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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> |
037741a6 | 36 | #include <linux/rtmutex.h> |
0af3fe1e | 37 | #include <linux/atomic.h> |
0af3fe1e | 38 | #include <linux/moduleparam.h> |
0af3fe1e | 39 | #include <linux/delay.h> |
0af3fe1e | 40 | #include <linux/slab.h> |
617783dd | 41 | #include <linux/percpu-rwsem.h> |
0af3fe1e PM |
42 | #include <linux/torture.h> |
43 | ||
44 | MODULE_LICENSE("GPL"); | |
45 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>"); | |
46 | ||
47 | torture_param(int, nwriters_stress, -1, | |
48 | "Number of write-locking stress-test threads"); | |
4f6332c1 DB |
49 | torture_param(int, nreaders_stress, -1, |
50 | "Number of read-locking stress-test threads"); | |
0af3fe1e PM |
51 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); |
52 | torture_param(int, onoff_interval, 0, | |
53 | "Time between CPU hotplugs (s), 0=disable"); | |
54 | torture_param(int, shuffle_interval, 3, | |
55 | "Number of jiffies between shuffles, 0=disable"); | |
56 | torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); | |
57 | torture_param(int, stat_interval, 60, | |
58 | "Number of seconds between stats printk()s"); | |
59 | torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); | |
60 | torture_param(bool, verbose, true, | |
61 | "Enable verbose debugging printk()s"); | |
62 | ||
63 | static char *torture_type = "spin_lock"; | |
64 | module_param(torture_type, charp, 0444); | |
65 | MODULE_PARM_DESC(torture_type, | |
42ddc75d | 66 | "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)"); |
0af3fe1e | 67 | |
0af3fe1e PM |
68 | static struct task_struct *stats_task; |
69 | static struct task_struct **writer_tasks; | |
4f6332c1 | 70 | static struct task_struct **reader_tasks; |
0af3fe1e | 71 | |
0af3fe1e | 72 | static bool lock_is_write_held; |
4f6332c1 | 73 | static bool lock_is_read_held; |
0af3fe1e | 74 | |
1e6757a9 DB |
75 | struct lock_stress_stats { |
76 | long n_lock_fail; | |
77 | long n_lock_acquired; | |
0af3fe1e | 78 | }; |
0af3fe1e | 79 | |
5db42981 | 80 | int torture_runnable = IS_ENABLED(MODULE); |
23a8e5c2 DB |
81 | module_param(torture_runnable, int, 0444); |
82 | MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init"); | |
0af3fe1e PM |
83 | |
84 | /* Forward reference. */ | |
85 | static void lock_torture_cleanup(void); | |
86 | ||
87 | /* | |
88 | * Operations vector for selecting different types of tests. | |
89 | */ | |
90 | struct lock_torture_ops { | |
91 | void (*init)(void); | |
92 | int (*writelock)(void); | |
93 | void (*write_delay)(struct torture_random_state *trsp); | |
095777c4 | 94 | void (*task_boost)(struct torture_random_state *trsp); |
0af3fe1e | 95 | void (*writeunlock)(void); |
4f6332c1 DB |
96 | int (*readlock)(void); |
97 | void (*read_delay)(struct torture_random_state *trsp); | |
98 | void (*readunlock)(void); | |
095777c4 DB |
99 | |
100 | unsigned long flags; /* for irq spinlocks */ | |
0af3fe1e PM |
101 | const char *name; |
102 | }; | |
103 | ||
630952c2 DB |
104 | struct lock_torture_cxt { |
105 | int nrealwriters_stress; | |
106 | int nrealreaders_stress; | |
107 | bool debug_lock; | |
108 | atomic_t n_lock_torture_errors; | |
109 | struct lock_torture_ops *cur_ops; | |
110 | struct lock_stress_stats *lwsa; /* writer statistics */ | |
111 | struct lock_stress_stats *lrsa; /* reader statistics */ | |
112 | }; | |
113 | static struct lock_torture_cxt cxt = { 0, 0, false, | |
114 | ATOMIC_INIT(0), | |
115 | NULL, NULL}; | |
0af3fe1e PM |
116 | /* |
117 | * Definitions for lock torture testing. | |
118 | */ | |
119 | ||
e086481b PM |
120 | static int torture_lock_busted_write_lock(void) |
121 | { | |
122 | return 0; /* BUGGY, do not use in real life!!! */ | |
123 | } | |
124 | ||
125 | static void torture_lock_busted_write_delay(struct torture_random_state *trsp) | |
126 | { | |
61d49d2f | 127 | const unsigned long longdelay_ms = 100; |
e086481b PM |
128 | |
129 | /* We want a long delay occasionally to force massive contention. */ | |
130 | if (!(torture_random(trsp) % | |
61d49d2f PM |
131 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
132 | mdelay(longdelay_ms); | |
e086481b | 133 | #ifdef CONFIG_PREEMPT |
630952c2 | 134 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
e086481b PM |
135 | preempt_schedule(); /* Allow test to be preempted. */ |
136 | #endif | |
137 | } | |
138 | ||
139 | static void torture_lock_busted_write_unlock(void) | |
140 | { | |
141 | /* BUGGY, do not use in real life!!! */ | |
142 | } | |
143 | ||
095777c4 DB |
144 | static void torture_boost_dummy(struct torture_random_state *trsp) |
145 | { | |
146 | /* Only rtmutexes care about priority */ | |
147 | } | |
148 | ||
e086481b PM |
149 | static struct lock_torture_ops lock_busted_ops = { |
150 | .writelock = torture_lock_busted_write_lock, | |
151 | .write_delay = torture_lock_busted_write_delay, | |
095777c4 | 152 | .task_boost = torture_boost_dummy, |
e086481b | 153 | .writeunlock = torture_lock_busted_write_unlock, |
4f6332c1 DB |
154 | .readlock = NULL, |
155 | .read_delay = NULL, | |
156 | .readunlock = NULL, | |
e086481b PM |
157 | .name = "lock_busted" |
158 | }; | |
159 | ||
0af3fe1e PM |
160 | static DEFINE_SPINLOCK(torture_spinlock); |
161 | ||
162 | static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) | |
163 | { | |
164 | spin_lock(&torture_spinlock); | |
165 | return 0; | |
166 | } | |
167 | ||
168 | static void torture_spin_lock_write_delay(struct torture_random_state *trsp) | |
169 | { | |
170 | const unsigned long shortdelay_us = 2; | |
61d49d2f | 171 | const unsigned long longdelay_ms = 100; |
0af3fe1e PM |
172 | |
173 | /* We want a short delay mostly to emulate likely code, and | |
174 | * we want a long delay occasionally to force massive contention. | |
175 | */ | |
176 | if (!(torture_random(trsp) % | |
61d49d2f PM |
177 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
178 | mdelay(longdelay_ms); | |
0af3fe1e | 179 | if (!(torture_random(trsp) % |
630952c2 | 180 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) |
0af3fe1e PM |
181 | udelay(shortdelay_us); |
182 | #ifdef CONFIG_PREEMPT | |
630952c2 | 183 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
0af3fe1e PM |
184 | preempt_schedule(); /* Allow test to be preempted. */ |
185 | #endif | |
186 | } | |
187 | ||
188 | static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock) | |
189 | { | |
190 | spin_unlock(&torture_spinlock); | |
191 | } | |
192 | ||
193 | static struct lock_torture_ops spin_lock_ops = { | |
194 | .writelock = torture_spin_lock_write_lock, | |
195 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 196 | .task_boost = torture_boost_dummy, |
0af3fe1e | 197 | .writeunlock = torture_spin_lock_write_unlock, |
4f6332c1 DB |
198 | .readlock = NULL, |
199 | .read_delay = NULL, | |
200 | .readunlock = NULL, | |
0af3fe1e PM |
201 | .name = "spin_lock" |
202 | }; | |
203 | ||
204 | static int torture_spin_lock_write_lock_irq(void) | |
219f800f | 205 | __acquires(torture_spinlock) |
0af3fe1e PM |
206 | { |
207 | unsigned long flags; | |
208 | ||
209 | spin_lock_irqsave(&torture_spinlock, flags); | |
630952c2 | 210 | cxt.cur_ops->flags = flags; |
0af3fe1e PM |
211 | return 0; |
212 | } | |
213 | ||
214 | static void torture_lock_spin_write_unlock_irq(void) | |
215 | __releases(torture_spinlock) | |
216 | { | |
630952c2 | 217 | spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags); |
0af3fe1e PM |
218 | } |
219 | ||
220 | static struct lock_torture_ops spin_lock_irq_ops = { | |
221 | .writelock = torture_spin_lock_write_lock_irq, | |
222 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 223 | .task_boost = torture_boost_dummy, |
0af3fe1e | 224 | .writeunlock = torture_lock_spin_write_unlock_irq, |
4f6332c1 DB |
225 | .readlock = NULL, |
226 | .read_delay = NULL, | |
227 | .readunlock = NULL, | |
0af3fe1e PM |
228 | .name = "spin_lock_irq" |
229 | }; | |
230 | ||
e34191fa DB |
231 | static DEFINE_RWLOCK(torture_rwlock); |
232 | ||
233 | static int torture_rwlock_write_lock(void) __acquires(torture_rwlock) | |
234 | { | |
235 | write_lock(&torture_rwlock); | |
236 | return 0; | |
237 | } | |
238 | ||
239 | static void torture_rwlock_write_delay(struct torture_random_state *trsp) | |
240 | { | |
241 | const unsigned long shortdelay_us = 2; | |
242 | const unsigned long longdelay_ms = 100; | |
243 | ||
244 | /* We want a short delay mostly to emulate likely code, and | |
245 | * we want a long delay occasionally to force massive contention. | |
246 | */ | |
247 | if (!(torture_random(trsp) % | |
248 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
249 | mdelay(longdelay_ms); | |
250 | else | |
251 | udelay(shortdelay_us); | |
252 | } | |
253 | ||
254 | static void torture_rwlock_write_unlock(void) __releases(torture_rwlock) | |
255 | { | |
256 | write_unlock(&torture_rwlock); | |
257 | } | |
258 | ||
259 | static int torture_rwlock_read_lock(void) __acquires(torture_rwlock) | |
260 | { | |
261 | read_lock(&torture_rwlock); | |
262 | return 0; | |
263 | } | |
264 | ||
265 | static void torture_rwlock_read_delay(struct torture_random_state *trsp) | |
266 | { | |
267 | const unsigned long shortdelay_us = 10; | |
268 | const unsigned long longdelay_ms = 100; | |
269 | ||
270 | /* We want a short delay mostly to emulate likely code, and | |
271 | * we want a long delay occasionally to force massive contention. | |
272 | */ | |
273 | if (!(torture_random(trsp) % | |
274 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) | |
275 | mdelay(longdelay_ms); | |
276 | else | |
277 | udelay(shortdelay_us); | |
278 | } | |
279 | ||
280 | static void torture_rwlock_read_unlock(void) __releases(torture_rwlock) | |
281 | { | |
282 | read_unlock(&torture_rwlock); | |
283 | } | |
284 | ||
285 | static struct lock_torture_ops rw_lock_ops = { | |
286 | .writelock = torture_rwlock_write_lock, | |
287 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 288 | .task_boost = torture_boost_dummy, |
e34191fa DB |
289 | .writeunlock = torture_rwlock_write_unlock, |
290 | .readlock = torture_rwlock_read_lock, | |
291 | .read_delay = torture_rwlock_read_delay, | |
292 | .readunlock = torture_rwlock_read_unlock, | |
293 | .name = "rw_lock" | |
294 | }; | |
295 | ||
296 | static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock) | |
297 | { | |
298 | unsigned long flags; | |
299 | ||
300 | write_lock_irqsave(&torture_rwlock, flags); | |
301 | cxt.cur_ops->flags = flags; | |
302 | return 0; | |
303 | } | |
304 | ||
305 | static void torture_rwlock_write_unlock_irq(void) | |
306 | __releases(torture_rwlock) | |
307 | { | |
308 | write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); | |
309 | } | |
310 | ||
311 | static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) | |
312 | { | |
313 | unsigned long flags; | |
314 | ||
315 | read_lock_irqsave(&torture_rwlock, flags); | |
316 | cxt.cur_ops->flags = flags; | |
317 | return 0; | |
318 | } | |
319 | ||
320 | static void torture_rwlock_read_unlock_irq(void) | |
321 | __releases(torture_rwlock) | |
322 | { | |
f548d99e | 323 | read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); |
e34191fa DB |
324 | } |
325 | ||
326 | static struct lock_torture_ops rw_lock_irq_ops = { | |
327 | .writelock = torture_rwlock_write_lock_irq, | |
328 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 329 | .task_boost = torture_boost_dummy, |
e34191fa DB |
330 | .writeunlock = torture_rwlock_write_unlock_irq, |
331 | .readlock = torture_rwlock_read_lock_irq, | |
332 | .read_delay = torture_rwlock_read_delay, | |
333 | .readunlock = torture_rwlock_read_unlock_irq, | |
334 | .name = "rw_lock_irq" | |
335 | }; | |
336 | ||
42ddc75d DB |
337 | static DEFINE_MUTEX(torture_mutex); |
338 | ||
339 | static int torture_mutex_lock(void) __acquires(torture_mutex) | |
340 | { | |
341 | mutex_lock(&torture_mutex); | |
342 | return 0; | |
343 | } | |
344 | ||
345 | static void torture_mutex_delay(struct torture_random_state *trsp) | |
346 | { | |
347 | const unsigned long longdelay_ms = 100; | |
348 | ||
349 | /* We want a long delay occasionally to force massive contention. */ | |
350 | if (!(torture_random(trsp) % | |
630952c2 | 351 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
42ddc75d DB |
352 | mdelay(longdelay_ms * 5); |
353 | else | |
354 | mdelay(longdelay_ms / 5); | |
355 | #ifdef CONFIG_PREEMPT | |
630952c2 | 356 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
42ddc75d DB |
357 | preempt_schedule(); /* Allow test to be preempted. */ |
358 | #endif | |
359 | } | |
360 | ||
361 | static void torture_mutex_unlock(void) __releases(torture_mutex) | |
362 | { | |
363 | mutex_unlock(&torture_mutex); | |
364 | } | |
365 | ||
366 | static struct lock_torture_ops mutex_lock_ops = { | |
367 | .writelock = torture_mutex_lock, | |
368 | .write_delay = torture_mutex_delay, | |
095777c4 | 369 | .task_boost = torture_boost_dummy, |
42ddc75d | 370 | .writeunlock = torture_mutex_unlock, |
4f6332c1 DB |
371 | .readlock = NULL, |
372 | .read_delay = NULL, | |
373 | .readunlock = NULL, | |
42ddc75d DB |
374 | .name = "mutex_lock" |
375 | }; | |
376 | ||
0186a6cb CW |
377 | #include <linux/ww_mutex.h> |
378 | static DEFINE_WW_CLASS(torture_ww_class); | |
379 | static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class); | |
380 | static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class); | |
381 | static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class); | |
382 | ||
383 | static int torture_ww_mutex_lock(void) | |
384 | __acquires(torture_ww_mutex_0) | |
385 | __acquires(torture_ww_mutex_1) | |
386 | __acquires(torture_ww_mutex_2) | |
387 | { | |
388 | LIST_HEAD(list); | |
389 | struct reorder_lock { | |
390 | struct list_head link; | |
391 | struct ww_mutex *lock; | |
392 | } locks[3], *ll, *ln; | |
393 | struct ww_acquire_ctx ctx; | |
394 | ||
395 | locks[0].lock = &torture_ww_mutex_0; | |
396 | list_add(&locks[0].link, &list); | |
397 | ||
398 | locks[1].lock = &torture_ww_mutex_1; | |
399 | list_add(&locks[1].link, &list); | |
400 | ||
401 | locks[2].lock = &torture_ww_mutex_2; | |
402 | list_add(&locks[2].link, &list); | |
403 | ||
404 | ww_acquire_init(&ctx, &torture_ww_class); | |
405 | ||
406 | list_for_each_entry(ll, &list, link) { | |
407 | int err; | |
408 | ||
409 | err = ww_mutex_lock(ll->lock, &ctx); | |
410 | if (!err) | |
411 | continue; | |
412 | ||
413 | ln = ll; | |
414 | list_for_each_entry_continue_reverse(ln, &list, link) | |
415 | ww_mutex_unlock(ln->lock); | |
416 | ||
417 | if (err != -EDEADLK) | |
418 | return err; | |
419 | ||
420 | ww_mutex_lock_slow(ll->lock, &ctx); | |
421 | list_move(&ll->link, &list); | |
422 | } | |
423 | ||
424 | ww_acquire_fini(&ctx); | |
425 | return 0; | |
426 | } | |
427 | ||
428 | static void torture_ww_mutex_unlock(void) | |
429 | __releases(torture_ww_mutex_0) | |
430 | __releases(torture_ww_mutex_1) | |
431 | __releases(torture_ww_mutex_2) | |
432 | { | |
433 | ww_mutex_unlock(&torture_ww_mutex_0); | |
434 | ww_mutex_unlock(&torture_ww_mutex_1); | |
435 | ww_mutex_unlock(&torture_ww_mutex_2); | |
436 | } | |
437 | ||
438 | static struct lock_torture_ops ww_mutex_lock_ops = { | |
439 | .writelock = torture_ww_mutex_lock, | |
440 | .write_delay = torture_mutex_delay, | |
441 | .task_boost = torture_boost_dummy, | |
442 | .writeunlock = torture_ww_mutex_unlock, | |
443 | .readlock = NULL, | |
444 | .read_delay = NULL, | |
445 | .readunlock = NULL, | |
446 | .name = "ww_mutex_lock" | |
447 | }; | |
448 | ||
095777c4 DB |
449 | #ifdef CONFIG_RT_MUTEXES |
450 | static DEFINE_RT_MUTEX(torture_rtmutex); | |
451 | ||
452 | static int torture_rtmutex_lock(void) __acquires(torture_rtmutex) | |
453 | { | |
454 | rt_mutex_lock(&torture_rtmutex); | |
455 | return 0; | |
456 | } | |
457 | ||
458 | static void torture_rtmutex_boost(struct torture_random_state *trsp) | |
459 | { | |
460 | int policy; | |
461 | struct sched_param param; | |
462 | const unsigned int factor = 50000; /* yes, quite arbitrary */ | |
463 | ||
464 | if (!rt_task(current)) { | |
465 | /* | |
1f190931 | 466 | * Boost priority once every ~50k operations. When the |
095777c4 DB |
467 | * task tries to take the lock, the rtmutex it will account |
468 | * for the new priority, and do any corresponding pi-dance. | |
469 | */ | |
1f190931 DB |
470 | if (trsp && !(torture_random(trsp) % |
471 | (cxt.nrealwriters_stress * factor))) { | |
095777c4 DB |
472 | policy = SCHED_FIFO; |
473 | param.sched_priority = MAX_RT_PRIO - 1; | |
474 | } else /* common case, do nothing */ | |
475 | return; | |
476 | } else { | |
477 | /* | |
478 | * The task will remain boosted for another ~500k operations, | |
479 | * then restored back to its original prio, and so forth. | |
480 | * | |
481 | * When @trsp is nil, we want to force-reset the task for | |
482 | * stopping the kthread. | |
483 | */ | |
484 | if (!trsp || !(torture_random(trsp) % | |
485 | (cxt.nrealwriters_stress * factor * 2))) { | |
486 | policy = SCHED_NORMAL; | |
487 | param.sched_priority = 0; | |
488 | } else /* common case, do nothing */ | |
489 | return; | |
490 | } | |
491 | ||
492 | sched_setscheduler_nocheck(current, policy, ¶m); | |
493 | } | |
494 | ||
495 | static void torture_rtmutex_delay(struct torture_random_state *trsp) | |
496 | { | |
497 | const unsigned long shortdelay_us = 2; | |
498 | const unsigned long longdelay_ms = 100; | |
499 | ||
500 | /* | |
501 | * We want a short delay mostly to emulate likely code, and | |
502 | * we want a long delay occasionally to force massive contention. | |
503 | */ | |
504 | if (!(torture_random(trsp) % | |
505 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
506 | mdelay(longdelay_ms); | |
507 | if (!(torture_random(trsp) % | |
508 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) | |
509 | udelay(shortdelay_us); | |
510 | #ifdef CONFIG_PREEMPT | |
511 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) | |
512 | preempt_schedule(); /* Allow test to be preempted. */ | |
513 | #endif | |
514 | } | |
515 | ||
516 | static void torture_rtmutex_unlock(void) __releases(torture_rtmutex) | |
517 | { | |
518 | rt_mutex_unlock(&torture_rtmutex); | |
519 | } | |
520 | ||
521 | static struct lock_torture_ops rtmutex_lock_ops = { | |
522 | .writelock = torture_rtmutex_lock, | |
523 | .write_delay = torture_rtmutex_delay, | |
524 | .task_boost = torture_rtmutex_boost, | |
525 | .writeunlock = torture_rtmutex_unlock, | |
526 | .readlock = NULL, | |
527 | .read_delay = NULL, | |
528 | .readunlock = NULL, | |
529 | .name = "rtmutex_lock" | |
530 | }; | |
531 | #endif | |
532 | ||
4a3b427f DB |
533 | static DECLARE_RWSEM(torture_rwsem); |
534 | static int torture_rwsem_down_write(void) __acquires(torture_rwsem) | |
535 | { | |
536 | down_write(&torture_rwsem); | |
537 | return 0; | |
538 | } | |
539 | ||
540 | static void torture_rwsem_write_delay(struct torture_random_state *trsp) | |
541 | { | |
542 | const unsigned long longdelay_ms = 100; | |
543 | ||
544 | /* We want a long delay occasionally to force massive contention. */ | |
545 | if (!(torture_random(trsp) % | |
630952c2 | 546 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
547 | mdelay(longdelay_ms * 10); |
548 | else | |
549 | mdelay(longdelay_ms / 10); | |
550 | #ifdef CONFIG_PREEMPT | |
630952c2 | 551 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
4a3b427f DB |
552 | preempt_schedule(); /* Allow test to be preempted. */ |
553 | #endif | |
554 | } | |
555 | ||
556 | static void torture_rwsem_up_write(void) __releases(torture_rwsem) | |
557 | { | |
558 | up_write(&torture_rwsem); | |
559 | } | |
560 | ||
561 | static int torture_rwsem_down_read(void) __acquires(torture_rwsem) | |
562 | { | |
563 | down_read(&torture_rwsem); | |
564 | return 0; | |
565 | } | |
566 | ||
567 | static void torture_rwsem_read_delay(struct torture_random_state *trsp) | |
568 | { | |
569 | const unsigned long longdelay_ms = 100; | |
570 | ||
571 | /* We want a long delay occasionally to force massive contention. */ | |
572 | if (!(torture_random(trsp) % | |
630952c2 | 573 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
574 | mdelay(longdelay_ms * 2); |
575 | else | |
576 | mdelay(longdelay_ms / 2); | |
577 | #ifdef CONFIG_PREEMPT | |
630952c2 | 578 | if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000))) |
4a3b427f DB |
579 | preempt_schedule(); /* Allow test to be preempted. */ |
580 | #endif | |
581 | } | |
582 | ||
583 | static void torture_rwsem_up_read(void) __releases(torture_rwsem) | |
584 | { | |
585 | up_read(&torture_rwsem); | |
586 | } | |
587 | ||
588 | static struct lock_torture_ops rwsem_lock_ops = { | |
589 | .writelock = torture_rwsem_down_write, | |
590 | .write_delay = torture_rwsem_write_delay, | |
095777c4 | 591 | .task_boost = torture_boost_dummy, |
4a3b427f DB |
592 | .writeunlock = torture_rwsem_up_write, |
593 | .readlock = torture_rwsem_down_read, | |
594 | .read_delay = torture_rwsem_read_delay, | |
595 | .readunlock = torture_rwsem_up_read, | |
596 | .name = "rwsem_lock" | |
597 | }; | |
598 | ||
617783dd PM |
599 | #include <linux/percpu-rwsem.h> |
600 | static struct percpu_rw_semaphore pcpu_rwsem; | |
601 | ||
602 | void torture_percpu_rwsem_init(void) | |
603 | { | |
604 | BUG_ON(percpu_init_rwsem(&pcpu_rwsem)); | |
605 | } | |
606 | ||
607 | static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem) | |
608 | { | |
609 | percpu_down_write(&pcpu_rwsem); | |
610 | return 0; | |
611 | } | |
612 | ||
613 | static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem) | |
614 | { | |
615 | percpu_up_write(&pcpu_rwsem); | |
616 | } | |
617 | ||
618 | static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem) | |
619 | { | |
620 | percpu_down_read(&pcpu_rwsem); | |
621 | return 0; | |
622 | } | |
623 | ||
624 | static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem) | |
625 | { | |
626 | percpu_up_read(&pcpu_rwsem); | |
627 | } | |
628 | ||
629 | static struct lock_torture_ops percpu_rwsem_lock_ops = { | |
630 | .init = torture_percpu_rwsem_init, | |
631 | .writelock = torture_percpu_rwsem_down_write, | |
632 | .write_delay = torture_rwsem_write_delay, | |
633 | .task_boost = torture_boost_dummy, | |
634 | .writeunlock = torture_percpu_rwsem_up_write, | |
635 | .readlock = torture_percpu_rwsem_down_read, | |
636 | .read_delay = torture_rwsem_read_delay, | |
637 | .readunlock = torture_percpu_rwsem_up_read, | |
638 | .name = "percpu_rwsem_lock" | |
639 | }; | |
640 | ||
0af3fe1e PM |
641 | /* |
642 | * Lock torture writer kthread. Repeatedly acquires and releases | |
643 | * the lock, checking for duplicate acquisitions. | |
644 | */ | |
645 | static int lock_torture_writer(void *arg) | |
646 | { | |
1e6757a9 | 647 | struct lock_stress_stats *lwsp = arg; |
0af3fe1e PM |
648 | static DEFINE_TORTURE_RANDOM(rand); |
649 | ||
650 | VERBOSE_TOROUT_STRING("lock_torture_writer task started"); | |
8698a745 | 651 | set_user_nice(current, MAX_NICE); |
0af3fe1e PM |
652 | |
653 | do { | |
da601c63 PM |
654 | if ((torture_random(&rand) & 0xfffff) == 0) |
655 | schedule_timeout_uninterruptible(1); | |
a1229491 | 656 | |
095777c4 | 657 | cxt.cur_ops->task_boost(&rand); |
630952c2 | 658 | cxt.cur_ops->writelock(); |
0af3fe1e | 659 | if (WARN_ON_ONCE(lock_is_write_held)) |
1e6757a9 | 660 | lwsp->n_lock_fail++; |
0af3fe1e | 661 | lock_is_write_held = 1; |
a1229491 DB |
662 | if (WARN_ON_ONCE(lock_is_read_held)) |
663 | lwsp->n_lock_fail++; /* rare, but... */ | |
664 | ||
1e6757a9 | 665 | lwsp->n_lock_acquired++; |
630952c2 | 666 | cxt.cur_ops->write_delay(&rand); |
0af3fe1e | 667 | lock_is_write_held = 0; |
630952c2 | 668 | cxt.cur_ops->writeunlock(); |
a1229491 | 669 | |
0af3fe1e PM |
670 | stutter_wait("lock_torture_writer"); |
671 | } while (!torture_must_stop()); | |
095777c4 DB |
672 | |
673 | cxt.cur_ops->task_boost(NULL); /* reset prio */ | |
0af3fe1e PM |
674 | torture_kthread_stopping("lock_torture_writer"); |
675 | return 0; | |
676 | } | |
677 | ||
4f6332c1 DB |
678 | /* |
679 | * Lock torture reader kthread. Repeatedly acquires and releases | |
680 | * the reader lock. | |
681 | */ | |
682 | static int lock_torture_reader(void *arg) | |
683 | { | |
684 | struct lock_stress_stats *lrsp = arg; | |
685 | static DEFINE_TORTURE_RANDOM(rand); | |
686 | ||
687 | VERBOSE_TOROUT_STRING("lock_torture_reader task started"); | |
688 | set_user_nice(current, MAX_NICE); | |
689 | ||
690 | do { | |
691 | if ((torture_random(&rand) & 0xfffff) == 0) | |
692 | schedule_timeout_uninterruptible(1); | |
a1229491 | 693 | |
630952c2 | 694 | cxt.cur_ops->readlock(); |
4f6332c1 | 695 | lock_is_read_held = 1; |
a1229491 DB |
696 | if (WARN_ON_ONCE(lock_is_write_held)) |
697 | lrsp->n_lock_fail++; /* rare, but... */ | |
698 | ||
4f6332c1 | 699 | lrsp->n_lock_acquired++; |
630952c2 | 700 | cxt.cur_ops->read_delay(&rand); |
4f6332c1 | 701 | lock_is_read_held = 0; |
630952c2 | 702 | cxt.cur_ops->readunlock(); |
a1229491 | 703 | |
4f6332c1 DB |
704 | stutter_wait("lock_torture_reader"); |
705 | } while (!torture_must_stop()); | |
706 | torture_kthread_stopping("lock_torture_reader"); | |
707 | return 0; | |
708 | } | |
709 | ||
0af3fe1e PM |
710 | /* |
711 | * Create an lock-torture-statistics message in the specified buffer. | |
712 | */ | |
4f6332c1 DB |
713 | static void __torture_print_stats(char *page, |
714 | struct lock_stress_stats *statp, bool write) | |
0af3fe1e PM |
715 | { |
716 | bool fail = 0; | |
4f6332c1 | 717 | int i, n_stress; |
0af3fe1e | 718 | long max = 0; |
4f6332c1 | 719 | long min = statp[0].n_lock_acquired; |
0af3fe1e PM |
720 | long long sum = 0; |
721 | ||
630952c2 | 722 | n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; |
4f6332c1 DB |
723 | for (i = 0; i < n_stress; i++) { |
724 | if (statp[i].n_lock_fail) | |
0af3fe1e | 725 | fail = true; |
4f6332c1 DB |
726 | sum += statp[i].n_lock_acquired; |
727 | if (max < statp[i].n_lock_fail) | |
728 | max = statp[i].n_lock_fail; | |
729 | if (min > statp[i].n_lock_fail) | |
730 | min = statp[i].n_lock_fail; | |
0af3fe1e | 731 | } |
0af3fe1e | 732 | page += sprintf(page, |
4f6332c1 DB |
733 | "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", |
734 | write ? "Writes" : "Reads ", | |
0af3fe1e PM |
735 | sum, max, min, max / 2 > min ? "???" : "", |
736 | fail, fail ? "!!!" : ""); | |
737 | if (fail) | |
630952c2 | 738 | atomic_inc(&cxt.n_lock_torture_errors); |
0af3fe1e PM |
739 | } |
740 | ||
741 | /* | |
742 | * Print torture statistics. Caller must ensure that there is only one | |
743 | * call to this function at a given time!!! This is normally accomplished | |
744 | * by relying on the module system to only have one copy of the module | |
745 | * loaded, and then by giving the lock_torture_stats kthread full control | |
746 | * (or the init/cleanup functions when lock_torture_stats thread is not | |
747 | * running). | |
748 | */ | |
749 | static void lock_torture_stats_print(void) | |
750 | { | |
630952c2 | 751 | int size = cxt.nrealwriters_stress * 200 + 8192; |
0af3fe1e PM |
752 | char *buf; |
753 | ||
630952c2 DB |
754 | if (cxt.cur_ops->readlock) |
755 | size += cxt.nrealreaders_stress * 200 + 8192; | |
4f6332c1 | 756 | |
0af3fe1e PM |
757 | buf = kmalloc(size, GFP_KERNEL); |
758 | if (!buf) { | |
759 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
760 | size); | |
761 | return; | |
762 | } | |
4f6332c1 | 763 | |
630952c2 | 764 | __torture_print_stats(buf, cxt.lwsa, true); |
0af3fe1e PM |
765 | pr_alert("%s", buf); |
766 | kfree(buf); | |
4f6332c1 | 767 | |
630952c2 | 768 | if (cxt.cur_ops->readlock) { |
4f6332c1 DB |
769 | buf = kmalloc(size, GFP_KERNEL); |
770 | if (!buf) { | |
771 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
772 | size); | |
773 | return; | |
774 | } | |
775 | ||
630952c2 | 776 | __torture_print_stats(buf, cxt.lrsa, false); |
4f6332c1 DB |
777 | pr_alert("%s", buf); |
778 | kfree(buf); | |
779 | } | |
0af3fe1e PM |
780 | } |
781 | ||
782 | /* | |
783 | * Periodically prints torture statistics, if periodic statistics printing | |
784 | * was specified via the stat_interval module parameter. | |
785 | * | |
786 | * No need to worry about fullstop here, since this one doesn't reference | |
787 | * volatile state or register callbacks. | |
788 | */ | |
789 | static int lock_torture_stats(void *arg) | |
790 | { | |
791 | VERBOSE_TOROUT_STRING("lock_torture_stats task started"); | |
792 | do { | |
793 | schedule_timeout_interruptible(stat_interval * HZ); | |
794 | lock_torture_stats_print(); | |
795 | torture_shutdown_absorb("lock_torture_stats"); | |
796 | } while (!torture_must_stop()); | |
797 | torture_kthread_stopping("lock_torture_stats"); | |
798 | return 0; | |
799 | } | |
800 | ||
801 | static inline void | |
802 | lock_torture_print_module_parms(struct lock_torture_ops *cur_ops, | |
803 | const char *tag) | |
804 | { | |
805 | pr_alert("%s" TORTURE_FLAG | |
4f6332c1 | 806 | "--- %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 |
807 | torture_type, tag, cxt.debug_lock ? " [debug]": "", |
808 | cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval, | |
4f6332c1 | 809 | verbose, shuffle_interval, stutter, shutdown_secs, |
0af3fe1e PM |
810 | onoff_interval, onoff_holdoff); |
811 | } | |
812 | ||
813 | static void lock_torture_cleanup(void) | |
814 | { | |
815 | int i; | |
816 | ||
d36a7a0d | 817 | if (torture_cleanup_begin()) |
0af3fe1e PM |
818 | return; |
819 | ||
c1c33b92 DB |
820 | /* |
821 | * Indicates early cleanup, meaning that the test has not run, | |
822 | * such as when passing bogus args when loading the module. As | |
823 | * such, only perform the underlying torture-specific cleanups, | |
824 | * and avoid anything related to locktorture. | |
825 | */ | |
826 | if (!cxt.lwsa) | |
827 | goto end; | |
828 | ||
0af3fe1e | 829 | if (writer_tasks) { |
630952c2 | 830 | for (i = 0; i < cxt.nrealwriters_stress; i++) |
0af3fe1e PM |
831 | torture_stop_kthread(lock_torture_writer, |
832 | writer_tasks[i]); | |
833 | kfree(writer_tasks); | |
834 | writer_tasks = NULL; | |
835 | } | |
836 | ||
4f6332c1 | 837 | if (reader_tasks) { |
630952c2 | 838 | for (i = 0; i < cxt.nrealreaders_stress; i++) |
4f6332c1 DB |
839 | torture_stop_kthread(lock_torture_reader, |
840 | reader_tasks[i]); | |
841 | kfree(reader_tasks); | |
842 | reader_tasks = NULL; | |
843 | } | |
844 | ||
0af3fe1e PM |
845 | torture_stop_kthread(lock_torture_stats, stats_task); |
846 | lock_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
847 | ||
630952c2 DB |
848 | if (atomic_read(&cxt.n_lock_torture_errors)) |
849 | lock_torture_print_module_parms(cxt.cur_ops, | |
0af3fe1e PM |
850 | "End of test: FAILURE"); |
851 | else if (torture_onoff_failures()) | |
630952c2 | 852 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e PM |
853 | "End of test: LOCK_HOTPLUG"); |
854 | else | |
630952c2 | 855 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e | 856 | "End of test: SUCCESS"); |
f4dbba59 YS |
857 | |
858 | kfree(cxt.lwsa); | |
859 | kfree(cxt.lrsa); | |
860 | ||
c1c33b92 | 861 | end: |
d36a7a0d | 862 | torture_cleanup_end(); |
0af3fe1e PM |
863 | } |
864 | ||
865 | static int __init lock_torture_init(void) | |
866 | { | |
4f6332c1 | 867 | int i, j; |
0af3fe1e PM |
868 | int firsterr = 0; |
869 | static struct lock_torture_ops *torture_ops[] = { | |
e34191fa DB |
870 | &lock_busted_ops, |
871 | &spin_lock_ops, &spin_lock_irq_ops, | |
872 | &rw_lock_ops, &rw_lock_irq_ops, | |
873 | &mutex_lock_ops, | |
0186a6cb | 874 | &ww_mutex_lock_ops, |
095777c4 DB |
875 | #ifdef CONFIG_RT_MUTEXES |
876 | &rtmutex_lock_ops, | |
877 | #endif | |
e34191fa | 878 | &rwsem_lock_ops, |
617783dd | 879 | &percpu_rwsem_lock_ops, |
0af3fe1e PM |
880 | }; |
881 | ||
23a8e5c2 | 882 | if (!torture_init_begin(torture_type, verbose, &torture_runnable)) |
5228084e | 883 | return -EBUSY; |
0af3fe1e PM |
884 | |
885 | /* Process args and tell the world that the torturer is on the job. */ | |
886 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
630952c2 DB |
887 | cxt.cur_ops = torture_ops[i]; |
888 | if (strcmp(torture_type, cxt.cur_ops->name) == 0) | |
0af3fe1e PM |
889 | break; |
890 | } | |
891 | if (i == ARRAY_SIZE(torture_ops)) { | |
892 | pr_alert("lock-torture: invalid torture type: \"%s\"\n", | |
893 | torture_type); | |
894 | pr_alert("lock-torture types:"); | |
895 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
896 | pr_alert(" %s", torture_ops[i]->name); | |
897 | pr_alert("\n"); | |
a36a9961 PM |
898 | firsterr = -EINVAL; |
899 | goto unwind; | |
0af3fe1e | 900 | } |
630952c2 | 901 | if (cxt.cur_ops->init) |
a36a9961 | 902 | cxt.cur_ops->init(); |
0af3fe1e PM |
903 | |
904 | if (nwriters_stress >= 0) | |
630952c2 | 905 | cxt.nrealwriters_stress = nwriters_stress; |
0af3fe1e | 906 | else |
630952c2 | 907 | cxt.nrealwriters_stress = 2 * num_online_cpus(); |
f095bfc0 DB |
908 | |
909 | #ifdef CONFIG_DEBUG_MUTEXES | |
910 | if (strncmp(torture_type, "mutex", 5) == 0) | |
630952c2 | 911 | cxt.debug_lock = true; |
f095bfc0 | 912 | #endif |
095777c4 DB |
913 | #ifdef CONFIG_DEBUG_RT_MUTEXES |
914 | if (strncmp(torture_type, "rtmutex", 7) == 0) | |
915 | cxt.debug_lock = true; | |
916 | #endif | |
f095bfc0 | 917 | #ifdef CONFIG_DEBUG_SPINLOCK |
e34191fa DB |
918 | if ((strncmp(torture_type, "spin", 4) == 0) || |
919 | (strncmp(torture_type, "rw_lock", 7) == 0)) | |
630952c2 | 920 | cxt.debug_lock = true; |
f095bfc0 | 921 | #endif |
0af3fe1e PM |
922 | |
923 | /* Initialize the statistics so that each run gets its own numbers. */ | |
924 | ||
925 | lock_is_write_held = 0; | |
630952c2 DB |
926 | cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); |
927 | if (cxt.lwsa == NULL) { | |
928 | VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); | |
0af3fe1e PM |
929 | firsterr = -ENOMEM; |
930 | goto unwind; | |
931 | } | |
630952c2 DB |
932 | for (i = 0; i < cxt.nrealwriters_stress; i++) { |
933 | cxt.lwsa[i].n_lock_fail = 0; | |
934 | cxt.lwsa[i].n_lock_acquired = 0; | |
0af3fe1e PM |
935 | } |
936 | ||
630952c2 | 937 | if (cxt.cur_ops->readlock) { |
4f6332c1 | 938 | if (nreaders_stress >= 0) |
630952c2 | 939 | cxt.nrealreaders_stress = nreaders_stress; |
4f6332c1 DB |
940 | else { |
941 | /* | |
942 | * By default distribute evenly the number of | |
943 | * readers and writers. We still run the same number | |
944 | * of threads as the writer-only locks default. | |
945 | */ | |
946 | if (nwriters_stress < 0) /* user doesn't care */ | |
630952c2 DB |
947 | cxt.nrealwriters_stress = num_online_cpus(); |
948 | cxt.nrealreaders_stress = cxt.nrealwriters_stress; | |
4f6332c1 DB |
949 | } |
950 | ||
951 | lock_is_read_held = 0; | |
630952c2 DB |
952 | cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); |
953 | if (cxt.lrsa == NULL) { | |
954 | VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); | |
4f6332c1 | 955 | firsterr = -ENOMEM; |
630952c2 | 956 | kfree(cxt.lwsa); |
c1c33b92 | 957 | cxt.lwsa = NULL; |
4f6332c1 DB |
958 | goto unwind; |
959 | } | |
0af3fe1e | 960 | |
630952c2 DB |
961 | for (i = 0; i < cxt.nrealreaders_stress; i++) { |
962 | cxt.lrsa[i].n_lock_fail = 0; | |
963 | cxt.lrsa[i].n_lock_acquired = 0; | |
4f6332c1 DB |
964 | } |
965 | } | |
c1c33b92 | 966 | |
630952c2 | 967 | lock_torture_print_module_parms(cxt.cur_ops, "Start of test"); |
4f6332c1 DB |
968 | |
969 | /* Prepare torture context. */ | |
0af3fe1e PM |
970 | if (onoff_interval > 0) { |
971 | firsterr = torture_onoff_init(onoff_holdoff * HZ, | |
972 | onoff_interval * HZ); | |
973 | if (firsterr) | |
974 | goto unwind; | |
975 | } | |
976 | if (shuffle_interval > 0) { | |
977 | firsterr = torture_shuffle_init(shuffle_interval); | |
978 | if (firsterr) | |
979 | goto unwind; | |
980 | } | |
981 | if (shutdown_secs > 0) { | |
982 | firsterr = torture_shutdown_init(shutdown_secs, | |
983 | lock_torture_cleanup); | |
984 | if (firsterr) | |
985 | goto unwind; | |
986 | } | |
987 | if (stutter > 0) { | |
988 | firsterr = torture_stutter_init(stutter); | |
989 | if (firsterr) | |
990 | goto unwind; | |
991 | } | |
992 | ||
630952c2 | 993 | writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), |
0af3fe1e PM |
994 | GFP_KERNEL); |
995 | if (writer_tasks == NULL) { | |
996 | VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); | |
997 | firsterr = -ENOMEM; | |
998 | goto unwind; | |
999 | } | |
4f6332c1 | 1000 | |
630952c2 DB |
1001 | if (cxt.cur_ops->readlock) { |
1002 | reader_tasks = kzalloc(cxt.nrealreaders_stress * sizeof(reader_tasks[0]), | |
4f6332c1 DB |
1003 | GFP_KERNEL); |
1004 | if (reader_tasks == NULL) { | |
1005 | VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory"); | |
f4dbba59 YS |
1006 | kfree(writer_tasks); |
1007 | writer_tasks = NULL; | |
4f6332c1 DB |
1008 | firsterr = -ENOMEM; |
1009 | goto unwind; | |
1010 | } | |
1011 | } | |
1012 | ||
1013 | /* | |
1014 | * Create the kthreads and start torturing (oh, those poor little locks). | |
1015 | * | |
1016 | * TODO: Note that we interleave writers with readers, giving writers a | |
1017 | * slight advantage, by creating its kthread first. This can be modified | |
1018 | * for very specific needs, or even let the user choose the policy, if | |
1019 | * ever wanted. | |
1020 | */ | |
630952c2 DB |
1021 | for (i = 0, j = 0; i < cxt.nrealwriters_stress || |
1022 | j < cxt.nrealreaders_stress; i++, j++) { | |
1023 | if (i >= cxt.nrealwriters_stress) | |
4f6332c1 DB |
1024 | goto create_reader; |
1025 | ||
1026 | /* Create writer. */ | |
630952c2 | 1027 | firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i], |
0af3fe1e PM |
1028 | writer_tasks[i]); |
1029 | if (firsterr) | |
1030 | goto unwind; | |
4f6332c1 DB |
1031 | |
1032 | create_reader: | |
630952c2 | 1033 | if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress)) |
4f6332c1 DB |
1034 | continue; |
1035 | /* Create reader. */ | |
630952c2 | 1036 | firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j], |
4f6332c1 DB |
1037 | reader_tasks[j]); |
1038 | if (firsterr) | |
1039 | goto unwind; | |
0af3fe1e PM |
1040 | } |
1041 | if (stat_interval > 0) { | |
1042 | firsterr = torture_create_kthread(lock_torture_stats, NULL, | |
1043 | stats_task); | |
1044 | if (firsterr) | |
1045 | goto unwind; | |
1046 | } | |
1047 | torture_init_end(); | |
1048 | return 0; | |
1049 | ||
1050 | unwind: | |
1051 | torture_init_end(); | |
1052 | lock_torture_cleanup(); | |
1053 | return firsterr; | |
1054 | } | |
1055 | ||
1056 | module_init(lock_torture_init); | |
1057 | module_exit(lock_torture_cleanup); |