Commit | Line | Data |
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a241ec65 | 1 | /* |
29766f1e | 2 | * Read-Copy Update module-based torture test facility |
a241ec65 PM |
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, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
b772e1dd | 18 | * Copyright (C) IBM Corporation, 2005, 2006 |
a241ec65 PM |
19 | * |
20 | * Authors: Paul E. McKenney <paulmck@us.ibm.com> | |
b772e1dd | 21 | * Josh Triplett <josh@freedesktop.org> |
a241ec65 PM |
22 | * |
23 | * See also: Documentation/RCU/torture.txt | |
24 | */ | |
25 | #include <linux/types.h> | |
26 | #include <linux/kernel.h> | |
27 | #include <linux/init.h> | |
28 | #include <linux/module.h> | |
29 | #include <linux/kthread.h> | |
30 | #include <linux/err.h> | |
31 | #include <linux/spinlock.h> | |
32 | #include <linux/smp.h> | |
33 | #include <linux/rcupdate.h> | |
34 | #include <linux/interrupt.h> | |
35 | #include <linux/sched.h> | |
36 | #include <asm/atomic.h> | |
37 | #include <linux/bitops.h> | |
38 | #include <linux/module.h> | |
39 | #include <linux/completion.h> | |
40 | #include <linux/moduleparam.h> | |
41 | #include <linux/percpu.h> | |
42 | #include <linux/notifier.h> | |
a241ec65 PM |
43 | #include <linux/cpu.h> |
44 | #include <linux/random.h> | |
45 | #include <linux/delay.h> | |
46 | #include <linux/byteorder/swabb.h> | |
47 | #include <linux/stat.h> | |
b2896d2e | 48 | #include <linux/srcu.h> |
a241ec65 PM |
49 | |
50 | MODULE_LICENSE("GPL"); | |
b772e1dd JT |
51 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " |
52 | "Josh Triplett <josh@freedesktop.org>"); | |
a241ec65 | 53 | |
4802211c | 54 | static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ |
b772e1dd | 55 | static int nfakewriters = 4; /* # fake writer threads */ |
d84f5203 | 56 | static int stat_interval; /* Interval between stats, in seconds. */ |
a241ec65 | 57 | /* Defaults to "only at end of test". */ |
d84f5203 SV |
58 | static int verbose; /* Print more debug info. */ |
59 | static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ | |
60 | static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/ | |
20d2e428 | 61 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ |
a241ec65 | 62 | |
8d3b33f6 | 63 | module_param(nreaders, int, 0); |
a241ec65 | 64 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
b772e1dd JT |
65 | module_param(nfakewriters, int, 0); |
66 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); | |
8d3b33f6 | 67 | module_param(stat_interval, int, 0); |
a241ec65 | 68 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
8d3b33f6 | 69 | module_param(verbose, bool, 0); |
a241ec65 | 70 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
8d3b33f6 | 71 | module_param(test_no_idle_hz, bool, 0); |
d84f5203 | 72 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
8d3b33f6 | 73 | module_param(shuffle_interval, int, 0); |
d84f5203 | 74 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
72e9bb54 | 75 | module_param(torture_type, charp, 0); |
b2896d2e | 76 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
77 | |
78 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 79 | #define PRINTK_STRING(s) \ |
72e9bb54 | 80 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 81 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 82 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 83 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 84 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
85 | |
86 | static char printk_buf[4096]; | |
87 | ||
88 | static int nrealreaders; | |
89 | static struct task_struct *writer_task; | |
b772e1dd | 90 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
91 | static struct task_struct **reader_tasks; |
92 | static struct task_struct *stats_task; | |
d84f5203 | 93 | static struct task_struct *shuffler_task; |
a241ec65 PM |
94 | |
95 | #define RCU_TORTURE_PIPE_LEN 10 | |
96 | ||
97 | struct rcu_torture { | |
98 | struct rcu_head rtort_rcu; | |
99 | int rtort_pipe_count; | |
100 | struct list_head rtort_free; | |
996417d2 | 101 | int rtort_mbtest; |
a241ec65 PM |
102 | }; |
103 | ||
104 | static int fullstop = 0; /* stop generating callbacks at test end. */ | |
105 | static LIST_HEAD(rcu_torture_freelist); | |
106 | static struct rcu_torture *rcu_torture_current = NULL; | |
107 | static long rcu_torture_current_version = 0; | |
108 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; | |
109 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
110 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
111 | { 0 }; | |
112 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
113 | { 0 }; | |
114 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
115 | static atomic_t n_rcu_torture_alloc; |
116 | static atomic_t n_rcu_torture_alloc_fail; | |
117 | static atomic_t n_rcu_torture_free; | |
118 | static atomic_t n_rcu_torture_mberror; | |
119 | static atomic_t n_rcu_torture_error; | |
e3033736 | 120 | static struct list_head rcu_torture_removed; |
a241ec65 PM |
121 | |
122 | /* | |
123 | * Allocate an element from the rcu_tortures pool. | |
124 | */ | |
97a41e26 | 125 | static struct rcu_torture * |
a241ec65 PM |
126 | rcu_torture_alloc(void) |
127 | { | |
128 | struct list_head *p; | |
129 | ||
adac1665 | 130 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
131 | if (list_empty(&rcu_torture_freelist)) { |
132 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 133 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
134 | return NULL; |
135 | } | |
136 | atomic_inc(&n_rcu_torture_alloc); | |
137 | p = rcu_torture_freelist.next; | |
138 | list_del_init(p); | |
adac1665 | 139 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
140 | return container_of(p, struct rcu_torture, rtort_free); |
141 | } | |
142 | ||
143 | /* | |
144 | * Free an element to the rcu_tortures pool. | |
145 | */ | |
146 | static void | |
147 | rcu_torture_free(struct rcu_torture *p) | |
148 | { | |
149 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 150 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 151 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 152 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
153 | } |
154 | ||
a241ec65 PM |
155 | struct rcu_random_state { |
156 | unsigned long rrs_state; | |
75cfef32 | 157 | long rrs_count; |
a241ec65 PM |
158 | }; |
159 | ||
160 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
161 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
162 | #define RCU_RANDOM_REFRESH 10000 | |
163 | ||
164 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
165 | ||
166 | /* | |
167 | * Crude but fast random-number generator. Uses a linear congruential | |
168 | * generator, with occasional help from get_random_bytes(). | |
169 | */ | |
75cfef32 | 170 | static unsigned long |
a241ec65 PM |
171 | rcu_random(struct rcu_random_state *rrsp) |
172 | { | |
173 | long refresh; | |
174 | ||
175 | if (--rrsp->rrs_count < 0) { | |
176 | get_random_bytes(&refresh, sizeof(refresh)); | |
177 | rrsp->rrs_state += refresh; | |
178 | rrsp->rrs_count = RCU_RANDOM_REFRESH; | |
179 | } | |
180 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
181 | return swahw32(rrsp->rrs_state); | |
182 | } | |
183 | ||
72e9bb54 PM |
184 | /* |
185 | * Operations vector for selecting different types of tests. | |
186 | */ | |
187 | ||
188 | struct rcu_torture_ops { | |
189 | void (*init)(void); | |
190 | void (*cleanup)(void); | |
191 | int (*readlock)(void); | |
b2896d2e | 192 | void (*readdelay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
193 | void (*readunlock)(int idx); |
194 | int (*completed)(void); | |
195 | void (*deferredfree)(struct rcu_torture *p); | |
b772e1dd | 196 | void (*sync)(void); |
72e9bb54 PM |
197 | int (*stats)(char *page); |
198 | char *name; | |
199 | }; | |
200 | static struct rcu_torture_ops *cur_ops = NULL; | |
201 | ||
202 | /* | |
203 | * Definitions for rcu torture testing. | |
204 | */ | |
205 | ||
a49a4af7 | 206 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
207 | { |
208 | rcu_read_lock(); | |
209 | return 0; | |
210 | } | |
211 | ||
b2896d2e PM |
212 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
213 | { | |
214 | long delay; | |
215 | const long longdelay = 200; | |
216 | ||
217 | /* We want there to be long-running readers, but not all the time. */ | |
218 | ||
219 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay); | |
220 | if (!delay) | |
221 | udelay(longdelay); | |
222 | } | |
223 | ||
a49a4af7 | 224 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
225 | { |
226 | rcu_read_unlock(); | |
227 | } | |
228 | ||
229 | static int rcu_torture_completed(void) | |
230 | { | |
231 | return rcu_batches_completed(); | |
232 | } | |
233 | ||
234 | static void | |
235 | rcu_torture_cb(struct rcu_head *p) | |
236 | { | |
237 | int i; | |
238 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
239 | ||
240 | if (fullstop) { | |
241 | /* Test is ending, just drop callbacks on the floor. */ | |
242 | /* The next initialization will pick up the pieces. */ | |
243 | return; | |
244 | } | |
245 | i = rp->rtort_pipe_count; | |
246 | if (i > RCU_TORTURE_PIPE_LEN) | |
247 | i = RCU_TORTURE_PIPE_LEN; | |
248 | atomic_inc(&rcu_torture_wcount[i]); | |
249 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
250 | rp->rtort_mbtest = 0; | |
251 | rcu_torture_free(rp); | |
252 | } else | |
253 | cur_ops->deferredfree(rp); | |
254 | } | |
255 | ||
256 | static void rcu_torture_deferred_free(struct rcu_torture *p) | |
257 | { | |
258 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
259 | } | |
260 | ||
261 | static struct rcu_torture_ops rcu_ops = { | |
262 | .init = NULL, | |
263 | .cleanup = NULL, | |
264 | .readlock = rcu_torture_read_lock, | |
b2896d2e | 265 | .readdelay = rcu_read_delay, |
72e9bb54 PM |
266 | .readunlock = rcu_torture_read_unlock, |
267 | .completed = rcu_torture_completed, | |
268 | .deferredfree = rcu_torture_deferred_free, | |
b772e1dd | 269 | .sync = synchronize_rcu, |
72e9bb54 PM |
270 | .stats = NULL, |
271 | .name = "rcu" | |
272 | }; | |
273 | ||
e3033736 JT |
274 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) |
275 | { | |
276 | int i; | |
277 | struct rcu_torture *rp; | |
278 | struct rcu_torture *rp1; | |
279 | ||
280 | cur_ops->sync(); | |
281 | list_add(&p->rtort_free, &rcu_torture_removed); | |
282 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
283 | i = rp->rtort_pipe_count; | |
284 | if (i > RCU_TORTURE_PIPE_LEN) | |
285 | i = RCU_TORTURE_PIPE_LEN; | |
286 | atomic_inc(&rcu_torture_wcount[i]); | |
287 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
288 | rp->rtort_mbtest = 0; | |
289 | list_del(&rp->rtort_free); | |
290 | rcu_torture_free(rp); | |
291 | } | |
292 | } | |
293 | } | |
294 | ||
295 | static void rcu_sync_torture_init(void) | |
296 | { | |
297 | INIT_LIST_HEAD(&rcu_torture_removed); | |
298 | } | |
299 | ||
20d2e428 JT |
300 | static struct rcu_torture_ops rcu_sync_ops = { |
301 | .init = rcu_sync_torture_init, | |
302 | .cleanup = NULL, | |
303 | .readlock = rcu_torture_read_lock, | |
304 | .readdelay = rcu_read_delay, | |
305 | .readunlock = rcu_torture_read_unlock, | |
306 | .completed = rcu_torture_completed, | |
307 | .deferredfree = rcu_sync_torture_deferred_free, | |
308 | .sync = synchronize_rcu, | |
309 | .stats = NULL, | |
310 | .name = "rcu_sync" | |
311 | }; | |
312 | ||
c32e0660 PM |
313 | /* |
314 | * Definitions for rcu_bh torture testing. | |
315 | */ | |
316 | ||
a49a4af7 | 317 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
318 | { |
319 | rcu_read_lock_bh(); | |
320 | return 0; | |
321 | } | |
322 | ||
a49a4af7 | 323 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
324 | { |
325 | rcu_read_unlock_bh(); | |
326 | } | |
327 | ||
328 | static int rcu_bh_torture_completed(void) | |
329 | { | |
330 | return rcu_batches_completed_bh(); | |
331 | } | |
332 | ||
333 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
334 | { | |
335 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
336 | } | |
337 | ||
b772e1dd JT |
338 | struct rcu_bh_torture_synchronize { |
339 | struct rcu_head head; | |
340 | struct completion completion; | |
341 | }; | |
342 | ||
343 | static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head) | |
344 | { | |
345 | struct rcu_bh_torture_synchronize *rcu; | |
346 | ||
347 | rcu = container_of(head, struct rcu_bh_torture_synchronize, head); | |
348 | complete(&rcu->completion); | |
349 | } | |
350 | ||
351 | static void rcu_bh_torture_synchronize(void) | |
352 | { | |
353 | struct rcu_bh_torture_synchronize rcu; | |
354 | ||
355 | init_completion(&rcu.completion); | |
356 | call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb); | |
357 | wait_for_completion(&rcu.completion); | |
358 | } | |
359 | ||
c32e0660 PM |
360 | static struct rcu_torture_ops rcu_bh_ops = { |
361 | .init = NULL, | |
362 | .cleanup = NULL, | |
363 | .readlock = rcu_bh_torture_read_lock, | |
b2896d2e | 364 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ |
c32e0660 PM |
365 | .readunlock = rcu_bh_torture_read_unlock, |
366 | .completed = rcu_bh_torture_completed, | |
367 | .deferredfree = rcu_bh_torture_deferred_free, | |
b772e1dd | 368 | .sync = rcu_bh_torture_synchronize, |
c32e0660 PM |
369 | .stats = NULL, |
370 | .name = "rcu_bh" | |
371 | }; | |
372 | ||
11a14701 JT |
373 | static struct rcu_torture_ops rcu_bh_sync_ops = { |
374 | .init = rcu_sync_torture_init, | |
375 | .cleanup = NULL, | |
376 | .readlock = rcu_bh_torture_read_lock, | |
377 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ | |
378 | .readunlock = rcu_bh_torture_read_unlock, | |
379 | .completed = rcu_bh_torture_completed, | |
380 | .deferredfree = rcu_sync_torture_deferred_free, | |
381 | .sync = rcu_bh_torture_synchronize, | |
382 | .stats = NULL, | |
383 | .name = "rcu_bh_sync" | |
384 | }; | |
385 | ||
b2896d2e PM |
386 | /* |
387 | * Definitions for srcu torture testing. | |
388 | */ | |
389 | ||
390 | static struct srcu_struct srcu_ctl; | |
b2896d2e PM |
391 | |
392 | static void srcu_torture_init(void) | |
393 | { | |
394 | init_srcu_struct(&srcu_ctl); | |
e3033736 | 395 | rcu_sync_torture_init(); |
b2896d2e PM |
396 | } |
397 | ||
398 | static void srcu_torture_cleanup(void) | |
399 | { | |
400 | synchronize_srcu(&srcu_ctl); | |
401 | cleanup_srcu_struct(&srcu_ctl); | |
402 | } | |
403 | ||
012d3ca8 | 404 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
405 | { |
406 | return srcu_read_lock(&srcu_ctl); | |
407 | } | |
408 | ||
409 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
410 | { | |
411 | long delay; | |
412 | const long uspertick = 1000000 / HZ; | |
413 | const long longdelay = 10; | |
414 | ||
415 | /* We want there to be long-running readers, but not all the time. */ | |
416 | ||
417 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
418 | if (!delay) | |
419 | schedule_timeout_interruptible(longdelay); | |
420 | } | |
421 | ||
012d3ca8 | 422 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
423 | { |
424 | srcu_read_unlock(&srcu_ctl, idx); | |
425 | } | |
426 | ||
427 | static int srcu_torture_completed(void) | |
428 | { | |
429 | return srcu_batches_completed(&srcu_ctl); | |
430 | } | |
431 | ||
b772e1dd JT |
432 | static void srcu_torture_synchronize(void) |
433 | { | |
434 | synchronize_srcu(&srcu_ctl); | |
435 | } | |
436 | ||
b2896d2e PM |
437 | static int srcu_torture_stats(char *page) |
438 | { | |
439 | int cnt = 0; | |
440 | int cpu; | |
441 | int idx = srcu_ctl.completed & 0x1; | |
442 | ||
443 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
444 | torture_type, TORTURE_FLAG, idx); | |
445 | for_each_possible_cpu(cpu) { | |
446 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
447 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
448 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
449 | } | |
450 | cnt += sprintf(&page[cnt], "\n"); | |
451 | return cnt; | |
452 | } | |
453 | ||
454 | static struct rcu_torture_ops srcu_ops = { | |
455 | .init = srcu_torture_init, | |
456 | .cleanup = srcu_torture_cleanup, | |
457 | .readlock = srcu_torture_read_lock, | |
458 | .readdelay = srcu_read_delay, | |
459 | .readunlock = srcu_torture_read_unlock, | |
460 | .completed = srcu_torture_completed, | |
e3033736 | 461 | .deferredfree = rcu_sync_torture_deferred_free, |
b772e1dd | 462 | .sync = srcu_torture_synchronize, |
b2896d2e PM |
463 | .stats = srcu_torture_stats, |
464 | .name = "srcu" | |
465 | }; | |
466 | ||
4b6c2cca JT |
467 | /* |
468 | * Definitions for sched torture testing. | |
469 | */ | |
470 | ||
471 | static int sched_torture_read_lock(void) | |
472 | { | |
473 | preempt_disable(); | |
474 | return 0; | |
475 | } | |
476 | ||
477 | static void sched_torture_read_unlock(int idx) | |
478 | { | |
479 | preempt_enable(); | |
480 | } | |
481 | ||
482 | static int sched_torture_completed(void) | |
483 | { | |
484 | return 0; | |
485 | } | |
486 | ||
487 | static void sched_torture_synchronize(void) | |
488 | { | |
489 | synchronize_sched(); | |
490 | } | |
491 | ||
492 | static struct rcu_torture_ops sched_ops = { | |
493 | .init = rcu_sync_torture_init, | |
494 | .cleanup = NULL, | |
495 | .readlock = sched_torture_read_lock, | |
496 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ | |
497 | .readunlock = sched_torture_read_unlock, | |
498 | .completed = sched_torture_completed, | |
499 | .deferredfree = rcu_sync_torture_deferred_free, | |
500 | .sync = sched_torture_synchronize, | |
501 | .stats = NULL, | |
502 | .name = "sched" | |
503 | }; | |
504 | ||
72e9bb54 | 505 | static struct rcu_torture_ops *torture_ops[] = |
11a14701 | 506 | { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops, &srcu_ops, |
4b6c2cca | 507 | &sched_ops, NULL }; |
72e9bb54 | 508 | |
a241ec65 PM |
509 | /* |
510 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
511 | * for that pointed to by rcu_torture_current, freeing the old structure | |
512 | * after a series of grace periods (the "pipeline"). | |
513 | */ | |
514 | static int | |
515 | rcu_torture_writer(void *arg) | |
516 | { | |
517 | int i; | |
518 | long oldbatch = rcu_batches_completed(); | |
519 | struct rcu_torture *rp; | |
520 | struct rcu_torture *old_rp; | |
521 | static DEFINE_RCU_RANDOM(rand); | |
522 | ||
523 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 | 524 | set_user_nice(current, 19); |
e4e6bdbb | 525 | current->flags |= PF_NOFREEZE; |
dbdf65b1 | 526 | |
a241ec65 PM |
527 | do { |
528 | schedule_timeout_uninterruptible(1); | |
a241ec65 PM |
529 | if ((rp = rcu_torture_alloc()) == NULL) |
530 | continue; | |
531 | rp->rtort_pipe_count = 0; | |
532 | udelay(rcu_random(&rand) & 0x3ff); | |
533 | old_rp = rcu_torture_current; | |
996417d2 | 534 | rp->rtort_mbtest = 1; |
a241ec65 PM |
535 | rcu_assign_pointer(rcu_torture_current, rp); |
536 | smp_wmb(); | |
537 | if (old_rp != NULL) { | |
538 | i = old_rp->rtort_pipe_count; | |
539 | if (i > RCU_TORTURE_PIPE_LEN) | |
540 | i = RCU_TORTURE_PIPE_LEN; | |
541 | atomic_inc(&rcu_torture_wcount[i]); | |
542 | old_rp->rtort_pipe_count++; | |
72e9bb54 | 543 | cur_ops->deferredfree(old_rp); |
a241ec65 PM |
544 | } |
545 | rcu_torture_current_version++; | |
72e9bb54 | 546 | oldbatch = cur_ops->completed(); |
a241ec65 PM |
547 | } while (!kthread_should_stop() && !fullstop); |
548 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); | |
549 | while (!kthread_should_stop()) | |
550 | schedule_timeout_uninterruptible(1); | |
551 | return 0; | |
552 | } | |
553 | ||
b772e1dd JT |
554 | /* |
555 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
556 | * delay between calls. | |
557 | */ | |
558 | static int | |
559 | rcu_torture_fakewriter(void *arg) | |
560 | { | |
561 | DEFINE_RCU_RANDOM(rand); | |
562 | ||
563 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
564 | set_user_nice(current, 19); | |
e4e6bdbb | 565 | current->flags |= PF_NOFREEZE; |
b772e1dd JT |
566 | |
567 | do { | |
568 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
569 | udelay(rcu_random(&rand) & 0x3ff); | |
570 | cur_ops->sync(); | |
571 | } while (!kthread_should_stop() && !fullstop); | |
572 | ||
573 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
574 | while (!kthread_should_stop()) | |
575 | schedule_timeout_uninterruptible(1); | |
576 | return 0; | |
577 | } | |
578 | ||
a241ec65 PM |
579 | /* |
580 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
581 | * incrementing the corresponding element of the pipeline array. The | |
582 | * counter in the element should never be greater than 1, otherwise, the | |
583 | * RCU implementation is broken. | |
584 | */ | |
585 | static int | |
586 | rcu_torture_reader(void *arg) | |
587 | { | |
588 | int completed; | |
72e9bb54 | 589 | int idx; |
a241ec65 PM |
590 | DEFINE_RCU_RANDOM(rand); |
591 | struct rcu_torture *p; | |
592 | int pipe_count; | |
593 | ||
594 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 595 | set_user_nice(current, 19); |
e4e6bdbb | 596 | current->flags |= PF_NOFREEZE; |
dbdf65b1 | 597 | |
a241ec65 | 598 | do { |
72e9bb54 PM |
599 | idx = cur_ops->readlock(); |
600 | completed = cur_ops->completed(); | |
a241ec65 PM |
601 | p = rcu_dereference(rcu_torture_current); |
602 | if (p == NULL) { | |
603 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 604 | cur_ops->readunlock(idx); |
a241ec65 PM |
605 | schedule_timeout_interruptible(HZ); |
606 | continue; | |
607 | } | |
996417d2 PM |
608 | if (p->rtort_mbtest == 0) |
609 | atomic_inc(&n_rcu_torture_mberror); | |
b2896d2e | 610 | cur_ops->readdelay(&rand); |
a241ec65 PM |
611 | preempt_disable(); |
612 | pipe_count = p->rtort_pipe_count; | |
613 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
614 | /* Should not happen, but... */ | |
615 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
616 | } | |
617 | ++__get_cpu_var(rcu_torture_count)[pipe_count]; | |
72e9bb54 | 618 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
619 | if (completed > RCU_TORTURE_PIPE_LEN) { |
620 | /* Should not happen, but... */ | |
621 | completed = RCU_TORTURE_PIPE_LEN; | |
622 | } | |
623 | ++__get_cpu_var(rcu_torture_batch)[completed]; | |
624 | preempt_enable(); | |
72e9bb54 | 625 | cur_ops->readunlock(idx); |
a241ec65 PM |
626 | schedule(); |
627 | } while (!kthread_should_stop() && !fullstop); | |
628 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); | |
629 | while (!kthread_should_stop()) | |
630 | schedule_timeout_uninterruptible(1); | |
631 | return 0; | |
632 | } | |
633 | ||
634 | /* | |
635 | * Create an RCU-torture statistics message in the specified buffer. | |
636 | */ | |
637 | static int | |
638 | rcu_torture_printk(char *page) | |
639 | { | |
640 | int cnt = 0; | |
641 | int cpu; | |
642 | int i; | |
643 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
644 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
645 | ||
0a945022 | 646 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
647 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
648 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
649 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
650 | } | |
651 | } | |
652 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
653 | if (pipesummary[i] != 0) | |
654 | break; | |
655 | } | |
72e9bb54 | 656 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 657 | cnt += sprintf(&page[cnt], |
996417d2 PM |
658 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
659 | "rtmbe: %d", | |
a241ec65 PM |
660 | rcu_torture_current, |
661 | rcu_torture_current_version, | |
662 | list_empty(&rcu_torture_freelist), | |
663 | atomic_read(&n_rcu_torture_alloc), | |
664 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 PM |
665 | atomic_read(&n_rcu_torture_free), |
666 | atomic_read(&n_rcu_torture_mberror)); | |
667 | if (atomic_read(&n_rcu_torture_mberror) != 0) | |
668 | cnt += sprintf(&page[cnt], " !!!"); | |
72e9bb54 | 669 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 670 | if (i > 1) { |
a241ec65 | 671 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 PM |
672 | atomic_inc(&n_rcu_torture_error); |
673 | } | |
a241ec65 PM |
674 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
675 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
676 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 677 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 678 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 679 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 680 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 681 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
682 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
683 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
684 | cnt += sprintf(&page[cnt], " %d", | |
685 | atomic_read(&rcu_torture_wcount[i])); | |
686 | } | |
687 | cnt += sprintf(&page[cnt], "\n"); | |
72e9bb54 PM |
688 | if (cur_ops->stats != NULL) |
689 | cnt += cur_ops->stats(&page[cnt]); | |
a241ec65 PM |
690 | return cnt; |
691 | } | |
692 | ||
693 | /* | |
694 | * Print torture statistics. Caller must ensure that there is only | |
695 | * one call to this function at a given time!!! This is normally | |
696 | * accomplished by relying on the module system to only have one copy | |
697 | * of the module loaded, and then by giving the rcu_torture_stats | |
698 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
699 | * thread is not running). | |
700 | */ | |
701 | static void | |
702 | rcu_torture_stats_print(void) | |
703 | { | |
704 | int cnt; | |
705 | ||
706 | cnt = rcu_torture_printk(printk_buf); | |
707 | printk(KERN_ALERT "%s", printk_buf); | |
708 | } | |
709 | ||
710 | /* | |
711 | * Periodically prints torture statistics, if periodic statistics printing | |
712 | * was specified via the stat_interval module parameter. | |
713 | * | |
714 | * No need to worry about fullstop here, since this one doesn't reference | |
715 | * volatile state or register callbacks. | |
716 | */ | |
717 | static int | |
718 | rcu_torture_stats(void *arg) | |
719 | { | |
720 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
721 | do { | |
722 | schedule_timeout_interruptible(stat_interval * HZ); | |
723 | rcu_torture_stats_print(); | |
724 | } while (!kthread_should_stop()); | |
725 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); | |
726 | return 0; | |
727 | } | |
728 | ||
d84f5203 SV |
729 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
730 | ||
731 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
732 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
733 | */ | |
b2896d2e | 734 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 SV |
735 | { |
736 | cpumask_t tmp_mask = CPU_MASK_ALL; | |
737 | int i; | |
738 | ||
739 | lock_cpu_hotplug(); | |
740 | ||
741 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
742 | if (num_online_cpus() == 1) { | |
743 | unlock_cpu_hotplug(); | |
744 | return; | |
745 | } | |
746 | ||
747 | if (rcu_idle_cpu != -1) | |
748 | cpu_clear(rcu_idle_cpu, tmp_mask); | |
749 | ||
750 | set_cpus_allowed(current, tmp_mask); | |
751 | ||
752 | if (reader_tasks != NULL) { | |
753 | for (i = 0; i < nrealreaders; i++) | |
754 | if (reader_tasks[i]) | |
755 | set_cpus_allowed(reader_tasks[i], tmp_mask); | |
756 | } | |
757 | ||
b772e1dd JT |
758 | if (fakewriter_tasks != NULL) { |
759 | for (i = 0; i < nfakewriters; i++) | |
760 | if (fakewriter_tasks[i]) | |
761 | set_cpus_allowed(fakewriter_tasks[i], tmp_mask); | |
762 | } | |
763 | ||
d84f5203 SV |
764 | if (writer_task) |
765 | set_cpus_allowed(writer_task, tmp_mask); | |
766 | ||
767 | if (stats_task) | |
768 | set_cpus_allowed(stats_task, tmp_mask); | |
769 | ||
770 | if (rcu_idle_cpu == -1) | |
771 | rcu_idle_cpu = num_online_cpus() - 1; | |
772 | else | |
773 | rcu_idle_cpu--; | |
774 | ||
775 | unlock_cpu_hotplug(); | |
776 | } | |
777 | ||
778 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
779 | * system to become idle at a time and cut off its timer ticks. This is meant | |
780 | * to test the support for such tickless idle CPU in RCU. | |
781 | */ | |
782 | static int | |
783 | rcu_torture_shuffle(void *arg) | |
784 | { | |
785 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
786 | do { | |
787 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
788 | rcu_torture_shuffle_tasks(); | |
789 | } while (!kthread_should_stop()); | |
790 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); | |
791 | return 0; | |
792 | } | |
793 | ||
95c38322 PM |
794 | static inline void |
795 | rcu_torture_print_module_parms(char *tag) | |
796 | { | |
b772e1dd JT |
797 | printk(KERN_ALERT "%s" TORTURE_FLAG |
798 | "--- %s: nreaders=%d nfakewriters=%d " | |
95c38322 PM |
799 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
800 | "shuffle_interval = %d\n", | |
b772e1dd JT |
801 | torture_type, tag, nrealreaders, nfakewriters, |
802 | stat_interval, verbose, test_no_idle_hz, shuffle_interval); | |
95c38322 PM |
803 | } |
804 | ||
a241ec65 PM |
805 | static void |
806 | rcu_torture_cleanup(void) | |
807 | { | |
808 | int i; | |
809 | ||
810 | fullstop = 1; | |
d84f5203 SV |
811 | if (shuffler_task != NULL) { |
812 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); | |
813 | kthread_stop(shuffler_task); | |
814 | } | |
815 | shuffler_task = NULL; | |
816 | ||
a241ec65 PM |
817 | if (writer_task != NULL) { |
818 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); | |
819 | kthread_stop(writer_task); | |
820 | } | |
821 | writer_task = NULL; | |
822 | ||
823 | if (reader_tasks != NULL) { | |
824 | for (i = 0; i < nrealreaders; i++) { | |
825 | if (reader_tasks[i] != NULL) { | |
826 | VERBOSE_PRINTK_STRING( | |
827 | "Stopping rcu_torture_reader task"); | |
828 | kthread_stop(reader_tasks[i]); | |
829 | } | |
830 | reader_tasks[i] = NULL; | |
831 | } | |
832 | kfree(reader_tasks); | |
833 | reader_tasks = NULL; | |
834 | } | |
835 | rcu_torture_current = NULL; | |
836 | ||
b772e1dd JT |
837 | if (fakewriter_tasks != NULL) { |
838 | for (i = 0; i < nfakewriters; i++) { | |
839 | if (fakewriter_tasks[i] != NULL) { | |
840 | VERBOSE_PRINTK_STRING( | |
841 | "Stopping rcu_torture_fakewriter task"); | |
842 | kthread_stop(fakewriter_tasks[i]); | |
843 | } | |
844 | fakewriter_tasks[i] = NULL; | |
845 | } | |
846 | kfree(fakewriter_tasks); | |
847 | fakewriter_tasks = NULL; | |
848 | } | |
849 | ||
a241ec65 PM |
850 | if (stats_task != NULL) { |
851 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); | |
852 | kthread_stop(stats_task); | |
853 | } | |
854 | stats_task = NULL; | |
855 | ||
856 | /* Wait for all RCU callbacks to fire. */ | |
89d46b87 | 857 | rcu_barrier(); |
a241ec65 | 858 | |
a241ec65 | 859 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 PM |
860 | |
861 | if (cur_ops->cleanup != NULL) | |
862 | cur_ops->cleanup(); | |
95c38322 PM |
863 | if (atomic_read(&n_rcu_torture_error)) |
864 | rcu_torture_print_module_parms("End of test: FAILURE"); | |
865 | else | |
866 | rcu_torture_print_module_parms("End of test: SUCCESS"); | |
a241ec65 PM |
867 | } |
868 | ||
869 | static int | |
870 | rcu_torture_init(void) | |
871 | { | |
872 | int i; | |
873 | int cpu; | |
874 | int firsterr = 0; | |
875 | ||
876 | /* Process args and tell the world that the torturer is on the job. */ | |
877 | ||
72e9bb54 PM |
878 | for (i = 0; cur_ops = torture_ops[i], cur_ops != NULL; i++) { |
879 | cur_ops = torture_ops[i]; | |
880 | if (strcmp(torture_type, cur_ops->name) == 0) { | |
881 | break; | |
882 | } | |
883 | } | |
884 | if (cur_ops == NULL) { | |
885 | printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", | |
886 | torture_type); | |
887 | return (-EINVAL); | |
888 | } | |
889 | if (cur_ops->init != NULL) | |
890 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ | |
891 | ||
a241ec65 PM |
892 | if (nreaders >= 0) |
893 | nrealreaders = nreaders; | |
894 | else | |
895 | nrealreaders = 2 * num_online_cpus(); | |
95c38322 | 896 | rcu_torture_print_module_parms("Start of test"); |
a241ec65 PM |
897 | fullstop = 0; |
898 | ||
899 | /* Set up the freelist. */ | |
900 | ||
901 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
902 | for (i = 0; i < sizeof(rcu_tortures) / sizeof(rcu_tortures[0]); i++) { | |
996417d2 | 903 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
904 | list_add_tail(&rcu_tortures[i].rtort_free, |
905 | &rcu_torture_freelist); | |
906 | } | |
907 | ||
908 | /* Initialize the statistics so that each run gets its own numbers. */ | |
909 | ||
910 | rcu_torture_current = NULL; | |
911 | rcu_torture_current_version = 0; | |
912 | atomic_set(&n_rcu_torture_alloc, 0); | |
913 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
914 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
915 | atomic_set(&n_rcu_torture_mberror, 0); |
916 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
917 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
918 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 919 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
920 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
921 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
922 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
923 | } | |
924 | } | |
925 | ||
926 | /* Start up the kthreads. */ | |
927 | ||
928 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
929 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
930 | "rcu_torture_writer"); | |
931 | if (IS_ERR(writer_task)) { | |
932 | firsterr = PTR_ERR(writer_task); | |
933 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
934 | writer_task = NULL; | |
935 | goto unwind; | |
936 | } | |
b772e1dd JT |
937 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
938 | GFP_KERNEL); | |
939 | if (fakewriter_tasks == NULL) { | |
940 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
941 | firsterr = -ENOMEM; | |
942 | goto unwind; | |
943 | } | |
944 | for (i = 0; i < nfakewriters; i++) { | |
945 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
946 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
947 | "rcu_torture_fakewriter"); | |
948 | if (IS_ERR(fakewriter_tasks[i])) { | |
949 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
950 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
951 | fakewriter_tasks[i] = NULL; | |
952 | goto unwind; | |
953 | } | |
954 | } | |
2860aaba | 955 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
956 | GFP_KERNEL); |
957 | if (reader_tasks == NULL) { | |
958 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
959 | firsterr = -ENOMEM; | |
960 | goto unwind; | |
961 | } | |
962 | for (i = 0; i < nrealreaders; i++) { | |
963 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
964 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
965 | "rcu_torture_reader"); | |
966 | if (IS_ERR(reader_tasks[i])) { | |
967 | firsterr = PTR_ERR(reader_tasks[i]); | |
968 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
969 | reader_tasks[i] = NULL; | |
970 | goto unwind; | |
971 | } | |
972 | } | |
973 | if (stat_interval > 0) { | |
974 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
975 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
976 | "rcu_torture_stats"); | |
977 | if (IS_ERR(stats_task)) { | |
978 | firsterr = PTR_ERR(stats_task); | |
979 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
980 | stats_task = NULL; | |
981 | goto unwind; | |
982 | } | |
983 | } | |
d84f5203 SV |
984 | if (test_no_idle_hz) { |
985 | rcu_idle_cpu = num_online_cpus() - 1; | |
986 | /* Create the shuffler thread */ | |
987 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
988 | "rcu_torture_shuffle"); | |
989 | if (IS_ERR(shuffler_task)) { | |
990 | firsterr = PTR_ERR(shuffler_task); | |
991 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
992 | shuffler_task = NULL; | |
993 | goto unwind; | |
994 | } | |
995 | } | |
a241ec65 PM |
996 | return 0; |
997 | ||
998 | unwind: | |
999 | rcu_torture_cleanup(); | |
1000 | return firsterr; | |
1001 | } | |
1002 | ||
1003 | module_init(rcu_torture_init); | |
1004 | module_exit(rcu_torture_cleanup); |