww_acquire_init(&ctx, &torture_ww_class);
385 list_for_each_entry(ll, &list, link) {
388 err = ww_mutex_lock(ll->lock, &ctx);
393 list_for_each_entry_continue_reverse(ln, &list, link)
394 ww_mutex_unlock(ln->lock);
399 ww_mutex_lock_slow(ll->lock, &ctx);
400 list_move(&ll->link, &list);
403 ww_acquire_fini(&ctx);
407 static void torture_ww_mutex_unlock(void)
408 __releases(torture_ww_mutex_0)
409 __releases(torture_ww_mutex_1)
410 __releases(torture_ww_mutex_2)
412 ww_mutex_unlock(&torture_ww_mutex_0);
413 ww_mutex_unlock(&torture_ww_mutex_1);
414 ww_mutex_unlock(&torture_ww_mutex_2);
417 static struct lock_torture_ops ww_mutex_lock_ops = {
418 .writelock = torture_ww_mutex_lock,
419 .write_delay = torture_mutex_delay,
420 .task_boost = torture_boost_dummy,
421 .writeunlock = torture_ww_mutex_unlock,
425 .name = "ww_mutex_lock"
428 #ifdef CONFIG_RT_MUTEXES
429 static DEFINE_RT_MUTEX(torture_rtmutex);
431 static int torture_rtmutex_lock(void) __acquires(torture_rtmutex)
433 rt_mutex_lock(&torture_rtmutex);
437 static void torture_rtmutex_boost(struct torture_random_state *trsp)
439 const unsigned int factor = 50000; /* yes, quite arbitrary */
441 if (!rt_task(current)) {
443 * Boost priority once every ~50k operations. When the
444 * task tries to take the lock, the rtmutex it will account
445 * for the new priority, and do any corresponding pi-dance.
447 if (trsp && !(torture_random(trsp) %
448 (cxt.nrealwriters_stress * factor))) {
449 sched_set_fifo(current);
450 } else /* common case, do nothing */
454 * The task will remain boosted for another ~500k operations,
455 * then restored back to its original prio, and so forth.
457 * When @trsp is nil, we want to force-reset the task for
458 * stopping the kthread.
460 if (!trsp || !(torture_random(trsp) %
461 (cxt.nrealwriters_stress * factor * 2))) {
462 sched_set_normal(current, 0);
463 } else /* common case, do nothing */
468 static void torture_rtmutex_delay(struct torture_random_state *trsp)
470 const unsigned long shortdelay_us = 2;
471 const unsigned long longdelay_ms = 100;
474 * We want a short delay mostly to emulate likely code, and
475 * we want a long delay occasionally to force massive contention.
477 if (!(torture_random(trsp) %
478 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
479 mdelay(longdelay_ms);
480 if (!(torture_random(trsp) %
481 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
482 udelay(shortdelay_us);
483 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
484 torture_preempt_schedule(); /* Allow test to be preempted. */
487 static void torture_rtmutex_unlock(void) __releases(torture_rtmutex)
489 rt_mutex_unlock(&torture_rtmutex);
492 static struct lock_torture_ops rtmutex_lock_ops = {
493 .writelock = torture_rtmutex_lock,
494 .write_delay = torture_rtmutex_delay,
495 .task_boost = torture_rtmutex_boost,
496 .writeunlock = torture_rtmutex_unlock,
500 .name = "rtmutex_lock"
504 static DECLARE_RWSEM(torture_rwsem);
505 static int torture_rwsem_down_write(void) __acquires(torture_rwsem)
507 down_write(&torture_rwsem);
511 static void torture_rwsem_write_delay(struct torture_random_state *trsp)
513 const unsigned long longdelay_ms = 100;
515 /* We want a long delay occasionally to force massive contention. */
516 if (!(torture_random(trsp) %
517 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
518 mdelay(longdelay_ms * 10);
520 mdelay(longdelay_ms / 10);
521 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
522 torture_preempt_schedule(); /* Allow test to be preempted. */
525 static void torture_rwsem_up_write(void) __releases(torture_rwsem)
527 up_write(&torture_rwsem);
530 static int torture_rwsem_down_read(void) __acquires(torture_rwsem)
532 down_read(&torture_rwsem);
536 static void torture_rwsem_read_delay(struct torture_random_state *trsp)
538 const unsigned long longdelay_ms = 100;
540 /* We want a long delay occasionally to force massive contention. */
541 if (!(torture_random(trsp) %
542 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
543 mdelay(longdelay_ms * 2);
545 mdelay(longdelay_ms / 2);
546 if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
547 torture_preempt_schedule(); /* Allow test to be preempted. */
550 static void torture_rwsem_up_read(void) __releases(torture_rwsem)
552 up_read(&torture_rwsem);
555 static struct lock_torture_ops rwsem_lock_ops = {
556 .writelock = torture_rwsem_down_write,
557 .write_delay = torture_rwsem_write_delay,
558 .task_boost = torture_boost_dummy,
559 .writeunlock = torture_rwsem_up_write,
560 .readlock = torture_rwsem_down_read,
561 .read_delay = torture_rwsem_read_delay,
562 .readunlock = torture_rwsem_up_read,
566 #include <linux/percpu-rwsem.h>
567 static struct percpu_rw_semaphore pcpu_rwsem;
569 static void torture_percpu_rwsem_init(void)
571 BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
574 static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem)
576 percpu_down_write(&pcpu_rwsem);
580 static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem)
582 percpu_up_write(&pcpu_rwsem);
585 static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem)
587 percpu_down_read(&pcpu_rwsem);
591 static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem)
593 percpu_up_read(&pcpu_rwsem);
596 static struct lock_torture_ops percpu_rwsem_lock_ops = {
597 .init = torture_percpu_rwsem_init,
598 .writelock = torture_percpu_rwsem_down_write,
599 .write_delay = torture_rwsem_write_delay,
600 .task_boost = torture_boost_dummy,
601 .writeunlock = torture_percpu_rwsem_up_write,
602 .readlock = torture_percpu_rwsem_down_read,
603 .read_delay = torture_rwsem_read_delay,
604 .readunlock = torture_percpu_rwsem_up_read,
605 .name = "percpu_rwsem_lock"
609 * Lock torture writer kthread. Repeatedly acquires and releases
610 * the lock, checking for duplicate acquisitions.
612 static int lock_torture_writer(void *arg)
614 struct lock_stress_stats *lwsp = arg;
615 DEFINE_TORTURE_RANDOM(rand);
617 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
618 set_user_nice(current, MAX_NICE);
621 if ((torture_random(&rand) & 0xfffff) == 0)
622 schedule_timeout_uninterruptible(1);
624 cxt.cur_ops->task_boost(&rand);
625 cxt.cur_ops->writelock();
626 if (WARN_ON_ONCE(lock_is_write_held))
628 lock_is_write_held = true;
629 if (WARN_ON_ONCE(lock_is_read_held))
630 lwsp->n_lock_fail++; /* rare, but... */
632 lwsp->n_lock_acquired++;
633 cxt.cur_ops->write_delay(&rand);
634 lock_is_write_held = false;
635 cxt.cur_ops->writeunlock();
637 stutter_wait("lock_torture_writer");
638 } while (!torture_must_stop());
640 cxt.cur_ops->task_boost(NULL); /* reset prio */
641 torture_kthread_stopping("lock_torture_writer");
646 * Lock torture reader kthread. Repeatedly acquires and releases
649 static int lock_torture_reader(void *arg)
651 struct lock_stress_stats *lrsp = arg;
652 DEFINE_TORTURE_RANDOM(rand);
654 VERBOSE_TOROUT_STRING("lock_torture_reader task started");
655 set_user_nice(current, MAX_NICE);
658 if ((torture_random(&rand) & 0xfffff) == 0)
659 schedule_timeout_uninterruptible(1);
661 cxt.cur_ops->readlock();
662 lock_is_read_held = true;
663 if (WARN_ON_ONCE(lock_is_write_held))
664 lrsp->n_lock_fail++; /* rare, but... */
666 lrsp->n_lock_acquired++;
667 cxt.cur_ops->read_delay(&rand);
668 lock_is_read_held = false;
669 cxt.cur_ops->readunlock();
671 stutter_wait("lock_torture_reader");
672 } while (!torture_must_stop());
673 torture_kthread_stopping("lock_torture_reader");
678 * Create an lock-torture-statistics message in the specified buffer.
680 static void __torture_print_stats(char *page,
681 struct lock_stress_stats *statp, bool write)
685 long max = 0, min = statp ? statp[0].n_lock_acquired : 0;
688 n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
689 for (i = 0; i < n_stress; i++) {
690 if (statp[i].n_lock_fail)
692 sum += statp[i].n_lock_acquired;
693 if (max < statp[i].n_lock_acquired)
694 max = statp[i].n_lock_acquired;
695 if (min > statp[i].n_lock_acquired)
696 min = statp[i].n_lock_acquired;
698 page += sprintf(page,
699 "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
700 write ? "Writes" : "Reads ",
702 !onoff_interval && max / 2 > min ? "???" : "",
703 fail, fail ? "!!!" : "");
705 atomic_inc(&cxt.n_lock_torture_errors);
709 * Print torture statistics. Caller must ensure that there is only one
710 * call to this function at a given time!!! This is normally accomplished
711 * by relying on the module system to only have one copy of the module
712 * loaded, and then by giving the lock_torture_stats kthread full control
713 * (or the init/cleanup functions when lock_torture_stats thread is not
716 static void lock_torture_stats_print(void)
718 int size = cxt.nrealwriters_stress * 200 + 8192;
721 if (cxt.cur_ops->readlock)
722 size += cxt.nrealreaders_stress * 200 + 8192;
724 buf = kmalloc(size, GFP_KERNEL);
726 pr_err("lock_torture_stats_print: Out of memory, need: %d",
731 __torture_print_stats(buf, cxt.lwsa, true);
735 if (cxt.cur_ops->readlock) {
736 buf = kmalloc(size, GFP_KERNEL);
738 pr_err("lock_torture_stats_print: Out of memory, need: %d",
743 __torture_print_stats(buf, cxt.lrsa, false);
750 * Periodically prints torture statistics, if periodic statistics printing
751 * was specified via the stat_interval module parameter.
753 * No need to worry about fullstop here, since this one doesn't reference
754 * volatile state or register callbacks.
756 static int lock_torture_stats(void *arg)
758 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
760 schedule_timeout_interruptible(stat_interval * HZ);
761 lock_torture_stats_print();
762 torture_shutdown_absorb("lock_torture_stats");
763 } while (!torture_must_stop());
764 torture_kthread_stopping("lock_torture_stats");
769 lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
772 pr_alert("%s" TORTURE_FLAG
773 "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
774 torture_type, tag, cxt.debug_lock ? " [debug]": "",
775 cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
776 verbose, shuffle_interval, stutter, shutdown_secs,
777 onoff_interval, onoff_holdoff);
780 static void lock_torture_cleanup(void)
784 if (torture_cleanup_begin())
788 * Indicates early cleanup, meaning that the test has not run,
789 * such as when passing bogus args when loading the module. As
790 * such, only perform the underlying torture-specific cleanups,
791 * and avoid anything related to locktorture.
793 if (!cxt.lwsa && !cxt.lrsa)
797 for (i = 0; i < cxt.nrealwriters_stress; i++)
798 torture_stop_kthread(lock_torture_writer,
805 for (i = 0; i < cxt.nrealreaders_stress; i++)
806 torture_stop_kthread(lock_torture_reader,
812 torture_stop_kthread(lock_torture_stats, stats_task);
813 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
815 if (atomic_read(&cxt.n_lock_torture_errors))
816 lock_torture_print_module_parms(cxt.cur_ops,
817 "End of test: FAILURE");
818 else if (torture_onoff_failures())
819 lock_torture_print_module_parms(cxt.cur_ops,
820 "End of test: LOCK_HOTPLUG");
822 lock_torture_print_module_parms(cxt.cur_ops,
823 "End of test: SUCCESS");
831 torture_cleanup_end();
834 static int __init lock_torture_init(void)
838 static struct lock_torture_ops *torture_ops[] = {
840 &spin_lock_ops, &spin_lock_irq_ops,
841 &rw_lock_ops, &rw_lock_irq_ops,
844 #ifdef CONFIG_RT_MUTEXES
848 &percpu_rwsem_lock_ops,
851 if (!torture_init_begin(torture_type, verbose))
854 /* Process args and tell the world that the torturer is on the job. */
855 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
856 cxt.cur_ops = torture_ops[i];
857 if (strcmp(torture_type, cxt.cur_ops->name) == 0)
860 if (i == ARRAY_SIZE(torture_ops)) {
861 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
863 pr_alert("lock-torture types:");
864 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
865 pr_alert(" %s", torture_ops[i]->name);
871 if (nwriters_stress == 0 && nreaders_stress == 0) {
872 pr_alert("lock-torture: must run at least one locking thread\n");
877 if (cxt.cur_ops->init)
880 if (nwriters_stress >= 0)
881 cxt.nrealwriters_stress = nwriters_stress;
883 cxt.nrealwriters_stress = 2 * num_online_cpus();
885 #ifdef CONFIG_DEBUG_MUTEXES
886 if (str_has_prefix(torture_type, "mutex"))
887 cxt.debug_lock = true;
889 #ifdef CONFIG_DEBUG_RT_MUTEXES
890 if (str_has_prefix(torture_type, "rtmutex"))
891 cxt.debug_lock = true;
893 #ifdef CONFIG_DEBUG_SPINLOCK
894 if ((str_has_prefix(torture_type, "spin")) ||
895 (str_has_prefix(torture_type, "rw_lock")))
896 cxt.debug_lock = true;
899 /* Initialize the statistics so that each run gets its own numbers. */
900 if (nwriters_stress) {
901 lock_is_write_held = false;
902 cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress,
905 if (cxt.lwsa == NULL) {
906 VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
911 for (i = 0; i < cxt.nrealwriters_stress; i++) {
912 cxt.lwsa[i].n_lock_fail = 0;
913 cxt.lwsa[i].n_lock_acquired = 0;
917 if (cxt.cur_ops->readlock) {
918 if (nreaders_stress >= 0)
919 cxt.nrealreaders_stress = nreaders_stress;
922 * By default distribute evenly the number of
923 * readers and writers. We still run the same number
924 * of threads as the writer-only locks default.
926 if (nwriters_stress < 0) /* user doesn't care */
927 cxt.nrealwriters_stress = num_online_cpus();
928 cxt.nrealreaders_stress = cxt.nrealwriters_stress;
931 if (nreaders_stress) {
932 lock_is_read_held = false;
933 cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress,
936 if (cxt.lrsa == NULL) {
937 VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
944 for (i = 0; i < cxt.nrealreaders_stress; i++) {
945 cxt.lrsa[i].n_lock_fail = 0;
946 cxt.lrsa[i].n_lock_acquired = 0;
951 lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
953 /* Prepare torture context. */
954 if (onoff_interval > 0) {
955 firsterr = torture_onoff_init(onoff_holdoff * HZ,
956 onoff_interval * HZ, NULL);
960 if (shuffle_interval > 0) {
961 firsterr = torture_shuffle_init(shuffle_interval);
965 if (shutdown_secs > 0) {
966 firsterr = torture_shutdown_init(shutdown_secs,
967 lock_torture_cleanup);
972 firsterr = torture_stutter_init(stutter, stutter);
977 if (nwriters_stress) {
978 writer_tasks = kcalloc(cxt.nrealwriters_stress,
979 sizeof(writer_tasks[0]),
981 if (writer_tasks == NULL) {
982 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
988 if (cxt.cur_ops->readlock) {
989 reader_tasks = kcalloc(cxt.nrealreaders_stress,
990 sizeof(reader_tasks[0]),
992 if (reader_tasks == NULL) {
993 VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
1002 * Create the kthreads and start torturing (oh, those poor little locks).
1004 * TODO: Note that we interleave writers with readers, giving writers a
1005 * slight advantage, by creating its kthread first. This can be modified
1006 * for very specific needs, or even let the user choose the policy, if
1009 for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
1010 j < cxt.nrealreaders_stress; i++, j++) {
1011 if (i >= cxt.nrealwriters_stress)
1014 /* Create writer. */
1015 firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
1021 if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
1023 /* Create reader. */
1024 firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
1029 if (stat_interval > 0) {
1030 firsterr = torture_create_kthread(lock_torture_stats, NULL,
1040 lock_torture_cleanup();
1044 module_init(lock_torture_init);
1045 module_exit(lock_torture_cleanup);