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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 | |
0af3fe1e PM |
80 | /* Forward reference. */ |
81 | static void lock_torture_cleanup(void); | |
82 | ||
83 | /* | |
84 | * Operations vector for selecting different types of tests. | |
85 | */ | |
86 | struct lock_torture_ops { | |
87 | void (*init)(void); | |
88 | int (*writelock)(void); | |
89 | void (*write_delay)(struct torture_random_state *trsp); | |
095777c4 | 90 | void (*task_boost)(struct torture_random_state *trsp); |
0af3fe1e | 91 | void (*writeunlock)(void); |
4f6332c1 DB |
92 | int (*readlock)(void); |
93 | void (*read_delay)(struct torture_random_state *trsp); | |
94 | void (*readunlock)(void); | |
095777c4 DB |
95 | |
96 | unsigned long flags; /* for irq spinlocks */ | |
0af3fe1e PM |
97 | const char *name; |
98 | }; | |
99 | ||
630952c2 DB |
100 | struct lock_torture_cxt { |
101 | int nrealwriters_stress; | |
102 | int nrealreaders_stress; | |
103 | bool debug_lock; | |
104 | atomic_t n_lock_torture_errors; | |
105 | struct lock_torture_ops *cur_ops; | |
106 | struct lock_stress_stats *lwsa; /* writer statistics */ | |
107 | struct lock_stress_stats *lrsa; /* reader statistics */ | |
108 | }; | |
109 | static struct lock_torture_cxt cxt = { 0, 0, false, | |
110 | ATOMIC_INIT(0), | |
111 | NULL, NULL}; | |
0af3fe1e PM |
112 | /* |
113 | * Definitions for lock torture testing. | |
114 | */ | |
115 | ||
e086481b PM |
116 | static int torture_lock_busted_write_lock(void) |
117 | { | |
118 | return 0; /* BUGGY, do not use in real life!!! */ | |
119 | } | |
120 | ||
121 | static void torture_lock_busted_write_delay(struct torture_random_state *trsp) | |
122 | { | |
61d49d2f | 123 | const unsigned long longdelay_ms = 100; |
e086481b PM |
124 | |
125 | /* We want a long delay occasionally to force massive contention. */ | |
126 | if (!(torture_random(trsp) % | |
61d49d2f PM |
127 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
128 | mdelay(longdelay_ms); | |
630952c2 | 129 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 130 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
e086481b PM |
131 | } |
132 | ||
133 | static void torture_lock_busted_write_unlock(void) | |
134 | { | |
135 | /* BUGGY, do not use in real life!!! */ | |
136 | } | |
137 | ||
095777c4 DB |
138 | static void torture_boost_dummy(struct torture_random_state *trsp) |
139 | { | |
140 | /* Only rtmutexes care about priority */ | |
141 | } | |
142 | ||
e086481b PM |
143 | static struct lock_torture_ops lock_busted_ops = { |
144 | .writelock = torture_lock_busted_write_lock, | |
145 | .write_delay = torture_lock_busted_write_delay, | |
095777c4 | 146 | .task_boost = torture_boost_dummy, |
e086481b | 147 | .writeunlock = torture_lock_busted_write_unlock, |
4f6332c1 DB |
148 | .readlock = NULL, |
149 | .read_delay = NULL, | |
150 | .readunlock = NULL, | |
e086481b PM |
151 | .name = "lock_busted" |
152 | }; | |
153 | ||
0af3fe1e PM |
154 | static DEFINE_SPINLOCK(torture_spinlock); |
155 | ||
156 | static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) | |
157 | { | |
158 | spin_lock(&torture_spinlock); | |
159 | return 0; | |
160 | } | |
161 | ||
162 | static void torture_spin_lock_write_delay(struct torture_random_state *trsp) | |
163 | { | |
164 | const unsigned long shortdelay_us = 2; | |
61d49d2f | 165 | const unsigned long longdelay_ms = 100; |
0af3fe1e PM |
166 | |
167 | /* We want a short delay mostly to emulate likely code, and | |
168 | * we want a long delay occasionally to force massive contention. | |
169 | */ | |
170 | if (!(torture_random(trsp) % | |
61d49d2f PM |
171 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
172 | mdelay(longdelay_ms); | |
0af3fe1e | 173 | if (!(torture_random(trsp) % |
630952c2 | 174 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) |
0af3fe1e | 175 | udelay(shortdelay_us); |
630952c2 | 176 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 177 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
0af3fe1e PM |
178 | } |
179 | ||
180 | static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock) | |
181 | { | |
182 | spin_unlock(&torture_spinlock); | |
183 | } | |
184 | ||
185 | static struct lock_torture_ops spin_lock_ops = { | |
186 | .writelock = torture_spin_lock_write_lock, | |
187 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 188 | .task_boost = torture_boost_dummy, |
0af3fe1e | 189 | .writeunlock = torture_spin_lock_write_unlock, |
4f6332c1 DB |
190 | .readlock = NULL, |
191 | .read_delay = NULL, | |
192 | .readunlock = NULL, | |
0af3fe1e PM |
193 | .name = "spin_lock" |
194 | }; | |
195 | ||
196 | static int torture_spin_lock_write_lock_irq(void) | |
219f800f | 197 | __acquires(torture_spinlock) |
0af3fe1e PM |
198 | { |
199 | unsigned long flags; | |
200 | ||
201 | spin_lock_irqsave(&torture_spinlock, flags); | |
630952c2 | 202 | cxt.cur_ops->flags = flags; |
0af3fe1e PM |
203 | return 0; |
204 | } | |
205 | ||
206 | static void torture_lock_spin_write_unlock_irq(void) | |
207 | __releases(torture_spinlock) | |
208 | { | |
630952c2 | 209 | spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags); |
0af3fe1e PM |
210 | } |
211 | ||
212 | static struct lock_torture_ops spin_lock_irq_ops = { | |
213 | .writelock = torture_spin_lock_write_lock_irq, | |
214 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 215 | .task_boost = torture_boost_dummy, |
0af3fe1e | 216 | .writeunlock = torture_lock_spin_write_unlock_irq, |
4f6332c1 DB |
217 | .readlock = NULL, |
218 | .read_delay = NULL, | |
219 | .readunlock = NULL, | |
0af3fe1e PM |
220 | .name = "spin_lock_irq" |
221 | }; | |
222 | ||
e34191fa DB |
223 | static DEFINE_RWLOCK(torture_rwlock); |
224 | ||
225 | static int torture_rwlock_write_lock(void) __acquires(torture_rwlock) | |
226 | { | |
227 | write_lock(&torture_rwlock); | |
228 | return 0; | |
229 | } | |
230 | ||
231 | static void torture_rwlock_write_delay(struct torture_random_state *trsp) | |
232 | { | |
233 | const unsigned long shortdelay_us = 2; | |
234 | const unsigned long longdelay_ms = 100; | |
235 | ||
236 | /* We want a short delay mostly to emulate likely code, and | |
237 | * we want a long delay occasionally to force massive contention. | |
238 | */ | |
239 | if (!(torture_random(trsp) % | |
240 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
241 | mdelay(longdelay_ms); | |
242 | else | |
243 | udelay(shortdelay_us); | |
244 | } | |
245 | ||
246 | static void torture_rwlock_write_unlock(void) __releases(torture_rwlock) | |
247 | { | |
248 | write_unlock(&torture_rwlock); | |
249 | } | |
250 | ||
251 | static int torture_rwlock_read_lock(void) __acquires(torture_rwlock) | |
252 | { | |
253 | read_lock(&torture_rwlock); | |
254 | return 0; | |
255 | } | |
256 | ||
257 | static void torture_rwlock_read_delay(struct torture_random_state *trsp) | |
258 | { | |
259 | const unsigned long shortdelay_us = 10; | |
260 | const unsigned long longdelay_ms = 100; | |
261 | ||
262 | /* We want a short delay mostly to emulate likely code, and | |
263 | * we want a long delay occasionally to force massive contention. | |
264 | */ | |
265 | if (!(torture_random(trsp) % | |
266 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) | |
267 | mdelay(longdelay_ms); | |
268 | else | |
269 | udelay(shortdelay_us); | |
270 | } | |
271 | ||
272 | static void torture_rwlock_read_unlock(void) __releases(torture_rwlock) | |
273 | { | |
274 | read_unlock(&torture_rwlock); | |
275 | } | |
276 | ||
277 | static struct lock_torture_ops rw_lock_ops = { | |
278 | .writelock = torture_rwlock_write_lock, | |
279 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 280 | .task_boost = torture_boost_dummy, |
e34191fa DB |
281 | .writeunlock = torture_rwlock_write_unlock, |
282 | .readlock = torture_rwlock_read_lock, | |
283 | .read_delay = torture_rwlock_read_delay, | |
284 | .readunlock = torture_rwlock_read_unlock, | |
285 | .name = "rw_lock" | |
286 | }; | |
287 | ||
288 | static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock) | |
289 | { | |
290 | unsigned long flags; | |
291 | ||
292 | write_lock_irqsave(&torture_rwlock, flags); | |
293 | cxt.cur_ops->flags = flags; | |
294 | return 0; | |
295 | } | |
296 | ||
297 | static void torture_rwlock_write_unlock_irq(void) | |
298 | __releases(torture_rwlock) | |
299 | { | |
300 | write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); | |
301 | } | |
302 | ||
303 | static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) | |
304 | { | |
305 | unsigned long flags; | |
306 | ||
307 | read_lock_irqsave(&torture_rwlock, flags); | |
308 | cxt.cur_ops->flags = flags; | |
309 | return 0; | |
310 | } | |
311 | ||
312 | static void torture_rwlock_read_unlock_irq(void) | |
313 | __releases(torture_rwlock) | |
314 | { | |
f548d99e | 315 | read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); |
e34191fa DB |
316 | } |
317 | ||
318 | static struct lock_torture_ops rw_lock_irq_ops = { | |
319 | .writelock = torture_rwlock_write_lock_irq, | |
320 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 321 | .task_boost = torture_boost_dummy, |
e34191fa DB |
322 | .writeunlock = torture_rwlock_write_unlock_irq, |
323 | .readlock = torture_rwlock_read_lock_irq, | |
324 | .read_delay = torture_rwlock_read_delay, | |
325 | .readunlock = torture_rwlock_read_unlock_irq, | |
326 | .name = "rw_lock_irq" | |
327 | }; | |
328 | ||
42ddc75d DB |
329 | static DEFINE_MUTEX(torture_mutex); |
330 | ||
331 | static int torture_mutex_lock(void) __acquires(torture_mutex) | |
332 | { | |
333 | mutex_lock(&torture_mutex); | |
334 | return 0; | |
335 | } | |
336 | ||
337 | static void torture_mutex_delay(struct torture_random_state *trsp) | |
338 | { | |
339 | const unsigned long longdelay_ms = 100; | |
340 | ||
341 | /* We want a long delay occasionally to force massive contention. */ | |
342 | if (!(torture_random(trsp) % | |
630952c2 | 343 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
42ddc75d DB |
344 | mdelay(longdelay_ms * 5); |
345 | else | |
346 | mdelay(longdelay_ms / 5); | |
630952c2 | 347 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 348 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
42ddc75d DB |
349 | } |
350 | ||
351 | static void torture_mutex_unlock(void) __releases(torture_mutex) | |
352 | { | |
353 | mutex_unlock(&torture_mutex); | |
354 | } | |
355 | ||
356 | static struct lock_torture_ops mutex_lock_ops = { | |
357 | .writelock = torture_mutex_lock, | |
358 | .write_delay = torture_mutex_delay, | |
095777c4 | 359 | .task_boost = torture_boost_dummy, |
42ddc75d | 360 | .writeunlock = torture_mutex_unlock, |
4f6332c1 DB |
361 | .readlock = NULL, |
362 | .read_delay = NULL, | |
363 | .readunlock = NULL, | |
42ddc75d DB |
364 | .name = "mutex_lock" |
365 | }; | |
366 | ||
0186a6cb CW |
367 | #include <linux/ww_mutex.h> |
368 | static DEFINE_WW_CLASS(torture_ww_class); | |
369 | static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class); | |
370 | static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class); | |
371 | static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class); | |
372 | ||
373 | static int torture_ww_mutex_lock(void) | |
374 | __acquires(torture_ww_mutex_0) | |
375 | __acquires(torture_ww_mutex_1) | |
376 | __acquires(torture_ww_mutex_2) | |
377 | { | |
378 | LIST_HEAD(list); | |
379 | struct reorder_lock { | |
380 | struct list_head link; | |
381 | struct ww_mutex *lock; | |
382 | } locks[3], *ll, *ln; | |
383 | struct ww_acquire_ctx ctx; | |
384 | ||
385 | locks[0].lock = &torture_ww_mutex_0; | |
386 | list_add(&locks[0].link, &list); | |
387 | ||
388 | locks[1].lock = &torture_ww_mutex_1; | |
389 | list_add(&locks[1].link, &list); | |
390 | ||
391 | locks[2].lock = &torture_ww_mutex_2; | |
392 | list_add(&locks[2].link, &list); | |
393 | ||
394 | ww_acquire_init(&ctx, &torture_ww_class); | |
395 | ||
396 | list_for_each_entry(ll, &list, link) { | |
397 | int err; | |
398 | ||
399 | err = ww_mutex_lock(ll->lock, &ctx); | |
400 | if (!err) | |
401 | continue; | |
402 | ||
403 | ln = ll; | |
404 | list_for_each_entry_continue_reverse(ln, &list, link) | |
405 | ww_mutex_unlock(ln->lock); | |
406 | ||
407 | if (err != -EDEADLK) | |
408 | return err; | |
409 | ||
410 | ww_mutex_lock_slow(ll->lock, &ctx); | |
411 | list_move(&ll->link, &list); | |
412 | } | |
413 | ||
414 | ww_acquire_fini(&ctx); | |
415 | return 0; | |
416 | } | |
417 | ||
418 | static void torture_ww_mutex_unlock(void) | |
419 | __releases(torture_ww_mutex_0) | |
420 | __releases(torture_ww_mutex_1) | |
421 | __releases(torture_ww_mutex_2) | |
422 | { | |
423 | ww_mutex_unlock(&torture_ww_mutex_0); | |
424 | ww_mutex_unlock(&torture_ww_mutex_1); | |
425 | ww_mutex_unlock(&torture_ww_mutex_2); | |
426 | } | |
427 | ||
428 | static struct lock_torture_ops ww_mutex_lock_ops = { | |
429 | .writelock = torture_ww_mutex_lock, | |
430 | .write_delay = torture_mutex_delay, | |
431 | .task_boost = torture_boost_dummy, | |
432 | .writeunlock = torture_ww_mutex_unlock, | |
433 | .readlock = NULL, | |
434 | .read_delay = NULL, | |
435 | .readunlock = NULL, | |
436 | .name = "ww_mutex_lock" | |
437 | }; | |
438 | ||
095777c4 DB |
439 | #ifdef CONFIG_RT_MUTEXES |
440 | static DEFINE_RT_MUTEX(torture_rtmutex); | |
441 | ||
442 | static int torture_rtmutex_lock(void) __acquires(torture_rtmutex) | |
443 | { | |
444 | rt_mutex_lock(&torture_rtmutex); | |
445 | return 0; | |
446 | } | |
447 | ||
448 | static void torture_rtmutex_boost(struct torture_random_state *trsp) | |
449 | { | |
450 | int policy; | |
451 | struct sched_param param; | |
452 | const unsigned int factor = 50000; /* yes, quite arbitrary */ | |
453 | ||
454 | if (!rt_task(current)) { | |
455 | /* | |
1f190931 | 456 | * Boost priority once every ~50k operations. When the |
095777c4 DB |
457 | * task tries to take the lock, the rtmutex it will account |
458 | * for the new priority, and do any corresponding pi-dance. | |
459 | */ | |
1f190931 DB |
460 | if (trsp && !(torture_random(trsp) % |
461 | (cxt.nrealwriters_stress * factor))) { | |
095777c4 DB |
462 | policy = SCHED_FIFO; |
463 | param.sched_priority = MAX_RT_PRIO - 1; | |
464 | } else /* common case, do nothing */ | |
465 | return; | |
466 | } else { | |
467 | /* | |
468 | * The task will remain boosted for another ~500k operations, | |
469 | * then restored back to its original prio, and so forth. | |
470 | * | |
471 | * When @trsp is nil, we want to force-reset the task for | |
472 | * stopping the kthread. | |
473 | */ | |
474 | if (!trsp || !(torture_random(trsp) % | |
475 | (cxt.nrealwriters_stress * factor * 2))) { | |
476 | policy = SCHED_NORMAL; | |
477 | param.sched_priority = 0; | |
478 | } else /* common case, do nothing */ | |
479 | return; | |
480 | } | |
481 | ||
482 | sched_setscheduler_nocheck(current, policy, ¶m); | |
483 | } | |
484 | ||
485 | static void torture_rtmutex_delay(struct torture_random_state *trsp) | |
486 | { | |
487 | const unsigned long shortdelay_us = 2; | |
488 | const unsigned long longdelay_ms = 100; | |
489 | ||
490 | /* | |
491 | * We want a short delay mostly to emulate likely code, and | |
492 | * we want a long delay occasionally to force massive contention. | |
493 | */ | |
494 | if (!(torture_random(trsp) % | |
495 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
496 | mdelay(longdelay_ms); | |
497 | if (!(torture_random(trsp) % | |
498 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) | |
499 | udelay(shortdelay_us); | |
095777c4 | 500 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 501 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
095777c4 DB |
502 | } |
503 | ||
504 | static void torture_rtmutex_unlock(void) __releases(torture_rtmutex) | |
505 | { | |
506 | rt_mutex_unlock(&torture_rtmutex); | |
507 | } | |
508 | ||
509 | static struct lock_torture_ops rtmutex_lock_ops = { | |
510 | .writelock = torture_rtmutex_lock, | |
511 | .write_delay = torture_rtmutex_delay, | |
512 | .task_boost = torture_rtmutex_boost, | |
513 | .writeunlock = torture_rtmutex_unlock, | |
514 | .readlock = NULL, | |
515 | .read_delay = NULL, | |
516 | .readunlock = NULL, | |
517 | .name = "rtmutex_lock" | |
518 | }; | |
519 | #endif | |
520 | ||
4a3b427f DB |
521 | static DECLARE_RWSEM(torture_rwsem); |
522 | static int torture_rwsem_down_write(void) __acquires(torture_rwsem) | |
523 | { | |
524 | down_write(&torture_rwsem); | |
525 | return 0; | |
526 | } | |
527 | ||
528 | static void torture_rwsem_write_delay(struct torture_random_state *trsp) | |
529 | { | |
530 | const unsigned long longdelay_ms = 100; | |
531 | ||
532 | /* We want a long delay occasionally to force massive contention. */ | |
533 | if (!(torture_random(trsp) % | |
630952c2 | 534 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
535 | mdelay(longdelay_ms * 10); |
536 | else | |
537 | mdelay(longdelay_ms / 10); | |
630952c2 | 538 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 539 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
4a3b427f DB |
540 | } |
541 | ||
542 | static void torture_rwsem_up_write(void) __releases(torture_rwsem) | |
543 | { | |
544 | up_write(&torture_rwsem); | |
545 | } | |
546 | ||
547 | static int torture_rwsem_down_read(void) __acquires(torture_rwsem) | |
548 | { | |
549 | down_read(&torture_rwsem); | |
550 | return 0; | |
551 | } | |
552 | ||
553 | static void torture_rwsem_read_delay(struct torture_random_state *trsp) | |
554 | { | |
555 | const unsigned long longdelay_ms = 100; | |
556 | ||
557 | /* We want a long delay occasionally to force massive contention. */ | |
558 | if (!(torture_random(trsp) % | |
f2f76260 | 559 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
560 | mdelay(longdelay_ms * 2); |
561 | else | |
562 | mdelay(longdelay_ms / 2); | |
630952c2 | 563 | if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000))) |
cc1321c9 | 564 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
4a3b427f DB |
565 | } |
566 | ||
567 | static void torture_rwsem_up_read(void) __releases(torture_rwsem) | |
568 | { | |
569 | up_read(&torture_rwsem); | |
570 | } | |
571 | ||
572 | static struct lock_torture_ops rwsem_lock_ops = { | |
573 | .writelock = torture_rwsem_down_write, | |
574 | .write_delay = torture_rwsem_write_delay, | |
095777c4 | 575 | .task_boost = torture_boost_dummy, |
4a3b427f DB |
576 | .writeunlock = torture_rwsem_up_write, |
577 | .readlock = torture_rwsem_down_read, | |
578 | .read_delay = torture_rwsem_read_delay, | |
579 | .readunlock = torture_rwsem_up_read, | |
580 | .name = "rwsem_lock" | |
581 | }; | |
582 | ||
617783dd PM |
583 | #include <linux/percpu-rwsem.h> |
584 | static struct percpu_rw_semaphore pcpu_rwsem; | |
585 | ||
586 | void torture_percpu_rwsem_init(void) | |
587 | { | |
588 | BUG_ON(percpu_init_rwsem(&pcpu_rwsem)); | |
589 | } | |
590 | ||
591 | static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem) | |
592 | { | |
593 | percpu_down_write(&pcpu_rwsem); | |
594 | return 0; | |
595 | } | |
596 | ||
597 | static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem) | |
598 | { | |
599 | percpu_up_write(&pcpu_rwsem); | |
600 | } | |
601 | ||
602 | static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem) | |
603 | { | |
604 | percpu_down_read(&pcpu_rwsem); | |
605 | return 0; | |
606 | } | |
607 | ||
608 | static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem) | |
609 | { | |
610 | percpu_up_read(&pcpu_rwsem); | |
611 | } | |
612 | ||
613 | static struct lock_torture_ops percpu_rwsem_lock_ops = { | |
614 | .init = torture_percpu_rwsem_init, | |
615 | .writelock = torture_percpu_rwsem_down_write, | |
616 | .write_delay = torture_rwsem_write_delay, | |
617 | .task_boost = torture_boost_dummy, | |
618 | .writeunlock = torture_percpu_rwsem_up_write, | |
619 | .readlock = torture_percpu_rwsem_down_read, | |
620 | .read_delay = torture_rwsem_read_delay, | |
621 | .readunlock = torture_percpu_rwsem_up_read, | |
622 | .name = "percpu_rwsem_lock" | |
623 | }; | |
624 | ||
0af3fe1e PM |
625 | /* |
626 | * Lock torture writer kthread. Repeatedly acquires and releases | |
627 | * the lock, checking for duplicate acquisitions. | |
628 | */ | |
629 | static int lock_torture_writer(void *arg) | |
630 | { | |
1e6757a9 | 631 | struct lock_stress_stats *lwsp = arg; |
0af3fe1e PM |
632 | static DEFINE_TORTURE_RANDOM(rand); |
633 | ||
634 | VERBOSE_TOROUT_STRING("lock_torture_writer task started"); | |
8698a745 | 635 | set_user_nice(current, MAX_NICE); |
0af3fe1e PM |
636 | |
637 | do { | |
da601c63 PM |
638 | if ((torture_random(&rand) & 0xfffff) == 0) |
639 | schedule_timeout_uninterruptible(1); | |
a1229491 | 640 | |
095777c4 | 641 | cxt.cur_ops->task_boost(&rand); |
630952c2 | 642 | cxt.cur_ops->writelock(); |
0af3fe1e | 643 | if (WARN_ON_ONCE(lock_is_write_held)) |
1e6757a9 | 644 | lwsp->n_lock_fail++; |
0af3fe1e | 645 | lock_is_write_held = 1; |
a1229491 DB |
646 | if (WARN_ON_ONCE(lock_is_read_held)) |
647 | lwsp->n_lock_fail++; /* rare, but... */ | |
648 | ||
1e6757a9 | 649 | lwsp->n_lock_acquired++; |
630952c2 | 650 | cxt.cur_ops->write_delay(&rand); |
0af3fe1e | 651 | lock_is_write_held = 0; |
630952c2 | 652 | cxt.cur_ops->writeunlock(); |
a1229491 | 653 | |
0af3fe1e PM |
654 | stutter_wait("lock_torture_writer"); |
655 | } while (!torture_must_stop()); | |
095777c4 DB |
656 | |
657 | cxt.cur_ops->task_boost(NULL); /* reset prio */ | |
0af3fe1e PM |
658 | torture_kthread_stopping("lock_torture_writer"); |
659 | return 0; | |
660 | } | |
661 | ||
4f6332c1 DB |
662 | /* |
663 | * Lock torture reader kthread. Repeatedly acquires and releases | |
664 | * the reader lock. | |
665 | */ | |
666 | static int lock_torture_reader(void *arg) | |
667 | { | |
668 | struct lock_stress_stats *lrsp = arg; | |
669 | static DEFINE_TORTURE_RANDOM(rand); | |
670 | ||
671 | VERBOSE_TOROUT_STRING("lock_torture_reader task started"); | |
672 | set_user_nice(current, MAX_NICE); | |
673 | ||
674 | do { | |
675 | if ((torture_random(&rand) & 0xfffff) == 0) | |
676 | schedule_timeout_uninterruptible(1); | |
a1229491 | 677 | |
630952c2 | 678 | cxt.cur_ops->readlock(); |
4f6332c1 | 679 | lock_is_read_held = 1; |
a1229491 DB |
680 | if (WARN_ON_ONCE(lock_is_write_held)) |
681 | lrsp->n_lock_fail++; /* rare, but... */ | |
682 | ||
4f6332c1 | 683 | lrsp->n_lock_acquired++; |
630952c2 | 684 | cxt.cur_ops->read_delay(&rand); |
4f6332c1 | 685 | lock_is_read_held = 0; |
630952c2 | 686 | cxt.cur_ops->readunlock(); |
a1229491 | 687 | |
4f6332c1 DB |
688 | stutter_wait("lock_torture_reader"); |
689 | } while (!torture_must_stop()); | |
690 | torture_kthread_stopping("lock_torture_reader"); | |
691 | return 0; | |
692 | } | |
693 | ||
0af3fe1e PM |
694 | /* |
695 | * Create an lock-torture-statistics message in the specified buffer. | |
696 | */ | |
4f6332c1 DB |
697 | static void __torture_print_stats(char *page, |
698 | struct lock_stress_stats *statp, bool write) | |
0af3fe1e PM |
699 | { |
700 | bool fail = 0; | |
4f6332c1 | 701 | int i, n_stress; |
2ce77d16 | 702 | long max = 0, min = statp ? statp[0].n_lock_acquired : 0; |
0af3fe1e PM |
703 | long long sum = 0; |
704 | ||
630952c2 | 705 | n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; |
4f6332c1 DB |
706 | for (i = 0; i < n_stress; i++) { |
707 | if (statp[i].n_lock_fail) | |
0af3fe1e | 708 | fail = true; |
4f6332c1 DB |
709 | sum += statp[i].n_lock_acquired; |
710 | if (max < statp[i].n_lock_fail) | |
711 | max = statp[i].n_lock_fail; | |
712 | if (min > statp[i].n_lock_fail) | |
713 | min = statp[i].n_lock_fail; | |
0af3fe1e | 714 | } |
0af3fe1e | 715 | page += sprintf(page, |
4f6332c1 DB |
716 | "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", |
717 | write ? "Writes" : "Reads ", | |
0af3fe1e PM |
718 | sum, max, min, max / 2 > min ? "???" : "", |
719 | fail, fail ? "!!!" : ""); | |
720 | if (fail) | |
630952c2 | 721 | atomic_inc(&cxt.n_lock_torture_errors); |
0af3fe1e PM |
722 | } |
723 | ||
724 | /* | |
725 | * Print torture statistics. Caller must ensure that there is only one | |
726 | * call to this function at a given time!!! This is normally accomplished | |
727 | * by relying on the module system to only have one copy of the module | |
728 | * loaded, and then by giving the lock_torture_stats kthread full control | |
729 | * (or the init/cleanup functions when lock_torture_stats thread is not | |
730 | * running). | |
731 | */ | |
732 | static void lock_torture_stats_print(void) | |
733 | { | |
630952c2 | 734 | int size = cxt.nrealwriters_stress * 200 + 8192; |
0af3fe1e PM |
735 | char *buf; |
736 | ||
630952c2 DB |
737 | if (cxt.cur_ops->readlock) |
738 | size += cxt.nrealreaders_stress * 200 + 8192; | |
4f6332c1 | 739 | |
0af3fe1e PM |
740 | buf = kmalloc(size, GFP_KERNEL); |
741 | if (!buf) { | |
742 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
743 | size); | |
744 | return; | |
745 | } | |
4f6332c1 | 746 | |
630952c2 | 747 | __torture_print_stats(buf, cxt.lwsa, true); |
0af3fe1e PM |
748 | pr_alert("%s", buf); |
749 | kfree(buf); | |
4f6332c1 | 750 | |
630952c2 | 751 | if (cxt.cur_ops->readlock) { |
4f6332c1 DB |
752 | buf = kmalloc(size, GFP_KERNEL); |
753 | if (!buf) { | |
754 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
755 | size); | |
756 | return; | |
757 | } | |
758 | ||
630952c2 | 759 | __torture_print_stats(buf, cxt.lrsa, false); |
4f6332c1 DB |
760 | pr_alert("%s", buf); |
761 | kfree(buf); | |
762 | } | |
0af3fe1e PM |
763 | } |
764 | ||
765 | /* | |
766 | * Periodically prints torture statistics, if periodic statistics printing | |
767 | * was specified via the stat_interval module parameter. | |
768 | * | |
769 | * No need to worry about fullstop here, since this one doesn't reference | |
770 | * volatile state or register callbacks. | |
771 | */ | |
772 | static int lock_torture_stats(void *arg) | |
773 | { | |
774 | VERBOSE_TOROUT_STRING("lock_torture_stats task started"); | |
775 | do { | |
776 | schedule_timeout_interruptible(stat_interval * HZ); | |
777 | lock_torture_stats_print(); | |
778 | torture_shutdown_absorb("lock_torture_stats"); | |
779 | } while (!torture_must_stop()); | |
780 | torture_kthread_stopping("lock_torture_stats"); | |
781 | return 0; | |
782 | } | |
783 | ||
784 | static inline void | |
785 | lock_torture_print_module_parms(struct lock_torture_ops *cur_ops, | |
786 | const char *tag) | |
787 | { | |
788 | pr_alert("%s" TORTURE_FLAG | |
4f6332c1 | 789 | "--- %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 |
790 | torture_type, tag, cxt.debug_lock ? " [debug]": "", |
791 | cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval, | |
4f6332c1 | 792 | verbose, shuffle_interval, stutter, shutdown_secs, |
0af3fe1e PM |
793 | onoff_interval, onoff_holdoff); |
794 | } | |
795 | ||
796 | static void lock_torture_cleanup(void) | |
797 | { | |
798 | int i; | |
799 | ||
d36a7a0d | 800 | if (torture_cleanup_begin()) |
0af3fe1e PM |
801 | return; |
802 | ||
c1c33b92 DB |
803 | /* |
804 | * Indicates early cleanup, meaning that the test has not run, | |
805 | * such as when passing bogus args when loading the module. As | |
806 | * such, only perform the underlying torture-specific cleanups, | |
807 | * and avoid anything related to locktorture. | |
808 | */ | |
2ce77d16 | 809 | if (!cxt.lwsa && !cxt.lrsa) |
c1c33b92 DB |
810 | goto end; |
811 | ||
0af3fe1e | 812 | if (writer_tasks) { |
630952c2 | 813 | for (i = 0; i < cxt.nrealwriters_stress; i++) |
0af3fe1e PM |
814 | torture_stop_kthread(lock_torture_writer, |
815 | writer_tasks[i]); | |
816 | kfree(writer_tasks); | |
817 | writer_tasks = NULL; | |
818 | } | |
819 | ||
4f6332c1 | 820 | if (reader_tasks) { |
630952c2 | 821 | for (i = 0; i < cxt.nrealreaders_stress; i++) |
4f6332c1 DB |
822 | torture_stop_kthread(lock_torture_reader, |
823 | reader_tasks[i]); | |
824 | kfree(reader_tasks); | |
825 | reader_tasks = NULL; | |
826 | } | |
827 | ||
0af3fe1e PM |
828 | torture_stop_kthread(lock_torture_stats, stats_task); |
829 | lock_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
830 | ||
630952c2 DB |
831 | if (atomic_read(&cxt.n_lock_torture_errors)) |
832 | lock_torture_print_module_parms(cxt.cur_ops, | |
0af3fe1e PM |
833 | "End of test: FAILURE"); |
834 | else if (torture_onoff_failures()) | |
630952c2 | 835 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e PM |
836 | "End of test: LOCK_HOTPLUG"); |
837 | else | |
630952c2 | 838 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e | 839 | "End of test: SUCCESS"); |
f4dbba59 YS |
840 | |
841 | kfree(cxt.lwsa); | |
842 | kfree(cxt.lrsa); | |
843 | ||
c1c33b92 | 844 | end: |
d36a7a0d | 845 | torture_cleanup_end(); |
0af3fe1e PM |
846 | } |
847 | ||
848 | static int __init lock_torture_init(void) | |
849 | { | |
4f6332c1 | 850 | int i, j; |
0af3fe1e PM |
851 | int firsterr = 0; |
852 | static struct lock_torture_ops *torture_ops[] = { | |
e34191fa DB |
853 | &lock_busted_ops, |
854 | &spin_lock_ops, &spin_lock_irq_ops, | |
855 | &rw_lock_ops, &rw_lock_irq_ops, | |
856 | &mutex_lock_ops, | |
0186a6cb | 857 | &ww_mutex_lock_ops, |
095777c4 DB |
858 | #ifdef CONFIG_RT_MUTEXES |
859 | &rtmutex_lock_ops, | |
860 | #endif | |
e34191fa | 861 | &rwsem_lock_ops, |
617783dd | 862 | &percpu_rwsem_lock_ops, |
0af3fe1e PM |
863 | }; |
864 | ||
a2f2577d | 865 | if (!torture_init_begin(torture_type, verbose)) |
5228084e | 866 | return -EBUSY; |
0af3fe1e PM |
867 | |
868 | /* Process args and tell the world that the torturer is on the job. */ | |
869 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
630952c2 DB |
870 | cxt.cur_ops = torture_ops[i]; |
871 | if (strcmp(torture_type, cxt.cur_ops->name) == 0) | |
0af3fe1e PM |
872 | break; |
873 | } | |
874 | if (i == ARRAY_SIZE(torture_ops)) { | |
875 | pr_alert("lock-torture: invalid torture type: \"%s\"\n", | |
876 | torture_type); | |
877 | pr_alert("lock-torture types:"); | |
878 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
879 | pr_alert(" %s", torture_ops[i]->name); | |
880 | pr_alert("\n"); | |
a36a9961 PM |
881 | firsterr = -EINVAL; |
882 | goto unwind; | |
0af3fe1e | 883 | } |
2ce77d16 DB |
884 | |
885 | if (nwriters_stress == 0 && nreaders_stress == 0) { | |
886 | pr_alert("lock-torture: must run at least one locking thread\n"); | |
887 | firsterr = -EINVAL; | |
888 | goto unwind; | |
889 | } | |
890 | ||
630952c2 | 891 | if (cxt.cur_ops->init) |
a36a9961 | 892 | cxt.cur_ops->init(); |
0af3fe1e PM |
893 | |
894 | if (nwriters_stress >= 0) | |
630952c2 | 895 | cxt.nrealwriters_stress = nwriters_stress; |
0af3fe1e | 896 | else |
630952c2 | 897 | cxt.nrealwriters_stress = 2 * num_online_cpus(); |
f095bfc0 DB |
898 | |
899 | #ifdef CONFIG_DEBUG_MUTEXES | |
900 | if (strncmp(torture_type, "mutex", 5) == 0) | |
630952c2 | 901 | cxt.debug_lock = true; |
f095bfc0 | 902 | #endif |
095777c4 DB |
903 | #ifdef CONFIG_DEBUG_RT_MUTEXES |
904 | if (strncmp(torture_type, "rtmutex", 7) == 0) | |
905 | cxt.debug_lock = true; | |
906 | #endif | |
f095bfc0 | 907 | #ifdef CONFIG_DEBUG_SPINLOCK |
e34191fa DB |
908 | if ((strncmp(torture_type, "spin", 4) == 0) || |
909 | (strncmp(torture_type, "rw_lock", 7) == 0)) | |
630952c2 | 910 | cxt.debug_lock = true; |
f095bfc0 | 911 | #endif |
0af3fe1e PM |
912 | |
913 | /* Initialize the statistics so that each run gets its own numbers. */ | |
2ce77d16 DB |
914 | if (nwriters_stress) { |
915 | lock_is_write_held = 0; | |
916 | cxt.lwsa = kmalloc(sizeof(*cxt.lwsa) * cxt.nrealwriters_stress, GFP_KERNEL); | |
917 | if (cxt.lwsa == NULL) { | |
918 | VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); | |
919 | firsterr = -ENOMEM; | |
920 | goto unwind; | |
921 | } | |
0af3fe1e | 922 | |
2ce77d16 DB |
923 | for (i = 0; i < cxt.nrealwriters_stress; i++) { |
924 | cxt.lwsa[i].n_lock_fail = 0; | |
925 | cxt.lwsa[i].n_lock_acquired = 0; | |
926 | } | |
0af3fe1e PM |
927 | } |
928 | ||
630952c2 | 929 | if (cxt.cur_ops->readlock) { |
4f6332c1 | 930 | if (nreaders_stress >= 0) |
630952c2 | 931 | cxt.nrealreaders_stress = nreaders_stress; |
4f6332c1 DB |
932 | else { |
933 | /* | |
934 | * By default distribute evenly the number of | |
935 | * readers and writers. We still run the same number | |
936 | * of threads as the writer-only locks default. | |
937 | */ | |
938 | if (nwriters_stress < 0) /* user doesn't care */ | |
630952c2 DB |
939 | cxt.nrealwriters_stress = num_online_cpus(); |
940 | cxt.nrealreaders_stress = cxt.nrealwriters_stress; | |
4f6332c1 DB |
941 | } |
942 | ||
2ce77d16 DB |
943 | if (nreaders_stress) { |
944 | lock_is_read_held = 0; | |
945 | cxt.lrsa = kmalloc(sizeof(*cxt.lrsa) * cxt.nrealreaders_stress, GFP_KERNEL); | |
946 | if (cxt.lrsa == NULL) { | |
947 | VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); | |
948 | firsterr = -ENOMEM; | |
949 | kfree(cxt.lwsa); | |
950 | cxt.lwsa = NULL; | |
951 | goto unwind; | |
952 | } | |
953 | ||
954 | for (i = 0; i < cxt.nrealreaders_stress; i++) { | |
955 | cxt.lrsa[i].n_lock_fail = 0; | |
956 | cxt.lrsa[i].n_lock_acquired = 0; | |
957 | } | |
4f6332c1 DB |
958 | } |
959 | } | |
c1c33b92 | 960 | |
630952c2 | 961 | lock_torture_print_module_parms(cxt.cur_ops, "Start of test"); |
4f6332c1 DB |
962 | |
963 | /* Prepare torture context. */ | |
0af3fe1e PM |
964 | if (onoff_interval > 0) { |
965 | firsterr = torture_onoff_init(onoff_holdoff * HZ, | |
966 | onoff_interval * HZ); | |
967 | if (firsterr) | |
968 | goto unwind; | |
969 | } | |
970 | if (shuffle_interval > 0) { | |
971 | firsterr = torture_shuffle_init(shuffle_interval); | |
972 | if (firsterr) | |
973 | goto unwind; | |
974 | } | |
975 | if (shutdown_secs > 0) { | |
976 | firsterr = torture_shutdown_init(shutdown_secs, | |
977 | lock_torture_cleanup); | |
978 | if (firsterr) | |
979 | goto unwind; | |
980 | } | |
981 | if (stutter > 0) { | |
982 | firsterr = torture_stutter_init(stutter); | |
983 | if (firsterr) | |
984 | goto unwind; | |
985 | } | |
986 | ||
2ce77d16 DB |
987 | if (nwriters_stress) { |
988 | writer_tasks = kzalloc(cxt.nrealwriters_stress * sizeof(writer_tasks[0]), | |
989 | GFP_KERNEL); | |
990 | if (writer_tasks == NULL) { | |
991 | VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); | |
992 | firsterr = -ENOMEM; | |
993 | goto unwind; | |
994 | } | |
0af3fe1e | 995 | } |
4f6332c1 | 996 | |
630952c2 DB |
997 | if (cxt.cur_ops->readlock) { |
998 | reader_tasks = kzalloc(cxt.nrealreaders_stress * sizeof(reader_tasks[0]), | |
4f6332c1 DB |
999 | GFP_KERNEL); |
1000 | if (reader_tasks == NULL) { | |
1001 | VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory"); | |
f4dbba59 YS |
1002 | kfree(writer_tasks); |
1003 | writer_tasks = NULL; | |
4f6332c1 DB |
1004 | firsterr = -ENOMEM; |
1005 | goto unwind; | |
1006 | } | |
1007 | } | |
1008 | ||
1009 | /* | |
1010 | * Create the kthreads and start torturing (oh, those poor little locks). | |
1011 | * | |
1012 | * TODO: Note that we interleave writers with readers, giving writers a | |
1013 | * slight advantage, by creating its kthread first. This can be modified | |
1014 | * for very specific needs, or even let the user choose the policy, if | |
1015 | * ever wanted. | |
1016 | */ | |
630952c2 DB |
1017 | for (i = 0, j = 0; i < cxt.nrealwriters_stress || |
1018 | j < cxt.nrealreaders_stress; i++, j++) { | |
1019 | if (i >= cxt.nrealwriters_stress) | |
4f6332c1 DB |
1020 | goto create_reader; |
1021 | ||
1022 | /* Create writer. */ | |
630952c2 | 1023 | firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i], |
0af3fe1e PM |
1024 | writer_tasks[i]); |
1025 | if (firsterr) | |
1026 | goto unwind; | |
4f6332c1 DB |
1027 | |
1028 | create_reader: | |
630952c2 | 1029 | if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress)) |
4f6332c1 DB |
1030 | continue; |
1031 | /* Create reader. */ | |
630952c2 | 1032 | firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j], |
4f6332c1 DB |
1033 | reader_tasks[j]); |
1034 | if (firsterr) | |
1035 | goto unwind; | |
0af3fe1e PM |
1036 | } |
1037 | if (stat_interval > 0) { | |
1038 | firsterr = torture_create_kthread(lock_torture_stats, NULL, | |
1039 | stats_task); | |
1040 | if (firsterr) | |
1041 | goto unwind; | |
1042 | } | |
1043 | torture_init_end(); | |
1044 | return 0; | |
1045 | ||
1046 | unwind: | |
1047 | torture_init_end(); | |
1048 | lock_torture_cleanup(); | |
1049 | return firsterr; | |
1050 | } | |
1051 | ||
1052 | module_init(lock_torture_init); | |
1053 | module_exit(lock_torture_cleanup); |