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5a4eb3cb | 1 | // SPDX-License-Identifier: GPL-2.0+ |
0af3fe1e PM |
2 | /* |
3 | * Module-based torture test facility for locking | |
4 | * | |
0af3fe1e PM |
5 | * Copyright (C) IBM Corporation, 2014 |
6 | * | |
5a4eb3cb | 7 | * Authors: Paul E. McKenney <paulmck@linux.ibm.com> |
095777c4 | 8 | * Davidlohr Bueso <dave@stgolabs.net> |
0af3fe1e PM |
9 | * Based on kernel/rcu/torture.c. |
10 | */ | |
60500037 PM |
11 | |
12 | #define pr_fmt(fmt) fmt | |
13 | ||
0af3fe1e | 14 | #include <linux/kernel.h> |
0af3fe1e PM |
15 | #include <linux/module.h> |
16 | #include <linux/kthread.h> | |
095777c4 | 17 | #include <linux/sched/rt.h> |
0af3fe1e | 18 | #include <linux/spinlock.h> |
e34191fa | 19 | #include <linux/rwlock.h> |
42ddc75d | 20 | #include <linux/mutex.h> |
c98fed9f | 21 | #include <linux/rwsem.h> |
0af3fe1e PM |
22 | #include <linux/smp.h> |
23 | #include <linux/interrupt.h> | |
24 | #include <linux/sched.h> | |
ae7e81c0 | 25 | #include <uapi/linux/sched/types.h> |
037741a6 | 26 | #include <linux/rtmutex.h> |
0af3fe1e | 27 | #include <linux/atomic.h> |
0af3fe1e | 28 | #include <linux/moduleparam.h> |
0af3fe1e | 29 | #include <linux/delay.h> |
0af3fe1e | 30 | #include <linux/slab.h> |
617783dd | 31 | #include <linux/percpu-rwsem.h> |
0af3fe1e PM |
32 | #include <linux/torture.h> |
33 | ||
34 | MODULE_LICENSE("GPL"); | |
5a4eb3cb | 35 | MODULE_AUTHOR("Paul E. McKenney <paulmck@linux.ibm.com>"); |
0af3fe1e PM |
36 | |
37 | torture_param(int, nwriters_stress, -1, | |
38 | "Number of write-locking stress-test threads"); | |
4f6332c1 DB |
39 | torture_param(int, nreaders_stress, -1, |
40 | "Number of read-locking stress-test threads"); | |
0af3fe1e PM |
41 | torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); |
42 | torture_param(int, onoff_interval, 0, | |
43 | "Time between CPU hotplugs (s), 0=disable"); | |
44 | torture_param(int, shuffle_interval, 3, | |
45 | "Number of jiffies between shuffles, 0=disable"); | |
46 | torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable."); | |
47 | torture_param(int, stat_interval, 60, | |
48 | "Number of seconds between stats printk()s"); | |
49 | torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable"); | |
90127d60 | 50 | torture_param(int, verbose, 1, |
0af3fe1e PM |
51 | "Enable verbose debugging printk()s"); |
52 | ||
53 | static char *torture_type = "spin_lock"; | |
54 | module_param(torture_type, charp, 0444); | |
55 | MODULE_PARM_DESC(torture_type, | |
42ddc75d | 56 | "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)"); |
0af3fe1e | 57 | |
0af3fe1e PM |
58 | static struct task_struct *stats_task; |
59 | static struct task_struct **writer_tasks; | |
4f6332c1 | 60 | static struct task_struct **reader_tasks; |
0af3fe1e | 61 | |
0af3fe1e | 62 | static bool lock_is_write_held; |
4f6332c1 | 63 | static bool lock_is_read_held; |
0af3fe1e | 64 | |
1e6757a9 DB |
65 | struct lock_stress_stats { |
66 | long n_lock_fail; | |
67 | long n_lock_acquired; | |
0af3fe1e | 68 | }; |
0af3fe1e | 69 | |
0af3fe1e PM |
70 | /* Forward reference. */ |
71 | static void lock_torture_cleanup(void); | |
72 | ||
73 | /* | |
74 | * Operations vector for selecting different types of tests. | |
75 | */ | |
76 | struct lock_torture_ops { | |
77 | void (*init)(void); | |
78 | int (*writelock)(void); | |
79 | void (*write_delay)(struct torture_random_state *trsp); | |
095777c4 | 80 | void (*task_boost)(struct torture_random_state *trsp); |
0af3fe1e | 81 | void (*writeunlock)(void); |
4f6332c1 DB |
82 | int (*readlock)(void); |
83 | void (*read_delay)(struct torture_random_state *trsp); | |
84 | void (*readunlock)(void); | |
095777c4 DB |
85 | |
86 | unsigned long flags; /* for irq spinlocks */ | |
0af3fe1e PM |
87 | const char *name; |
88 | }; | |
89 | ||
630952c2 DB |
90 | struct lock_torture_cxt { |
91 | int nrealwriters_stress; | |
92 | int nrealreaders_stress; | |
93 | bool debug_lock; | |
94 | atomic_t n_lock_torture_errors; | |
95 | struct lock_torture_ops *cur_ops; | |
96 | struct lock_stress_stats *lwsa; /* writer statistics */ | |
97 | struct lock_stress_stats *lrsa; /* reader statistics */ | |
98 | }; | |
99 | static struct lock_torture_cxt cxt = { 0, 0, false, | |
100 | ATOMIC_INIT(0), | |
101 | NULL, NULL}; | |
0af3fe1e PM |
102 | /* |
103 | * Definitions for lock torture testing. | |
104 | */ | |
105 | ||
e086481b PM |
106 | static int torture_lock_busted_write_lock(void) |
107 | { | |
108 | return 0; /* BUGGY, do not use in real life!!! */ | |
109 | } | |
110 | ||
111 | static void torture_lock_busted_write_delay(struct torture_random_state *trsp) | |
112 | { | |
61d49d2f | 113 | const unsigned long longdelay_ms = 100; |
e086481b PM |
114 | |
115 | /* We want a long delay occasionally to force massive contention. */ | |
116 | if (!(torture_random(trsp) % | |
61d49d2f PM |
117 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
118 | mdelay(longdelay_ms); | |
630952c2 | 119 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 120 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
e086481b PM |
121 | } |
122 | ||
123 | static void torture_lock_busted_write_unlock(void) | |
124 | { | |
125 | /* BUGGY, do not use in real life!!! */ | |
126 | } | |
127 | ||
095777c4 DB |
128 | static void torture_boost_dummy(struct torture_random_state *trsp) |
129 | { | |
130 | /* Only rtmutexes care about priority */ | |
131 | } | |
132 | ||
e086481b PM |
133 | static struct lock_torture_ops lock_busted_ops = { |
134 | .writelock = torture_lock_busted_write_lock, | |
135 | .write_delay = torture_lock_busted_write_delay, | |
095777c4 | 136 | .task_boost = torture_boost_dummy, |
e086481b | 137 | .writeunlock = torture_lock_busted_write_unlock, |
4f6332c1 DB |
138 | .readlock = NULL, |
139 | .read_delay = NULL, | |
140 | .readunlock = NULL, | |
e086481b PM |
141 | .name = "lock_busted" |
142 | }; | |
143 | ||
0af3fe1e PM |
144 | static DEFINE_SPINLOCK(torture_spinlock); |
145 | ||
146 | static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock) | |
147 | { | |
148 | spin_lock(&torture_spinlock); | |
149 | return 0; | |
150 | } | |
151 | ||
152 | static void torture_spin_lock_write_delay(struct torture_random_state *trsp) | |
153 | { | |
154 | const unsigned long shortdelay_us = 2; | |
61d49d2f | 155 | const unsigned long longdelay_ms = 100; |
0af3fe1e PM |
156 | |
157 | /* We want a short delay mostly to emulate likely code, and | |
158 | * we want a long delay occasionally to force massive contention. | |
159 | */ | |
160 | if (!(torture_random(trsp) % | |
61d49d2f PM |
161 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
162 | mdelay(longdelay_ms); | |
0af3fe1e | 163 | if (!(torture_random(trsp) % |
630952c2 | 164 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) |
0af3fe1e | 165 | udelay(shortdelay_us); |
630952c2 | 166 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 167 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
0af3fe1e PM |
168 | } |
169 | ||
170 | static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock) | |
171 | { | |
172 | spin_unlock(&torture_spinlock); | |
173 | } | |
174 | ||
175 | static struct lock_torture_ops spin_lock_ops = { | |
176 | .writelock = torture_spin_lock_write_lock, | |
177 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 178 | .task_boost = torture_boost_dummy, |
0af3fe1e | 179 | .writeunlock = torture_spin_lock_write_unlock, |
4f6332c1 DB |
180 | .readlock = NULL, |
181 | .read_delay = NULL, | |
182 | .readunlock = NULL, | |
0af3fe1e PM |
183 | .name = "spin_lock" |
184 | }; | |
185 | ||
186 | static int torture_spin_lock_write_lock_irq(void) | |
219f800f | 187 | __acquires(torture_spinlock) |
0af3fe1e PM |
188 | { |
189 | unsigned long flags; | |
190 | ||
191 | spin_lock_irqsave(&torture_spinlock, flags); | |
630952c2 | 192 | cxt.cur_ops->flags = flags; |
0af3fe1e PM |
193 | return 0; |
194 | } | |
195 | ||
196 | static void torture_lock_spin_write_unlock_irq(void) | |
197 | __releases(torture_spinlock) | |
198 | { | |
630952c2 | 199 | spin_unlock_irqrestore(&torture_spinlock, cxt.cur_ops->flags); |
0af3fe1e PM |
200 | } |
201 | ||
202 | static struct lock_torture_ops spin_lock_irq_ops = { | |
203 | .writelock = torture_spin_lock_write_lock_irq, | |
204 | .write_delay = torture_spin_lock_write_delay, | |
095777c4 | 205 | .task_boost = torture_boost_dummy, |
0af3fe1e | 206 | .writeunlock = torture_lock_spin_write_unlock_irq, |
4f6332c1 DB |
207 | .readlock = NULL, |
208 | .read_delay = NULL, | |
209 | .readunlock = NULL, | |
0af3fe1e PM |
210 | .name = "spin_lock_irq" |
211 | }; | |
212 | ||
e34191fa DB |
213 | static DEFINE_RWLOCK(torture_rwlock); |
214 | ||
215 | static int torture_rwlock_write_lock(void) __acquires(torture_rwlock) | |
216 | { | |
217 | write_lock(&torture_rwlock); | |
218 | return 0; | |
219 | } | |
220 | ||
221 | static void torture_rwlock_write_delay(struct torture_random_state *trsp) | |
222 | { | |
223 | const unsigned long shortdelay_us = 2; | |
224 | const unsigned long longdelay_ms = 100; | |
225 | ||
226 | /* We want a short delay mostly to emulate likely code, and | |
227 | * we want a long delay occasionally to force massive contention. | |
228 | */ | |
229 | if (!(torture_random(trsp) % | |
230 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
231 | mdelay(longdelay_ms); | |
232 | else | |
233 | udelay(shortdelay_us); | |
234 | } | |
235 | ||
236 | static void torture_rwlock_write_unlock(void) __releases(torture_rwlock) | |
237 | { | |
238 | write_unlock(&torture_rwlock); | |
239 | } | |
240 | ||
241 | static int torture_rwlock_read_lock(void) __acquires(torture_rwlock) | |
242 | { | |
243 | read_lock(&torture_rwlock); | |
244 | return 0; | |
245 | } | |
246 | ||
247 | static void torture_rwlock_read_delay(struct torture_random_state *trsp) | |
248 | { | |
249 | const unsigned long shortdelay_us = 10; | |
250 | const unsigned long longdelay_ms = 100; | |
251 | ||
252 | /* We want a short delay mostly to emulate likely code, and | |
253 | * we want a long delay occasionally to force massive contention. | |
254 | */ | |
255 | if (!(torture_random(trsp) % | |
256 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) | |
257 | mdelay(longdelay_ms); | |
258 | else | |
259 | udelay(shortdelay_us); | |
260 | } | |
261 | ||
262 | static void torture_rwlock_read_unlock(void) __releases(torture_rwlock) | |
263 | { | |
264 | read_unlock(&torture_rwlock); | |
265 | } | |
266 | ||
267 | static struct lock_torture_ops rw_lock_ops = { | |
268 | .writelock = torture_rwlock_write_lock, | |
269 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 270 | .task_boost = torture_boost_dummy, |
e34191fa DB |
271 | .writeunlock = torture_rwlock_write_unlock, |
272 | .readlock = torture_rwlock_read_lock, | |
273 | .read_delay = torture_rwlock_read_delay, | |
274 | .readunlock = torture_rwlock_read_unlock, | |
275 | .name = "rw_lock" | |
276 | }; | |
277 | ||
278 | static int torture_rwlock_write_lock_irq(void) __acquires(torture_rwlock) | |
279 | { | |
280 | unsigned long flags; | |
281 | ||
282 | write_lock_irqsave(&torture_rwlock, flags); | |
283 | cxt.cur_ops->flags = flags; | |
284 | return 0; | |
285 | } | |
286 | ||
287 | static void torture_rwlock_write_unlock_irq(void) | |
288 | __releases(torture_rwlock) | |
289 | { | |
290 | write_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); | |
291 | } | |
292 | ||
293 | static int torture_rwlock_read_lock_irq(void) __acquires(torture_rwlock) | |
294 | { | |
295 | unsigned long flags; | |
296 | ||
297 | read_lock_irqsave(&torture_rwlock, flags); | |
298 | cxt.cur_ops->flags = flags; | |
299 | return 0; | |
300 | } | |
301 | ||
302 | static void torture_rwlock_read_unlock_irq(void) | |
303 | __releases(torture_rwlock) | |
304 | { | |
f548d99e | 305 | read_unlock_irqrestore(&torture_rwlock, cxt.cur_ops->flags); |
e34191fa DB |
306 | } |
307 | ||
308 | static struct lock_torture_ops rw_lock_irq_ops = { | |
309 | .writelock = torture_rwlock_write_lock_irq, | |
310 | .write_delay = torture_rwlock_write_delay, | |
095777c4 | 311 | .task_boost = torture_boost_dummy, |
e34191fa DB |
312 | .writeunlock = torture_rwlock_write_unlock_irq, |
313 | .readlock = torture_rwlock_read_lock_irq, | |
314 | .read_delay = torture_rwlock_read_delay, | |
315 | .readunlock = torture_rwlock_read_unlock_irq, | |
316 | .name = "rw_lock_irq" | |
317 | }; | |
318 | ||
42ddc75d DB |
319 | static DEFINE_MUTEX(torture_mutex); |
320 | ||
321 | static int torture_mutex_lock(void) __acquires(torture_mutex) | |
322 | { | |
323 | mutex_lock(&torture_mutex); | |
324 | return 0; | |
325 | } | |
326 | ||
327 | static void torture_mutex_delay(struct torture_random_state *trsp) | |
328 | { | |
329 | const unsigned long longdelay_ms = 100; | |
330 | ||
331 | /* We want a long delay occasionally to force massive contention. */ | |
332 | if (!(torture_random(trsp) % | |
630952c2 | 333 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
42ddc75d DB |
334 | mdelay(longdelay_ms * 5); |
335 | else | |
336 | mdelay(longdelay_ms / 5); | |
630952c2 | 337 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 338 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
42ddc75d DB |
339 | } |
340 | ||
341 | static void torture_mutex_unlock(void) __releases(torture_mutex) | |
342 | { | |
343 | mutex_unlock(&torture_mutex); | |
344 | } | |
345 | ||
346 | static struct lock_torture_ops mutex_lock_ops = { | |
347 | .writelock = torture_mutex_lock, | |
348 | .write_delay = torture_mutex_delay, | |
095777c4 | 349 | .task_boost = torture_boost_dummy, |
42ddc75d | 350 | .writeunlock = torture_mutex_unlock, |
4f6332c1 DB |
351 | .readlock = NULL, |
352 | .read_delay = NULL, | |
353 | .readunlock = NULL, | |
42ddc75d DB |
354 | .name = "mutex_lock" |
355 | }; | |
356 | ||
0186a6cb | 357 | #include <linux/ww_mutex.h> |
08295b3b | 358 | static DEFINE_WD_CLASS(torture_ww_class); |
0186a6cb CW |
359 | static DEFINE_WW_MUTEX(torture_ww_mutex_0, &torture_ww_class); |
360 | static DEFINE_WW_MUTEX(torture_ww_mutex_1, &torture_ww_class); | |
361 | static DEFINE_WW_MUTEX(torture_ww_mutex_2, &torture_ww_class); | |
362 | ||
363 | static int torture_ww_mutex_lock(void) | |
364 | __acquires(torture_ww_mutex_0) | |
365 | __acquires(torture_ww_mutex_1) | |
366 | __acquires(torture_ww_mutex_2) | |
367 | { | |
368 | LIST_HEAD(list); | |
369 | struct reorder_lock { | |
370 | struct list_head link; | |
371 | struct ww_mutex *lock; | |
372 | } locks[3], *ll, *ln; | |
373 | struct ww_acquire_ctx ctx; | |
374 | ||
375 | locks[0].lock = &torture_ww_mutex_0; | |
376 | list_add(&locks[0].link, &list); | |
377 | ||
378 | locks[1].lock = &torture_ww_mutex_1; | |
379 | list_add(&locks[1].link, &list); | |
380 | ||
381 | locks[2].lock = &torture_ww_mutex_2; | |
382 | list_add(&locks[2].link, &list); | |
383 | ||
384 | ww_acquire_init(&ctx, &torture_ww_class); | |
385 | ||
386 | list_for_each_entry(ll, &list, link) { | |
387 | int err; | |
388 | ||
389 | err = ww_mutex_lock(ll->lock, &ctx); | |
390 | if (!err) | |
391 | continue; | |
392 | ||
393 | ln = ll; | |
394 | list_for_each_entry_continue_reverse(ln, &list, link) | |
395 | ww_mutex_unlock(ln->lock); | |
396 | ||
397 | if (err != -EDEADLK) | |
398 | return err; | |
399 | ||
400 | ww_mutex_lock_slow(ll->lock, &ctx); | |
401 | list_move(&ll->link, &list); | |
402 | } | |
403 | ||
404 | ww_acquire_fini(&ctx); | |
405 | return 0; | |
406 | } | |
407 | ||
408 | static void torture_ww_mutex_unlock(void) | |
409 | __releases(torture_ww_mutex_0) | |
410 | __releases(torture_ww_mutex_1) | |
411 | __releases(torture_ww_mutex_2) | |
412 | { | |
413 | ww_mutex_unlock(&torture_ww_mutex_0); | |
414 | ww_mutex_unlock(&torture_ww_mutex_1); | |
415 | ww_mutex_unlock(&torture_ww_mutex_2); | |
416 | } | |
417 | ||
418 | static struct lock_torture_ops ww_mutex_lock_ops = { | |
419 | .writelock = torture_ww_mutex_lock, | |
420 | .write_delay = torture_mutex_delay, | |
421 | .task_boost = torture_boost_dummy, | |
422 | .writeunlock = torture_ww_mutex_unlock, | |
423 | .readlock = NULL, | |
424 | .read_delay = NULL, | |
425 | .readunlock = NULL, | |
426 | .name = "ww_mutex_lock" | |
427 | }; | |
428 | ||
095777c4 DB |
429 | #ifdef CONFIG_RT_MUTEXES |
430 | static DEFINE_RT_MUTEX(torture_rtmutex); | |
431 | ||
432 | static int torture_rtmutex_lock(void) __acquires(torture_rtmutex) | |
433 | { | |
434 | rt_mutex_lock(&torture_rtmutex); | |
435 | return 0; | |
436 | } | |
437 | ||
438 | static void torture_rtmutex_boost(struct torture_random_state *trsp) | |
439 | { | |
440 | int policy; | |
441 | struct sched_param param; | |
442 | const unsigned int factor = 50000; /* yes, quite arbitrary */ | |
443 | ||
444 | if (!rt_task(current)) { | |
445 | /* | |
1f190931 | 446 | * Boost priority once every ~50k operations. When the |
095777c4 DB |
447 | * task tries to take the lock, the rtmutex it will account |
448 | * for the new priority, and do any corresponding pi-dance. | |
449 | */ | |
1f190931 DB |
450 | if (trsp && !(torture_random(trsp) % |
451 | (cxt.nrealwriters_stress * factor))) { | |
095777c4 DB |
452 | policy = SCHED_FIFO; |
453 | param.sched_priority = MAX_RT_PRIO - 1; | |
454 | } else /* common case, do nothing */ | |
455 | return; | |
456 | } else { | |
457 | /* | |
458 | * The task will remain boosted for another ~500k operations, | |
459 | * then restored back to its original prio, and so forth. | |
460 | * | |
461 | * When @trsp is nil, we want to force-reset the task for | |
462 | * stopping the kthread. | |
463 | */ | |
464 | if (!trsp || !(torture_random(trsp) % | |
465 | (cxt.nrealwriters_stress * factor * 2))) { | |
466 | policy = SCHED_NORMAL; | |
467 | param.sched_priority = 0; | |
468 | } else /* common case, do nothing */ | |
469 | return; | |
470 | } | |
471 | ||
472 | sched_setscheduler_nocheck(current, policy, ¶m); | |
473 | } | |
474 | ||
475 | static void torture_rtmutex_delay(struct torture_random_state *trsp) | |
476 | { | |
477 | const unsigned long shortdelay_us = 2; | |
478 | const unsigned long longdelay_ms = 100; | |
479 | ||
480 | /* | |
481 | * We want a short delay mostly to emulate likely code, and | |
482 | * we want a long delay occasionally to force massive contention. | |
483 | */ | |
484 | if (!(torture_random(trsp) % | |
485 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) | |
486 | mdelay(longdelay_ms); | |
487 | if (!(torture_random(trsp) % | |
488 | (cxt.nrealwriters_stress * 2 * shortdelay_us))) | |
489 | udelay(shortdelay_us); | |
095777c4 | 490 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 491 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
095777c4 DB |
492 | } |
493 | ||
494 | static void torture_rtmutex_unlock(void) __releases(torture_rtmutex) | |
495 | { | |
496 | rt_mutex_unlock(&torture_rtmutex); | |
497 | } | |
498 | ||
499 | static struct lock_torture_ops rtmutex_lock_ops = { | |
500 | .writelock = torture_rtmutex_lock, | |
501 | .write_delay = torture_rtmutex_delay, | |
502 | .task_boost = torture_rtmutex_boost, | |
503 | .writeunlock = torture_rtmutex_unlock, | |
504 | .readlock = NULL, | |
505 | .read_delay = NULL, | |
506 | .readunlock = NULL, | |
507 | .name = "rtmutex_lock" | |
508 | }; | |
509 | #endif | |
510 | ||
4a3b427f DB |
511 | static DECLARE_RWSEM(torture_rwsem); |
512 | static int torture_rwsem_down_write(void) __acquires(torture_rwsem) | |
513 | { | |
514 | down_write(&torture_rwsem); | |
515 | return 0; | |
516 | } | |
517 | ||
518 | static void torture_rwsem_write_delay(struct torture_random_state *trsp) | |
519 | { | |
520 | const unsigned long longdelay_ms = 100; | |
521 | ||
522 | /* We want a long delay occasionally to force massive contention. */ | |
523 | if (!(torture_random(trsp) % | |
630952c2 | 524 | (cxt.nrealwriters_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
525 | mdelay(longdelay_ms * 10); |
526 | else | |
527 | mdelay(longdelay_ms / 10); | |
630952c2 | 528 | if (!(torture_random(trsp) % (cxt.nrealwriters_stress * 20000))) |
cc1321c9 | 529 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
4a3b427f DB |
530 | } |
531 | ||
532 | static void torture_rwsem_up_write(void) __releases(torture_rwsem) | |
533 | { | |
534 | up_write(&torture_rwsem); | |
535 | } | |
536 | ||
537 | static int torture_rwsem_down_read(void) __acquires(torture_rwsem) | |
538 | { | |
539 | down_read(&torture_rwsem); | |
540 | return 0; | |
541 | } | |
542 | ||
543 | static void torture_rwsem_read_delay(struct torture_random_state *trsp) | |
544 | { | |
545 | const unsigned long longdelay_ms = 100; | |
546 | ||
547 | /* We want a long delay occasionally to force massive contention. */ | |
548 | if (!(torture_random(trsp) % | |
f2f76260 | 549 | (cxt.nrealreaders_stress * 2000 * longdelay_ms))) |
4a3b427f DB |
550 | mdelay(longdelay_ms * 2); |
551 | else | |
552 | mdelay(longdelay_ms / 2); | |
630952c2 | 553 | if (!(torture_random(trsp) % (cxt.nrealreaders_stress * 20000))) |
cc1321c9 | 554 | torture_preempt_schedule(); /* Allow test to be preempted. */ |
4a3b427f DB |
555 | } |
556 | ||
557 | static void torture_rwsem_up_read(void) __releases(torture_rwsem) | |
558 | { | |
559 | up_read(&torture_rwsem); | |
560 | } | |
561 | ||
562 | static struct lock_torture_ops rwsem_lock_ops = { | |
563 | .writelock = torture_rwsem_down_write, | |
564 | .write_delay = torture_rwsem_write_delay, | |
095777c4 | 565 | .task_boost = torture_boost_dummy, |
4a3b427f DB |
566 | .writeunlock = torture_rwsem_up_write, |
567 | .readlock = torture_rwsem_down_read, | |
568 | .read_delay = torture_rwsem_read_delay, | |
569 | .readunlock = torture_rwsem_up_read, | |
570 | .name = "rwsem_lock" | |
571 | }; | |
572 | ||
617783dd PM |
573 | #include <linux/percpu-rwsem.h> |
574 | static struct percpu_rw_semaphore pcpu_rwsem; | |
575 | ||
576 | void torture_percpu_rwsem_init(void) | |
577 | { | |
578 | BUG_ON(percpu_init_rwsem(&pcpu_rwsem)); | |
579 | } | |
580 | ||
581 | static int torture_percpu_rwsem_down_write(void) __acquires(pcpu_rwsem) | |
582 | { | |
583 | percpu_down_write(&pcpu_rwsem); | |
584 | return 0; | |
585 | } | |
586 | ||
587 | static void torture_percpu_rwsem_up_write(void) __releases(pcpu_rwsem) | |
588 | { | |
589 | percpu_up_write(&pcpu_rwsem); | |
590 | } | |
591 | ||
592 | static int torture_percpu_rwsem_down_read(void) __acquires(pcpu_rwsem) | |
593 | { | |
594 | percpu_down_read(&pcpu_rwsem); | |
595 | return 0; | |
596 | } | |
597 | ||
598 | static void torture_percpu_rwsem_up_read(void) __releases(pcpu_rwsem) | |
599 | { | |
600 | percpu_up_read(&pcpu_rwsem); | |
601 | } | |
602 | ||
603 | static struct lock_torture_ops percpu_rwsem_lock_ops = { | |
604 | .init = torture_percpu_rwsem_init, | |
605 | .writelock = torture_percpu_rwsem_down_write, | |
606 | .write_delay = torture_rwsem_write_delay, | |
607 | .task_boost = torture_boost_dummy, | |
608 | .writeunlock = torture_percpu_rwsem_up_write, | |
609 | .readlock = torture_percpu_rwsem_down_read, | |
610 | .read_delay = torture_rwsem_read_delay, | |
611 | .readunlock = torture_percpu_rwsem_up_read, | |
612 | .name = "percpu_rwsem_lock" | |
613 | }; | |
614 | ||
0af3fe1e PM |
615 | /* |
616 | * Lock torture writer kthread. Repeatedly acquires and releases | |
617 | * the lock, checking for duplicate acquisitions. | |
618 | */ | |
619 | static int lock_torture_writer(void *arg) | |
620 | { | |
1e6757a9 | 621 | struct lock_stress_stats *lwsp = arg; |
0af3fe1e PM |
622 | static DEFINE_TORTURE_RANDOM(rand); |
623 | ||
624 | VERBOSE_TOROUT_STRING("lock_torture_writer task started"); | |
8698a745 | 625 | set_user_nice(current, MAX_NICE); |
0af3fe1e PM |
626 | |
627 | do { | |
da601c63 PM |
628 | if ((torture_random(&rand) & 0xfffff) == 0) |
629 | schedule_timeout_uninterruptible(1); | |
a1229491 | 630 | |
095777c4 | 631 | cxt.cur_ops->task_boost(&rand); |
630952c2 | 632 | cxt.cur_ops->writelock(); |
0af3fe1e | 633 | if (WARN_ON_ONCE(lock_is_write_held)) |
1e6757a9 | 634 | lwsp->n_lock_fail++; |
0af3fe1e | 635 | lock_is_write_held = 1; |
a1229491 DB |
636 | if (WARN_ON_ONCE(lock_is_read_held)) |
637 | lwsp->n_lock_fail++; /* rare, but... */ | |
638 | ||
1e6757a9 | 639 | lwsp->n_lock_acquired++; |
630952c2 | 640 | cxt.cur_ops->write_delay(&rand); |
0af3fe1e | 641 | lock_is_write_held = 0; |
630952c2 | 642 | cxt.cur_ops->writeunlock(); |
a1229491 | 643 | |
0af3fe1e PM |
644 | stutter_wait("lock_torture_writer"); |
645 | } while (!torture_must_stop()); | |
095777c4 DB |
646 | |
647 | cxt.cur_ops->task_boost(NULL); /* reset prio */ | |
0af3fe1e PM |
648 | torture_kthread_stopping("lock_torture_writer"); |
649 | return 0; | |
650 | } | |
651 | ||
4f6332c1 DB |
652 | /* |
653 | * Lock torture reader kthread. Repeatedly acquires and releases | |
654 | * the reader lock. | |
655 | */ | |
656 | static int lock_torture_reader(void *arg) | |
657 | { | |
658 | struct lock_stress_stats *lrsp = arg; | |
659 | static DEFINE_TORTURE_RANDOM(rand); | |
660 | ||
661 | VERBOSE_TOROUT_STRING("lock_torture_reader task started"); | |
662 | set_user_nice(current, MAX_NICE); | |
663 | ||
664 | do { | |
665 | if ((torture_random(&rand) & 0xfffff) == 0) | |
666 | schedule_timeout_uninterruptible(1); | |
a1229491 | 667 | |
630952c2 | 668 | cxt.cur_ops->readlock(); |
4f6332c1 | 669 | lock_is_read_held = 1; |
a1229491 DB |
670 | if (WARN_ON_ONCE(lock_is_write_held)) |
671 | lrsp->n_lock_fail++; /* rare, but... */ | |
672 | ||
4f6332c1 | 673 | lrsp->n_lock_acquired++; |
630952c2 | 674 | cxt.cur_ops->read_delay(&rand); |
4f6332c1 | 675 | lock_is_read_held = 0; |
630952c2 | 676 | cxt.cur_ops->readunlock(); |
a1229491 | 677 | |
4f6332c1 DB |
678 | stutter_wait("lock_torture_reader"); |
679 | } while (!torture_must_stop()); | |
680 | torture_kthread_stopping("lock_torture_reader"); | |
681 | return 0; | |
682 | } | |
683 | ||
0af3fe1e PM |
684 | /* |
685 | * Create an lock-torture-statistics message in the specified buffer. | |
686 | */ | |
4f6332c1 DB |
687 | static void __torture_print_stats(char *page, |
688 | struct lock_stress_stats *statp, bool write) | |
0af3fe1e PM |
689 | { |
690 | bool fail = 0; | |
4f6332c1 | 691 | int i, n_stress; |
2ce77d16 | 692 | long max = 0, min = statp ? statp[0].n_lock_acquired : 0; |
0af3fe1e PM |
693 | long long sum = 0; |
694 | ||
630952c2 | 695 | n_stress = write ? cxt.nrealwriters_stress : cxt.nrealreaders_stress; |
4f6332c1 DB |
696 | for (i = 0; i < n_stress; i++) { |
697 | if (statp[i].n_lock_fail) | |
0af3fe1e | 698 | fail = true; |
4f6332c1 DB |
699 | sum += statp[i].n_lock_acquired; |
700 | if (max < statp[i].n_lock_fail) | |
701 | max = statp[i].n_lock_fail; | |
702 | if (min > statp[i].n_lock_fail) | |
703 | min = statp[i].n_lock_fail; | |
0af3fe1e | 704 | } |
0af3fe1e | 705 | page += sprintf(page, |
4f6332c1 DB |
706 | "%s: Total: %lld Max/Min: %ld/%ld %s Fail: %d %s\n", |
707 | write ? "Writes" : "Reads ", | |
0af3fe1e PM |
708 | sum, max, min, max / 2 > min ? "???" : "", |
709 | fail, fail ? "!!!" : ""); | |
710 | if (fail) | |
630952c2 | 711 | atomic_inc(&cxt.n_lock_torture_errors); |
0af3fe1e PM |
712 | } |
713 | ||
714 | /* | |
715 | * Print torture statistics. Caller must ensure that there is only one | |
716 | * call to this function at a given time!!! This is normally accomplished | |
717 | * by relying on the module system to only have one copy of the module | |
718 | * loaded, and then by giving the lock_torture_stats kthread full control | |
719 | * (or the init/cleanup functions when lock_torture_stats thread is not | |
720 | * running). | |
721 | */ | |
722 | static void lock_torture_stats_print(void) | |
723 | { | |
630952c2 | 724 | int size = cxt.nrealwriters_stress * 200 + 8192; |
0af3fe1e PM |
725 | char *buf; |
726 | ||
630952c2 DB |
727 | if (cxt.cur_ops->readlock) |
728 | size += cxt.nrealreaders_stress * 200 + 8192; | |
4f6332c1 | 729 | |
0af3fe1e PM |
730 | buf = kmalloc(size, GFP_KERNEL); |
731 | if (!buf) { | |
732 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
733 | size); | |
734 | return; | |
735 | } | |
4f6332c1 | 736 | |
630952c2 | 737 | __torture_print_stats(buf, cxt.lwsa, true); |
0af3fe1e PM |
738 | pr_alert("%s", buf); |
739 | kfree(buf); | |
4f6332c1 | 740 | |
630952c2 | 741 | if (cxt.cur_ops->readlock) { |
4f6332c1 DB |
742 | buf = kmalloc(size, GFP_KERNEL); |
743 | if (!buf) { | |
744 | pr_err("lock_torture_stats_print: Out of memory, need: %d", | |
745 | size); | |
746 | return; | |
747 | } | |
748 | ||
630952c2 | 749 | __torture_print_stats(buf, cxt.lrsa, false); |
4f6332c1 DB |
750 | pr_alert("%s", buf); |
751 | kfree(buf); | |
752 | } | |
0af3fe1e PM |
753 | } |
754 | ||
755 | /* | |
756 | * Periodically prints torture statistics, if periodic statistics printing | |
757 | * was specified via the stat_interval module parameter. | |
758 | * | |
759 | * No need to worry about fullstop here, since this one doesn't reference | |
760 | * volatile state or register callbacks. | |
761 | */ | |
762 | static int lock_torture_stats(void *arg) | |
763 | { | |
764 | VERBOSE_TOROUT_STRING("lock_torture_stats task started"); | |
765 | do { | |
766 | schedule_timeout_interruptible(stat_interval * HZ); | |
767 | lock_torture_stats_print(); | |
768 | torture_shutdown_absorb("lock_torture_stats"); | |
769 | } while (!torture_must_stop()); | |
770 | torture_kthread_stopping("lock_torture_stats"); | |
771 | return 0; | |
772 | } | |
773 | ||
774 | static inline void | |
775 | lock_torture_print_module_parms(struct lock_torture_ops *cur_ops, | |
776 | const char *tag) | |
777 | { | |
778 | pr_alert("%s" TORTURE_FLAG | |
4f6332c1 | 779 | "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n", |
630952c2 DB |
780 | torture_type, tag, cxt.debug_lock ? " [debug]": "", |
781 | cxt.nrealwriters_stress, cxt.nrealreaders_stress, stat_interval, | |
4f6332c1 | 782 | verbose, shuffle_interval, stutter, shutdown_secs, |
0af3fe1e PM |
783 | onoff_interval, onoff_holdoff); |
784 | } | |
785 | ||
786 | static void lock_torture_cleanup(void) | |
787 | { | |
788 | int i; | |
789 | ||
d36a7a0d | 790 | if (torture_cleanup_begin()) |
0af3fe1e PM |
791 | return; |
792 | ||
c1c33b92 DB |
793 | /* |
794 | * Indicates early cleanup, meaning that the test has not run, | |
795 | * such as when passing bogus args when loading the module. As | |
796 | * such, only perform the underlying torture-specific cleanups, | |
797 | * and avoid anything related to locktorture. | |
798 | */ | |
2ce77d16 | 799 | if (!cxt.lwsa && !cxt.lrsa) |
c1c33b92 DB |
800 | goto end; |
801 | ||
0af3fe1e | 802 | if (writer_tasks) { |
630952c2 | 803 | for (i = 0; i < cxt.nrealwriters_stress; i++) |
0af3fe1e PM |
804 | torture_stop_kthread(lock_torture_writer, |
805 | writer_tasks[i]); | |
806 | kfree(writer_tasks); | |
807 | writer_tasks = NULL; | |
808 | } | |
809 | ||
4f6332c1 | 810 | if (reader_tasks) { |
630952c2 | 811 | for (i = 0; i < cxt.nrealreaders_stress; i++) |
4f6332c1 DB |
812 | torture_stop_kthread(lock_torture_reader, |
813 | reader_tasks[i]); | |
814 | kfree(reader_tasks); | |
815 | reader_tasks = NULL; | |
816 | } | |
817 | ||
0af3fe1e PM |
818 | torture_stop_kthread(lock_torture_stats, stats_task); |
819 | lock_torture_stats_print(); /* -After- the stats thread is stopped! */ | |
820 | ||
630952c2 DB |
821 | if (atomic_read(&cxt.n_lock_torture_errors)) |
822 | lock_torture_print_module_parms(cxt.cur_ops, | |
0af3fe1e PM |
823 | "End of test: FAILURE"); |
824 | else if (torture_onoff_failures()) | |
630952c2 | 825 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e PM |
826 | "End of test: LOCK_HOTPLUG"); |
827 | else | |
630952c2 | 828 | lock_torture_print_module_parms(cxt.cur_ops, |
0af3fe1e | 829 | "End of test: SUCCESS"); |
f4dbba59 YS |
830 | |
831 | kfree(cxt.lwsa); | |
a9d6938d | 832 | cxt.lwsa = NULL; |
f4dbba59 | 833 | kfree(cxt.lrsa); |
a9d6938d | 834 | cxt.lrsa = NULL; |
f4dbba59 | 835 | |
c1c33b92 | 836 | end: |
d36a7a0d | 837 | torture_cleanup_end(); |
0af3fe1e PM |
838 | } |
839 | ||
840 | static int __init lock_torture_init(void) | |
841 | { | |
4f6332c1 | 842 | int i, j; |
0af3fe1e PM |
843 | int firsterr = 0; |
844 | static struct lock_torture_ops *torture_ops[] = { | |
e34191fa DB |
845 | &lock_busted_ops, |
846 | &spin_lock_ops, &spin_lock_irq_ops, | |
847 | &rw_lock_ops, &rw_lock_irq_ops, | |
848 | &mutex_lock_ops, | |
0186a6cb | 849 | &ww_mutex_lock_ops, |
095777c4 DB |
850 | #ifdef CONFIG_RT_MUTEXES |
851 | &rtmutex_lock_ops, | |
852 | #endif | |
e34191fa | 853 | &rwsem_lock_ops, |
617783dd | 854 | &percpu_rwsem_lock_ops, |
0af3fe1e PM |
855 | }; |
856 | ||
a2f2577d | 857 | if (!torture_init_begin(torture_type, verbose)) |
5228084e | 858 | return -EBUSY; |
0af3fe1e PM |
859 | |
860 | /* Process args and tell the world that the torturer is on the job. */ | |
861 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { | |
630952c2 DB |
862 | cxt.cur_ops = torture_ops[i]; |
863 | if (strcmp(torture_type, cxt.cur_ops->name) == 0) | |
0af3fe1e PM |
864 | break; |
865 | } | |
866 | if (i == ARRAY_SIZE(torture_ops)) { | |
867 | pr_alert("lock-torture: invalid torture type: \"%s\"\n", | |
868 | torture_type); | |
869 | pr_alert("lock-torture types:"); | |
870 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
871 | pr_alert(" %s", torture_ops[i]->name); | |
872 | pr_alert("\n"); | |
a36a9961 PM |
873 | firsterr = -EINVAL; |
874 | goto unwind; | |
0af3fe1e | 875 | } |
2ce77d16 DB |
876 | |
877 | if (nwriters_stress == 0 && nreaders_stress == 0) { | |
878 | pr_alert("lock-torture: must run at least one locking thread\n"); | |
879 | firsterr = -EINVAL; | |
880 | goto unwind; | |
881 | } | |
882 | ||
630952c2 | 883 | if (cxt.cur_ops->init) |
a36a9961 | 884 | cxt.cur_ops->init(); |
0af3fe1e PM |
885 | |
886 | if (nwriters_stress >= 0) | |
630952c2 | 887 | cxt.nrealwriters_stress = nwriters_stress; |
0af3fe1e | 888 | else |
630952c2 | 889 | cxt.nrealwriters_stress = 2 * num_online_cpus(); |
f095bfc0 DB |
890 | |
891 | #ifdef CONFIG_DEBUG_MUTEXES | |
892 | if (strncmp(torture_type, "mutex", 5) == 0) | |
630952c2 | 893 | cxt.debug_lock = true; |
f095bfc0 | 894 | #endif |
095777c4 DB |
895 | #ifdef CONFIG_DEBUG_RT_MUTEXES |
896 | if (strncmp(torture_type, "rtmutex", 7) == 0) | |
897 | cxt.debug_lock = true; | |
898 | #endif | |
f095bfc0 | 899 | #ifdef CONFIG_DEBUG_SPINLOCK |
e34191fa DB |
900 | if ((strncmp(torture_type, "spin", 4) == 0) || |
901 | (strncmp(torture_type, "rw_lock", 7) == 0)) | |
630952c2 | 902 | cxt.debug_lock = true; |
f095bfc0 | 903 | #endif |
0af3fe1e PM |
904 | |
905 | /* Initialize the statistics so that each run gets its own numbers. */ | |
2ce77d16 DB |
906 | if (nwriters_stress) { |
907 | lock_is_write_held = 0; | |
6da2ec56 KC |
908 | cxt.lwsa = kmalloc_array(cxt.nrealwriters_stress, |
909 | sizeof(*cxt.lwsa), | |
910 | GFP_KERNEL); | |
2ce77d16 DB |
911 | if (cxt.lwsa == NULL) { |
912 | VERBOSE_TOROUT_STRING("cxt.lwsa: Out of memory"); | |
913 | firsterr = -ENOMEM; | |
914 | goto unwind; | |
915 | } | |
0af3fe1e | 916 | |
2ce77d16 DB |
917 | for (i = 0; i < cxt.nrealwriters_stress; i++) { |
918 | cxt.lwsa[i].n_lock_fail = 0; | |
919 | cxt.lwsa[i].n_lock_acquired = 0; | |
920 | } | |
0af3fe1e PM |
921 | } |
922 | ||
630952c2 | 923 | if (cxt.cur_ops->readlock) { |
4f6332c1 | 924 | if (nreaders_stress >= 0) |
630952c2 | 925 | cxt.nrealreaders_stress = nreaders_stress; |
4f6332c1 DB |
926 | else { |
927 | /* | |
928 | * By default distribute evenly the number of | |
929 | * readers and writers. We still run the same number | |
930 | * of threads as the writer-only locks default. | |
931 | */ | |
932 | if (nwriters_stress < 0) /* user doesn't care */ | |
630952c2 DB |
933 | cxt.nrealwriters_stress = num_online_cpus(); |
934 | cxt.nrealreaders_stress = cxt.nrealwriters_stress; | |
4f6332c1 DB |
935 | } |
936 | ||
2ce77d16 DB |
937 | if (nreaders_stress) { |
938 | lock_is_read_held = 0; | |
6da2ec56 KC |
939 | cxt.lrsa = kmalloc_array(cxt.nrealreaders_stress, |
940 | sizeof(*cxt.lrsa), | |
941 | GFP_KERNEL); | |
2ce77d16 DB |
942 | if (cxt.lrsa == NULL) { |
943 | VERBOSE_TOROUT_STRING("cxt.lrsa: Out of memory"); | |
944 | firsterr = -ENOMEM; | |
945 | kfree(cxt.lwsa); | |
946 | cxt.lwsa = NULL; | |
947 | goto unwind; | |
948 | } | |
949 | ||
950 | for (i = 0; i < cxt.nrealreaders_stress; i++) { | |
951 | cxt.lrsa[i].n_lock_fail = 0; | |
952 | cxt.lrsa[i].n_lock_acquired = 0; | |
953 | } | |
4f6332c1 DB |
954 | } |
955 | } | |
c1c33b92 | 956 | |
630952c2 | 957 | lock_torture_print_module_parms(cxt.cur_ops, "Start of test"); |
4f6332c1 DB |
958 | |
959 | /* Prepare torture context. */ | |
0af3fe1e PM |
960 | if (onoff_interval > 0) { |
961 | firsterr = torture_onoff_init(onoff_holdoff * HZ, | |
3a6cb58f | 962 | onoff_interval * HZ, NULL); |
0af3fe1e PM |
963 | if (firsterr) |
964 | goto unwind; | |
965 | } | |
966 | if (shuffle_interval > 0) { | |
967 | firsterr = torture_shuffle_init(shuffle_interval); | |
968 | if (firsterr) | |
969 | goto unwind; | |
970 | } | |
971 | if (shutdown_secs > 0) { | |
972 | firsterr = torture_shutdown_init(shutdown_secs, | |
973 | lock_torture_cleanup); | |
974 | if (firsterr) | |
975 | goto unwind; | |
976 | } | |
977 | if (stutter > 0) { | |
ff3bf92d | 978 | firsterr = torture_stutter_init(stutter, stutter); |
0af3fe1e PM |
979 | if (firsterr) |
980 | goto unwind; | |
981 | } | |
982 | ||
2ce77d16 | 983 | if (nwriters_stress) { |
6396bb22 KC |
984 | writer_tasks = kcalloc(cxt.nrealwriters_stress, |
985 | sizeof(writer_tasks[0]), | |
2ce77d16 DB |
986 | GFP_KERNEL); |
987 | if (writer_tasks == NULL) { | |
988 | VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory"); | |
989 | firsterr = -ENOMEM; | |
990 | goto unwind; | |
991 | } | |
0af3fe1e | 992 | } |
4f6332c1 | 993 | |
630952c2 | 994 | if (cxt.cur_ops->readlock) { |
6396bb22 KC |
995 | reader_tasks = kcalloc(cxt.nrealreaders_stress, |
996 | sizeof(reader_tasks[0]), | |
4f6332c1 DB |
997 | GFP_KERNEL); |
998 | if (reader_tasks == NULL) { | |
999 | VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory"); | |
f4dbba59 YS |
1000 | kfree(writer_tasks); |
1001 | writer_tasks = NULL; | |
4f6332c1 DB |
1002 | firsterr = -ENOMEM; |
1003 | goto unwind; | |
1004 | } | |
1005 | } | |
1006 | ||
1007 | /* | |
1008 | * Create the kthreads and start torturing (oh, those poor little locks). | |
1009 | * | |
1010 | * TODO: Note that we interleave writers with readers, giving writers a | |
1011 | * slight advantage, by creating its kthread first. This can be modified | |
1012 | * for very specific needs, or even let the user choose the policy, if | |
1013 | * ever wanted. | |
1014 | */ | |
630952c2 DB |
1015 | for (i = 0, j = 0; i < cxt.nrealwriters_stress || |
1016 | j < cxt.nrealreaders_stress; i++, j++) { | |
1017 | if (i >= cxt.nrealwriters_stress) | |
4f6332c1 DB |
1018 | goto create_reader; |
1019 | ||
1020 | /* Create writer. */ | |
630952c2 | 1021 | firsterr = torture_create_kthread(lock_torture_writer, &cxt.lwsa[i], |
0af3fe1e PM |
1022 | writer_tasks[i]); |
1023 | if (firsterr) | |
1024 | goto unwind; | |
4f6332c1 DB |
1025 | |
1026 | create_reader: | |
630952c2 | 1027 | if (cxt.cur_ops->readlock == NULL || (j >= cxt.nrealreaders_stress)) |
4f6332c1 DB |
1028 | continue; |
1029 | /* Create reader. */ | |
630952c2 | 1030 | firsterr = torture_create_kthread(lock_torture_reader, &cxt.lrsa[j], |
4f6332c1 DB |
1031 | reader_tasks[j]); |
1032 | if (firsterr) | |
1033 | goto unwind; | |
0af3fe1e PM |
1034 | } |
1035 | if (stat_interval > 0) { | |
1036 | firsterr = torture_create_kthread(lock_torture_stats, NULL, | |
1037 | stats_task); | |
1038 | if (firsterr) | |
1039 | goto unwind; | |
1040 | } | |
1041 | torture_init_end(); | |
1042 | return 0; | |
1043 | ||
1044 | unwind: | |
1045 | torture_init_end(); | |
1046 | lock_torture_cleanup(); | |
1047 | return firsterr; | |
1048 | } | |
1049 | ||
1050 | module_init(lock_torture_init); | |
1051 | module_exit(lock_torture_cleanup); |