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0af3fe1e PM |
1 | /* |
2 | * Module-based torture test facility for locking | |
3 | * | |
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. | |
8 | * | |
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. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, you can access it online at | |
16 | * http://www.gnu.org/licenses/gpl-2.0.html. | |
17 | * | |
18 | * Copyright (C) IBM Corporation, 2014 | |
19 | * | |
095777c4 DB |
20 | * Authors: Paul E. McKenney <paulmck@us.ibm.com> |
21 | * Davidlohr Bueso <dave@stgolabs.net> | |
0af3fe1e PM |
22 | * Based on kernel/rcu/torture.c. |
23 | */ | |
0af3fe1e | 24 | #include <linux/kernel.h> |
0af3fe1e PM |
25 | #include <linux/module.h> |
26 | #include <linux/kthread.h> | |
095777c4 | 27 | #include <linux/sched/rt.h> |
0af3fe1e | 28 | #include <linux/spinlock.h> |
e34191fa | 29 | #include <linux/rwlock.h> |
42ddc75d | 30 | #include <linux/mutex.h> |
c98fed9f | 31 | #include <linux/rwsem.h> |
0af3fe1e PM |
32 | #include <linux/smp.h> |
33 | #include <linux/interrupt.h> | |
34 | #include <linux/sched.h> | |
ae7e81c0 | 35 | #include <uapi/linux/sched/types.h> |
0af3fe1e | 36 | #include <linux/atomic.h> |
0af3fe1e | 37 | #include <linux/moduleparam.h> |
0af3fe1e | 38 | #include <linux/delay.h> |
0af3fe1e | 39 | #include <linux/slab.h> |
617783dd | 40 | #include <linux/percpu-rwsem.h> |
0af3fe1e PM |
41 | #include <linux/torture.h> |
42 | ||
43 | MODULE_LICENSE("GPL"); | |
44 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); | |
45 | ||
46 | torture_param(int, nwriters_stress, -1, | |
47 | "Number of write-locking stress-test threads"); | |
4f6332c1 DB |
48 | torture_param(int, nreaders_stress, -1, |
49 | "Number of read-locking stress-test threads"); | |
0af3fe1e PM |
50 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); |
51 | torture_param(int, onoff_interval, 0, | |
52 | "Time between CPU hotplugs (s), 0=disable"); | |
53 | torture_param(int, shuffle_interval, 3, | |
54 | "Number of jiffies between shuffles, 0=disable"); | |
55 | torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); | |
56 | torture_param(int, stat_interval, 60, | |
57 | "Number of seconds between stats printk()s"); | |
58 | torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); | |
59 | torture_param(bool, verbose, true, | |
60 | "Enable verbose debugging printk()s"); | |
61 | ||
62 | static char *torture_type = "spin_lock"; | |
63 | module_param(torture_type, charp, 0444); | |
64 | MODULE_PARM_DESC(torture_type, | |
42ddc75d | 65 | "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)"); |
0af3fe1e | 66 | |
0af3fe1e PM |
67 | static struct task_struct *stats_task; |
68 | static struct task_struct **writer_tasks; | |
4f6332c1 | 69 | static struct task_struct **reader_tasks; |
0af3fe1e | 70 | |
0af3fe1e | 71 | static bool lock_is_write_held; |
4f6332c1 | 72 | static bool lock_is_read_held; |
0af3fe1e | 73 | |
1e6757a9 DB |
74 | struct lock_stress_stats { |
75 | long n_lock_fail; | |
76 | long n_lock_acquired; | |
0af3fe1e | 77 | }; |
0af3fe1e | 78 | |
5db42981 | 79 | int torture_runnable = IS_ENABLED(MODULE); |
23a8e5c2 DB |
80 | module_param(torture_runnable, int, 0444); |
81 | MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init"); | |
0af3fe1e PM |
82 | |
83 | /* Forward reference. */ | |
84 | static void lock_torture_cleanup(void); | |
85 | ||
86 | /* | |
87 | * Operations vector for selecting different types of tests. | |
88 | */ | |
89 | struct lock_torture_ops { | |
90 | void (*init)(void); | |
91 | int (*writelock)(void); | |
92 | void (*write_delay)(struct torture_random_state *trsp); | |
095777c4 | 93 | void (*task_boost)(struct torture_random_state *trsp); |
0af3fe1e | 94 | void (*writeunlock)(void); |
4f6332c1 DB |
95 | int (*readlock)(void); |
96 | void (*read_delay)(struct torture_random_state *trsp); | |
97 | void (*readunlock)(void); | |
095777c4 DB |
98 | |
99 | unsigned long flags; /* for irq spinlocks */ | |
0af3fe1e PM |
100 | const char *name; |
101 | }; | |
102 | ||
630952c2 DB |
103 | struct lock_torture_cxt { |
104 | int nrealwriters_stress; | |
105 | int nrealreaders_stress; | |
106 | bool debug_lock; | |
107 | atomic_t n_lock_torture_errors; | |
108 | struct lock_torture_ops *cur_ops; | |
109 | struct lock_stress_stats *lwsa; /* writer statistics */ | |
110 | struct lock_stress_stats *lrsa; /* reader statistics */ | |
111 | }; | |
112 | static struct lock_torture_cxt cxt = { 0, 0, false, | |
113 | ATOMIC_INIT(0), | |
114 | NULL, NULL}; | |
0af3fe1e PM |
115 | /* |
116 | * Definitions for lock torture testing. | |
117 | */ | |
118 | ||
e086481b PM |
119 | static int torture_lock_busted_write_lock(void) |
120 | { | |
121 | return 0; /* BUGGY, do not use in real life!!! */ | |
122 | } | |
123 | ||
124 | static void torture_lock_busted_write_delay(struct torture_random_state *trsp) | |
125 | { | |
61d49d2f | 126 | const unsigned long longdelay_ms = 100; |
e086481b PM |
127 | |
128 | /* We want a long delay occasionally to force massive contention. */ | |
129 | if (!(torture_random(trsp) % | |
61d49d2f PM |
130 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
131 | mdelay(longdelay_ms); | |
e086481b | 132 | #ifdef CONFIG_PREEMPT |
630952c2 | 133 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
e086481b PM |
134 | preempt_schedule(); /* Allow test to be preempted. */ |
135 | #endif | |
136 | } | |
137 | ||
138 | static void torture_lock_busted_write_unlock(void) | |
139 | { | |
140 | /* BUGGY, do not use in real life!!! */ | |
141 | } | |
142 | ||
095777c4 DB |
143 | static void torture_boost_dummy(struct torture_random_state *trsp) |
144 | { | |
145 | /* Only rtmutexes care about priority */ | |
146 | } | |
147 | ||
e086481b PM |
148 | static struct lock_torture_ops lock_busted_ops = { |
149 | .writelock = torture_lock_busted_write_lock, | |
150 | .write_delay = torture_lock_busted_write_delay, | |
095777c4 | 151 | .task_boost = torture_boost_dummy, |
e086481b | 152 | .writeunlock = torture_lock_busted_write_unlock, |
4f6332c1 DB |
153 | .readlock = NULL, |
154 | .read_delay = NULL, | |
155 | .readunlock = NULL, | |
e086481b PM |
156 | .name = "lock_busted" |
157 | }; | |
158 | ||
0af3fe1e PM |
159 | static DEFINE_SPINLOCK(torture_spinlock); |
160 | ||
161 | static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) | |
162 | { | |
163 | spin_lock(&torture_spinlock); | |
164 | return 0; | |
165 | } | |
166 | ||
167 | static void torture_spin_lock_write_delay(struct torture_random_state *trsp) | |
168 | { | |
169 | const unsigned long shortdelay_us = 2; | |
61d49d2f | 170 | const unsigned long longdelay_ms = 100; |
0af3fe1e PM |
171 | |
172 | /* We want a short delay mostly to emulate likely code, and | |
173 | * we want a long delay occasionally to force massive contention. | |
174 | */ | |
175 | if (!(torture_random(trsp) % | |
61d49d2f PM |
176 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
177 | mdelay(longdelay_ms); | |
0af3fe1e | 178 | if (!(torture_random(trsp) % |
630952c2 | 179 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) |
0af3fe1e PM |
180 | udelay(shortdelay_us); |
181 | #ifdef CONFIG_PREEMPT | |
630952c2 | 182 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
0af3fe1e PM |
183 | preempt_schedule(); /* Allow test to be preempted. */ |
184 | #endif | |
185 | } | |
186 | ||
187 | static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock) | |
188 | { | |
189 | spin_unlock(&torture_spinlock); | |
190 | } | |
191 | ||
192 | static struct lock_torture_ops spin_lock_ops = { | |
193 | .writelock = torture_spin_lock_write_lock, | |
194 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 195 | .task_boost = torture_boost_dummy, |
0af3fe1e | 196 | .writeunlock = torture_spin_lock_write_unlock, |
4f6332c1 DB |
197 | .readlock = NULL, |
198 | .read_delay = NULL, | |
199 | .readunlock = NULL, | |
0af3fe1e PM |
200 | .name = "spin_lock" |
201 | }; | |
202 | ||
203 | static int torture_spin_lock_write_lock_irq(void) | |
219f800f | 204 | __acquires(torture_spinlock) |
0af3fe1e PM |
205 | { |
206 | unsigned long flags; | |
207 | ||
208 | spin_lock_irqsave(&torture_spinlock, flags); | |
630952c2 | 209 | cxt.cur_ops->flags = flags; |
0af3fe1e PM |
210 | return 0; |
211 | } | |
212 | ||
213 | static void torture_lock_spin_write_unlock_irq(void) | |
214 | __releases(torture_spinlock) | |
215 | { | |
630952c2 | 216 | spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags); |
0af3fe1e PM |
217 | } |
218 | ||
219 | static struct lock_torture_ops spin_lock_irq_ops = { | |
220 | .writelock = torture_spin_lock_write_lock_irq, | |
221 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 222 | .task_boost = torture_boost_dummy, |
0af3fe1e | 223 | .writeunlock = torture_lock_spin_write_unlock_irq, |
4f6332c1 DB |
224 | .readlock = NULL, |
225 | .read_delay = NULL, | |
226 | .readunlock = NULL, | |
0af3fe1e PM |
227 | .name = "spin_lock_irq" |
228 | }; | |
229 | ||
e34191fa DB |
230 | static DEFINE_RWLOCK(torture_rwlock); |
231 | ||
232 | static int torture_rwlock_write_lock(void) __acquires(torture_rwlock) | |
233 | { | |
234 | write_lock(&torture_rwlock); | |
235 | return 0; | |
236 | } | |
237 | ||
238 | static void torture_rwlock_write_delay(struct torture_random_state *trsp) | |
239 | { | |
240 | const unsigned long shortdelay_us = 2; | |
241 | const unsigned long longdelay_ms = 100; | |
242 | ||
243 | /* We want a short delay mostly to emulate likely code, and | |
244 | * we want a long delay occasionally to force massive contention. | |
245 | */ | |
246 | if (!(torture_random(trsp) % | |
247 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
248 | mdelay(longdelay_ms); | |
249 | else | |
250 | udelay(shortdelay_us); | |
251 | } | |
252 | ||
253 | static void torture_rwlock_write_unlock(void) __releases(torture_rwlock) | |
254 | { | |
255 | write_unlock(&torture_rwlock); | |
256 | } | |
257 | ||
258 | static int torture_rwlock_read_lock(void) __acquires(torture_rwlock) | |
259 | { | |
260 | read_lock(&torture_rwlock); | |
261 | return 0; | |
262 | } | |
263 | ||
264 | static void torture_rwlock_read_delay(struct torture_random_state *trsp) | |
265 | { | |
266 | const unsigned long shortdelay_us = 10; | |
267 | const unsigned long longdelay_ms = 100; | |
268 | ||
269 | /* We want a short delay mostly to emulate likely code, and | |
270 | * we want a long delay occasionally to force massive contention. | |
271 | */ | |
272 | if (!(torture_random(trsp) % | |
273 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) | |
274 | mdelay(longdelay_ms); | |
275 | else | |
276 | udelay(shortdelay_us); | |
277 | } | |
278 | ||
279 | static void torture_rwlock_read_unlock(void) __releases(torture_rwlock) | |
280 | { | |
281 | read_unlock(&torture_rwlock); | |
282 | } | |
283 | ||
284 | static struct lock_torture_ops rw_lock_ops = { | |
285 | .writelock = torture_rwlock_write_lock, | |
286 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 287 | .task_boost = torture_boost_dummy, |
e34191fa DB |
288 | .writeunlock = torture_rwlock_write_unlock, |
289 | .readlock = torture_rwlock_read_lock, | |
290 | .read_delay = torture_rwlock_read_delay, | |
291 | .readunlock = torture_rwlock_read_unlock, | |
292 | .name = "rw_lock" | |
293 | }; | |
294 | ||
295 | static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock) | |
296 | { | |
297 | unsigned long flags; | |
298 | ||
299 | write_lock_irqsave(&torture_rwlock, flags); | |
300 | cxt.cur_ops->flags = flags; | |
301 | return 0; | |
302 | } | |
303 | ||
304 | static void torture_rwlock_write_unlock_irq(void) | |
305 | __releases(torture_rwlock) | |
306 | { | |
307 | write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); | |
308 | } | |
309 | ||
310 | static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) | |
311 | { | |
312 | unsigned long flags; | |
313 | ||
314 | read_lock_irqsave(&torture_rwlock, flags); | |
315 | cxt.cur_ops->flags = flags; | |
316 | return 0; | |
317 | } | |
318 | ||
319 | static void torture_rwlock_read_unlock_irq(void) | |
320 | __releases(torture_rwlock) | |
321 | { | |
f548d99e | 322 | read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); |
e34191fa DB |
323 | } |
324 | ||
325 | static struct lock_torture_ops rw_lock_irq_ops = { | |
326 | .writelock = torture_rwlock_write_lock_irq, | |
327 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 328 | .task_boost = torture_boost_dummy, |
e34191fa DB |
329 | .writeunlock = torture_rwlock_write_unlock_irq, |
330 | .readlock = torture_rwlock_read_lock_irq, | |
331 | .read_delay = torture_rwlock_read_delay, | |
332 | .readunlock = torture_rwlock_read_unlock_irq, | |
333 | .name = "rw_lock_irq" | |
334 | }; | |
335 | ||
42ddc75d DB |
336 | static DEFINE_MUTEX(torture_mutex); |
337 | ||
338 | static int torture_mutex_lock(void) __acquires(torture_mutex) | |
339 | { | |
340 | mutex_lock(&torture_mutex); | |
341 | return 0; | |
342 | } | |
343 | ||
344 | static void torture_mutex_delay(struct torture_random_state *trsp) | |
345 | { | |
346 | const unsigned long longdelay_ms = 100; | |
347 | ||
348 | /* We want a long delay occasionally to force massive contention. */ | |
349 | if (!(torture_random(trsp) % | |
630952c2 | 350 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
42ddc75d DB |
351 | mdelay(longdelay_ms * 5); |
352 | else | |
353 | mdelay(longdelay_ms / 5); | |
354 | #ifdef CONFIG_PREEMPT | |
630952c2 | 355 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
42ddc75d DB |
356 | preempt_schedule(); /* Allow test to be preempted. */ |
357 | #endif | |
358 | } | |
359 | ||
360 | static void torture_mutex_unlock(void) __releases(torture_mutex) | |
361 | { | |
362 | mutex_unlock(&torture_mutex); | |
363 | } | |
364 | ||
365 | static struct lock_torture_ops mutex_lock_ops = { | |
366 | .writelock = torture_mutex_lock, | |
367 | .write_delay = torture_mutex_delay, | |
095777c4 | 368 | .task_boost = torture_boost_dummy, |
42ddc75d | 369 | .writeunlock = torture_mutex_unlock, |
4f6332c1 DB |
370 | .readlock = NULL, |
371 | .read_delay = NULL, | |
372 | .readunlock = NULL, | |
42ddc75d DB |
373 | .name = "mutex_lock" |
374 | }; | |
375 | ||
0186a6cb CW |
376 | #include <linux/ww_mutex.h> |
377 | static DEFINE_WW_CLASS(torture_ww_class); | |
378 | static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class); | |
379 | static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class); | |
380 | static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class); | |
381 | ||
382 | static int torture_ww_mutex_lock(void) | |
383 | __acquires(torture_ww_mutex_0) | |
384 | __acquires(torture_ww_mutex_1) | |
385 | __acquires(torture_ww_mutex_2) | |
386 | { | |
387 | LIST_HEAD(list); | |
388 | struct reorder_lock { | |
389 | struct list_head link; | |
390 | struct ww_mutex *lock; | |
391 | } locks[3], *ll, *ln; | |
392 | struct ww_acquire_ctx ctx; | |
393 | ||
394 | locks[0].lock = &torture_ww_mutex_0; | |
395 | list_add(&locks[0].link, &list); | |
396 | ||
397 | locks[1].lock = &torture_ww_mutex_1; | |
398 | list_add(&locks[1].link, &list); | |
399 | ||
400 | locks[2].lock = &torture_ww_mutex_2; | |
401 | list_add(&locks[2].link, &list); | |
402 | ||
403 | ww_acquire_init(&ctx, &torture_ww_class); | |
404 | ||
405 | list_for_each_entry(ll, &list, link) { | |
406 | int err; | |
407 | ||
408 | err = ww_mutex_lock(ll->lock, &ctx); | |
409 | if (!err) | |
410 | continue; | |
411 | ||
412 | ln = ll; | |
413 | list_for_each_entry_continue_reverse(ln, &list, link) | |
414 | ww_mutex_unlock(ln->lock); | |
415 | ||
416 | if (err != -EDEADLK) | |
417 | return err; | |
418 | ||
419 | ww_mutex_lock_slow(ll->lock, &ctx); | |
420 | list_move(&ll->link, &list); | |
421 | } | |
422 | ||
423 | ww_acquire_fini(&ctx); | |
424 | return 0; | |
425 | } | |
426 | ||
427 | static void torture_ww_mutex_unlock(void) | |
428 | __releases(torture_ww_mutex_0) | |
429 | __releases(torture_ww_mutex_1) | |
430 | __releases(torture_ww_mutex_2) | |
431 | { | |
432 | ww_mutex_unlock(&torture_ww_mutex_0); | |
433 | ww_mutex_unlock(&torture_ww_mutex_1); | |
434 | ww_mutex_unlock(&torture_ww_mutex_2); | |
435 | } | |
436 | ||
437 | static struct lock_torture_ops ww_mutex_lock_ops = { | |
438 | .writelock = torture_ww_mutex_lock, | |
439 | .write_delay = torture_mutex_delay, | |
440 | .task_boost = torture_boost_dummy, | |
441 | .writeunlock = torture_ww_mutex_unlock, | |
442 | .readlock = NULL, | |
443 | .read_delay = NULL, | |
444 | .readunlock = NULL, | |
445 | .name = "ww_mutex_lock" | |
446 | }; | |
447 | ||
095777c4 DB |
448 | #ifdef CONFIG_RT_MUTEXES |
449 | static DEFINE_RT_MUTEX(torture_rtmutex); | |
450 | ||
451 | static int torture_rtmutex_lock(void) __acquires(torture_rtmutex) | |
452 | { | |
453 | rt_mutex_lock(&torture_rtmutex); | |
454 | return 0; | |
455 | } | |
456 | ||
457 | static void torture_rtmutex_boost(struct torture_random_state *trsp) | |
458 | { | |
459 | int policy; | |
460 | struct sched_param param; | |
461 | const unsigned int factor = 50000; /* yes, quite arbitrary */ | |
462 | ||
463 | if (!rt_task(current)) { | |
464 | /* | |
1f190931 | 465 | * Boost priority once every ~50k operations. When the |
095777c4 DB |
466 | * task tries to take the lock, the rtmutex it will account |
467 | * for the new priority, and do any corresponding pi-dance. | |
468 | */ | |
1f190931 DB |
469 | if (trsp && !(torture_random(trsp) % |
470 | (cxt.nrealwriters_stress * factor))) { | |
095777c4 DB |
471 | policy = SCHED_FIFO; |
472 | param.sched_priority = MAX_RT_PRIO - 1; | |
473 | } else /* common case, do nothing */ | |
474 | return; | |
475 | } else { | |
476 | /* | |
477 | * The task will remain boosted for another ~500k operations, | |
478 | * then restored back to its original prio, and so forth. | |
479 | * | |
480 | * When @trsp is nil, we want to force-reset the task for | |
481 | * stopping the kthread. | |
482 | */ | |
483 | if (!trsp || !(torture_random(trsp) % | |
484 | (cxt.nrealwriters_stress * factor * 2))) { | |
485 | policy = SCHED_NORMAL; | |
486 | param.sched_priority = 0; | |
487 | } else /* common case, do nothing */ | |
488 | return; | |
489 | } | |
490 | ||
491 | sched_setscheduler_nocheck(current, policy, ¶m); | |
492 | } | |
493 | ||
494 | static void torture_rtmutex_delay(struct torture_random_state *trsp) | |
495 | { | |
496 | const unsigned long shortdelay_us = 2; | |
497 | const unsigned long longdelay_ms = 100; | |
498 | ||
499 | /* | |
500 | * We want a short delay mostly to emulate likely code, and | |
501 | * we want a long delay occasionally to force massive contention. | |
502 | */ | |
503 | if (!(torture_random(trsp) % | |
504 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
505 | mdelay(longdelay_ms); | |
506 | if (!(torture_random(trsp) % | |
507 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) | |
508 | udelay(shortdelay_us); | |
509 | #ifdef CONFIG_PREEMPT | |
510 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) | |
511 | preempt_schedule(); /* Allow test to be preempted. */ | |
512 | #endif | |
513 | } | |
514 | ||
515 | static void torture_rtmutex_unlock(void) __releases(torture_rtmutex) | |
516 | { | |
517 | rt_mutex_unlock(&torture_rtmutex); | |
518 | } | |
519 | ||
520 | static struct lock_torture_ops rtmutex_lock_ops = { | |
521 | .writelock = torture_rtmutex_lock, | |
522 | .write_delay = torture_rtmutex_delay, | |
523 | .task_boost = torture_rtmutex_boost, | |
524 | .writeunlock = torture_rtmutex_unlock, | |
525 | .readlock = NULL, | |
526 | .read_delay = NULL, | |
527 | .readunlock = NULL, | |
528 | .name = "rtmutex_lock" | |
529 | }; | |
530 | #endif | |
531 | ||
4a3b427f DB |
532 | static DECLARE_RWSEM(torture_rwsem); |
533 | static int torture_rwsem_down_write(void) __acquires(torture_rwsem) | |
534 | { | |
535 | down_write(&torture_rwsem); | |
536 | return 0; | |
537 | } | |
538 | ||
539 | static void torture_rwsem_write_delay(struct torture_random_state *trsp) | |
540 | { | |
541 | const unsigned long longdelay_ms = 100; | |
542 | ||
543 | /* We want a long delay occasionally to force massive contention. */ | |
544 | if (!(torture_random(trsp) % | |
630952c2 | 545 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
546 | mdelay(longdelay_ms * 10); |
547 | else | |
548 | mdelay(longdelay_ms / 10); | |
549 | #ifdef CONFIG_PREEMPT | |
630952c2 | 550 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
4a3b427f DB |
551 | preempt_schedule(); /* Allow test to be preempted. */ |
552 | #endif | |
553 | } | |
554 | ||
555 | static void torture_rwsem_up_write(void) __releases(torture_rwsem) | |
556 | { | |
557 | up_write(&torture_rwsem); | |
558 | } | |
559 | ||
560 | static int torture_rwsem_down_read(void) __acquires(torture_rwsem) | |
561 | { | |
562 | down_read(&torture_rwsem); | |
563 | return 0; | |
564 | } | |
565 | ||
566 | static void torture_rwsem_read_delay(struct torture_random_state *trsp) | |
567 | { | |
568 | const unsigned long longdelay_ms = 100; | |
569 | ||
570 | /* We want a long delay occasionally to force massive contention. */ | |
571 | if (!(torture_random(trsp) % | |
630952c2 | 572 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
573 | mdelay(longdelay_ms * 2); |
574 | else | |
575 | mdelay(longdelay_ms / 2); | |
576 | #ifdef CONFIG_PREEMPT | |
630952c2 | 577 | if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000))) |
4a3b427f DB |
578 | preempt_schedule(); /* Allow test to be preempted. */ |
579 | #endif | |
580 | } | |
581 | ||
582 | static void torture_rwsem_up_read(void) __releases(torture_rwsem) | |
583 | { | |
584 | up_read(&torture_rwsem); | |
585 | } | |
586 | ||
587 | static struct lock_torture_ops rwsem_lock_ops = { | |
588 | .writelock = torture_rwsem_down_write, | |
589 | .write_delay = torture_rwsem_write_delay, | |
095777c4 | 590 | .task_boost = torture_boost_dummy, |
4a3b427f DB |
591 | .writeunlock = torture_rwsem_up_write, |
592 | .readlock = torture_rwsem_down_read, | |
593 | .read_delay = torture_rwsem_read_delay, | |
594 | .readunlock = torture_rwsem_up_read, | |
595 | .name = "rwsem_lock" | |
596 | }; | |
597 | ||
617783dd PM |
598 | #include <linux/percpu-rwsem.h> |
599 | static struct percpu_rw_semaphore pcpu_rwsem; | |
600 | ||
601 | void torture_percpu_rwsem_init(void) | |
602 | { | |
603 | BUG_ON(percpu_init_rwsem(&pcpu_rwsem)); | |
604 | } | |
605 | ||
606 | static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem) | |
607 | { | |
608 | percpu_down_write(&pcpu_rwsem); | |
609 | return 0; | |
610 | } | |
611 | ||
612 | static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem) | |
613 | { | |
614 | percpu_up_write(&pcpu_rwsem); | |
615 | } | |
616 | ||
617 | static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem) | |
618 | { | |
619 | percpu_down_read(&pcpu_rwsem); | |
620 | return 0; | |
621 | } | |
622 | ||
623 | static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem) | |
624 | { | |
625 | percpu_up_read(&pcpu_rwsem); | |
626 | } | |
627 | ||
628 | static struct lock_torture_ops percpu_rwsem_lock_ops = { | |
629 | .init = torture_percpu_rwsem_init, | |
630 | .writelock = torture_percpu_rwsem_down_write, | |
631 | .write_delay = torture_rwsem_write_delay, | |
632 | .task_boost = torture_boost_dummy, | |
633 | .writeunlock = torture_percpu_rwsem_up_write, | |
634 | .readlock = torture_percpu_rwsem_down_read, | |
635 | .read_delay = torture_rwsem_read_delay, | |
636 | .readunlock = torture_percpu_rwsem_up_read, | |
637 | .name = "percpu_rwsem_lock" | |
638 | }; | |
639 | ||
0af3fe1e PM |
640 | /* |
641 | * Lock torture writer kthread. Repeatedly acquires and releases | |
642 | * the lock, checking for duplicate acquisitions. | |
643 | */ | |
644 | static int lock_torture_writer(void *arg) | |
645 | { | |
1e6757a9 | 646 | struct lock_stress_stats *lwsp = arg; |
0af3fe1e PM |
647 | static DEFINE_TORTURE_RANDOM(rand); |
648 | ||
649 | VERBOSE_TOROUT_STRING("lock_torture_writer task started"); | |
8698a745 | 650 | set_user_nice(current, MAX_NICE); |
0af3fe1e PM |
651 | |
652 | do { | |
da601c63 PM |
653 | if ((torture_random(&rand) & 0xfffff) == 0) |
654 | schedule_timeout_uninterruptible(1); | |
a1229491 | 655 | |
095777c4 | 656 | cxt.cur_ops->task_boost(&rand); |
630952c2 | 657 | cxt.cur_ops->writelock(); |
0af3fe1e | 658 | if (WARN_ON_ONCE(lock_is_write_held)) |
1e6757a9 | 659 | lwsp->n_lock_fail++; |
0af3fe1e | 660 | lock_is_write_held = 1; |
a1229491 DB |
661 | if (WARN_ON_ONCE(lock_is_read_held)) |
662 | lwsp->n_lock_fail++; /* rare, but... */ | |
663 | ||
1e6757a9 | 664 | lwsp->n_lock_acquired++; |
630952c2 | 665 | cxt.cur_ops->write_delay(&rand); |
0af3fe1e | 666 | lock_is_write_held = 0; |
630952c2 | 667 | cxt.cur_ops->writeunlock(); |
a1229491 | 668 | |
0af3fe1e PM |
669 | stutter_wait("lock_torture_writer"); |
670 | } while (!torture_must_stop()); | |
095777c4 DB |
671 | |
672 | cxt.cur_ops->task_boost(NULL); /* reset prio */ | |
0af3fe1e PM |
673 | torture_kthread_stopping("lock_torture_writer"); |
674 | return 0; | |
675 | } | |
676 | ||
4f6332c1 DB |
677 | /* |
678 | * Lock torture reader kthread. Repeatedly acquires and releases | |
679 | * the reader lock. | |
680 | */ | |
681 | static int lock_torture_reader(void *arg) | |
682 | { | |
683 | struct lock_stress_stats *lrsp = arg; | |
684 | static DEFINE_TORTURE_RANDOM(rand); | |
685 | ||
686 | VERBOSE_TOROUT_STRING("lock_torture_reader task started"); | |
687 | set_user_nice(current, MAX_NICE); | |
688 | ||
689 | do { | |
690 | if ((torture_random(&rand) & 0xfffff) == 0) | |
691 | schedule_timeout_uninterruptible(1); | |
a1229491 | 692 | |
630952c2 | 693 | cxt.cur_ops->readlock(); |
4f6332c1 | 694 | lock_is_read_held = 1; |
a1229491 DB |
695 | if (WARN_ON_ONCE(lock_is_write_held)) |
696 | lrsp->n_lock_fail++; /* rare, but... */ | |
697 | ||
4f6332c1 | 698 | lrsp->n_lock_acquired++; |
630952c2 | 699 | cxt.cur_ops->read_delay(&rand); |
4f6332c1 | 700 | lock_is_read_held = 0; |
630952c2 | 701 | cxt.cur_ops->readunlock(); |
a1229491 | 702 | |
4f6332c1 DB |
703 | stutter_wait("lock_torture_reader"); |
704 | } while (!torture_must_stop()); | |
705 | torture_kthread_stopping("lock_torture_reader"); | |
706 | return 0; | |
707 | } | |
708 | ||
0af3fe1e PM |
709 | /* |
710 | * Create an lock-torture-statistics message in the specified buffer. | |
711 | */ | |
4f6332c1 DB |
712 | static void __torture_print_stats(char *page, |
713 | struct lock_stress_stats *statp, bool write) | |
0af3fe1e PM |
714 | { |
715 | bool fail = 0; | |
4f6332c1 | 716 | int i, n_stress; |
0af3fe1e | 717 | long max = 0; |
4f6332c1 | 718 | long min = statp[0].n_lock_acquired; |
0af3fe1e PM |
719 | long long sum = 0; |
720 | ||
630952c2 | 721 | n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; |
4f6332c1 DB |
722 | for (i = 0; i < n_stress; i++) { |
723 | if (statp[i].n_lock_fail) | |
0af3fe1e | 724 | fail = true; |
4f6332c1 DB |
725 | sum += statp[i].n_lock_acquired; |
726 | if (max < statp[i].n_lock_fail) | |
727 | max = statp[i].n_lock_fail; | |
728 | if (min > statp[i].n_lock_fail) | |
729 | min = statp[i].n_lock_fail; | |
0af3fe1e | 730 | } |
0af3fe1e | 731 | page += sprintf(page, |
4f6332c1 DB |
732 | "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", |
733 | write ? "Writes" : "Reads ", | |
0af3fe1e PM |
734 | sum, max, min, max / 2 > min ? "???" : "", |
735 | fail, fail ? "!!!" : ""); | |
736 | if (fail) | |
630952c2 | 737 | atomic_inc(&cxt.n_lock_torture_errors); |
0af3fe1e PM |
738 | } |
739 | ||
740 | /* | |
741 | * Print torture statistics. Caller must ensure that there is only one | |
742 | * call to this function at a given time!!! This is normally accomplished | |
743 | * by relying on the module system to only have one copy of the module | |
744 | * loaded, and then by giving the lock_torture_stats kthread full control | |
745 | * (or the init/cleanup functions when lock_torture_stats thread is not | |
746 | * running). | |
747 | */ | |
748 | static void lock_torture_stats_print(void) | |
749 | { | |
630952c2 | 750 | int size = cxt.nrealwriters_stress * 200 + 8192; |
0af3fe1e PM |
751 | char *buf; |
752 | ||
630952c2 DB |
753 | if (cxt.cur_ops->readlock) |
754 | size += cxt.nrealreaders_stress * 200 + 8192; | |
4f6332c1 | 755 | |
0af3fe1e PM |
756 | buf = kmalloc(size, GFP_KERNEL); |
757 | if (!buf) { | |
758 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
759 | size); | |
760 | return; | |
761 | } | |
4f6332c1 | 762 | |
630952c2 | 763 | __torture_print_stats(buf, cxt.lwsa, true); |
0af3fe1e PM |
764 | pr_alert("%s", buf); |
765 | kfree(buf); | |
4f6332c1 | 766 | |
630952c2 | 767 | if (cxt.cur_ops->readlock) { |
4f6332c1 DB |
768 | buf = kmalloc(size, GFP_KERNEL); |
769 | if (!buf) { | |
770 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
771 | size); | |
772 | return; | |
773 | } | |
774 | ||
630952c2 | 775 | __torture_print_stats(buf, cxt.lrsa, false); |
4f6332c1 DB |
776 | pr_alert("%s", buf); |
777 | kfree(buf); | |
778 | } | |
0af3fe1e PM |
779 | } |
780 | ||
781 | /* | |
782 | * Periodically prints torture statistics, if periodic statistics printing | |
783 | * was specified via the stat_interval module parameter. | |
784 | * | |
785 | * No need to worry about fullstop here, since this one doesn't reference | |
786 | * volatile state or register callbacks. | |
787 | */ | |
788 | static int lock_torture_stats(void *arg) | |
789 | { | |
790 | VERBOSE_TOROUT_STRING("lock_torture_stats task started"); | |
791 | do { | |
792 | schedule_timeout_interruptible(stat_interval * HZ); | |
793 | lock_torture_stats_print(); | |
794 | torture_shutdown_absorb("lock_torture_stats"); | |
795 | } while (!torture_must_stop()); | |
796 | torture_kthread_stopping("lock_torture_stats"); | |
797 | return 0; | |
798 | } | |
799 | ||
800 | static inline void | |
801 | lock_torture_print_module_parms(struct lock_torture_ops *cur_ops, | |
802 | const char *tag) | |
803 | { | |
804 | pr_alert("%s" TORTURE_FLAG | |
4f6332c1 | 805 | "--- %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", |
630952c2 DB |
806 | torture_type, tag, cxt.debug_lock ? " [debug]": "", |
807 | cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval, | |
4f6332c1 | 808 | verbose, shuffle_interval, stutter, shutdown_secs, |
0af3fe1e PM |
809 | onoff_interval, onoff_holdoff); |
810 | } | |
811 | ||
812 | static void lock_torture_cleanup(void) | |
813 | { | |
814 | int i; | |
815 | ||
d36a7a0d | 816 | if (torture_cleanup_begin()) |
0af3fe1e PM |
817 | return; |
818 | ||
c1c33b92 DB |
819 | /* |
820 | * Indicates early cleanup, meaning that the test has not run, | |
821 | * such as when passing bogus args when loading the module. As | |
822 | * such, only perform the underlying torture-specific cleanups, | |
823 | * and avoid anything related to locktorture. | |
824 | */ | |
825 | if (!cxt.lwsa) | |
826 | goto end; | |
827 | ||
0af3fe1e | 828 | if (writer_tasks) { |
630952c2 | 829 | for (i = 0; i < cxt.nrealwriters_stress; i++) |
0af3fe1e PM |
830 | torture_stop_kthread(lock_torture_writer, |
831 | writer_tasks[i]); | |
832 | kfree(writer_tasks); | |
833 | writer_tasks = NULL; | |
834 | } | |
835 | ||
4f6332c1 | 836 | if (reader_tasks) { |
630952c2 | 837 | for (i = 0; i < cxt.nrealreaders_stress; i++) |
4f6332c1 DB |
838 | torture_stop_kthread(lock_torture_reader, |
839 | reader_tasks[i]); | |
840 | kfree(reader_tasks); | |
841 | reader_tasks = NULL; | |
842 | } | |
843 | ||
0af3fe1e PM |
844 | torture_stop_kthread(lock_torture_stats, stats_task); |
845 | lock_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
846 | ||
630952c2 DB |
847 | if (atomic_read(&cxt.n_lock_torture_errors)) |
848 | lock_torture_print_module_parms(cxt.cur_ops, | |
0af3fe1e PM |
849 | "End of test: FAILURE"); |
850 | else if (torture_onoff_failures()) | |
630952c2 | 851 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e PM |
852 | "End of test: LOCK_HOTPLUG"); |
853 | else | |
630952c2 | 854 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e | 855 | "End of test: SUCCESS"); |
f4dbba59 YS |
856 | |
857 | kfree(cxt.lwsa); | |
858 | kfree(cxt.lrsa); | |
859 | ||
c1c33b92 | 860 | end: |
d36a7a0d | 861 | torture_cleanup_end(); |
0af3fe1e PM |
862 | } |
863 | ||
864 | static int __init lock_torture_init(void) | |
865 | { | |
4f6332c1 | 866 | int i, j; |
0af3fe1e PM |
867 | int firsterr = 0; |
868 | static struct lock_torture_ops *torture_ops[] = { | |
e34191fa DB |
869 | &lock_busted_ops, |
870 | &spin_lock_ops, &spin_lock_irq_ops, | |
871 | &rw_lock_ops, &rw_lock_irq_ops, | |
872 | &mutex_lock_ops, | |
0186a6cb | 873 | &ww_mutex_lock_ops, |
095777c4 DB |
874 | #ifdef CONFIG_RT_MUTEXES |
875 | &rtmutex_lock_ops, | |
876 | #endif | |
e34191fa | 877 | &rwsem_lock_ops, |
617783dd | 878 | &percpu_rwsem_lock_ops, |
0af3fe1e PM |
879 | }; |
880 | ||
23a8e5c2 | 881 | if (!torture_init_begin(torture_type, verbose, &torture_runnable)) |
5228084e | 882 | return -EBUSY; |
0af3fe1e PM |
883 | |
884 | /* Process args and tell the world that the torturer is on the job. */ | |
885 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
630952c2 DB |
886 | cxt.cur_ops = torture_ops[i]; |
887 | if (strcmp(torture_type, cxt.cur_ops->name) == 0) | |
0af3fe1e PM |
888 | break; |
889 | } | |
890 | if (i == ARRAY_SIZE(torture_ops)) { | |
891 | pr_alert("lock-torture: invalid torture type: \"%s\"\n", | |
892 | torture_type); | |
893 | pr_alert("lock-torture types:"); | |
894 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
895 | pr_alert(" %s", torture_ops[i]->name); | |
896 | pr_alert("\n"); | |
a36a9961 PM |
897 | firsterr = -EINVAL; |
898 | goto unwind; | |
0af3fe1e | 899 | } |
630952c2 | 900 | if (cxt.cur_ops->init) |
a36a9961 | 901 | cxt.cur_ops->init(); |
0af3fe1e PM |
902 | |
903 | if (nwriters_stress >= 0) | |
630952c2 | 904 | cxt.nrealwriters_stress = nwriters_stress; |
0af3fe1e | 905 | else |
630952c2 | 906 | cxt.nrealwriters_stress = 2 * num_online_cpus(); |
f095bfc0 DB |
907 | |
908 | #ifdef CONFIG_DEBUG_MUTEXES | |
909 | if (strncmp(torture_type, "mutex", 5) == 0) | |
630952c2 | 910 | cxt.debug_lock = true; |
f095bfc0 | 911 | #endif |
095777c4 DB |
912 | #ifdef CONFIG_DEBUG_RT_MUTEXES |
913 | if (strncmp(torture_type, "rtmutex", 7) == 0) | |
914 | cxt.debug_lock = true; | |
915 | #endif | |
f095bfc0 | 916 | #ifdef CONFIG_DEBUG_SPINLOCK |
e34191fa DB |
917 | if ((strncmp(torture_type, "spin", 4) == 0) || |
918 | (strncmp(torture_type, "rw_lock", 7) == 0)) | |
630952c2 | 919 | cxt.debug_lock = true; |
f095bfc0 | 920 | #endif |
0af3fe1e PM |
921 | |
922 | /* Initialize the statistics so that each run gets its own numbers. */ | |
923 | ||
924 | lock_is_write_held = 0; | |
630952c2 DB |
925 | cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); |
926 | if (cxt.lwsa == NULL) { | |
927 | VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); | |
0af3fe1e PM |
928 | firsterr = -ENOMEM; |
929 | goto unwind; | |
930 | } | |
630952c2 DB |
931 | for (i = 0; i < cxt.nrealwriters_stress; i++) { |
932 | cxt.lwsa[i].n_lock_fail = 0; | |
933 | cxt.lwsa[i].n_lock_acquired = 0; | |
0af3fe1e PM |
934 | } |
935 | ||
630952c2 | 936 | if (cxt.cur_ops->readlock) { |
4f6332c1 | 937 | if (nreaders_stress >= 0) |
630952c2 | 938 | cxt.nrealreaders_stress = nreaders_stress; |
4f6332c1 DB |
939 | else { |
940 | /* | |
941 | * By default distribute evenly the number of | |
942 | * readers and writers. We still run the same number | |
943 | * of threads as the writer-only locks default. | |
944 | */ | |
945 | if (nwriters_stress < 0) /* user doesn't care */ | |
630952c2 DB |
946 | cxt.nrealwriters_stress = num_online_cpus(); |
947 | cxt.nrealreaders_stress = cxt.nrealwriters_stress; | |
4f6332c1 DB |
948 | } |
949 | ||
950 | lock_is_read_held = 0; | |
630952c2 DB |
951 | cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); |
952 | if (cxt.lrsa == NULL) { | |
953 | VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); | |
4f6332c1 | 954 | firsterr = -ENOMEM; |
630952c2 | 955 | kfree(cxt.lwsa); |
c1c33b92 | 956 | cxt.lwsa = NULL; |
4f6332c1 DB |
957 | goto unwind; |
958 | } | |
0af3fe1e | 959 | |
630952c2 DB |
960 | for (i = 0; i < cxt.nrealreaders_stress; i++) { |
961 | cxt.lrsa[i].n_lock_fail = 0; | |
962 | cxt.lrsa[i].n_lock_acquired = 0; | |
4f6332c1 DB |
963 | } |
964 | } | |
c1c33b92 | 965 | |
630952c2 | 966 | lock_torture_print_module_parms(cxt.cur_ops, "Start of test"); |
4f6332c1 DB |
967 | |
968 | /* Prepare torture context. */ | |
0af3fe1e PM |
969 | if (onoff_interval > 0) { |
970 | firsterr = torture_onoff_init(onoff_holdoff * HZ, | |
971 | onoff_interval * HZ); | |
972 | if (firsterr) | |
973 | goto unwind; | |
974 | } | |
975 | if (shuffle_interval > 0) { | |
976 | firsterr = torture_shuffle_init(shuffle_interval); | |
977 | if (firsterr) | |
978 | goto unwind; | |
979 | } | |
980 | if (shutdown_secs > 0) { | |
981 | firsterr = torture_shutdown_init(shutdown_secs, | |
982 | lock_torture_cleanup); | |
983 | if (firsterr) | |
984 | goto unwind; | |
985 | } | |
986 | if (stutter > 0) { | |
987 | firsterr = torture_stutter_init(stutter); | |
988 | if (firsterr) | |
989 | goto unwind; | |
990 | } | |
991 | ||
630952c2 | 992 | writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), |
0af3fe1e PM |
993 | GFP_KERNEL); |
994 | if (writer_tasks == NULL) { | |
995 | VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); | |
996 | firsterr = -ENOMEM; | |
997 | goto unwind; | |
998 | } | |
4f6332c1 | 999 | |
630952c2 DB |
1000 | if (cxt.cur_ops->readlock) { |
1001 | reader_tasks = kzalloc(cxt.nrealreaders_stress * sizeof(reader_tasks[0]), | |
4f6332c1 DB |
1002 | GFP_KERNEL); |
1003 | if (reader_tasks == NULL) { | |
1004 | VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory"); | |
f4dbba59 YS |
1005 | kfree(writer_tasks); |
1006 | writer_tasks = NULL; | |
4f6332c1 DB |
1007 | firsterr = -ENOMEM; |
1008 | goto unwind; | |
1009 | } | |
1010 | } | |
1011 | ||
1012 | /* | |
1013 | * Create the kthreads and start torturing (oh, those poor little locks). | |
1014 | * | |
1015 | * TODO: Note that we interleave writers with readers, giving writers a | |
1016 | * slight advantage, by creating its kthread first. This can be modified | |
1017 | * for very specific needs, or even let the user choose the policy, if | |
1018 | * ever wanted. | |
1019 | */ | |
630952c2 DB |
1020 | for (i = 0, j = 0; i < cxt.nrealwriters_stress || |
1021 | j < cxt.nrealreaders_stress; i++, j++) { | |
1022 | if (i >= cxt.nrealwriters_stress) | |
4f6332c1 DB |
1023 | goto create_reader; |
1024 | ||
1025 | /* Create writer. */ | |
630952c2 | 1026 | firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i], |
0af3fe1e PM |
1027 | writer_tasks[i]); |
1028 | if (firsterr) | |
1029 | goto unwind; | |
4f6332c1 DB |
1030 | |
1031 | create_reader: | |
630952c2 | 1032 | if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress)) |
4f6332c1 DB |
1033 | continue; |
1034 | /* Create reader. */ | |
630952c2 | 1035 | firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j], |
4f6332c1 DB |
1036 | reader_tasks[j]); |
1037 | if (firsterr) | |
1038 | goto unwind; | |
0af3fe1e PM |
1039 | } |
1040 | if (stat_interval > 0) { | |
1041 | firsterr = torture_create_kthread(lock_torture_stats, NULL, | |
1042 | stats_task); | |
1043 | if (firsterr) | |
1044 | goto unwind; | |
1045 | } | |
1046 | torture_init_end(); | |
1047 | return 0; | |
1048 | ||
1049 | unwind: | |
1050 | torture_init_end(); | |
1051 | lock_torture_cleanup(); | |
1052 | return firsterr; | |
1053 | } | |
1054 | ||
1055 | module_init(lock_torture_init); | |
1056 | module_exit(lock_torture_cleanup); |