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/torture.h>
31 #include <linux/reboot.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;
63 static unsigned long last_lock_release;
65 struct lock_stress_stats {
70 /* Forward reference. */
71 static void lock_torture_cleanup(void);
74 * Operations vector for selecting different types of tests.
76 struct lock_torture_ops {
79 int (*writelock)(int tid);
80 void (*write_delay)(struct torture_random_state *trsp);
81 void (*task_boost)(struct torture_random_state *trsp);
82 void (*writeunlock)(int tid);
83 int (*readlock)(int tid);
84 void (*read_delay)(struct torture_random_state *trsp);
85 void (*readunlock)(int tid);
87 unsigned long flags; /* for irq spinlocks */
91 struct lock_torture_cxt {
92 int nrealwriters_stress;
93 int nrealreaders_stress;
96 atomic_t n_lock_torture_errors;
97 struct lock_torture_ops *cur_ops;
98 struct lock_stress_stats *lwsa; /* writer statistics */
99 struct lock_stress_stats *lrsa; /* reader statistics */
101 static struct lock_torture_cxt cxt = { 0, 0, false, false,
105 * Definitions for lock torture testing.
108 static int torture_lock_busted_write_lock(int tid __maybe_unused)
110 return 0; /* BUGGY, do not use in real life!!! */
113 static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
115 const unsigned long longdelay_ms = 100;
117 /* We want a long delay occasionally to force massive contention. */
118 if (!(torture_random(trsp) %
119 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
120 mdelay(longdelay_ms);
121 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
122 torture_preempt_schedule(); /* Allow test to be preempted. */
125 static void torture_lock_busted_write_unlock(int tid __maybe_unused)
127 /* BUGGY, do not use in real life!!! */
130 static void torture_boost_dummy(struct torture_random_state *trsp)
132 /* Only rtmutexes care about priority */
135 static struct lock_torture_ops lock_busted_ops = {
136 .writelock = torture_lock_busted_write_lock,
137 .write_delay = torture_lock_busted_write_delay,
138 .task_boost = torture_boost_dummy,
139 .writeunlock = torture_lock_busted_write_unlock,
143 .name = "lock_busted"
146 static DEFINE_SPINLOCK(torture_spinlock);
148 static int torture_spin_lock_write_lock(int tid __maybe_unused)
149 __acquires(torture_spinlock)
151 spin_lock(&torture_spinlock);
155 static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
157 const unsigned long shortdelay_us = 2;
158 const unsigned long longdelay_ms = 100;
160 /* We want a short delay mostly to emulate likely code, and
161 * we want a long delay occasionally to force massive contention.
163 if (!(torture_random(trsp) %
164 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
165 mdelay(longdelay_ms);
166 if (!(torture_random(trsp) %
167 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
168 udelay(shortdelay_us);
169 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
170 torture_preempt_schedule(); /* Allow test to be preempted. */
173 static void torture_spin_lock_write_unlock(int tid __maybe_unused)
174 __releases(torture_spinlock)
176 spin_unlock(&torture_spinlock);
179 static struct lock_torture_ops spin_lock_ops = {
180 .writelock = torture_spin_lock_write_lock,
181 .write_delay = torture_spin_lock_write_delay,
182 .task_boost = torture_boost_dummy,
183 .writeunlock = torture_spin_lock_write_unlock,
190 static int torture_spin_lock_write_lock_irq(int tid __maybe_unused)
191 __acquires(torture_spinlock)
195 spin_lock_irqsave(&torture_spinlock, flags);
196 cxt.cur_ops->flags = flags;
200 static void torture_lock_spin_write_unlock_irq(int tid __maybe_unused)
201 __releases(torture_spinlock)
203 spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
206 static struct lock_torture_ops spin_lock_irq_ops = {
207 .writelock = torture_spin_lock_write_lock_irq,
208 .write_delay = torture_spin_lock_write_delay,
209 .task_boost = torture_boost_dummy,
210 .writeunlock = torture_lock_spin_write_unlock_irq,
214 .name = "spin_lock_irq"
217 static DEFINE_RWLOCK(torture_rwlock);
219 static int torture_rwlock_write_lock(int tid __maybe_unused)
220 __acquires(torture_rwlock)
222 write_lock(&torture_rwlock);
226 static void torture_rwlock_write_delay(struct torture_random_state *trsp)
228 const unsigned long shortdelay_us = 2;
229 const unsigned long longdelay_ms = 100;
231 /* We want a short delay mostly to emulate likely code, and
232 * we want a long delay occasionally to force massive contention.
234 if (!(torture_random(trsp) %
235 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
236 mdelay(longdelay_ms);
238 udelay(shortdelay_us);
241 static void torture_rwlock_write_unlock(int tid __maybe_unused)
242 __releases(torture_rwlock)
244 write_unlock(&torture_rwlock);
247 static int torture_rwlock_read_lock(int tid __maybe_unused)
248 __acquires(torture_rwlock)
250 read_lock(&torture_rwlock);
254 static void torture_rwlock_read_delay(struct torture_random_state *trsp)
256 const unsigned long shortdelay_us = 10;
257 const unsigned long longdelay_ms = 100;
259 /* We want a short delay mostly to emulate likely code, and
260 * we want a long delay occasionally to force massive contention.
262 if (!(torture_random(trsp) %
263 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
264 mdelay(longdelay_ms);
266 udelay(shortdelay_us);
269 static void torture_rwlock_read_unlock(int tid __maybe_unused)
270 __releases(torture_rwlock)
272 read_unlock(&torture_rwlock);
275 static struct lock_torture_ops rw_lock_ops = {
276 .writelock = torture_rwlock_write_lock,
277 .write_delay = torture_rwlock_write_delay,
278 .task_boost = torture_boost_dummy,
279 .writeunlock = torture_rwlock_write_unlock,
280 .readlock = torture_rwlock_read_lock,
281 .read_delay = torture_rwlock_read_delay,
282 .readunlock = torture_rwlock_read_unlock,
286 static int torture_rwlock_write_lock_irq(int tid __maybe_unused)
287 __acquires(torture_rwlock)
291 write_lock_irqsave(&torture_rwlock, flags);
292 cxt.cur_ops->flags = flags;
296 static void torture_rwlock_write_unlock_irq(int tid __maybe_unused)
297 __releases(torture_rwlock)
299 write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
302 static int torture_rwlock_read_lock_irq(int tid __maybe_unused)
303 __acquires(torture_rwlock)
307 read_lock_irqsave(&torture_rwlock, flags);
308 cxt.cur_ops->flags = flags;
312 static void torture_rwlock_read_unlock_irq(int tid __maybe_unused)
313 __releases(torture_rwlock)
315 read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
318 static struct lock_torture_ops rw_lock_irq_ops = {
319 .writelock = torture_rwlock_write_lock_irq,
320 .write_delay = torture_rwlock_write_delay,
321 .task_boost = torture_boost_dummy,
322 .writeunlock = torture_rwlock_write_unlock_irq,
323 .readlock = torture_rwlock_read_lock_irq,
324 .read_delay = torture_rwlock_read_delay,
325 .readunlock = torture_rwlock_read_unlock_irq,
326 .name = "rw_lock_irq"
329 static DEFINE_MUTEX(torture_mutex);
331 static int torture_mutex_lock(int tid __maybe_unused)
332 __acquires(torture_mutex)
334 mutex_lock(&torture_mutex);
338 static void torture_mutex_delay(struct torture_random_state *trsp)
340 const unsigned long longdelay_ms = 100;
342 /* We want a long delay occasionally to force massive contention. */
343 if (!(torture_random(trsp) %
344 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
345 mdelay(longdelay_ms * 5);
347 mdelay(longdelay_ms / 5);
348 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
349 torture_preempt_schedule(); /* Allow test to be preempted. */
352 static void torture_mutex_unlock(int tid __maybe_unused)
353 __releases(torture_mutex)
355 mutex_unlock(&torture_mutex);
358 static struct lock_torture_ops mutex_lock_ops = {
359 .writelock = torture_mutex_lock,
360 .write_delay = torture_mutex_delay,
361 .task_boost = torture_boost_dummy,
362 .writeunlock = torture_mutex_unlock,
369 #include <linux/ww_mutex.h>
371 * The torture ww_mutexes should belong to the same lock class as
372 * torture_ww_class to avoid lockdep problem. The ww_mutex_init()
373 * function is called for initialization to ensure that.
375 static DEFINE_WD_CLASS(torture_ww_class);
376 static struct ww_mutex torture_ww_mutex_0, torture_ww_mutex_1, torture_ww_mutex_2;
377 static struct ww_acquire_ctx *ww_acquire_ctxs;
379 static void torture_ww_mutex_init(void)
381 ww_mutex_init(&torture_ww_mutex_0, &torture_ww_class);
382 ww_mutex_init(&torture_ww_mutex_1, &torture_ww_class);
383 ww_mutex_init(&torture_ww_mutex_2, &torture_ww_class);
385 ww_acquire_ctxs = kmalloc_array(cxt.nrealwriters_stress,
386 sizeof(*ww_acquire_ctxs),
388 if (!ww_acquire_ctxs)
389 VERBOSE_TOROUT_STRING("ww_acquire_ctx: Out of memory");
392 static void torture_ww_mutex_exit(void)
394 kfree(ww_acquire_ctxs);
397 static int torture_ww_mutex_lock(int tid)
398 __acquires(torture_ww_mutex_0)
399 __acquires(torture_ww_mutex_1)
400 __acquires(torture_ww_mutex_2)
403 struct reorder_lock {
404 struct list_head link;
405 struct ww_mutex *lock;
406 } locks[3], *ll, *ln;
407 struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
409 locks[0].lock = &torture_ww_mutex_0;
410 list_add(&locks[0].link, &list);
412 locks[1].lock = &torture_ww_mutex_1;
413 list_add(&locks[1].link, &list);
415 locks[2].lock = &torture_ww_mutex_2;
416 list_add(&locks[2].link, &list);
418 ww_acquire_init(ctx, &torture_ww_class);
420 list_for_each_entry(ll, &list, link) {
423 err = ww_mutex_lock(ll->lock, ctx);
428 list_for_each_entry_continue_reverse(ln, &list, link)
429 ww_mutex_unlock(ln->lock);
434 ww_mutex_lock_slow(ll->lock, ctx);
435 list_move(&ll->link, &list);
441 static void torture_ww_mutex_unlock(int tid)
442 __releases(torture_ww_mutex_0)
443 __releases(torture_ww_mutex_1)
444 __releases(torture_ww_mutex_2)
446 struct ww_acquire_ctx *ctx = &ww_acquire_ctxs[tid];
448 ww_mutex_unlock(&torture_ww_mutex_0);
449 ww_mutex_unlock(&torture_ww_mutex_1);
450 ww_mutex_unlock(&torture_ww_mutex_2);
451 ww_acquire_fini(ctx);
454 static struct lock_torture_ops ww_mutex_lock_ops = {
455 .init = torture_ww_mutex_init,
456 .exit = torture_ww_mutex_exit,
457 .writelock = torture_ww_mutex_lock,
458 .write_delay = torture_mutex_delay,
459 .task_boost = torture_boost_dummy,
460 .writeunlock = torture_ww_mutex_unlock,
464 .name = "ww_mutex_lock"
467 #ifdef CONFIG_RT_MUTEXES
468 static DEFINE_RT_MUTEX(torture_rtmutex);
470 static int torture_rtmutex_lock(int tid __maybe_unused)
471 __acquires(torture_rtmutex)
473 rt_mutex_lock(&torture_rtmutex);
477 static void torture_rtmutex_boost(struct torture_random_state *trsp)
479 const unsigned int factor = 50000; /* yes, quite arbitrary */
481 if (!rt_task(current)) {
483 * Boost priority once every ~50k operations. When the
484 * task tries to take the lock, the rtmutex it will account
485 * for the new priority, and do any corresponding pi-dance.
487 if (trsp && !(torture_random(trsp) %
488 (cxt.nrealwriters_stress * factor))) {
489 sched_set_fifo(current);
490 } else /* common case, do nothing */
494 * The task will remain boosted for another ~500k operations,
495 * then restored back to its original prio, and so forth.
497 * When @trsp is nil, we want to force-reset the task for
498 * stopping the kthread.
500 if (!trsp || !(torture_random(trsp) %
501 (cxt.nrealwriters_stress * factor * 2))) {
502 sched_set_normal(current, 0);
503 } else /* common case, do nothing */
508 static void torture_rtmutex_delay(struct torture_random_state *trsp)
510 const unsigned long shortdelay_us = 2;
511 const unsigned long longdelay_ms = 100;
514 * We want a short delay mostly to emulate likely code, and
515 * we want a long delay occasionally to force massive contention.
517 if (!(torture_random(trsp) %
518 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
519 mdelay(longdelay_ms);
520 if (!(torture_random(trsp) %
521 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
522 udelay(shortdelay_us);
523 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
524 torture_preempt_schedule(); /* Allow test to be preempted. */
527 static void torture_rtmutex_unlock(int tid __maybe_unused)
528 __releases(torture_rtmutex)
530 rt_mutex_unlock(&torture_rtmutex);
533 static struct lock_torture_ops rtmutex_lock_ops = {
534 .writelock = torture_rtmutex_lock,
535 .write_delay = torture_rtmutex_delay,
536 .task_boost = torture_rtmutex_boost,
537 .writeunlock = torture_rtmutex_unlock,
541 .name = "rtmutex_lock"
545 static DECLARE_RWSEM(torture_rwsem);
546 static int torture_rwsem_down_write(int tid __maybe_unused)
547 __acquires(torture_rwsem)
549 down_write(&torture_rwsem);
553 static void torture_rwsem_write_delay(struct torture_random_state *trsp)
555 const unsigned long longdelay_ms = 100;
557 /* We want a long delay occasionally to force massive contention. */
558 if (!(torture_random(trsp) %
559 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
560 mdelay(longdelay_ms * 10);
562 mdelay(longdelay_ms / 10);
563 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
564 torture_preempt_schedule(); /* Allow test to be preempted. */
567 static void torture_rwsem_up_write(int tid __maybe_unused)
568 __releases(torture_rwsem)
570 up_write(&torture_rwsem);
573 static int torture_rwsem_down_read(int tid __maybe_unused)
574 __acquires(torture_rwsem)
576 down_read(&torture_rwsem);
580 static void torture_rwsem_read_delay(struct torture_random_state *trsp)
582 const unsigned long longdelay_ms = 100;
584 /* We want a long delay occasionally to force massive contention. */
585 if (!(torture_random(trsp) %
586 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
587 mdelay(longdelay_ms * 2);
589 mdelay(longdelay_ms / 2);
590 if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
591 torture_preempt_schedule(); /* Allow test to be preempted. */
594 static void torture_rwsem_up_read(int tid __maybe_unused)
595 __releases(torture_rwsem)
597 up_read(&torture_rwsem);
600 static struct lock_torture_ops rwsem_lock_ops = {
601 .writelock = torture_rwsem_down_write,
602 .write_delay = torture_rwsem_write_delay,
603 .task_boost = torture_boost_dummy,
604 .writeunlock = torture_rwsem_up_write,
605 .readlock = torture_rwsem_down_read,
606 .read_delay = torture_rwsem_read_delay,
607 .readunlock = torture_rwsem_up_read,
611 #include <linux/percpu-rwsem.h>
612 static struct percpu_rw_semaphore pcpu_rwsem;
614 static void torture_percpu_rwsem_init(void)
616 BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
619 static void torture_percpu_rwsem_exit(void)
621 percpu_free_rwsem(&pcpu_rwsem);
624 static int torture_percpu_rwsem_down_write(int tid __maybe_unused)
625 __acquires(pcpu_rwsem)
627 percpu_down_write(&pcpu_rwsem);
631 static void torture_percpu_rwsem_up_write(int tid __maybe_unused)
632 __releases(pcpu_rwsem)
634 percpu_up_write(&pcpu_rwsem);
637 static int torture_percpu_rwsem_down_read(int tid __maybe_unused)
638 __acquires(pcpu_rwsem)
640 percpu_down_read(&pcpu_rwsem);
644 static void torture_percpu_rwsem_up_read(int tid __maybe_unused)
645 __releases(pcpu_rwsem)
647 percpu_up_read(&pcpu_rwsem);
650 static struct lock_torture_ops percpu_rwsem_lock_ops = {
651 .init = torture_percpu_rwsem_init,
652 .exit = torture_percpu_rwsem_exit,
653 .writelock = torture_percpu_rwsem_down_write,
654 .write_delay = torture_rwsem_write_delay,
655 .task_boost = torture_boost_dummy,
656 .writeunlock = torture_percpu_rwsem_up_write,
657 .readlock = torture_percpu_rwsem_down_read,
658 .read_delay = torture_rwsem_read_delay,
659 .readunlock = torture_percpu_rwsem_up_read,
660 .name = "percpu_rwsem_lock"
664 * Lock torture writer kthread. Repeatedly acquires and releases
665 * the lock, checking for duplicate acquisitions.
667 static int lock_torture_writer(void *arg)
669 struct lock_stress_stats *lwsp = arg;
670 int tid = lwsp - cxt.lwsa;
671 DEFINE_TORTURE_RANDOM(rand);
673 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
674 set_user_nice(current, MAX_NICE);
677 if ((torture_random(&rand) & 0xfffff) == 0)
678 schedule_timeout_uninterruptible(1);
680 cxt.cur_ops->task_boost(&rand);
681 cxt.cur_ops->writelock(tid);
682 if (WARN_ON_ONCE(lock_is_write_held))
684 lock_is_write_held = true;
685 if (WARN_ON_ONCE(lock_is_read_held))
686 lwsp->n_lock_fail++; /* rare, but... */
688 lwsp->n_lock_acquired++;
689 cxt.cur_ops->write_delay(&rand);
690 lock_is_write_held = false;
691 WRITE_ONCE(last_lock_release, jiffies);
692 cxt.cur_ops->writeunlock(tid);
694 stutter_wait("lock_torture_writer");
695 } while (!torture_must_stop());
697 cxt.cur_ops->task_boost(NULL); /* reset prio */
698 torture_kthread_stopping("lock_torture_writer");
703 * Lock torture reader kthread. Repeatedly acquires and releases
706 static int lock_torture_reader(void *arg)
708 struct lock_stress_stats *lrsp = arg;
709 int tid = lrsp - cxt.lrsa;
710 DEFINE_TORTURE_RANDOM(rand);
712 VERBOSE_TOROUT_STRING("lock_torture_reader task started");
713 set_user_nice(current, MAX_NICE);
716 if ((torture_random(&rand) & 0xfffff) == 0)
717 schedule_timeout_uninterruptible(1);
719 cxt.cur_ops->readlock(tid);
720 lock_is_read_held = true;
721 if (WARN_ON_ONCE(lock_is_write_held))
722 lrsp->n_lock_fail++; /* rare, but... */
724 lrsp->n_lock_acquired++;
725 cxt.cur_ops->read_delay(&rand);
726 lock_is_read_held = false;
727 cxt.cur_ops->readunlock(tid);
729 stutter_wait("lock_torture_reader");
730 } while (!torture_must_stop());
731 torture_kthread_stopping("lock_torture_reader");
736 * Create an lock-torture-statistics message in the specified buffer.
738 static void __torture_print_stats(char *page,
739 struct lock_stress_stats *statp, bool write)
743 long max = 0, min = statp ? statp[0].n_lock_acquired : 0;
746 n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
747 for (i = 0; i < n_stress; i++) {
748 if (statp[i].n_lock_fail)
750 sum += statp[i].n_lock_acquired;
751 if (max < statp[i].n_lock_acquired)
752 max = statp[i].n_lock_acquired;
753 if (min > statp[i].n_lock_acquired)
754 min = statp[i].n_lock_acquired;
756 page += sprintf(page,
757 "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
758 write ? "Writes" : "Reads ",
760 !onoff_interval && max / 2 > min ? "???" : "",
761 fail, fail ? "!!!" : "");
763 atomic_inc(&cxt.n_lock_torture_errors);
767 * Print torture statistics. Caller must ensure that there is only one
768 * call to this function at a given time!!! This is normally accomplished
769 * by relying on the module system to only have one copy of the module
770 * loaded, and then by giving the lock_torture_stats kthread full control
771 * (or the init/cleanup functions when lock_torture_stats thread is not
774 static void lock_torture_stats_print(void)
776 int size = cxt.nrealwriters_stress * 200 + 8192;
779 if (cxt.cur_ops->readlock)
780 size += cxt.nrealreaders_stress * 200 + 8192;
782 buf = kmalloc(size, GFP_KERNEL);
784 pr_err("lock_torture_stats_print: Out of memory, need: %d",
789 __torture_print_stats(buf, cxt.lwsa, true);
793 if (cxt.cur_ops->readlock) {
794 buf = kmalloc(size, GFP_KERNEL);
796 pr_err("lock_torture_stats_print: Out of memory, need: %d",
801 __torture_print_stats(buf, cxt.lrsa, false);
808 * Periodically prints torture statistics, if periodic statistics printing
809 * was specified via the stat_interval module parameter.
811 * No need to worry about fullstop here, since this one doesn't reference
812 * volatile state or register callbacks.
814 static int lock_torture_stats(void *arg)
816 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
818 schedule_timeout_interruptible(stat_interval * HZ);
819 lock_torture_stats_print();
820 torture_shutdown_absorb("lock_torture_stats");
821 } while (!torture_must_stop());
822 torture_kthread_stopping("lock_torture_stats");
827 lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
830 pr_alert("%s" TORTURE_FLAG
831 "--- %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",
832 torture_type, tag, cxt.debug_lock ? " [debug]": "",
833 cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
834 verbose, shuffle_interval, stutter, shutdown_secs,
835 onoff_interval, onoff_holdoff);
838 static void lock_torture_cleanup(void)
842 if (torture_cleanup_begin())
846 * Indicates early cleanup, meaning that the test has not run,
847 * such as when passing bogus args when loading the module.
848 * However cxt->cur_ops.init() may have been invoked, so beside
849 * perform the underlying torture-specific cleanups, cur_ops.exit()
850 * will be invoked if needed.
852 if (!cxt.lwsa && !cxt.lrsa)
856 for (i = 0; i < cxt.nrealwriters_stress; i++)
857 torture_stop_kthread(lock_torture_writer,
864 for (i = 0; i < cxt.nrealreaders_stress; i++)
865 torture_stop_kthread(lock_torture_reader,
871 torture_stop_kthread(lock_torture_stats, stats_task);
872 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
874 if (atomic_read(&cxt.n_lock_torture_errors))
875 lock_torture_print_module_parms(cxt.cur_ops,
876 "End of test: FAILURE");
877 else if (torture_onoff_failures())
878 lock_torture_print_module_parms(cxt.cur_ops,
879 "End of test: LOCK_HOTPLUG");
881 lock_torture_print_module_parms(cxt.cur_ops,
882 "End of test: SUCCESS");
890 if (cxt.init_called) {
891 if (cxt.cur_ops->exit)
893 cxt.init_called = false;
895 torture_cleanup_end();
898 static int __init lock_torture_init(void)
902 static struct lock_torture_ops *torture_ops[] = {
904 &spin_lock_ops, &spin_lock_irq_ops,
905 &rw_lock_ops, &rw_lock_irq_ops,
908 #ifdef CONFIG_RT_MUTEXES
912 &percpu_rwsem_lock_ops,
915 if (!torture_init_begin(torture_type, verbose))
918 /* Process args and tell the world that the torturer is on the job. */
919 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
920 cxt.cur_ops = torture_ops[i];
921 if (strcmp(torture_type, cxt.cur_ops->name) == 0)
924 if (i == ARRAY_SIZE(torture_ops)) {
925 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
927 pr_alert("lock-torture types:");
928 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
929 pr_alert(" %s", torture_ops[i]->name);
935 if (nwriters_stress == 0 &&
936 (!cxt.cur_ops->readlock || nreaders_stress == 0)) {
937 pr_alert("lock-torture: must run at least one locking thread\n");
942 if (nwriters_stress >= 0)
943 cxt.nrealwriters_stress = nwriters_stress;
945 cxt.nrealwriters_stress = 2 * num_online_cpus();
947 if (cxt.cur_ops->init) {
949 cxt.init_called = true;
952 #ifdef CONFIG_DEBUG_MUTEXES
953 if (str_has_prefix(torture_type, "mutex"))
954 cxt.debug_lock = true;
956 #ifdef CONFIG_DEBUG_RT_MUTEXES
957 if (str_has_prefix(torture_type, "rtmutex"))
958 cxt.debug_lock = true;
960 #ifdef CONFIG_DEBUG_SPINLOCK
961 if ((str_has_prefix(torture_type, "spin")) ||
962 (str_has_prefix(torture_type, "rw_lock")))
963 cxt.debug_lock = true;
966 /* Initialize the statistics so that each run gets its own numbers. */
967 if (nwriters_stress) {
968 lock_is_write_held = false;
969 cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress,
972 if (cxt.lwsa == NULL) {
973 VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
978 for (i = 0; i < cxt.nrealwriters_stress; i++) {
979 cxt.lwsa[i].n_lock_fail = 0;
980 cxt.lwsa[i].n_lock_acquired = 0;
984 if (cxt.cur_ops->readlock) {
985 if (nreaders_stress >= 0)
986 cxt.nrealreaders_stress = nreaders_stress;
989 * By default distribute evenly the number of
990 * readers and writers. We still run the same number
991 * of threads as the writer-only locks default.
993 if (nwriters_stress < 0) /* user doesn't care */
994 cxt.nrealwriters_stress = num_online_cpus();
995 cxt.nrealreaders_stress = cxt.nrealwriters_stress;
998 if (nreaders_stress) {
999 lock_is_read_held = false;
1000 cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress,
1003 if (cxt.lrsa == NULL) {
1004 VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
1011 for (i = 0; i < cxt.nrealreaders_stress; i++) {
1012 cxt.lrsa[i].n_lock_fail = 0;
1013 cxt.lrsa[i].n_lock_acquired = 0;
1018 lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
1020 /* Prepare torture context. */
1021 if (onoff_interval > 0) {
1022 firsterr = torture_onoff_init(onoff_holdoff * HZ,
1023 onoff_interval * HZ, NULL);
1027 if (shuffle_interval > 0) {
1028 firsterr = torture_shuffle_init(shuffle_interval);
1032 if (shutdown_secs > 0) {
1033 firsterr = torture_shutdown_init(shutdown_secs,
1034 lock_torture_cleanup);
1039 firsterr = torture_stutter_init(stutter, stutter);
1044 if (nwriters_stress) {
1045 writer_tasks = kcalloc(cxt.nrealwriters_stress,
1046 sizeof(writer_tasks[0]),
1048 if (writer_tasks == NULL) {
1049 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
1055 if (cxt.cur_ops->readlock) {
1056 reader_tasks = kcalloc(cxt.nrealreaders_stress,
1057 sizeof(reader_tasks[0]),
1059 if (reader_tasks == NULL) {
1060 VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
1061 kfree(writer_tasks);
1062 writer_tasks = NULL;
1069 * Create the kthreads and start torturing (oh, those poor little locks).
1071 * TODO: Note that we interleave writers with readers, giving writers a
1072 * slight advantage, by creating its kthread first. This can be modified
1073 * for very specific needs, or even let the user choose the policy, if
1076 for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
1077 j < cxt.nrealreaders_stress; i++, j++) {
1078 if (i >= cxt.nrealwriters_stress)
1081 /* Create writer. */
1082 firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
1088 if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
1090 /* Create reader. */
1091 firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
1096 if (stat_interval > 0) {
1097 firsterr = torture_create_kthread(lock_torture_stats, NULL,
1107 lock_torture_cleanup();
1108 if (shutdown_secs) {
1109 WARN_ON(!IS_MODULE(CONFIG_LOCK_TORTURE_TEST));
1115 module_init(lock_torture_init);
1116 module_exit(lock_torture_cleanup);