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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> | |
a71fca58 | 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> | |
a241ec65 PM |
38 | #include <linux/completion.h> |
39 | #include <linux/moduleparam.h> | |
40 | #include <linux/percpu.h> | |
41 | #include <linux/notifier.h> | |
343e9099 | 42 | #include <linux/reboot.h> |
83144186 | 43 | #include <linux/freezer.h> |
a241ec65 | 44 | #include <linux/cpu.h> |
a241ec65 | 45 | #include <linux/delay.h> |
a241ec65 | 46 | #include <linux/stat.h> |
b2896d2e | 47 | #include <linux/srcu.h> |
1aeb272c | 48 | #include <linux/slab.h> |
f07767fd | 49 | #include <asm/byteorder.h> |
a241ec65 PM |
50 | |
51 | MODULE_LICENSE("GPL"); | |
b772e1dd | 52 | MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and " |
a71fca58 | 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. */ | |
d120f65f PM |
61 | static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/ |
62 | static int stutter = 5; /* Start/stop testing interval (in sec) */ | |
0729fbf3 | 63 | static int irqreader = 1; /* RCU readers from irq (timers). */ |
bf66f18e PM |
64 | static int fqs_duration = 0; /* Duration of bursts (us), 0 to disable. */ |
65 | static int fqs_holdoff = 0; /* Hold time within burst (us). */ | |
66 | static int fqs_stutter = 3; /* Wait time between bursts (s). */ | |
20d2e428 | 67 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ |
a241ec65 | 68 | |
d6ad6711 | 69 | module_param(nreaders, int, 0444); |
a241ec65 | 70 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
d6ad6711 | 71 | module_param(nfakewriters, int, 0444); |
b772e1dd | 72 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); |
d6ad6711 | 73 | module_param(stat_interval, int, 0444); |
a241ec65 | 74 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
d6ad6711 | 75 | module_param(verbose, bool, 0444); |
a241ec65 | 76 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
d6ad6711 | 77 | module_param(test_no_idle_hz, bool, 0444); |
d84f5203 | 78 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
d6ad6711 | 79 | module_param(shuffle_interval, int, 0444); |
d84f5203 | 80 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
d120f65f PM |
81 | module_param(stutter, int, 0444); |
82 | MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); | |
0729fbf3 PM |
83 | module_param(irqreader, int, 0444); |
84 | MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); | |
bf66f18e PM |
85 | module_param(fqs_duration, int, 0444); |
86 | MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)"); | |
87 | module_param(fqs_holdoff, int, 0444); | |
88 | MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)"); | |
89 | module_param(fqs_stutter, int, 0444); | |
90 | MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)"); | |
d6ad6711 | 91 | module_param(torture_type, charp, 0444); |
b2896d2e | 92 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
93 | |
94 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 95 | #define PRINTK_STRING(s) \ |
72e9bb54 | 96 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 97 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 98 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 99 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 100 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
101 | |
102 | static char printk_buf[4096]; | |
103 | ||
104 | static int nrealreaders; | |
105 | static struct task_struct *writer_task; | |
b772e1dd | 106 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
107 | static struct task_struct **reader_tasks; |
108 | static struct task_struct *stats_task; | |
d84f5203 | 109 | static struct task_struct *shuffler_task; |
d120f65f | 110 | static struct task_struct *stutter_task; |
bf66f18e | 111 | static struct task_struct *fqs_task; |
a241ec65 PM |
112 | |
113 | #define RCU_TORTURE_PIPE_LEN 10 | |
114 | ||
115 | struct rcu_torture { | |
116 | struct rcu_head rtort_rcu; | |
117 | int rtort_pipe_count; | |
118 | struct list_head rtort_free; | |
996417d2 | 119 | int rtort_mbtest; |
a241ec65 PM |
120 | }; |
121 | ||
a241ec65 | 122 | static LIST_HEAD(rcu_torture_freelist); |
a71fca58 PM |
123 | static struct rcu_torture *rcu_torture_current; |
124 | static long rcu_torture_current_version; | |
a241ec65 PM |
125 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
126 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
127 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
128 | { 0 }; | |
129 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
130 | { 0 }; | |
131 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
132 | static atomic_t n_rcu_torture_alloc; |
133 | static atomic_t n_rcu_torture_alloc_fail; | |
134 | static atomic_t n_rcu_torture_free; | |
135 | static atomic_t n_rcu_torture_mberror; | |
136 | static atomic_t n_rcu_torture_error; | |
a71fca58 | 137 | static long n_rcu_torture_timers; |
e3033736 | 138 | static struct list_head rcu_torture_removed; |
73d0a4b1 | 139 | static cpumask_var_t shuffle_tmp_mask; |
a241ec65 | 140 | |
a71fca58 | 141 | static int stutter_pause_test; |
d120f65f | 142 | |
31a72bce PM |
143 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) |
144 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
145 | #else | |
146 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
147 | #endif | |
148 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
149 | ||
c9d557c1 PM |
150 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
151 | ||
152 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
153 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
154 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
155 | static int fullstop = FULLSTOP_RMMOD; | |
156 | DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */ | |
157 | /* of kthreads. */ | |
343e9099 PM |
158 | |
159 | /* | |
c9d557c1 | 160 | * Detect and respond to a system shutdown. |
343e9099 PM |
161 | */ |
162 | static int | |
163 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
164 | unsigned long unused2, void *unused3) | |
165 | { | |
c59ab97e | 166 | mutex_lock(&fullstop_mutex); |
c9d557c1 | 167 | if (fullstop == FULLSTOP_DONTSTOP) |
c59ab97e | 168 | fullstop = FULLSTOP_SHUTDOWN; |
c9d557c1 PM |
169 | else |
170 | printk(KERN_WARNING /* but going down anyway, so... */ | |
171 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
c59ab97e | 172 | mutex_unlock(&fullstop_mutex); |
343e9099 PM |
173 | return NOTIFY_DONE; |
174 | } | |
175 | ||
c9d557c1 PM |
176 | /* |
177 | * Absorb kthreads into a kernel function that won't return, so that | |
178 | * they won't ever access module text or data again. | |
179 | */ | |
180 | static void rcutorture_shutdown_absorb(char *title) | |
181 | { | |
182 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
183 | printk(KERN_NOTICE | |
184 | "rcutorture thread %s parking due to system shutdown\n", | |
185 | title); | |
186 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
187 | } | |
188 | } | |
189 | ||
a241ec65 PM |
190 | /* |
191 | * Allocate an element from the rcu_tortures pool. | |
192 | */ | |
97a41e26 | 193 | static struct rcu_torture * |
a241ec65 PM |
194 | rcu_torture_alloc(void) |
195 | { | |
196 | struct list_head *p; | |
197 | ||
adac1665 | 198 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
199 | if (list_empty(&rcu_torture_freelist)) { |
200 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 201 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
202 | return NULL; |
203 | } | |
204 | atomic_inc(&n_rcu_torture_alloc); | |
205 | p = rcu_torture_freelist.next; | |
206 | list_del_init(p); | |
adac1665 | 207 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
208 | return container_of(p, struct rcu_torture, rtort_free); |
209 | } | |
210 | ||
211 | /* | |
212 | * Free an element to the rcu_tortures pool. | |
213 | */ | |
214 | static void | |
215 | rcu_torture_free(struct rcu_torture *p) | |
216 | { | |
217 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 218 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 219 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 220 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
221 | } |
222 | ||
a241ec65 PM |
223 | struct rcu_random_state { |
224 | unsigned long rrs_state; | |
75cfef32 | 225 | long rrs_count; |
a241ec65 PM |
226 | }; |
227 | ||
228 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
229 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
230 | #define RCU_RANDOM_REFRESH 10000 | |
231 | ||
232 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
233 | ||
234 | /* | |
235 | * Crude but fast random-number generator. Uses a linear congruential | |
c17ac855 | 236 | * generator, with occasional help from cpu_clock(). |
a241ec65 | 237 | */ |
75cfef32 | 238 | static unsigned long |
a241ec65 PM |
239 | rcu_random(struct rcu_random_state *rrsp) |
240 | { | |
a241ec65 | 241 | if (--rrsp->rrs_count < 0) { |
c676329a | 242 | rrsp->rrs_state += (unsigned long)local_clock(); |
a241ec65 PM |
243 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
244 | } | |
245 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
246 | return swahw32(rrsp->rrs_state); | |
247 | } | |
248 | ||
d120f65f | 249 | static void |
c9d557c1 | 250 | rcu_stutter_wait(char *title) |
d120f65f | 251 | { |
c9d557c1 | 252 | while (stutter_pause_test || !rcutorture_runnable) { |
e3d7be27 PM |
253 | if (rcutorture_runnable) |
254 | schedule_timeout_interruptible(1); | |
255 | else | |
3ccf79f4 | 256 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
c9d557c1 | 257 | rcutorture_shutdown_absorb(title); |
343e9099 | 258 | } |
d120f65f PM |
259 | } |
260 | ||
72e9bb54 PM |
261 | /* |
262 | * Operations vector for selecting different types of tests. | |
263 | */ | |
264 | ||
265 | struct rcu_torture_ops { | |
266 | void (*init)(void); | |
267 | void (*cleanup)(void); | |
268 | int (*readlock)(void); | |
0acc512c | 269 | void (*read_delay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
270 | void (*readunlock)(int idx); |
271 | int (*completed)(void); | |
0acc512c | 272 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 273 | void (*sync)(void); |
2326974d | 274 | void (*cb_barrier)(void); |
bf66f18e | 275 | void (*fqs)(void); |
72e9bb54 | 276 | int (*stats)(char *page); |
0acc512c | 277 | int irq_capable; |
72e9bb54 PM |
278 | char *name; |
279 | }; | |
a71fca58 PM |
280 | |
281 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
282 | |
283 | /* | |
284 | * Definitions for rcu torture testing. | |
285 | */ | |
286 | ||
a49a4af7 | 287 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
288 | { |
289 | rcu_read_lock(); | |
290 | return 0; | |
291 | } | |
292 | ||
b2896d2e PM |
293 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
294 | { | |
b8d57a76 JT |
295 | const unsigned long shortdelay_us = 200; |
296 | const unsigned long longdelay_ms = 50; | |
b2896d2e | 297 | |
b8d57a76 JT |
298 | /* We want a short delay sometimes to make a reader delay the grace |
299 | * period, and we want a long delay occasionally to trigger | |
300 | * force_quiescent_state. */ | |
b2896d2e | 301 | |
b8d57a76 JT |
302 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) |
303 | mdelay(longdelay_ms); | |
304 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
305 | udelay(shortdelay_us); | |
e546f485 LJ |
306 | #ifdef CONFIG_PREEMPT |
307 | if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) | |
308 | preempt_schedule(); /* No QS if preempt_disable() in effect */ | |
309 | #endif | |
b2896d2e PM |
310 | } |
311 | ||
a49a4af7 | 312 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
313 | { |
314 | rcu_read_unlock(); | |
315 | } | |
316 | ||
317 | static int rcu_torture_completed(void) | |
318 | { | |
319 | return rcu_batches_completed(); | |
320 | } | |
321 | ||
322 | static void | |
323 | rcu_torture_cb(struct rcu_head *p) | |
324 | { | |
325 | int i; | |
326 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
327 | ||
c9d557c1 | 328 | if (fullstop != FULLSTOP_DONTSTOP) { |
72e9bb54 PM |
329 | /* Test is ending, just drop callbacks on the floor. */ |
330 | /* The next initialization will pick up the pieces. */ | |
331 | return; | |
332 | } | |
333 | i = rp->rtort_pipe_count; | |
334 | if (i > RCU_TORTURE_PIPE_LEN) | |
335 | i = RCU_TORTURE_PIPE_LEN; | |
336 | atomic_inc(&rcu_torture_wcount[i]); | |
337 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
338 | rp->rtort_mbtest = 0; | |
339 | rcu_torture_free(rp); | |
340 | } else | |
0acc512c | 341 | cur_ops->deferred_free(rp); |
72e9bb54 PM |
342 | } |
343 | ||
d9a3da06 PM |
344 | static int rcu_no_completed(void) |
345 | { | |
346 | return 0; | |
347 | } | |
348 | ||
72e9bb54 PM |
349 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
350 | { | |
351 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
352 | } | |
353 | ||
354 | static struct rcu_torture_ops rcu_ops = { | |
0acc512c PM |
355 | .init = NULL, |
356 | .cleanup = NULL, | |
357 | .readlock = rcu_torture_read_lock, | |
358 | .read_delay = rcu_read_delay, | |
359 | .readunlock = rcu_torture_read_unlock, | |
360 | .completed = rcu_torture_completed, | |
361 | .deferred_free = rcu_torture_deferred_free, | |
362 | .sync = synchronize_rcu, | |
363 | .cb_barrier = rcu_barrier, | |
bf66f18e | 364 | .fqs = rcu_force_quiescent_state, |
0acc512c | 365 | .stats = NULL, |
a71fca58 PM |
366 | .irq_capable = 1, |
367 | .name = "rcu" | |
72e9bb54 PM |
368 | }; |
369 | ||
e3033736 JT |
370 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) |
371 | { | |
372 | int i; | |
373 | struct rcu_torture *rp; | |
374 | struct rcu_torture *rp1; | |
375 | ||
376 | cur_ops->sync(); | |
377 | list_add(&p->rtort_free, &rcu_torture_removed); | |
378 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
379 | i = rp->rtort_pipe_count; | |
380 | if (i > RCU_TORTURE_PIPE_LEN) | |
381 | i = RCU_TORTURE_PIPE_LEN; | |
382 | atomic_inc(&rcu_torture_wcount[i]); | |
383 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
384 | rp->rtort_mbtest = 0; | |
385 | list_del(&rp->rtort_free); | |
386 | rcu_torture_free(rp); | |
387 | } | |
388 | } | |
389 | } | |
390 | ||
391 | static void rcu_sync_torture_init(void) | |
392 | { | |
393 | INIT_LIST_HEAD(&rcu_torture_removed); | |
394 | } | |
395 | ||
20d2e428 | 396 | static struct rcu_torture_ops rcu_sync_ops = { |
0acc512c PM |
397 | .init = rcu_sync_torture_init, |
398 | .cleanup = NULL, | |
399 | .readlock = rcu_torture_read_lock, | |
400 | .read_delay = rcu_read_delay, | |
401 | .readunlock = rcu_torture_read_unlock, | |
402 | .completed = rcu_torture_completed, | |
403 | .deferred_free = rcu_sync_torture_deferred_free, | |
404 | .sync = synchronize_rcu, | |
405 | .cb_barrier = NULL, | |
bf66f18e | 406 | .fqs = rcu_force_quiescent_state, |
0acc512c PM |
407 | .stats = NULL, |
408 | .irq_capable = 1, | |
409 | .name = "rcu_sync" | |
20d2e428 JT |
410 | }; |
411 | ||
d9a3da06 PM |
412 | static struct rcu_torture_ops rcu_expedited_ops = { |
413 | .init = rcu_sync_torture_init, | |
414 | .cleanup = NULL, | |
415 | .readlock = rcu_torture_read_lock, | |
416 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
417 | .readunlock = rcu_torture_read_unlock, | |
418 | .completed = rcu_no_completed, | |
419 | .deferred_free = rcu_sync_torture_deferred_free, | |
420 | .sync = synchronize_rcu_expedited, | |
421 | .cb_barrier = NULL, | |
bf66f18e | 422 | .fqs = rcu_force_quiescent_state, |
d9a3da06 PM |
423 | .stats = NULL, |
424 | .irq_capable = 1, | |
425 | .name = "rcu_expedited" | |
426 | }; | |
427 | ||
c32e0660 PM |
428 | /* |
429 | * Definitions for rcu_bh torture testing. | |
430 | */ | |
431 | ||
a49a4af7 | 432 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
433 | { |
434 | rcu_read_lock_bh(); | |
435 | return 0; | |
436 | } | |
437 | ||
a49a4af7 | 438 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
439 | { |
440 | rcu_read_unlock_bh(); | |
441 | } | |
442 | ||
443 | static int rcu_bh_torture_completed(void) | |
444 | { | |
445 | return rcu_batches_completed_bh(); | |
446 | } | |
447 | ||
448 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
449 | { | |
450 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
451 | } | |
452 | ||
b772e1dd JT |
453 | struct rcu_bh_torture_synchronize { |
454 | struct rcu_head head; | |
455 | struct completion completion; | |
456 | }; | |
457 | ||
458 | static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head) | |
459 | { | |
460 | struct rcu_bh_torture_synchronize *rcu; | |
461 | ||
462 | rcu = container_of(head, struct rcu_bh_torture_synchronize, head); | |
463 | complete(&rcu->completion); | |
464 | } | |
465 | ||
466 | static void rcu_bh_torture_synchronize(void) | |
467 | { | |
468 | struct rcu_bh_torture_synchronize rcu; | |
469 | ||
72d5a9f7 | 470 | init_rcu_head_on_stack(&rcu.head); |
b772e1dd JT |
471 | init_completion(&rcu.completion); |
472 | call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb); | |
473 | wait_for_completion(&rcu.completion); | |
72d5a9f7 | 474 | destroy_rcu_head_on_stack(&rcu.head); |
b772e1dd JT |
475 | } |
476 | ||
c32e0660 | 477 | static struct rcu_torture_ops rcu_bh_ops = { |
0acc512c PM |
478 | .init = NULL, |
479 | .cleanup = NULL, | |
480 | .readlock = rcu_bh_torture_read_lock, | |
481 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
482 | .readunlock = rcu_bh_torture_read_unlock, | |
483 | .completed = rcu_bh_torture_completed, | |
484 | .deferred_free = rcu_bh_torture_deferred_free, | |
485 | .sync = rcu_bh_torture_synchronize, | |
486 | .cb_barrier = rcu_barrier_bh, | |
bf66f18e | 487 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
488 | .stats = NULL, |
489 | .irq_capable = 1, | |
490 | .name = "rcu_bh" | |
c32e0660 PM |
491 | }; |
492 | ||
11a14701 | 493 | static struct rcu_torture_ops rcu_bh_sync_ops = { |
0acc512c PM |
494 | .init = rcu_sync_torture_init, |
495 | .cleanup = NULL, | |
496 | .readlock = rcu_bh_torture_read_lock, | |
497 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
498 | .readunlock = rcu_bh_torture_read_unlock, | |
499 | .completed = rcu_bh_torture_completed, | |
500 | .deferred_free = rcu_sync_torture_deferred_free, | |
501 | .sync = rcu_bh_torture_synchronize, | |
502 | .cb_barrier = NULL, | |
bf66f18e | 503 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
504 | .stats = NULL, |
505 | .irq_capable = 1, | |
506 | .name = "rcu_bh_sync" | |
11a14701 JT |
507 | }; |
508 | ||
b2896d2e PM |
509 | /* |
510 | * Definitions for srcu torture testing. | |
511 | */ | |
512 | ||
513 | static struct srcu_struct srcu_ctl; | |
b2896d2e PM |
514 | |
515 | static void srcu_torture_init(void) | |
516 | { | |
517 | init_srcu_struct(&srcu_ctl); | |
e3033736 | 518 | rcu_sync_torture_init(); |
b2896d2e PM |
519 | } |
520 | ||
521 | static void srcu_torture_cleanup(void) | |
522 | { | |
523 | synchronize_srcu(&srcu_ctl); | |
524 | cleanup_srcu_struct(&srcu_ctl); | |
525 | } | |
526 | ||
012d3ca8 | 527 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
528 | { |
529 | return srcu_read_lock(&srcu_ctl); | |
530 | } | |
531 | ||
532 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
533 | { | |
534 | long delay; | |
535 | const long uspertick = 1000000 / HZ; | |
536 | const long longdelay = 10; | |
537 | ||
538 | /* We want there to be long-running readers, but not all the time. */ | |
539 | ||
540 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
541 | if (!delay) | |
542 | schedule_timeout_interruptible(longdelay); | |
e546f485 LJ |
543 | else |
544 | rcu_read_delay(rrsp); | |
b2896d2e PM |
545 | } |
546 | ||
012d3ca8 | 547 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
548 | { |
549 | srcu_read_unlock(&srcu_ctl, idx); | |
550 | } | |
551 | ||
552 | static int srcu_torture_completed(void) | |
553 | { | |
554 | return srcu_batches_completed(&srcu_ctl); | |
555 | } | |
556 | ||
b772e1dd JT |
557 | static void srcu_torture_synchronize(void) |
558 | { | |
559 | synchronize_srcu(&srcu_ctl); | |
560 | } | |
561 | ||
b2896d2e PM |
562 | static int srcu_torture_stats(char *page) |
563 | { | |
564 | int cnt = 0; | |
565 | int cpu; | |
566 | int idx = srcu_ctl.completed & 0x1; | |
567 | ||
568 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
569 | torture_type, TORTURE_FLAG, idx); | |
570 | for_each_possible_cpu(cpu) { | |
571 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
572 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
573 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
574 | } | |
575 | cnt += sprintf(&page[cnt], "\n"); | |
576 | return cnt; | |
577 | } | |
578 | ||
579 | static struct rcu_torture_ops srcu_ops = { | |
0acc512c PM |
580 | .init = srcu_torture_init, |
581 | .cleanup = srcu_torture_cleanup, | |
582 | .readlock = srcu_torture_read_lock, | |
583 | .read_delay = srcu_read_delay, | |
584 | .readunlock = srcu_torture_read_unlock, | |
585 | .completed = srcu_torture_completed, | |
586 | .deferred_free = rcu_sync_torture_deferred_free, | |
587 | .sync = srcu_torture_synchronize, | |
588 | .cb_barrier = NULL, | |
589 | .stats = srcu_torture_stats, | |
590 | .name = "srcu" | |
b2896d2e PM |
591 | }; |
592 | ||
804bb837 PM |
593 | static void srcu_torture_synchronize_expedited(void) |
594 | { | |
595 | synchronize_srcu_expedited(&srcu_ctl); | |
596 | } | |
597 | ||
598 | static struct rcu_torture_ops srcu_expedited_ops = { | |
599 | .init = srcu_torture_init, | |
600 | .cleanup = srcu_torture_cleanup, | |
601 | .readlock = srcu_torture_read_lock, | |
602 | .read_delay = srcu_read_delay, | |
603 | .readunlock = srcu_torture_read_unlock, | |
604 | .completed = srcu_torture_completed, | |
605 | .deferred_free = rcu_sync_torture_deferred_free, | |
606 | .sync = srcu_torture_synchronize_expedited, | |
607 | .cb_barrier = NULL, | |
608 | .stats = srcu_torture_stats, | |
609 | .name = "srcu_expedited" | |
610 | }; | |
611 | ||
4b6c2cca JT |
612 | /* |
613 | * Definitions for sched torture testing. | |
614 | */ | |
615 | ||
616 | static int sched_torture_read_lock(void) | |
617 | { | |
618 | preempt_disable(); | |
619 | return 0; | |
620 | } | |
621 | ||
622 | static void sched_torture_read_unlock(int idx) | |
623 | { | |
624 | preempt_enable(); | |
625 | } | |
626 | ||
2326974d PM |
627 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) |
628 | { | |
629 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
630 | } | |
631 | ||
4b6c2cca JT |
632 | static void sched_torture_synchronize(void) |
633 | { | |
634 | synchronize_sched(); | |
635 | } | |
636 | ||
637 | static struct rcu_torture_ops sched_ops = { | |
0acc512c PM |
638 | .init = rcu_sync_torture_init, |
639 | .cleanup = NULL, | |
640 | .readlock = sched_torture_read_lock, | |
641 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
642 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 643 | .completed = rcu_no_completed, |
0acc512c PM |
644 | .deferred_free = rcu_sched_torture_deferred_free, |
645 | .sync = sched_torture_synchronize, | |
646 | .cb_barrier = rcu_barrier_sched, | |
bf66f18e | 647 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
648 | .stats = NULL, |
649 | .irq_capable = 1, | |
650 | .name = "sched" | |
4b6c2cca JT |
651 | }; |
652 | ||
804bb837 | 653 | static struct rcu_torture_ops sched_sync_ops = { |
0acc512c PM |
654 | .init = rcu_sync_torture_init, |
655 | .cleanup = NULL, | |
656 | .readlock = sched_torture_read_lock, | |
657 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
658 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 659 | .completed = rcu_no_completed, |
0acc512c PM |
660 | .deferred_free = rcu_sync_torture_deferred_free, |
661 | .sync = sched_torture_synchronize, | |
662 | .cb_barrier = NULL, | |
bf66f18e | 663 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
664 | .stats = NULL, |
665 | .name = "sched_sync" | |
666 | }; | |
667 | ||
0acc512c PM |
668 | static struct rcu_torture_ops sched_expedited_ops = { |
669 | .init = rcu_sync_torture_init, | |
670 | .cleanup = NULL, | |
671 | .readlock = sched_torture_read_lock, | |
672 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
673 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 674 | .completed = rcu_no_completed, |
0acc512c PM |
675 | .deferred_free = rcu_sync_torture_deferred_free, |
676 | .sync = synchronize_sched_expedited, | |
677 | .cb_barrier = NULL, | |
bf66f18e | 678 | .fqs = rcu_sched_force_quiescent_state, |
969c7921 | 679 | .stats = NULL, |
0acc512c PM |
680 | .irq_capable = 1, |
681 | .name = "sched_expedited" | |
2326974d PM |
682 | }; |
683 | ||
bf66f18e PM |
684 | /* |
685 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
686 | * bursts of calls to force_quiescent_state(), increasing the probability | |
687 | * of occurrence of some important types of race conditions. | |
688 | */ | |
689 | static int | |
690 | rcu_torture_fqs(void *arg) | |
691 | { | |
692 | unsigned long fqs_resume_time; | |
693 | int fqs_burst_remaining; | |
694 | ||
695 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); | |
696 | do { | |
697 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
698 | while (jiffies - fqs_resume_time > LONG_MAX) { | |
699 | schedule_timeout_interruptible(1); | |
700 | } | |
701 | fqs_burst_remaining = fqs_duration; | |
702 | while (fqs_burst_remaining > 0) { | |
703 | cur_ops->fqs(); | |
704 | udelay(fqs_holdoff); | |
705 | fqs_burst_remaining -= fqs_holdoff; | |
706 | } | |
707 | rcu_stutter_wait("rcu_torture_fqs"); | |
708 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
709 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping"); | |
710 | rcutorture_shutdown_absorb("rcu_torture_fqs"); | |
711 | while (!kthread_should_stop()) | |
712 | schedule_timeout_uninterruptible(1); | |
713 | return 0; | |
714 | } | |
715 | ||
a241ec65 PM |
716 | /* |
717 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
718 | * for that pointed to by rcu_torture_current, freeing the old structure | |
719 | * after a series of grace periods (the "pipeline"). | |
720 | */ | |
721 | static int | |
722 | rcu_torture_writer(void *arg) | |
723 | { | |
724 | int i; | |
725 | long oldbatch = rcu_batches_completed(); | |
726 | struct rcu_torture *rp; | |
727 | struct rcu_torture *old_rp; | |
728 | static DEFINE_RCU_RANDOM(rand); | |
729 | ||
730 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
731 | set_user_nice(current, 19); |
732 | ||
a241ec65 PM |
733 | do { |
734 | schedule_timeout_uninterruptible(1); | |
a71fca58 PM |
735 | rp = rcu_torture_alloc(); |
736 | if (rp == NULL) | |
a241ec65 PM |
737 | continue; |
738 | rp->rtort_pipe_count = 0; | |
739 | udelay(rcu_random(&rand) & 0x3ff); | |
740 | old_rp = rcu_torture_current; | |
996417d2 | 741 | rp->rtort_mbtest = 1; |
a241ec65 | 742 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 743 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 744 | if (old_rp) { |
a241ec65 PM |
745 | i = old_rp->rtort_pipe_count; |
746 | if (i > RCU_TORTURE_PIPE_LEN) | |
747 | i = RCU_TORTURE_PIPE_LEN; | |
748 | atomic_inc(&rcu_torture_wcount[i]); | |
749 | old_rp->rtort_pipe_count++; | |
0acc512c | 750 | cur_ops->deferred_free(old_rp); |
a241ec65 PM |
751 | } |
752 | rcu_torture_current_version++; | |
72e9bb54 | 753 | oldbatch = cur_ops->completed(); |
c9d557c1 PM |
754 | rcu_stutter_wait("rcu_torture_writer"); |
755 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 756 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
c9d557c1 PM |
757 | rcutorture_shutdown_absorb("rcu_torture_writer"); |
758 | while (!kthread_should_stop()) | |
a241ec65 PM |
759 | schedule_timeout_uninterruptible(1); |
760 | return 0; | |
761 | } | |
762 | ||
b772e1dd JT |
763 | /* |
764 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
765 | * delay between calls. | |
766 | */ | |
767 | static int | |
768 | rcu_torture_fakewriter(void *arg) | |
769 | { | |
770 | DEFINE_RCU_RANDOM(rand); | |
771 | ||
772 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
773 | set_user_nice(current, 19); | |
774 | ||
775 | do { | |
776 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
777 | udelay(rcu_random(&rand) & 0x3ff); | |
778 | cur_ops->sync(); | |
c9d557c1 PM |
779 | rcu_stutter_wait("rcu_torture_fakewriter"); |
780 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
b772e1dd JT |
781 | |
782 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
c9d557c1 PM |
783 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); |
784 | while (!kthread_should_stop()) | |
b772e1dd JT |
785 | schedule_timeout_uninterruptible(1); |
786 | return 0; | |
787 | } | |
788 | ||
0729fbf3 PM |
789 | /* |
790 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
791 | * incrementing the corresponding element of the pipeline array. The | |
792 | * counter in the element should never be greater than 1, otherwise, the | |
793 | * RCU implementation is broken. | |
794 | */ | |
795 | static void rcu_torture_timer(unsigned long unused) | |
796 | { | |
797 | int idx; | |
798 | int completed; | |
799 | static DEFINE_RCU_RANDOM(rand); | |
800 | static DEFINE_SPINLOCK(rand_lock); | |
801 | struct rcu_torture *p; | |
802 | int pipe_count; | |
803 | ||
804 | idx = cur_ops->readlock(); | |
805 | completed = cur_ops->completed(); | |
632ee200 PM |
806 | p = rcu_dereference_check(rcu_torture_current, |
807 | rcu_read_lock_held() || | |
808 | rcu_read_lock_bh_held() || | |
809 | rcu_read_lock_sched_held() || | |
810 | srcu_read_lock_held(&srcu_ctl)); | |
0729fbf3 PM |
811 | if (p == NULL) { |
812 | /* Leave because rcu_torture_writer is not yet underway */ | |
813 | cur_ops->readunlock(idx); | |
814 | return; | |
815 | } | |
816 | if (p->rtort_mbtest == 0) | |
817 | atomic_inc(&n_rcu_torture_mberror); | |
818 | spin_lock(&rand_lock); | |
0acc512c | 819 | cur_ops->read_delay(&rand); |
0729fbf3 PM |
820 | n_rcu_torture_timers++; |
821 | spin_unlock(&rand_lock); | |
822 | preempt_disable(); | |
823 | pipe_count = p->rtort_pipe_count; | |
824 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
825 | /* Should not happen, but... */ | |
826 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
827 | } | |
dd17c8f7 | 828 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
0729fbf3 PM |
829 | completed = cur_ops->completed() - completed; |
830 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
831 | /* Should not happen, but... */ | |
832 | completed = RCU_TORTURE_PIPE_LEN; | |
833 | } | |
dd17c8f7 | 834 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 PM |
835 | preempt_enable(); |
836 | cur_ops->readunlock(idx); | |
837 | } | |
838 | ||
a241ec65 PM |
839 | /* |
840 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
841 | * incrementing the corresponding element of the pipeline array. The | |
842 | * counter in the element should never be greater than 1, otherwise, the | |
843 | * RCU implementation is broken. | |
844 | */ | |
845 | static int | |
846 | rcu_torture_reader(void *arg) | |
847 | { | |
848 | int completed; | |
72e9bb54 | 849 | int idx; |
a241ec65 PM |
850 | DEFINE_RCU_RANDOM(rand); |
851 | struct rcu_torture *p; | |
852 | int pipe_count; | |
0729fbf3 | 853 | struct timer_list t; |
a241ec65 PM |
854 | |
855 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 856 | set_user_nice(current, 19); |
0acc512c | 857 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 858 | setup_timer_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 859 | |
a241ec65 | 860 | do { |
0acc512c | 861 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 862 | if (!timer_pending(&t)) |
6155fec9 | 863 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 864 | } |
72e9bb54 PM |
865 | idx = cur_ops->readlock(); |
866 | completed = cur_ops->completed(); | |
632ee200 PM |
867 | p = rcu_dereference_check(rcu_torture_current, |
868 | rcu_read_lock_held() || | |
869 | rcu_read_lock_bh_held() || | |
870 | rcu_read_lock_sched_held() || | |
871 | srcu_read_lock_held(&srcu_ctl)); | |
a241ec65 PM |
872 | if (p == NULL) { |
873 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 874 | cur_ops->readunlock(idx); |
a241ec65 PM |
875 | schedule_timeout_interruptible(HZ); |
876 | continue; | |
877 | } | |
996417d2 PM |
878 | if (p->rtort_mbtest == 0) |
879 | atomic_inc(&n_rcu_torture_mberror); | |
0acc512c | 880 | cur_ops->read_delay(&rand); |
a241ec65 PM |
881 | preempt_disable(); |
882 | pipe_count = p->rtort_pipe_count; | |
883 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
884 | /* Should not happen, but... */ | |
885 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
886 | } | |
dd17c8f7 | 887 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
72e9bb54 | 888 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
889 | if (completed > RCU_TORTURE_PIPE_LEN) { |
890 | /* Should not happen, but... */ | |
891 | completed = RCU_TORTURE_PIPE_LEN; | |
892 | } | |
dd17c8f7 | 893 | __this_cpu_inc(rcu_torture_batch[completed]); |
a241ec65 | 894 | preempt_enable(); |
72e9bb54 | 895 | cur_ops->readunlock(idx); |
a241ec65 | 896 | schedule(); |
c9d557c1 PM |
897 | rcu_stutter_wait("rcu_torture_reader"); |
898 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 899 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
c9d557c1 | 900 | rcutorture_shutdown_absorb("rcu_torture_reader"); |
0acc512c | 901 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 902 | del_timer_sync(&t); |
c9d557c1 | 903 | while (!kthread_should_stop()) |
a241ec65 PM |
904 | schedule_timeout_uninterruptible(1); |
905 | return 0; | |
906 | } | |
907 | ||
908 | /* | |
909 | * Create an RCU-torture statistics message in the specified buffer. | |
910 | */ | |
911 | static int | |
912 | rcu_torture_printk(char *page) | |
913 | { | |
914 | int cnt = 0; | |
915 | int cpu; | |
916 | int i; | |
917 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
918 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
919 | ||
0a945022 | 920 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
921 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
922 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
923 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
924 | } | |
925 | } | |
926 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
927 | if (pipesummary[i] != 0) | |
928 | break; | |
929 | } | |
72e9bb54 | 930 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 931 | cnt += sprintf(&page[cnt], |
996417d2 | 932 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
0729fbf3 | 933 | "rtmbe: %d nt: %ld", |
a241ec65 PM |
934 | rcu_torture_current, |
935 | rcu_torture_current_version, | |
936 | list_empty(&rcu_torture_freelist), | |
937 | atomic_read(&n_rcu_torture_alloc), | |
938 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 | 939 | atomic_read(&n_rcu_torture_free), |
0729fbf3 PM |
940 | atomic_read(&n_rcu_torture_mberror), |
941 | n_rcu_torture_timers); | |
996417d2 PM |
942 | if (atomic_read(&n_rcu_torture_mberror) != 0) |
943 | cnt += sprintf(&page[cnt], " !!!"); | |
72e9bb54 | 944 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 945 | if (i > 1) { |
a241ec65 | 946 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 | 947 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 948 | WARN_ON_ONCE(1); |
996417d2 | 949 | } |
a241ec65 PM |
950 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
951 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
952 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 953 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 954 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 955 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 956 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 957 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
958 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
959 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
960 | cnt += sprintf(&page[cnt], " %d", | |
961 | atomic_read(&rcu_torture_wcount[i])); | |
962 | } | |
963 | cnt += sprintf(&page[cnt], "\n"); | |
c8e5b163 | 964 | if (cur_ops->stats) |
72e9bb54 | 965 | cnt += cur_ops->stats(&page[cnt]); |
a241ec65 PM |
966 | return cnt; |
967 | } | |
968 | ||
969 | /* | |
970 | * Print torture statistics. Caller must ensure that there is only | |
971 | * one call to this function at a given time!!! This is normally | |
972 | * accomplished by relying on the module system to only have one copy | |
973 | * of the module loaded, and then by giving the rcu_torture_stats | |
974 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
975 | * thread is not running). | |
976 | */ | |
977 | static void | |
978 | rcu_torture_stats_print(void) | |
979 | { | |
980 | int cnt; | |
981 | ||
982 | cnt = rcu_torture_printk(printk_buf); | |
983 | printk(KERN_ALERT "%s", printk_buf); | |
984 | } | |
985 | ||
986 | /* | |
987 | * Periodically prints torture statistics, if periodic statistics printing | |
988 | * was specified via the stat_interval module parameter. | |
989 | * | |
990 | * No need to worry about fullstop here, since this one doesn't reference | |
991 | * volatile state or register callbacks. | |
992 | */ | |
993 | static int | |
994 | rcu_torture_stats(void *arg) | |
995 | { | |
996 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
997 | do { | |
998 | schedule_timeout_interruptible(stat_interval * HZ); | |
999 | rcu_torture_stats_print(); | |
c9d557c1 PM |
1000 | rcutorture_shutdown_absorb("rcu_torture_stats"); |
1001 | } while (!kthread_should_stop()); | |
a241ec65 PM |
1002 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
1003 | return 0; | |
1004 | } | |
1005 | ||
d84f5203 SV |
1006 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
1007 | ||
1008 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
1009 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
1010 | */ | |
b2896d2e | 1011 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 | 1012 | { |
d84f5203 SV |
1013 | int i; |
1014 | ||
73d0a4b1 | 1015 | cpumask_setall(shuffle_tmp_mask); |
86ef5c9a | 1016 | get_online_cpus(); |
d84f5203 SV |
1017 | |
1018 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
c9d557c1 PM |
1019 | if (num_online_cpus() == 1) { |
1020 | put_online_cpus(); | |
1021 | return; | |
1022 | } | |
d84f5203 SV |
1023 | |
1024 | if (rcu_idle_cpu != -1) | |
73d0a4b1 | 1025 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); |
d84f5203 | 1026 | |
73d0a4b1 | 1027 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); |
d84f5203 | 1028 | |
c8e5b163 | 1029 | if (reader_tasks) { |
d84f5203 SV |
1030 | for (i = 0; i < nrealreaders; i++) |
1031 | if (reader_tasks[i]) | |
f70316da | 1032 | set_cpus_allowed_ptr(reader_tasks[i], |
73d0a4b1 | 1033 | shuffle_tmp_mask); |
d84f5203 SV |
1034 | } |
1035 | ||
c8e5b163 | 1036 | if (fakewriter_tasks) { |
b772e1dd JT |
1037 | for (i = 0; i < nfakewriters; i++) |
1038 | if (fakewriter_tasks[i]) | |
f70316da | 1039 | set_cpus_allowed_ptr(fakewriter_tasks[i], |
73d0a4b1 | 1040 | shuffle_tmp_mask); |
b772e1dd JT |
1041 | } |
1042 | ||
d84f5203 | 1043 | if (writer_task) |
73d0a4b1 | 1044 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); |
d84f5203 SV |
1045 | |
1046 | if (stats_task) | |
73d0a4b1 | 1047 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); |
d84f5203 SV |
1048 | |
1049 | if (rcu_idle_cpu == -1) | |
1050 | rcu_idle_cpu = num_online_cpus() - 1; | |
1051 | else | |
1052 | rcu_idle_cpu--; | |
1053 | ||
86ef5c9a | 1054 | put_online_cpus(); |
d84f5203 SV |
1055 | } |
1056 | ||
1057 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
1058 | * system to become idle at a time and cut off its timer ticks. This is meant | |
1059 | * to test the support for such tickless idle CPU in RCU. | |
1060 | */ | |
1061 | static int | |
1062 | rcu_torture_shuffle(void *arg) | |
1063 | { | |
1064 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
1065 | do { | |
1066 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1067 | rcu_torture_shuffle_tasks(); | |
c9d557c1 PM |
1068 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); |
1069 | } while (!kthread_should_stop()); | |
d84f5203 SV |
1070 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
1071 | return 0; | |
1072 | } | |
1073 | ||
d120f65f PM |
1074 | /* Cause the rcutorture test to "stutter", starting and stopping all |
1075 | * threads periodically. | |
1076 | */ | |
1077 | static int | |
1078 | rcu_torture_stutter(void *arg) | |
1079 | { | |
1080 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1081 | do { | |
1082 | schedule_timeout_interruptible(stutter * HZ); | |
1083 | stutter_pause_test = 1; | |
c9d557c1 | 1084 | if (!kthread_should_stop()) |
d120f65f PM |
1085 | schedule_timeout_interruptible(stutter * HZ); |
1086 | stutter_pause_test = 0; | |
c9d557c1 PM |
1087 | rcutorture_shutdown_absorb("rcu_torture_stutter"); |
1088 | } while (!kthread_should_stop()); | |
d120f65f PM |
1089 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); |
1090 | return 0; | |
1091 | } | |
1092 | ||
95c38322 PM |
1093 | static inline void |
1094 | rcu_torture_print_module_parms(char *tag) | |
1095 | { | |
b772e1dd JT |
1096 | printk(KERN_ALERT "%s" TORTURE_FLAG |
1097 | "--- %s: nreaders=%d nfakewriters=%d " | |
95c38322 | 1098 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
bf66f18e PM |
1099 | "shuffle_interval=%d stutter=%d irqreader=%d " |
1100 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d\n", | |
b772e1dd | 1101 | torture_type, tag, nrealreaders, nfakewriters, |
d120f65f | 1102 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, |
bf66f18e | 1103 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter); |
95c38322 PM |
1104 | } |
1105 | ||
343e9099 PM |
1106 | static struct notifier_block rcutorture_nb = { |
1107 | .notifier_call = rcutorture_shutdown_notify, | |
1108 | }; | |
1109 | ||
a241ec65 PM |
1110 | static void |
1111 | rcu_torture_cleanup(void) | |
1112 | { | |
1113 | int i; | |
1114 | ||
343e9099 | 1115 | mutex_lock(&fullstop_mutex); |
c9d557c1 PM |
1116 | if (fullstop == FULLSTOP_SHUTDOWN) { |
1117 | printk(KERN_WARNING /* but going down anyway, so... */ | |
1118 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
343e9099 | 1119 | mutex_unlock(&fullstop_mutex); |
c9d557c1 | 1120 | schedule_timeout_uninterruptible(10); |
343e9099 PM |
1121 | if (cur_ops->cb_barrier != NULL) |
1122 | cur_ops->cb_barrier(); | |
1123 | return; | |
1124 | } | |
c9d557c1 | 1125 | fullstop = FULLSTOP_RMMOD; |
343e9099 PM |
1126 | mutex_unlock(&fullstop_mutex); |
1127 | unregister_reboot_notifier(&rcutorture_nb); | |
d120f65f PM |
1128 | if (stutter_task) { |
1129 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1130 | kthread_stop(stutter_task); | |
1131 | } | |
1132 | stutter_task = NULL; | |
c8e5b163 | 1133 | if (shuffler_task) { |
d84f5203 SV |
1134 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
1135 | kthread_stop(shuffler_task); | |
73d0a4b1 | 1136 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1137 | } |
1138 | shuffler_task = NULL; | |
1139 | ||
c8e5b163 | 1140 | if (writer_task) { |
a241ec65 PM |
1141 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
1142 | kthread_stop(writer_task); | |
1143 | } | |
1144 | writer_task = NULL; | |
1145 | ||
c8e5b163 | 1146 | if (reader_tasks) { |
a241ec65 | 1147 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 1148 | if (reader_tasks[i]) { |
a241ec65 PM |
1149 | VERBOSE_PRINTK_STRING( |
1150 | "Stopping rcu_torture_reader task"); | |
1151 | kthread_stop(reader_tasks[i]); | |
1152 | } | |
1153 | reader_tasks[i] = NULL; | |
1154 | } | |
1155 | kfree(reader_tasks); | |
1156 | reader_tasks = NULL; | |
1157 | } | |
1158 | rcu_torture_current = NULL; | |
1159 | ||
c8e5b163 | 1160 | if (fakewriter_tasks) { |
b772e1dd | 1161 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 1162 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
1163 | VERBOSE_PRINTK_STRING( |
1164 | "Stopping rcu_torture_fakewriter task"); | |
1165 | kthread_stop(fakewriter_tasks[i]); | |
1166 | } | |
1167 | fakewriter_tasks[i] = NULL; | |
1168 | } | |
1169 | kfree(fakewriter_tasks); | |
1170 | fakewriter_tasks = NULL; | |
1171 | } | |
1172 | ||
c8e5b163 | 1173 | if (stats_task) { |
a241ec65 PM |
1174 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
1175 | kthread_stop(stats_task); | |
1176 | } | |
1177 | stats_task = NULL; | |
1178 | ||
bf66f18e PM |
1179 | if (fqs_task) { |
1180 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task"); | |
1181 | kthread_stop(fqs_task); | |
1182 | } | |
1183 | fqs_task = NULL; | |
1184 | ||
a241ec65 | 1185 | /* Wait for all RCU callbacks to fire. */ |
2326974d PM |
1186 | |
1187 | if (cur_ops->cb_barrier != NULL) | |
1188 | cur_ops->cb_barrier(); | |
a241ec65 | 1189 | |
a241ec65 | 1190 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 1191 | |
c8e5b163 | 1192 | if (cur_ops->cleanup) |
72e9bb54 | 1193 | cur_ops->cleanup(); |
95c38322 PM |
1194 | if (atomic_read(&n_rcu_torture_error)) |
1195 | rcu_torture_print_module_parms("End of test: FAILURE"); | |
1196 | else | |
1197 | rcu_torture_print_module_parms("End of test: SUCCESS"); | |
a241ec65 PM |
1198 | } |
1199 | ||
6f8bc500 | 1200 | static int __init |
a241ec65 PM |
1201 | rcu_torture_init(void) |
1202 | { | |
1203 | int i; | |
1204 | int cpu; | |
1205 | int firsterr = 0; | |
ade5fb81 | 1206 | static struct rcu_torture_ops *torture_ops[] = |
d9a3da06 PM |
1207 | { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops, |
1208 | &rcu_bh_ops, &rcu_bh_sync_ops, | |
804bb837 PM |
1209 | &srcu_ops, &srcu_expedited_ops, |
1210 | &sched_ops, &sched_sync_ops, &sched_expedited_ops, }; | |
a241ec65 | 1211 | |
343e9099 PM |
1212 | mutex_lock(&fullstop_mutex); |
1213 | ||
a241ec65 | 1214 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 1215 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 1216 | cur_ops = torture_ops[i]; |
ade5fb81 | 1217 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 1218 | break; |
72e9bb54 | 1219 | } |
ade5fb81 | 1220 | if (i == ARRAY_SIZE(torture_ops)) { |
cf886c44 | 1221 | printk(KERN_ALERT "rcu-torture: invalid torture type: \"%s\"\n", |
72e9bb54 | 1222 | torture_type); |
cf886c44 PM |
1223 | printk(KERN_ALERT "rcu-torture types:"); |
1224 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
1225 | printk(KERN_ALERT " %s", torture_ops[i]->name); | |
1226 | printk(KERN_ALERT "\n"); | |
343e9099 | 1227 | mutex_unlock(&fullstop_mutex); |
a71fca58 | 1228 | return -EINVAL; |
72e9bb54 | 1229 | } |
bf66f18e PM |
1230 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
1231 | printk(KERN_ALERT "rcu-torture: ->fqs NULL and non-zero " | |
1232 | "fqs_duration, fqs disabled.\n"); | |
1233 | fqs_duration = 0; | |
1234 | } | |
c8e5b163 | 1235 | if (cur_ops->init) |
72e9bb54 PM |
1236 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
1237 | ||
a241ec65 PM |
1238 | if (nreaders >= 0) |
1239 | nrealreaders = nreaders; | |
1240 | else | |
1241 | nrealreaders = 2 * num_online_cpus(); | |
95c38322 | 1242 | rcu_torture_print_module_parms("Start of test"); |
c9d557c1 | 1243 | fullstop = FULLSTOP_DONTSTOP; |
a241ec65 PM |
1244 | |
1245 | /* Set up the freelist. */ | |
1246 | ||
1247 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 1248 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 1249 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
1250 | list_add_tail(&rcu_tortures[i].rtort_free, |
1251 | &rcu_torture_freelist); | |
1252 | } | |
1253 | ||
1254 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1255 | ||
1256 | rcu_torture_current = NULL; | |
1257 | rcu_torture_current_version = 0; | |
1258 | atomic_set(&n_rcu_torture_alloc, 0); | |
1259 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1260 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
1261 | atomic_set(&n_rcu_torture_mberror, 0); |
1262 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
1263 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
1264 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 1265 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1266 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1267 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1268 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1269 | } | |
1270 | } | |
1271 | ||
1272 | /* Start up the kthreads. */ | |
1273 | ||
1274 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
1275 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
1276 | "rcu_torture_writer"); | |
1277 | if (IS_ERR(writer_task)) { | |
1278 | firsterr = PTR_ERR(writer_task); | |
1279 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1280 | writer_task = NULL; | |
1281 | goto unwind; | |
1282 | } | |
b772e1dd | 1283 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
a71fca58 | 1284 | GFP_KERNEL); |
b772e1dd JT |
1285 | if (fakewriter_tasks == NULL) { |
1286 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1287 | firsterr = -ENOMEM; | |
1288 | goto unwind; | |
1289 | } | |
1290 | for (i = 0; i < nfakewriters; i++) { | |
1291 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
1292 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
a71fca58 | 1293 | "rcu_torture_fakewriter"); |
b772e1dd JT |
1294 | if (IS_ERR(fakewriter_tasks[i])) { |
1295 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
1296 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
1297 | fakewriter_tasks[i] = NULL; | |
1298 | goto unwind; | |
1299 | } | |
1300 | } | |
2860aaba | 1301 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
1302 | GFP_KERNEL); |
1303 | if (reader_tasks == NULL) { | |
1304 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1305 | firsterr = -ENOMEM; | |
1306 | goto unwind; | |
1307 | } | |
1308 | for (i = 0; i < nrealreaders; i++) { | |
1309 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
1310 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
1311 | "rcu_torture_reader"); | |
1312 | if (IS_ERR(reader_tasks[i])) { | |
1313 | firsterr = PTR_ERR(reader_tasks[i]); | |
1314 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
1315 | reader_tasks[i] = NULL; | |
1316 | goto unwind; | |
1317 | } | |
1318 | } | |
1319 | if (stat_interval > 0) { | |
1320 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
1321 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
1322 | "rcu_torture_stats"); | |
1323 | if (IS_ERR(stats_task)) { | |
1324 | firsterr = PTR_ERR(stats_task); | |
1325 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
1326 | stats_task = NULL; | |
1327 | goto unwind; | |
1328 | } | |
1329 | } | |
d84f5203 SV |
1330 | if (test_no_idle_hz) { |
1331 | rcu_idle_cpu = num_online_cpus() - 1; | |
73d0a4b1 RR |
1332 | |
1333 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
1334 | firsterr = -ENOMEM; | |
1335 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
1336 | goto unwind; | |
1337 | } | |
1338 | ||
d84f5203 SV |
1339 | /* Create the shuffler thread */ |
1340 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
1341 | "rcu_torture_shuffle"); | |
1342 | if (IS_ERR(shuffler_task)) { | |
73d0a4b1 | 1343 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1344 | firsterr = PTR_ERR(shuffler_task); |
1345 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
1346 | shuffler_task = NULL; | |
1347 | goto unwind; | |
1348 | } | |
1349 | } | |
d120f65f PM |
1350 | if (stutter < 0) |
1351 | stutter = 0; | |
1352 | if (stutter) { | |
1353 | /* Create the stutter thread */ | |
1354 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
1355 | "rcu_torture_stutter"); | |
1356 | if (IS_ERR(stutter_task)) { | |
1357 | firsterr = PTR_ERR(stutter_task); | |
1358 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
1359 | stutter_task = NULL; | |
1360 | goto unwind; | |
1361 | } | |
1362 | } | |
bf66f18e PM |
1363 | if (fqs_duration < 0) |
1364 | fqs_duration = 0; | |
1365 | if (fqs_duration) { | |
1366 | /* Create the stutter thread */ | |
1367 | fqs_task = kthread_run(rcu_torture_fqs, NULL, | |
1368 | "rcu_torture_fqs"); | |
1369 | if (IS_ERR(fqs_task)) { | |
1370 | firsterr = PTR_ERR(fqs_task); | |
1371 | VERBOSE_PRINTK_ERRSTRING("Failed to create fqs"); | |
1372 | fqs_task = NULL; | |
1373 | goto unwind; | |
1374 | } | |
1375 | } | |
343e9099 PM |
1376 | register_reboot_notifier(&rcutorture_nb); |
1377 | mutex_unlock(&fullstop_mutex); | |
a241ec65 PM |
1378 | return 0; |
1379 | ||
1380 | unwind: | |
343e9099 | 1381 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
1382 | rcu_torture_cleanup(); |
1383 | return firsterr; | |
1384 | } | |
1385 | ||
1386 | module_init(rcu_torture_init); | |
1387 | module_exit(rcu_torture_cleanup); |