Loading...
Note: File does not exist in v3.5.6.
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Module-based torture test facility for locking
4 *
5 * Copyright (C) IBM Corporation, 2014
6 *
7 * Authors: Paul E. McKenney <paulmck@linux.ibm.com>
8 * Davidlohr Bueso <dave@stgolabs.net>
9 * Based on kernel/rcu/torture.c.
10 */
11
12#define pr_fmt(fmt) fmt
13
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/rwlock.h>
20#include <linux/mutex.h>
21#include <linux/rwsem.h>
22#include <linux/smp.h>
23#include <linux/interrupt.h>
24#include <linux/sched.h>
25#include <uapi/linux/sched/types.h>
26#include <linux/rtmutex.h>
27#include <linux/atomic.h>
28#include <linux/moduleparam.h>
29#include <linux/delay.h>
30#include <linux/slab.h>
31#include <linux/percpu-rwsem.h>
32#include <linux/torture.h>
33
34MODULE_LICENSE("GPL");
35MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>");
36
37torture_param(int, nwriters_stress, -1,
38 "Number of write-locking stress-test threads");
39torture_param(int, nreaders_stress, -1,
40 "Number of read-locking stress-test threads");
41torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
42torture_param(int, onoff_interval, 0,
43 "Time between CPU hotplugs (s), 0=disable");
44torture_param(int, shuffle_interval, 3,
45 "Number of jiffies between shuffles, 0=disable");
46torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
47torture_param(int, stat_interval, 60,
48 "Number of seconds between stats printk()s");
49torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
50torture_param(int, verbose, 1,
51 "Enable verbose debugging printk()s");
52
53static char *torture_type = "spin_lock";
54module_param(torture_type, charp, 0444);
55MODULE_PARM_DESC(torture_type,
56 "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
57
58static struct task_struct *stats_task;
59static struct task_struct **writer_tasks;
60static struct task_struct **reader_tasks;
61
62static bool lock_is_write_held;
63static bool lock_is_read_held;
64
65struct lock_stress_stats {
66 long n_lock_fail;
67 long n_lock_acquired;
68};
69
70/* Forward reference. */
71static void lock_torture_cleanup(void);
72
73/*
74 * Operations vector for selecting different types of tests.
75 */
76struct lock_torture_ops {
77 void (*init)(void);
78 int (*writelock)(void);
79 void (*write_delay)(struct torture_random_state *trsp);
80 void (*task_boost)(struct torture_random_state *trsp);
81 void (*writeunlock)(void);
82 int (*readlock)(void);
83 void (*read_delay)(struct torture_random_state *trsp);
84 void (*readunlock)(void);
85
86 unsigned long flags; /* for irq spinlocks */
87 const char *name;
88};
89
90struct lock_torture_cxt {
91 int nrealwriters_stress;
92 int nrealreaders_stress;
93 bool debug_lock;
94 atomic_t n_lock_torture_errors;
95 struct lock_torture_ops *cur_ops;
96 struct lock_stress_stats *lwsa; /* writer statistics */
97 struct lock_stress_stats *lrsa; /* reader statistics */
98};
99static struct lock_torture_cxt cxt = { 0, 0, false,
100 ATOMIC_INIT(0),
101 NULL, NULL};
102/*
103 * Definitions for lock torture testing.
104 */
105
106static int torture_lock_busted_write_lock(void)
107{
108 return 0; /* BUGGY, do not use in real life!!! */
109}
110
111static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
112{
113 const unsigned long longdelay_ms = 100;
114
115 /* We want a long delay occasionally to force massive contention. */
116 if (!(torture_random(trsp) %
117 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
118 mdelay(longdelay_ms);
119 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
120 torture_preempt_schedule(); /* Allow test to be preempted. */
121}
122
123static void torture_lock_busted_write_unlock(void)
124{
125 /* BUGGY, do not use in real life!!! */
126}
127
128static void torture_boost_dummy(struct torture_random_state *trsp)
129{
130 /* Only rtmutexes care about priority */
131}
132
133static struct lock_torture_ops lock_busted_ops = {
134 .writelock = torture_lock_busted_write_lock,
135 .write_delay = torture_lock_busted_write_delay,
136 .task_boost = torture_boost_dummy,
137 .writeunlock = torture_lock_busted_write_unlock,
138 .readlock = NULL,
139 .read_delay = NULL,
140 .readunlock = NULL,
141 .name = "lock_busted"
142};
143
144static DEFINE_SPINLOCK(torture_spinlock);
145
146static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
147{
148 spin_lock(&torture_spinlock);
149 return 0;
150}
151
152static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
153{
154 const unsigned long shortdelay_us = 2;
155 const unsigned long longdelay_ms = 100;
156
157 /* We want a short delay mostly to emulate likely code, and
158 * we want a long delay occasionally to force massive contention.
159 */
160 if (!(torture_random(trsp) %
161 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
162 mdelay(longdelay_ms);
163 if (!(torture_random(trsp) %
164 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
165 udelay(shortdelay_us);
166 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
167 torture_preempt_schedule(); /* Allow test to be preempted. */
168}
169
170static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
171{
172 spin_unlock(&torture_spinlock);
173}
174
175static struct lock_torture_ops spin_lock_ops = {
176 .writelock = torture_spin_lock_write_lock,
177 .write_delay = torture_spin_lock_write_delay,
178 .task_boost = torture_boost_dummy,
179 .writeunlock = torture_spin_lock_write_unlock,
180 .readlock = NULL,
181 .read_delay = NULL,
182 .readunlock = NULL,
183 .name = "spin_lock"
184};
185
186static int torture_spin_lock_write_lock_irq(void)
187__acquires(torture_spinlock)
188{
189 unsigned long flags;
190
191 spin_lock_irqsave(&torture_spinlock, flags);
192 cxt.cur_ops->flags = flags;
193 return 0;
194}
195
196static void torture_lock_spin_write_unlock_irq(void)
197__releases(torture_spinlock)
198{
199 spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags);
200}
201
202static struct lock_torture_ops spin_lock_irq_ops = {
203 .writelock = torture_spin_lock_write_lock_irq,
204 .write_delay = torture_spin_lock_write_delay,
205 .task_boost = torture_boost_dummy,
206 .writeunlock = torture_lock_spin_write_unlock_irq,
207 .readlock = NULL,
208 .read_delay = NULL,
209 .readunlock = NULL,
210 .name = "spin_lock_irq"
211};
212
213static DEFINE_RWLOCK(torture_rwlock);
214
215static int torture_rwlock_write_lock(void) __acquires(torture_rwlock)
216{
217 write_lock(&torture_rwlock);
218 return 0;
219}
220
221static void torture_rwlock_write_delay(struct torture_random_state *trsp)
222{
223 const unsigned long shortdelay_us = 2;
224 const unsigned long longdelay_ms = 100;
225
226 /* We want a short delay mostly to emulate likely code, and
227 * we want a long delay occasionally to force massive contention.
228 */
229 if (!(torture_random(trsp) %
230 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
231 mdelay(longdelay_ms);
232 else
233 udelay(shortdelay_us);
234}
235
236static void torture_rwlock_write_unlock(void) __releases(torture_rwlock)
237{
238 write_unlock(&torture_rwlock);
239}
240
241static int torture_rwlock_read_lock(void) __acquires(torture_rwlock)
242{
243 read_lock(&torture_rwlock);
244 return 0;
245}
246
247static void torture_rwlock_read_delay(struct torture_random_state *trsp)
248{
249 const unsigned long shortdelay_us = 10;
250 const unsigned long longdelay_ms = 100;
251
252 /* We want a short delay mostly to emulate likely code, and
253 * we want a long delay occasionally to force massive contention.
254 */
255 if (!(torture_random(trsp) %
256 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
257 mdelay(longdelay_ms);
258 else
259 udelay(shortdelay_us);
260}
261
262static void torture_rwlock_read_unlock(void) __releases(torture_rwlock)
263{
264 read_unlock(&torture_rwlock);
265}
266
267static struct lock_torture_ops rw_lock_ops = {
268 .writelock = torture_rwlock_write_lock,
269 .write_delay = torture_rwlock_write_delay,
270 .task_boost = torture_boost_dummy,
271 .writeunlock = torture_rwlock_write_unlock,
272 .readlock = torture_rwlock_read_lock,
273 .read_delay = torture_rwlock_read_delay,
274 .readunlock = torture_rwlock_read_unlock,
275 .name = "rw_lock"
276};
277
278static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock)
279{
280 unsigned long flags;
281
282 write_lock_irqsave(&torture_rwlock, flags);
283 cxt.cur_ops->flags = flags;
284 return 0;
285}
286
287static void torture_rwlock_write_unlock_irq(void)
288__releases(torture_rwlock)
289{
290 write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
291}
292
293static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock)
294{
295 unsigned long flags;
296
297 read_lock_irqsave(&torture_rwlock, flags);
298 cxt.cur_ops->flags = flags;
299 return 0;
300}
301
302static void torture_rwlock_read_unlock_irq(void)
303__releases(torture_rwlock)
304{
305 read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags);
306}
307
308static struct lock_torture_ops rw_lock_irq_ops = {
309 .writelock = torture_rwlock_write_lock_irq,
310 .write_delay = torture_rwlock_write_delay,
311 .task_boost = torture_boost_dummy,
312 .writeunlock = torture_rwlock_write_unlock_irq,
313 .readlock = torture_rwlock_read_lock_irq,
314 .read_delay = torture_rwlock_read_delay,
315 .readunlock = torture_rwlock_read_unlock_irq,
316 .name = "rw_lock_irq"
317};
318
319static DEFINE_MUTEX(torture_mutex);
320
321static int torture_mutex_lock(void) __acquires(torture_mutex)
322{
323 mutex_lock(&torture_mutex);
324 return 0;
325}
326
327static void torture_mutex_delay(struct torture_random_state *trsp)
328{
329 const unsigned long longdelay_ms = 100;
330
331 /* We want a long delay occasionally to force massive contention. */
332 if (!(torture_random(trsp) %
333 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
334 mdelay(longdelay_ms * 5);
335 else
336 mdelay(longdelay_ms / 5);
337 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
338 torture_preempt_schedule(); /* Allow test to be preempted. */
339}
340
341static void torture_mutex_unlock(void) __releases(torture_mutex)
342{
343 mutex_unlock(&torture_mutex);
344}
345
346static struct lock_torture_ops mutex_lock_ops = {
347 .writelock = torture_mutex_lock,
348 .write_delay = torture_mutex_delay,
349 .task_boost = torture_boost_dummy,
350 .writeunlock = torture_mutex_unlock,
351 .readlock = NULL,
352 .read_delay = NULL,
353 .readunlock = NULL,
354 .name = "mutex_lock"
355};
356
357#include <linux/ww_mutex.h>
358static DEFINE_WD_CLASS(torture_ww_class);
359static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class);
360static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class);
361static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class);
362
363static int torture_ww_mutex_lock(void)
364__acquires(torture_ww_mutex_0)
365__acquires(torture_ww_mutex_1)
366__acquires(torture_ww_mutex_2)
367{
368 LIST_HEAD(list);
369 struct reorder_lock {
370 struct list_head link;
371 struct ww_mutex *lock;
372 } locks[3], *ll, *ln;
373 struct ww_acquire_ctx ctx;
374
375 locks[0].lock = &torture_ww_mutex_0;
376 list_add(&locks[0].link, &list);
377
378 locks[1].lock = &torture_ww_mutex_1;
379 list_add(&locks[1].link, &list);
380
381 locks[2].lock = &torture_ww_mutex_2;
382 list_add(&locks[2].link, &list);
383
384 ww_acquire_init(&ctx, &torture_ww_class);
385
386 list_for_each_entry(ll, &list, link) {
387 int err;
388
389 err = ww_mutex_lock(ll->lock, &ctx);
390 if (!err)
391 continue;
392
393 ln = ll;
394 list_for_each_entry_continue_reverse(ln, &list, link)
395 ww_mutex_unlock(ln->lock);
396
397 if (err != -EDEADLK)
398 return err;
399
400 ww_mutex_lock_slow(ll->lock, &ctx);
401 list_move(&ll->link, &list);
402 }
403
404 ww_acquire_fini(&ctx);
405 return 0;
406}
407
408static void torture_ww_mutex_unlock(void)
409__releases(torture_ww_mutex_0)
410__releases(torture_ww_mutex_1)
411__releases(torture_ww_mutex_2)
412{
413 ww_mutex_unlock(&torture_ww_mutex_0);
414 ww_mutex_unlock(&torture_ww_mutex_1);
415 ww_mutex_unlock(&torture_ww_mutex_2);
416}
417
418static struct lock_torture_ops ww_mutex_lock_ops = {
419 .writelock = torture_ww_mutex_lock,
420 .write_delay = torture_mutex_delay,
421 .task_boost = torture_boost_dummy,
422 .writeunlock = torture_ww_mutex_unlock,
423 .readlock = NULL,
424 .read_delay = NULL,
425 .readunlock = NULL,
426 .name = "ww_mutex_lock"
427};
428
429#ifdef CONFIG_RT_MUTEXES
430static DEFINE_RT_MUTEX(torture_rtmutex);
431
432static int torture_rtmutex_lock(void) __acquires(torture_rtmutex)
433{
434 rt_mutex_lock(&torture_rtmutex);
435 return 0;
436}
437
438static void torture_rtmutex_boost(struct torture_random_state *trsp)
439{
440 int policy;
441 struct sched_param param;
442 const unsigned int factor = 50000; /* yes, quite arbitrary */
443
444 if (!rt_task(current)) {
445 /*
446 * Boost priority once every ~50k operations. When the
447 * task tries to take the lock, the rtmutex it will account
448 * for the new priority, and do any corresponding pi-dance.
449 */
450 if (trsp && !(torture_random(trsp) %
451 (cxt.nrealwriters_stress * factor))) {
452 policy = SCHED_FIFO;
453 param.sched_priority = MAX_RT_PRIO - 1;
454 } else /* common case, do nothing */
455 return;
456 } else {
457 /*
458 * The task will remain boosted for another ~500k operations,
459 * then restored back to its original prio, and so forth.
460 *
461 * When @trsp is nil, we want to force-reset the task for
462 * stopping the kthread.
463 */
464 if (!trsp || !(torture_random(trsp) %
465 (cxt.nrealwriters_stress * factor * 2))) {
466 policy = SCHED_NORMAL;
467 param.sched_priority = 0;
468 } else /* common case, do nothing */
469 return;
470 }
471
472 sched_setscheduler_nocheck(current, policy, ¶m);
473}
474
475static void torture_rtmutex_delay(struct torture_random_state *trsp)
476{
477 const unsigned long shortdelay_us = 2;
478 const unsigned long longdelay_ms = 100;
479
480 /*
481 * We want a short delay mostly to emulate likely code, and
482 * we want a long delay occasionally to force massive contention.
483 */
484 if (!(torture_random(trsp) %
485 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
486 mdelay(longdelay_ms);
487 if (!(torture_random(trsp) %
488 (cxt.nrealwriters_stress * 2 * shortdelay_us)))
489 udelay(shortdelay_us);
490 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
491 torture_preempt_schedule(); /* Allow test to be preempted. */
492}
493
494static void torture_rtmutex_unlock(void) __releases(torture_rtmutex)
495{
496 rt_mutex_unlock(&torture_rtmutex);
497}
498
499static struct lock_torture_ops rtmutex_lock_ops = {
500 .writelock = torture_rtmutex_lock,
501 .write_delay = torture_rtmutex_delay,
502 .task_boost = torture_rtmutex_boost,
503 .writeunlock = torture_rtmutex_unlock,
504 .readlock = NULL,
505 .read_delay = NULL,
506 .readunlock = NULL,
507 .name = "rtmutex_lock"
508};
509#endif
510
511static DECLARE_RWSEM(torture_rwsem);
512static int torture_rwsem_down_write(void) __acquires(torture_rwsem)
513{
514 down_write(&torture_rwsem);
515 return 0;
516}
517
518static void torture_rwsem_write_delay(struct torture_random_state *trsp)
519{
520 const unsigned long longdelay_ms = 100;
521
522 /* We want a long delay occasionally to force massive contention. */
523 if (!(torture_random(trsp) %
524 (cxt.nrealwriters_stress * 2000 * longdelay_ms)))
525 mdelay(longdelay_ms * 10);
526 else
527 mdelay(longdelay_ms / 10);
528 if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000)))
529 torture_preempt_schedule(); /* Allow test to be preempted. */
530}
531
532static void torture_rwsem_up_write(void) __releases(torture_rwsem)
533{
534 up_write(&torture_rwsem);
535}
536
537static int torture_rwsem_down_read(void) __acquires(torture_rwsem)
538{
539 down_read(&torture_rwsem);
540 return 0;
541}
542
543static void torture_rwsem_read_delay(struct torture_random_state *trsp)
544{
545 const unsigned long longdelay_ms = 100;
546
547 /* We want a long delay occasionally to force massive contention. */
548 if (!(torture_random(trsp) %
549 (cxt.nrealreaders_stress * 2000 * longdelay_ms)))
550 mdelay(longdelay_ms * 2);
551 else
552 mdelay(longdelay_ms / 2);
553 if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000)))
554 torture_preempt_schedule(); /* Allow test to be preempted. */
555}
556
557static void torture_rwsem_up_read(void) __releases(torture_rwsem)
558{
559 up_read(&torture_rwsem);
560}
561
562static struct lock_torture_ops rwsem_lock_ops = {
563 .writelock = torture_rwsem_down_write,
564 .write_delay = torture_rwsem_write_delay,
565 .task_boost = torture_boost_dummy,
566 .writeunlock = torture_rwsem_up_write,
567 .readlock = torture_rwsem_down_read,
568 .read_delay = torture_rwsem_read_delay,
569 .readunlock = torture_rwsem_up_read,
570 .name = "rwsem_lock"
571};
572
573#include <linux/percpu-rwsem.h>
574static struct percpu_rw_semaphore pcpu_rwsem;
575
576void torture_percpu_rwsem_init(void)
577{
578 BUG_ON(percpu_init_rwsem(&pcpu_rwsem));
579}
580
581static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem)
582{
583 percpu_down_write(&pcpu_rwsem);
584 return 0;
585}
586
587static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem)
588{
589 percpu_up_write(&pcpu_rwsem);
590}
591
592static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem)
593{
594 percpu_down_read(&pcpu_rwsem);
595 return 0;
596}
597
598static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem)
599{
600 percpu_up_read(&pcpu_rwsem);
601}
602
603static struct lock_torture_ops percpu_rwsem_lock_ops = {
604 .init = torture_percpu_rwsem_init,
605 .writelock = torture_percpu_rwsem_down_write,
606 .write_delay = torture_rwsem_write_delay,
607 .task_boost = torture_boost_dummy,
608 .writeunlock = torture_percpu_rwsem_up_write,
609 .readlock = torture_percpu_rwsem_down_read,
610 .read_delay = torture_rwsem_read_delay,
611 .readunlock = torture_percpu_rwsem_up_read,
612 .name = "percpu_rwsem_lock"
613};
614
615/*
616 * Lock torture writer kthread. Repeatedly acquires and releases
617 * the lock, checking for duplicate acquisitions.
618 */
619static int lock_torture_writer(void *arg)
620{
621 struct lock_stress_stats *lwsp = arg;
622 static DEFINE_TORTURE_RANDOM(rand);
623
624 VERBOSE_TOROUT_STRING("lock_torture_writer task started");
625 set_user_nice(current, MAX_NICE);
626
627 do {
628 if ((torture_random(&rand) & 0xfffff) == 0)
629 schedule_timeout_uninterruptible(1);
630
631 cxt.cur_ops->task_boost(&rand);
632 cxt.cur_ops->writelock();
633 if (WARN_ON_ONCE(lock_is_write_held))
634 lwsp->n_lock_fail++;
635 lock_is_write_held = 1;
636 if (WARN_ON_ONCE(lock_is_read_held))
637 lwsp->n_lock_fail++; /* rare, but... */
638
639 lwsp->n_lock_acquired++;
640 cxt.cur_ops->write_delay(&rand);
641 lock_is_write_held = 0;
642 cxt.cur_ops->writeunlock();
643
644 stutter_wait("lock_torture_writer");
645 } while (!torture_must_stop());
646
647 cxt.cur_ops->task_boost(NULL); /* reset prio */
648 torture_kthread_stopping("lock_torture_writer");
649 return 0;
650}
651
652/*
653 * Lock torture reader kthread. Repeatedly acquires and releases
654 * the reader lock.
655 */
656static int lock_torture_reader(void *arg)
657{
658 struct lock_stress_stats *lrsp = arg;
659 static DEFINE_TORTURE_RANDOM(rand);
660
661 VERBOSE_TOROUT_STRING("lock_torture_reader task started");
662 set_user_nice(current, MAX_NICE);
663
664 do {
665 if ((torture_random(&rand) & 0xfffff) == 0)
666 schedule_timeout_uninterruptible(1);
667
668 cxt.cur_ops->readlock();
669 lock_is_read_held = 1;
670 if (WARN_ON_ONCE(lock_is_write_held))
671 lrsp->n_lock_fail++; /* rare, but... */
672
673 lrsp->n_lock_acquired++;
674 cxt.cur_ops->read_delay(&rand);
675 lock_is_read_held = 0;
676 cxt.cur_ops->readunlock();
677
678 stutter_wait("lock_torture_reader");
679 } while (!torture_must_stop());
680 torture_kthread_stopping("lock_torture_reader");
681 return 0;
682}
683
684/*
685 * Create an lock-torture-statistics message in the specified buffer.
686 */
687static void __torture_print_stats(char *page,
688 struct lock_stress_stats *statp, bool write)
689{
690 bool fail = 0;
691 int i, n_stress;
692 long max = 0, min = statp ? statp[0].n_lock_acquired : 0;
693 long long sum = 0;
694
695 n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress;
696 for (i = 0; i < n_stress; i++) {
697 if (statp[i].n_lock_fail)
698 fail = true;
699 sum += statp[i].n_lock_acquired;
700 if (max < statp[i].n_lock_fail)
701 max = statp[i].n_lock_fail;
702 if (min > statp[i].n_lock_fail)
703 min = statp[i].n_lock_fail;
704 }
705 page += sprintf(page,
706 "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n",
707 write ? "Writes" : "Reads ",
708 sum, max, min, max / 2 > min ? "???" : "",
709 fail, fail ? "!!!" : "");
710 if (fail)
711 atomic_inc(&cxt.n_lock_torture_errors);
712}
713
714/*
715 * Print torture statistics. Caller must ensure that there is only one
716 * call to this function at a given time!!! This is normally accomplished
717 * by relying on the module system to only have one copy of the module
718 * loaded, and then by giving the lock_torture_stats kthread full control
719 * (or the init/cleanup functions when lock_torture_stats thread is not
720 * running).
721 */
722static void lock_torture_stats_print(void)
723{
724 int size = cxt.nrealwriters_stress * 200 + 8192;
725 char *buf;
726
727 if (cxt.cur_ops->readlock)
728 size += cxt.nrealreaders_stress * 200 + 8192;
729
730 buf = kmalloc(size, GFP_KERNEL);
731 if (!buf) {
732 pr_err("lock_torture_stats_print: Out of memory, need: %d",
733 size);
734 return;
735 }
736
737 __torture_print_stats(buf, cxt.lwsa, true);
738 pr_alert("%s", buf);
739 kfree(buf);
740
741 if (cxt.cur_ops->readlock) {
742 buf = kmalloc(size, GFP_KERNEL);
743 if (!buf) {
744 pr_err("lock_torture_stats_print: Out of memory, need: %d",
745 size);
746 return;
747 }
748
749 __torture_print_stats(buf, cxt.lrsa, false);
750 pr_alert("%s", buf);
751 kfree(buf);
752 }
753}
754
755/*
756 * Periodically prints torture statistics, if periodic statistics printing
757 * was specified via the stat_interval module parameter.
758 *
759 * No need to worry about fullstop here, since this one doesn't reference
760 * volatile state or register callbacks.
761 */
762static int lock_torture_stats(void *arg)
763{
764 VERBOSE_TOROUT_STRING("lock_torture_stats task started");
765 do {
766 schedule_timeout_interruptible(stat_interval * HZ);
767 lock_torture_stats_print();
768 torture_shutdown_absorb("lock_torture_stats");
769 } while (!torture_must_stop());
770 torture_kthread_stopping("lock_torture_stats");
771 return 0;
772}
773
774static inline void
775lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
776 const char *tag)
777{
778 pr_alert("%s" TORTURE_FLAG
779 "--- %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",
780 torture_type, tag, cxt.debug_lock ? " [debug]": "",
781 cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval,
782 verbose, shuffle_interval, stutter, shutdown_secs,
783 onoff_interval, onoff_holdoff);
784}
785
786static void lock_torture_cleanup(void)
787{
788 int i;
789
790 if (torture_cleanup_begin())
791 return;
792
793 /*
794 * Indicates early cleanup, meaning that the test has not run,
795 * such as when passing bogus args when loading the module. As
796 * such, only perform the underlying torture-specific cleanups,
797 * and avoid anything related to locktorture.
798 */
799 if (!cxt.lwsa && !cxt.lrsa)
800 goto end;
801
802 if (writer_tasks) {
803 for (i = 0; i < cxt.nrealwriters_stress; i++)
804 torture_stop_kthread(lock_torture_writer,
805 writer_tasks[i]);
806 kfree(writer_tasks);
807 writer_tasks = NULL;
808 }
809
810 if (reader_tasks) {
811 for (i = 0; i < cxt.nrealreaders_stress; i++)
812 torture_stop_kthread(lock_torture_reader,
813 reader_tasks[i]);
814 kfree(reader_tasks);
815 reader_tasks = NULL;
816 }
817
818 torture_stop_kthread(lock_torture_stats, stats_task);
819 lock_torture_stats_print(); /* -After- the stats thread is stopped! */
820
821 if (atomic_read(&cxt.n_lock_torture_errors))
822 lock_torture_print_module_parms(cxt.cur_ops,
823 "End of test: FAILURE");
824 else if (torture_onoff_failures())
825 lock_torture_print_module_parms(cxt.cur_ops,
826 "End of test: LOCK_HOTPLUG");
827 else
828 lock_torture_print_module_parms(cxt.cur_ops,
829 "End of test: SUCCESS");
830
831 kfree(cxt.lwsa);
832 cxt.lwsa = NULL;
833 kfree(cxt.lrsa);
834 cxt.lrsa = NULL;
835
836end:
837 torture_cleanup_end();
838}
839
840static int __init lock_torture_init(void)
841{
842 int i, j;
843 int firsterr = 0;
844 static struct lock_torture_ops *torture_ops[] = {
845 &lock_busted_ops,
846 &spin_lock_ops, &spin_lock_irq_ops,
847 &rw_lock_ops, &rw_lock_irq_ops,
848 &mutex_lock_ops,
849 &ww_mutex_lock_ops,
850#ifdef CONFIG_RT_MUTEXES
851 &rtmutex_lock_ops,
852#endif
853 &rwsem_lock_ops,
854 &percpu_rwsem_lock_ops,
855 };
856
857 if (!torture_init_begin(torture_type, verbose))
858 return -EBUSY;
859
860 /* Process args and tell the world that the torturer is on the job. */
861 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
862 cxt.cur_ops = torture_ops[i];
863 if (strcmp(torture_type, cxt.cur_ops->name) == 0)
864 break;
865 }
866 if (i == ARRAY_SIZE(torture_ops)) {
867 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
868 torture_type);
869 pr_alert("lock-torture types:");
870 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
871 pr_alert(" %s", torture_ops[i]->name);
872 pr_alert("\n");
873 firsterr = -EINVAL;
874 goto unwind;
875 }
876
877 if (nwriters_stress == 0 && nreaders_stress == 0) {
878 pr_alert("lock-torture: must run at least one locking thread\n");
879 firsterr = -EINVAL;
880 goto unwind;
881 }
882
883 if (cxt.cur_ops->init)
884 cxt.cur_ops->init();
885
886 if (nwriters_stress >= 0)
887 cxt.nrealwriters_stress = nwriters_stress;
888 else
889 cxt.nrealwriters_stress = 2 * num_online_cpus();
890
891#ifdef CONFIG_DEBUG_MUTEXES
892 if (strncmp(torture_type, "mutex", 5) == 0)
893 cxt.debug_lock = true;
894#endif
895#ifdef CONFIG_DEBUG_RT_MUTEXES
896 if (strncmp(torture_type, "rtmutex", 7) == 0)
897 cxt.debug_lock = true;
898#endif
899#ifdef CONFIG_DEBUG_SPINLOCK
900 if ((strncmp(torture_type, "spin", 4) == 0) ||
901 (strncmp(torture_type, "rw_lock", 7) == 0))
902 cxt.debug_lock = true;
903#endif
904
905 /* Initialize the statistics so that each run gets its own numbers. */
906 if (nwriters_stress) {
907 lock_is_write_held = 0;
908 cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress,
909 sizeof(*cxt.lwsa),
910 GFP_KERNEL);
911 if (cxt.lwsa == NULL) {
912 VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory");
913 firsterr = -ENOMEM;
914 goto unwind;
915 }
916
917 for (i = 0; i < cxt.nrealwriters_stress; i++) {
918 cxt.lwsa[i].n_lock_fail = 0;
919 cxt.lwsa[i].n_lock_acquired = 0;
920 }
921 }
922
923 if (cxt.cur_ops->readlock) {
924 if (nreaders_stress >= 0)
925 cxt.nrealreaders_stress = nreaders_stress;
926 else {
927 /*
928 * By default distribute evenly the number of
929 * readers and writers. We still run the same number
930 * of threads as the writer-only locks default.
931 */
932 if (nwriters_stress < 0) /* user doesn't care */
933 cxt.nrealwriters_stress = num_online_cpus();
934 cxt.nrealreaders_stress = cxt.nrealwriters_stress;
935 }
936
937 if (nreaders_stress) {
938 lock_is_read_held = 0;
939 cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress,
940 sizeof(*cxt.lrsa),
941 GFP_KERNEL);
942 if (cxt.lrsa == NULL) {
943 VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory");
944 firsterr = -ENOMEM;
945 kfree(cxt.lwsa);
946 cxt.lwsa = NULL;
947 goto unwind;
948 }
949
950 for (i = 0; i < cxt.nrealreaders_stress; i++) {
951 cxt.lrsa[i].n_lock_fail = 0;
952 cxt.lrsa[i].n_lock_acquired = 0;
953 }
954 }
955 }
956
957 lock_torture_print_module_parms(cxt.cur_ops, "Start of test");
958
959 /* Prepare torture context. */
960 if (onoff_interval > 0) {
961 firsterr = torture_onoff_init(onoff_holdoff * HZ,
962 onoff_interval * HZ, NULL);
963 if (firsterr)
964 goto unwind;
965 }
966 if (shuffle_interval > 0) {
967 firsterr = torture_shuffle_init(shuffle_interval);
968 if (firsterr)
969 goto unwind;
970 }
971 if (shutdown_secs > 0) {
972 firsterr = torture_shutdown_init(shutdown_secs,
973 lock_torture_cleanup);
974 if (firsterr)
975 goto unwind;
976 }
977 if (stutter > 0) {
978 firsterr = torture_stutter_init(stutter, stutter);
979 if (firsterr)
980 goto unwind;
981 }
982
983 if (nwriters_stress) {
984 writer_tasks = kcalloc(cxt.nrealwriters_stress,
985 sizeof(writer_tasks[0]),
986 GFP_KERNEL);
987 if (writer_tasks == NULL) {
988 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
989 firsterr = -ENOMEM;
990 goto unwind;
991 }
992 }
993
994 if (cxt.cur_ops->readlock) {
995 reader_tasks = kcalloc(cxt.nrealreaders_stress,
996 sizeof(reader_tasks[0]),
997 GFP_KERNEL);
998 if (reader_tasks == NULL) {
999 VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
1000 kfree(writer_tasks);
1001 writer_tasks = NULL;
1002 firsterr = -ENOMEM;
1003 goto unwind;
1004 }
1005 }
1006
1007 /*
1008 * Create the kthreads and start torturing (oh, those poor little locks).
1009 *
1010 * TODO: Note that we interleave writers with readers, giving writers a
1011 * slight advantage, by creating its kthread first. This can be modified
1012 * for very specific needs, or even let the user choose the policy, if
1013 * ever wanted.
1014 */
1015 for (i = 0, j = 0; i < cxt.nrealwriters_stress ||
1016 j < cxt.nrealreaders_stress; i++, j++) {
1017 if (i >= cxt.nrealwriters_stress)
1018 goto create_reader;
1019
1020 /* Create writer. */
1021 firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i],
1022 writer_tasks[i]);
1023 if (firsterr)
1024 goto unwind;
1025
1026 create_reader:
1027 if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress))
1028 continue;
1029 /* Create reader. */
1030 firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j],
1031 reader_tasks[j]);
1032 if (firsterr)
1033 goto unwind;
1034 }
1035 if (stat_interval > 0) {
1036 firsterr = torture_create_kthread(lock_torture_stats, NULL,
1037 stats_task);
1038 if (firsterr)
1039 goto unwind;
1040 }
1041 torture_init_end();
1042 return 0;
1043
1044unwind:
1045 torture_init_end();
1046 lock_torture_cleanup();
1047 return firsterr;
1048}
1049
1050module_init(lock_torture_init);
1051module_exit(lock_torture_cleanup);