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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> | |
83144186 | 43 | #include <linux/freezer.h> |
a241ec65 PM |
44 | #include <linux/cpu.h> |
45 | #include <linux/random.h> | |
46 | #include <linux/delay.h> | |
47 | #include <linux/byteorder/swabb.h> | |
48 | #include <linux/stat.h> | |
b2896d2e | 49 | #include <linux/srcu.h> |
a241ec65 PM |
50 | |
51 | MODULE_LICENSE("GPL"); | |
b772e1dd JT |
52 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " |
53 | "Josh Triplett <josh@freedesktop.org>"); | |
a241ec65 | 54 | |
4802211c | 55 | static int nreaders = -1; /* # reader threads, defaults to 2*ncpus */ |
b772e1dd | 56 | static int nfakewriters = 4; /* # fake writer threads */ |
d84f5203 | 57 | static int stat_interval; /* Interval between stats, in seconds. */ |
a241ec65 | 58 | /* Defaults to "only at end of test". */ |
d84f5203 SV |
59 | static int verbose; /* Print more debug info. */ |
60 | static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */ | |
61 | static int shuffle_interval = 5; /* Interval between shuffles (in sec)*/ | |
20d2e428 | 62 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ |
a241ec65 | 63 | |
d6ad6711 | 64 | module_param(nreaders, int, 0444); |
a241ec65 | 65 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
d6ad6711 | 66 | module_param(nfakewriters, int, 0444); |
b772e1dd | 67 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); |
d6ad6711 | 68 | module_param(stat_interval, int, 0444); |
a241ec65 | 69 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
d6ad6711 | 70 | module_param(verbose, bool, 0444); |
a241ec65 | 71 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
d6ad6711 | 72 | module_param(test_no_idle_hz, bool, 0444); |
d84f5203 | 73 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
d6ad6711 | 74 | module_param(shuffle_interval, int, 0444); |
d84f5203 | 75 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
d6ad6711 | 76 | module_param(torture_type, charp, 0444); |
b2896d2e | 77 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
78 | |
79 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 80 | #define PRINTK_STRING(s) \ |
72e9bb54 | 81 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 82 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 83 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 84 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 85 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
86 | |
87 | static char printk_buf[4096]; | |
88 | ||
89 | static int nrealreaders; | |
90 | static struct task_struct *writer_task; | |
b772e1dd | 91 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
92 | static struct task_struct **reader_tasks; |
93 | static struct task_struct *stats_task; | |
d84f5203 | 94 | static struct task_struct *shuffler_task; |
a241ec65 PM |
95 | |
96 | #define RCU_TORTURE_PIPE_LEN 10 | |
97 | ||
98 | struct rcu_torture { | |
99 | struct rcu_head rtort_rcu; | |
100 | int rtort_pipe_count; | |
101 | struct list_head rtort_free; | |
996417d2 | 102 | int rtort_mbtest; |
a241ec65 PM |
103 | }; |
104 | ||
105 | static int fullstop = 0; /* stop generating callbacks at test end. */ | |
106 | static LIST_HEAD(rcu_torture_freelist); | |
107 | static struct rcu_torture *rcu_torture_current = NULL; | |
108 | static long rcu_torture_current_version = 0; | |
109 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; | |
110 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
111 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
112 | { 0 }; | |
113 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
114 | { 0 }; | |
115 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
116 | static atomic_t n_rcu_torture_alloc; |
117 | static atomic_t n_rcu_torture_alloc_fail; | |
118 | static atomic_t n_rcu_torture_free; | |
119 | static atomic_t n_rcu_torture_mberror; | |
120 | static atomic_t n_rcu_torture_error; | |
e3033736 | 121 | static struct list_head rcu_torture_removed; |
a241ec65 PM |
122 | |
123 | /* | |
124 | * Allocate an element from the rcu_tortures pool. | |
125 | */ | |
97a41e26 | 126 | static struct rcu_torture * |
a241ec65 PM |
127 | rcu_torture_alloc(void) |
128 | { | |
129 | struct list_head *p; | |
130 | ||
adac1665 | 131 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
132 | if (list_empty(&rcu_torture_freelist)) { |
133 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 134 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
135 | return NULL; |
136 | } | |
137 | atomic_inc(&n_rcu_torture_alloc); | |
138 | p = rcu_torture_freelist.next; | |
139 | list_del_init(p); | |
adac1665 | 140 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
141 | return container_of(p, struct rcu_torture, rtort_free); |
142 | } | |
143 | ||
144 | /* | |
145 | * Free an element to the rcu_tortures pool. | |
146 | */ | |
147 | static void | |
148 | rcu_torture_free(struct rcu_torture *p) | |
149 | { | |
150 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 151 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 152 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 153 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
154 | } |
155 | ||
a241ec65 PM |
156 | struct rcu_random_state { |
157 | unsigned long rrs_state; | |
75cfef32 | 158 | long rrs_count; |
a241ec65 PM |
159 | }; |
160 | ||
161 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
162 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
163 | #define RCU_RANDOM_REFRESH 10000 | |
164 | ||
165 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
166 | ||
167 | /* | |
168 | * Crude but fast random-number generator. Uses a linear congruential | |
169 | * generator, with occasional help from get_random_bytes(). | |
170 | */ | |
75cfef32 | 171 | static unsigned long |
a241ec65 PM |
172 | rcu_random(struct rcu_random_state *rrsp) |
173 | { | |
174 | long refresh; | |
175 | ||
176 | if (--rrsp->rrs_count < 0) { | |
177 | get_random_bytes(&refresh, sizeof(refresh)); | |
178 | rrsp->rrs_state += refresh; | |
179 | rrsp->rrs_count = RCU_RANDOM_REFRESH; | |
180 | } | |
181 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
182 | return swahw32(rrsp->rrs_state); | |
183 | } | |
184 | ||
72e9bb54 PM |
185 | /* |
186 | * Operations vector for selecting different types of tests. | |
187 | */ | |
188 | ||
189 | struct rcu_torture_ops { | |
190 | void (*init)(void); | |
191 | void (*cleanup)(void); | |
192 | int (*readlock)(void); | |
b2896d2e | 193 | void (*readdelay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
194 | void (*readunlock)(int idx); |
195 | int (*completed)(void); | |
196 | void (*deferredfree)(struct rcu_torture *p); | |
b772e1dd | 197 | void (*sync)(void); |
72e9bb54 PM |
198 | int (*stats)(char *page); |
199 | char *name; | |
200 | }; | |
201 | static struct rcu_torture_ops *cur_ops = NULL; | |
202 | ||
203 | /* | |
204 | * Definitions for rcu torture testing. | |
205 | */ | |
206 | ||
a49a4af7 | 207 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
208 | { |
209 | rcu_read_lock(); | |
210 | return 0; | |
211 | } | |
212 | ||
b2896d2e PM |
213 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
214 | { | |
215 | long delay; | |
216 | const long longdelay = 200; | |
217 | ||
218 | /* We want there to be long-running readers, but not all the time. */ | |
219 | ||
220 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay); | |
221 | if (!delay) | |
222 | udelay(longdelay); | |
223 | } | |
224 | ||
a49a4af7 | 225 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
226 | { |
227 | rcu_read_unlock(); | |
228 | } | |
229 | ||
230 | static int rcu_torture_completed(void) | |
231 | { | |
232 | return rcu_batches_completed(); | |
233 | } | |
234 | ||
235 | static void | |
236 | rcu_torture_cb(struct rcu_head *p) | |
237 | { | |
238 | int i; | |
239 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
240 | ||
241 | if (fullstop) { | |
242 | /* Test is ending, just drop callbacks on the floor. */ | |
243 | /* The next initialization will pick up the pieces. */ | |
244 | return; | |
245 | } | |
246 | i = rp->rtort_pipe_count; | |
247 | if (i > RCU_TORTURE_PIPE_LEN) | |
248 | i = RCU_TORTURE_PIPE_LEN; | |
249 | atomic_inc(&rcu_torture_wcount[i]); | |
250 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
251 | rp->rtort_mbtest = 0; | |
252 | rcu_torture_free(rp); | |
253 | } else | |
254 | cur_ops->deferredfree(rp); | |
255 | } | |
256 | ||
257 | static void rcu_torture_deferred_free(struct rcu_torture *p) | |
258 | { | |
259 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
260 | } | |
261 | ||
262 | static struct rcu_torture_ops rcu_ops = { | |
263 | .init = NULL, | |
264 | .cleanup = NULL, | |
265 | .readlock = rcu_torture_read_lock, | |
b2896d2e | 266 | .readdelay = rcu_read_delay, |
72e9bb54 PM |
267 | .readunlock = rcu_torture_read_unlock, |
268 | .completed = rcu_torture_completed, | |
269 | .deferredfree = rcu_torture_deferred_free, | |
b772e1dd | 270 | .sync = synchronize_rcu, |
72e9bb54 PM |
271 | .stats = NULL, |
272 | .name = "rcu" | |
273 | }; | |
274 | ||
e3033736 JT |
275 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) |
276 | { | |
277 | int i; | |
278 | struct rcu_torture *rp; | |
279 | struct rcu_torture *rp1; | |
280 | ||
281 | cur_ops->sync(); | |
282 | list_add(&p->rtort_free, &rcu_torture_removed); | |
283 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
284 | i = rp->rtort_pipe_count; | |
285 | if (i > RCU_TORTURE_PIPE_LEN) | |
286 | i = RCU_TORTURE_PIPE_LEN; | |
287 | atomic_inc(&rcu_torture_wcount[i]); | |
288 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
289 | rp->rtort_mbtest = 0; | |
290 | list_del(&rp->rtort_free); | |
291 | rcu_torture_free(rp); | |
292 | } | |
293 | } | |
294 | } | |
295 | ||
296 | static void rcu_sync_torture_init(void) | |
297 | { | |
298 | INIT_LIST_HEAD(&rcu_torture_removed); | |
299 | } | |
300 | ||
20d2e428 JT |
301 | static struct rcu_torture_ops rcu_sync_ops = { |
302 | .init = rcu_sync_torture_init, | |
303 | .cleanup = NULL, | |
304 | .readlock = rcu_torture_read_lock, | |
305 | .readdelay = rcu_read_delay, | |
306 | .readunlock = rcu_torture_read_unlock, | |
307 | .completed = rcu_torture_completed, | |
308 | .deferredfree = rcu_sync_torture_deferred_free, | |
309 | .sync = synchronize_rcu, | |
310 | .stats = NULL, | |
311 | .name = "rcu_sync" | |
312 | }; | |
313 | ||
c32e0660 PM |
314 | /* |
315 | * Definitions for rcu_bh torture testing. | |
316 | */ | |
317 | ||
a49a4af7 | 318 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
319 | { |
320 | rcu_read_lock_bh(); | |
321 | return 0; | |
322 | } | |
323 | ||
a49a4af7 | 324 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
325 | { |
326 | rcu_read_unlock_bh(); | |
327 | } | |
328 | ||
329 | static int rcu_bh_torture_completed(void) | |
330 | { | |
331 | return rcu_batches_completed_bh(); | |
332 | } | |
333 | ||
334 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
335 | { | |
336 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
337 | } | |
338 | ||
b772e1dd JT |
339 | struct rcu_bh_torture_synchronize { |
340 | struct rcu_head head; | |
341 | struct completion completion; | |
342 | }; | |
343 | ||
344 | static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head) | |
345 | { | |
346 | struct rcu_bh_torture_synchronize *rcu; | |
347 | ||
348 | rcu = container_of(head, struct rcu_bh_torture_synchronize, head); | |
349 | complete(&rcu->completion); | |
350 | } | |
351 | ||
352 | static void rcu_bh_torture_synchronize(void) | |
353 | { | |
354 | struct rcu_bh_torture_synchronize rcu; | |
355 | ||
356 | init_completion(&rcu.completion); | |
357 | call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb); | |
358 | wait_for_completion(&rcu.completion); | |
359 | } | |
360 | ||
c32e0660 PM |
361 | static struct rcu_torture_ops rcu_bh_ops = { |
362 | .init = NULL, | |
363 | .cleanup = NULL, | |
364 | .readlock = rcu_bh_torture_read_lock, | |
b2896d2e | 365 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ |
c32e0660 PM |
366 | .readunlock = rcu_bh_torture_read_unlock, |
367 | .completed = rcu_bh_torture_completed, | |
368 | .deferredfree = rcu_bh_torture_deferred_free, | |
b772e1dd | 369 | .sync = rcu_bh_torture_synchronize, |
c32e0660 PM |
370 | .stats = NULL, |
371 | .name = "rcu_bh" | |
372 | }; | |
373 | ||
11a14701 JT |
374 | static struct rcu_torture_ops rcu_bh_sync_ops = { |
375 | .init = rcu_sync_torture_init, | |
376 | .cleanup = NULL, | |
377 | .readlock = rcu_bh_torture_read_lock, | |
378 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ | |
379 | .readunlock = rcu_bh_torture_read_unlock, | |
380 | .completed = rcu_bh_torture_completed, | |
381 | .deferredfree = rcu_sync_torture_deferred_free, | |
382 | .sync = rcu_bh_torture_synchronize, | |
383 | .stats = NULL, | |
384 | .name = "rcu_bh_sync" | |
385 | }; | |
386 | ||
b2896d2e PM |
387 | /* |
388 | * Definitions for srcu torture testing. | |
389 | */ | |
390 | ||
391 | static struct srcu_struct srcu_ctl; | |
b2896d2e PM |
392 | |
393 | static void srcu_torture_init(void) | |
394 | { | |
395 | init_srcu_struct(&srcu_ctl); | |
e3033736 | 396 | rcu_sync_torture_init(); |
b2896d2e PM |
397 | } |
398 | ||
399 | static void srcu_torture_cleanup(void) | |
400 | { | |
401 | synchronize_srcu(&srcu_ctl); | |
402 | cleanup_srcu_struct(&srcu_ctl); | |
403 | } | |
404 | ||
012d3ca8 | 405 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
406 | { |
407 | return srcu_read_lock(&srcu_ctl); | |
408 | } | |
409 | ||
410 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
411 | { | |
412 | long delay; | |
413 | const long uspertick = 1000000 / HZ; | |
414 | const long longdelay = 10; | |
415 | ||
416 | /* We want there to be long-running readers, but not all the time. */ | |
417 | ||
418 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
419 | if (!delay) | |
420 | schedule_timeout_interruptible(longdelay); | |
421 | } | |
422 | ||
012d3ca8 | 423 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
424 | { |
425 | srcu_read_unlock(&srcu_ctl, idx); | |
426 | } | |
427 | ||
428 | static int srcu_torture_completed(void) | |
429 | { | |
430 | return srcu_batches_completed(&srcu_ctl); | |
431 | } | |
432 | ||
b772e1dd JT |
433 | static void srcu_torture_synchronize(void) |
434 | { | |
435 | synchronize_srcu(&srcu_ctl); | |
436 | } | |
437 | ||
b2896d2e PM |
438 | static int srcu_torture_stats(char *page) |
439 | { | |
440 | int cnt = 0; | |
441 | int cpu; | |
442 | int idx = srcu_ctl.completed & 0x1; | |
443 | ||
444 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
445 | torture_type, TORTURE_FLAG, idx); | |
446 | for_each_possible_cpu(cpu) { | |
447 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
448 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
449 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
450 | } | |
451 | cnt += sprintf(&page[cnt], "\n"); | |
452 | return cnt; | |
453 | } | |
454 | ||
455 | static struct rcu_torture_ops srcu_ops = { | |
456 | .init = srcu_torture_init, | |
457 | .cleanup = srcu_torture_cleanup, | |
458 | .readlock = srcu_torture_read_lock, | |
459 | .readdelay = srcu_read_delay, | |
460 | .readunlock = srcu_torture_read_unlock, | |
461 | .completed = srcu_torture_completed, | |
e3033736 | 462 | .deferredfree = rcu_sync_torture_deferred_free, |
b772e1dd | 463 | .sync = srcu_torture_synchronize, |
b2896d2e PM |
464 | .stats = srcu_torture_stats, |
465 | .name = "srcu" | |
466 | }; | |
467 | ||
4b6c2cca JT |
468 | /* |
469 | * Definitions for sched torture testing. | |
470 | */ | |
471 | ||
472 | static int sched_torture_read_lock(void) | |
473 | { | |
474 | preempt_disable(); | |
475 | return 0; | |
476 | } | |
477 | ||
478 | static void sched_torture_read_unlock(int idx) | |
479 | { | |
480 | preempt_enable(); | |
481 | } | |
482 | ||
483 | static int sched_torture_completed(void) | |
484 | { | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static void sched_torture_synchronize(void) | |
489 | { | |
490 | synchronize_sched(); | |
491 | } | |
492 | ||
493 | static struct rcu_torture_ops sched_ops = { | |
494 | .init = rcu_sync_torture_init, | |
495 | .cleanup = NULL, | |
496 | .readlock = sched_torture_read_lock, | |
497 | .readdelay = rcu_read_delay, /* just reuse rcu's version. */ | |
498 | .readunlock = sched_torture_read_unlock, | |
499 | .completed = sched_torture_completed, | |
500 | .deferredfree = rcu_sync_torture_deferred_free, | |
501 | .sync = sched_torture_synchronize, | |
502 | .stats = NULL, | |
503 | .name = "sched" | |
504 | }; | |
505 | ||
a241ec65 PM |
506 | /* |
507 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
508 | * for that pointed to by rcu_torture_current, freeing the old structure | |
509 | * after a series of grace periods (the "pipeline"). | |
510 | */ | |
511 | static int | |
512 | rcu_torture_writer(void *arg) | |
513 | { | |
514 | int i; | |
515 | long oldbatch = rcu_batches_completed(); | |
516 | struct rcu_torture *rp; | |
517 | struct rcu_torture *old_rp; | |
518 | static DEFINE_RCU_RANDOM(rand); | |
519 | ||
520 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
521 | set_user_nice(current, 19); |
522 | ||
a241ec65 PM |
523 | do { |
524 | schedule_timeout_uninterruptible(1); | |
a241ec65 PM |
525 | if ((rp = rcu_torture_alloc()) == NULL) |
526 | continue; | |
527 | rp->rtort_pipe_count = 0; | |
528 | udelay(rcu_random(&rand) & 0x3ff); | |
529 | old_rp = rcu_torture_current; | |
996417d2 | 530 | rp->rtort_mbtest = 1; |
a241ec65 PM |
531 | rcu_assign_pointer(rcu_torture_current, rp); |
532 | smp_wmb(); | |
c8e5b163 | 533 | if (old_rp) { |
a241ec65 PM |
534 | i = old_rp->rtort_pipe_count; |
535 | if (i > RCU_TORTURE_PIPE_LEN) | |
536 | i = RCU_TORTURE_PIPE_LEN; | |
537 | atomic_inc(&rcu_torture_wcount[i]); | |
538 | old_rp->rtort_pipe_count++; | |
72e9bb54 | 539 | cur_ops->deferredfree(old_rp); |
a241ec65 PM |
540 | } |
541 | rcu_torture_current_version++; | |
72e9bb54 | 542 | oldbatch = cur_ops->completed(); |
a241ec65 PM |
543 | } while (!kthread_should_stop() && !fullstop); |
544 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); | |
545 | while (!kthread_should_stop()) | |
546 | schedule_timeout_uninterruptible(1); | |
547 | return 0; | |
548 | } | |
549 | ||
b772e1dd JT |
550 | /* |
551 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
552 | * delay between calls. | |
553 | */ | |
554 | static int | |
555 | rcu_torture_fakewriter(void *arg) | |
556 | { | |
557 | DEFINE_RCU_RANDOM(rand); | |
558 | ||
559 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
560 | set_user_nice(current, 19); | |
561 | ||
562 | do { | |
563 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
564 | udelay(rcu_random(&rand) & 0x3ff); | |
565 | cur_ops->sync(); | |
566 | } while (!kthread_should_stop() && !fullstop); | |
567 | ||
568 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
569 | while (!kthread_should_stop()) | |
570 | schedule_timeout_uninterruptible(1); | |
571 | return 0; | |
572 | } | |
573 | ||
a241ec65 PM |
574 | /* |
575 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
576 | * incrementing the corresponding element of the pipeline array. The | |
577 | * counter in the element should never be greater than 1, otherwise, the | |
578 | * RCU implementation is broken. | |
579 | */ | |
580 | static int | |
581 | rcu_torture_reader(void *arg) | |
582 | { | |
583 | int completed; | |
72e9bb54 | 584 | int idx; |
a241ec65 PM |
585 | DEFINE_RCU_RANDOM(rand); |
586 | struct rcu_torture *p; | |
587 | int pipe_count; | |
588 | ||
589 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 IM |
590 | set_user_nice(current, 19); |
591 | ||
a241ec65 | 592 | do { |
72e9bb54 PM |
593 | idx = cur_ops->readlock(); |
594 | completed = cur_ops->completed(); | |
a241ec65 PM |
595 | p = rcu_dereference(rcu_torture_current); |
596 | if (p == NULL) { | |
597 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 598 | cur_ops->readunlock(idx); |
a241ec65 PM |
599 | schedule_timeout_interruptible(HZ); |
600 | continue; | |
601 | } | |
996417d2 PM |
602 | if (p->rtort_mbtest == 0) |
603 | atomic_inc(&n_rcu_torture_mberror); | |
b2896d2e | 604 | cur_ops->readdelay(&rand); |
a241ec65 PM |
605 | preempt_disable(); |
606 | pipe_count = p->rtort_pipe_count; | |
607 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
608 | /* Should not happen, but... */ | |
609 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
610 | } | |
611 | ++__get_cpu_var(rcu_torture_count)[pipe_count]; | |
72e9bb54 | 612 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
613 | if (completed > RCU_TORTURE_PIPE_LEN) { |
614 | /* Should not happen, but... */ | |
615 | completed = RCU_TORTURE_PIPE_LEN; | |
616 | } | |
617 | ++__get_cpu_var(rcu_torture_batch)[completed]; | |
618 | preempt_enable(); | |
72e9bb54 | 619 | cur_ops->readunlock(idx); |
a241ec65 PM |
620 | schedule(); |
621 | } while (!kthread_should_stop() && !fullstop); | |
622 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); | |
623 | while (!kthread_should_stop()) | |
624 | schedule_timeout_uninterruptible(1); | |
625 | return 0; | |
626 | } | |
627 | ||
628 | /* | |
629 | * Create an RCU-torture statistics message in the specified buffer. | |
630 | */ | |
631 | static int | |
632 | rcu_torture_printk(char *page) | |
633 | { | |
634 | int cnt = 0; | |
635 | int cpu; | |
636 | int i; | |
637 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
638 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
639 | ||
0a945022 | 640 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
641 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
642 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
643 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
644 | } | |
645 | } | |
646 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
647 | if (pipesummary[i] != 0) | |
648 | break; | |
649 | } | |
72e9bb54 | 650 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 651 | cnt += sprintf(&page[cnt], |
996417d2 PM |
652 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
653 | "rtmbe: %d", | |
a241ec65 PM |
654 | rcu_torture_current, |
655 | rcu_torture_current_version, | |
656 | list_empty(&rcu_torture_freelist), | |
657 | atomic_read(&n_rcu_torture_alloc), | |
658 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 PM |
659 | atomic_read(&n_rcu_torture_free), |
660 | atomic_read(&n_rcu_torture_mberror)); | |
661 | if (atomic_read(&n_rcu_torture_mberror) != 0) | |
662 | cnt += sprintf(&page[cnt], " !!!"); | |
72e9bb54 | 663 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 664 | if (i > 1) { |
a241ec65 | 665 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 PM |
666 | atomic_inc(&n_rcu_torture_error); |
667 | } | |
a241ec65 PM |
668 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
669 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
670 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 671 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 672 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 673 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 674 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 675 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
676 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
677 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
678 | cnt += sprintf(&page[cnt], " %d", | |
679 | atomic_read(&rcu_torture_wcount[i])); | |
680 | } | |
681 | cnt += sprintf(&page[cnt], "\n"); | |
c8e5b163 | 682 | if (cur_ops->stats) |
72e9bb54 | 683 | cnt += cur_ops->stats(&page[cnt]); |
a241ec65 PM |
684 | return cnt; |
685 | } | |
686 | ||
687 | /* | |
688 | * Print torture statistics. Caller must ensure that there is only | |
689 | * one call to this function at a given time!!! This is normally | |
690 | * accomplished by relying on the module system to only have one copy | |
691 | * of the module loaded, and then by giving the rcu_torture_stats | |
692 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
693 | * thread is not running). | |
694 | */ | |
695 | static void | |
696 | rcu_torture_stats_print(void) | |
697 | { | |
698 | int cnt; | |
699 | ||
700 | cnt = rcu_torture_printk(printk_buf); | |
701 | printk(KERN_ALERT "%s", printk_buf); | |
702 | } | |
703 | ||
704 | /* | |
705 | * Periodically prints torture statistics, if periodic statistics printing | |
706 | * was specified via the stat_interval module parameter. | |
707 | * | |
708 | * No need to worry about fullstop here, since this one doesn't reference | |
709 | * volatile state or register callbacks. | |
710 | */ | |
711 | static int | |
712 | rcu_torture_stats(void *arg) | |
713 | { | |
714 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
715 | do { | |
716 | schedule_timeout_interruptible(stat_interval * HZ); | |
717 | rcu_torture_stats_print(); | |
718 | } while (!kthread_should_stop()); | |
719 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); | |
720 | return 0; | |
721 | } | |
722 | ||
d84f5203 SV |
723 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
724 | ||
725 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
726 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
727 | */ | |
b2896d2e | 728 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 SV |
729 | { |
730 | cpumask_t tmp_mask = CPU_MASK_ALL; | |
731 | int i; | |
732 | ||
733 | lock_cpu_hotplug(); | |
734 | ||
735 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
736 | if (num_online_cpus() == 1) { | |
737 | unlock_cpu_hotplug(); | |
738 | return; | |
739 | } | |
740 | ||
741 | if (rcu_idle_cpu != -1) | |
742 | cpu_clear(rcu_idle_cpu, tmp_mask); | |
743 | ||
744 | set_cpus_allowed(current, tmp_mask); | |
745 | ||
c8e5b163 | 746 | if (reader_tasks) { |
d84f5203 SV |
747 | for (i = 0; i < nrealreaders; i++) |
748 | if (reader_tasks[i]) | |
749 | set_cpus_allowed(reader_tasks[i], tmp_mask); | |
750 | } | |
751 | ||
c8e5b163 | 752 | if (fakewriter_tasks) { |
b772e1dd JT |
753 | for (i = 0; i < nfakewriters; i++) |
754 | if (fakewriter_tasks[i]) | |
755 | set_cpus_allowed(fakewriter_tasks[i], tmp_mask); | |
756 | } | |
757 | ||
d84f5203 SV |
758 | if (writer_task) |
759 | set_cpus_allowed(writer_task, tmp_mask); | |
760 | ||
761 | if (stats_task) | |
762 | set_cpus_allowed(stats_task, tmp_mask); | |
763 | ||
764 | if (rcu_idle_cpu == -1) | |
765 | rcu_idle_cpu = num_online_cpus() - 1; | |
766 | else | |
767 | rcu_idle_cpu--; | |
768 | ||
769 | unlock_cpu_hotplug(); | |
770 | } | |
771 | ||
772 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
773 | * system to become idle at a time and cut off its timer ticks. This is meant | |
774 | * to test the support for such tickless idle CPU in RCU. | |
775 | */ | |
776 | static int | |
777 | rcu_torture_shuffle(void *arg) | |
778 | { | |
779 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
780 | do { | |
781 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
782 | rcu_torture_shuffle_tasks(); | |
783 | } while (!kthread_should_stop()); | |
784 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); | |
785 | return 0; | |
786 | } | |
787 | ||
95c38322 PM |
788 | static inline void |
789 | rcu_torture_print_module_parms(char *tag) | |
790 | { | |
b772e1dd JT |
791 | printk(KERN_ALERT "%s" TORTURE_FLAG |
792 | "--- %s: nreaders=%d nfakewriters=%d " | |
95c38322 PM |
793 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
794 | "shuffle_interval = %d\n", | |
b772e1dd JT |
795 | torture_type, tag, nrealreaders, nfakewriters, |
796 | stat_interval, verbose, test_no_idle_hz, shuffle_interval); | |
95c38322 PM |
797 | } |
798 | ||
a241ec65 PM |
799 | static void |
800 | rcu_torture_cleanup(void) | |
801 | { | |
802 | int i; | |
803 | ||
804 | fullstop = 1; | |
c8e5b163 | 805 | if (shuffler_task) { |
d84f5203 SV |
806 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
807 | kthread_stop(shuffler_task); | |
808 | } | |
809 | shuffler_task = NULL; | |
810 | ||
c8e5b163 | 811 | if (writer_task) { |
a241ec65 PM |
812 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
813 | kthread_stop(writer_task); | |
814 | } | |
815 | writer_task = NULL; | |
816 | ||
c8e5b163 | 817 | if (reader_tasks) { |
a241ec65 | 818 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 819 | if (reader_tasks[i]) { |
a241ec65 PM |
820 | VERBOSE_PRINTK_STRING( |
821 | "Stopping rcu_torture_reader task"); | |
822 | kthread_stop(reader_tasks[i]); | |
823 | } | |
824 | reader_tasks[i] = NULL; | |
825 | } | |
826 | kfree(reader_tasks); | |
827 | reader_tasks = NULL; | |
828 | } | |
829 | rcu_torture_current = NULL; | |
830 | ||
c8e5b163 | 831 | if (fakewriter_tasks) { |
b772e1dd | 832 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 833 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
834 | VERBOSE_PRINTK_STRING( |
835 | "Stopping rcu_torture_fakewriter task"); | |
836 | kthread_stop(fakewriter_tasks[i]); | |
837 | } | |
838 | fakewriter_tasks[i] = NULL; | |
839 | } | |
840 | kfree(fakewriter_tasks); | |
841 | fakewriter_tasks = NULL; | |
842 | } | |
843 | ||
c8e5b163 | 844 | if (stats_task) { |
a241ec65 PM |
845 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
846 | kthread_stop(stats_task); | |
847 | } | |
848 | stats_task = NULL; | |
849 | ||
850 | /* Wait for all RCU callbacks to fire. */ | |
89d46b87 | 851 | rcu_barrier(); |
a241ec65 | 852 | |
a241ec65 | 853 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 854 | |
c8e5b163 | 855 | if (cur_ops->cleanup) |
72e9bb54 | 856 | cur_ops->cleanup(); |
95c38322 PM |
857 | if (atomic_read(&n_rcu_torture_error)) |
858 | rcu_torture_print_module_parms("End of test: FAILURE"); | |
859 | else | |
860 | rcu_torture_print_module_parms("End of test: SUCCESS"); | |
a241ec65 PM |
861 | } |
862 | ||
6f8bc500 | 863 | static int __init |
a241ec65 PM |
864 | rcu_torture_init(void) |
865 | { | |
866 | int i; | |
867 | int cpu; | |
868 | int firsterr = 0; | |
ade5fb81 JT |
869 | static struct rcu_torture_ops *torture_ops[] = |
870 | { &rcu_ops, &rcu_sync_ops, &rcu_bh_ops, &rcu_bh_sync_ops, | |
871 | &srcu_ops, &sched_ops, }; | |
a241ec65 PM |
872 | |
873 | /* Process args and tell the world that the torturer is on the job. */ | |
ade5fb81 | 874 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 875 | cur_ops = torture_ops[i]; |
ade5fb81 | 876 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 877 | break; |
72e9bb54 | 878 | } |
ade5fb81 | 879 | if (i == ARRAY_SIZE(torture_ops)) { |
72e9bb54 PM |
880 | printk(KERN_ALERT "rcutorture: invalid torture type: \"%s\"\n", |
881 | torture_type); | |
882 | return (-EINVAL); | |
883 | } | |
c8e5b163 | 884 | if (cur_ops->init) |
72e9bb54 PM |
885 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
886 | ||
a241ec65 PM |
887 | if (nreaders >= 0) |
888 | nrealreaders = nreaders; | |
889 | else | |
890 | nrealreaders = 2 * num_online_cpus(); | |
95c38322 | 891 | rcu_torture_print_module_parms("Start of test"); |
a241ec65 PM |
892 | fullstop = 0; |
893 | ||
894 | /* Set up the freelist. */ | |
895 | ||
896 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 897 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 898 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
899 | list_add_tail(&rcu_tortures[i].rtort_free, |
900 | &rcu_torture_freelist); | |
901 | } | |
902 | ||
903 | /* Initialize the statistics so that each run gets its own numbers. */ | |
904 | ||
905 | rcu_torture_current = NULL; | |
906 | rcu_torture_current_version = 0; | |
907 | atomic_set(&n_rcu_torture_alloc, 0); | |
908 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
909 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
910 | atomic_set(&n_rcu_torture_mberror, 0); |
911 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
912 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
913 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 914 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
915 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
916 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
917 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
918 | } | |
919 | } | |
920 | ||
921 | /* Start up the kthreads. */ | |
922 | ||
923 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
924 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
925 | "rcu_torture_writer"); | |
926 | if (IS_ERR(writer_task)) { | |
927 | firsterr = PTR_ERR(writer_task); | |
928 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
929 | writer_task = NULL; | |
930 | goto unwind; | |
931 | } | |
b772e1dd JT |
932 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
933 | GFP_KERNEL); | |
934 | if (fakewriter_tasks == NULL) { | |
935 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
936 | firsterr = -ENOMEM; | |
937 | goto unwind; | |
938 | } | |
939 | for (i = 0; i < nfakewriters; i++) { | |
940 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
941 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
942 | "rcu_torture_fakewriter"); | |
943 | if (IS_ERR(fakewriter_tasks[i])) { | |
944 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
945 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
946 | fakewriter_tasks[i] = NULL; | |
947 | goto unwind; | |
948 | } | |
949 | } | |
2860aaba | 950 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
951 | GFP_KERNEL); |
952 | if (reader_tasks == NULL) { | |
953 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
954 | firsterr = -ENOMEM; | |
955 | goto unwind; | |
956 | } | |
957 | for (i = 0; i < nrealreaders; i++) { | |
958 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
959 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
960 | "rcu_torture_reader"); | |
961 | if (IS_ERR(reader_tasks[i])) { | |
962 | firsterr = PTR_ERR(reader_tasks[i]); | |
963 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
964 | reader_tasks[i] = NULL; | |
965 | goto unwind; | |
966 | } | |
967 | } | |
968 | if (stat_interval > 0) { | |
969 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
970 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
971 | "rcu_torture_stats"); | |
972 | if (IS_ERR(stats_task)) { | |
973 | firsterr = PTR_ERR(stats_task); | |
974 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
975 | stats_task = NULL; | |
976 | goto unwind; | |
977 | } | |
978 | } | |
d84f5203 SV |
979 | if (test_no_idle_hz) { |
980 | rcu_idle_cpu = num_online_cpus() - 1; | |
981 | /* Create the shuffler thread */ | |
982 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
983 | "rcu_torture_shuffle"); | |
984 | if (IS_ERR(shuffler_task)) { | |
985 | firsterr = PTR_ERR(shuffler_task); | |
986 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
987 | shuffler_task = NULL; | |
988 | goto unwind; | |
989 | } | |
990 | } | |
a241ec65 PM |
991 | return 0; |
992 | ||
993 | unwind: | |
994 | rcu_torture_cleanup(); | |
995 | return firsterr; | |
996 | } | |
997 | ||
998 | module_init(rcu_torture_init); | |
999 | module_exit(rcu_torture_cleanup); |