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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> | |
60063497 | 36 | #include <linux/atomic.h> |
a241ec65 | 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). */ |
d5f546d8 PM |
64 | static int fqs_duration; /* Duration of bursts (us), 0 to disable. */ |
65 | static int fqs_holdoff; /* Hold time within burst (us). */ | |
bf66f18e | 66 | static int fqs_stutter = 3; /* Wait time between bursts (s). */ |
b58bdcca | 67 | static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */ |
d5f546d8 | 68 | static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */ |
8e8be45e PM |
69 | static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */ |
70 | static int test_boost_interval = 7; /* Interval between boost tests, seconds. */ | |
71 | static int test_boost_duration = 4; /* Duration of each boost test, seconds. */ | |
20d2e428 | 72 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ |
a241ec65 | 73 | |
d6ad6711 | 74 | module_param(nreaders, int, 0444); |
a241ec65 | 75 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
d6ad6711 | 76 | module_param(nfakewriters, int, 0444); |
b772e1dd | 77 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); |
3721bc1d | 78 | module_param(stat_interval, int, 0644); |
a241ec65 | 79 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
d6ad6711 | 80 | module_param(verbose, bool, 0444); |
a241ec65 | 81 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
d6ad6711 | 82 | module_param(test_no_idle_hz, bool, 0444); |
d84f5203 | 83 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
d6ad6711 | 84 | module_param(shuffle_interval, int, 0444); |
d84f5203 | 85 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
d120f65f PM |
86 | module_param(stutter, int, 0444); |
87 | MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); | |
0729fbf3 PM |
88 | module_param(irqreader, int, 0444); |
89 | MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); | |
bf66f18e PM |
90 | module_param(fqs_duration, int, 0444); |
91 | MODULE_PARM_DESC(fqs_duration, "Duration of fqs bursts (us)"); | |
92 | module_param(fqs_holdoff, int, 0444); | |
93 | MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)"); | |
94 | module_param(fqs_stutter, int, 0444); | |
95 | MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)"); | |
b58bdcca PM |
96 | module_param(onoff_interval, int, 0444); |
97 | MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable"); | |
d5f546d8 PM |
98 | module_param(shutdown_secs, int, 0444); |
99 | MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable."); | |
8e8be45e PM |
100 | module_param(test_boost, int, 0444); |
101 | MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); | |
102 | module_param(test_boost_interval, int, 0444); | |
103 | MODULE_PARM_DESC(test_boost_interval, "Interval between boost tests, seconds."); | |
104 | module_param(test_boost_duration, int, 0444); | |
105 | MODULE_PARM_DESC(test_boost_duration, "Duration of each boost test, seconds."); | |
d6ad6711 | 106 | module_param(torture_type, charp, 0444); |
b2896d2e | 107 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
108 | |
109 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 110 | #define PRINTK_STRING(s) \ |
72e9bb54 | 111 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 112 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 113 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 114 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 115 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
116 | |
117 | static char printk_buf[4096]; | |
118 | ||
119 | static int nrealreaders; | |
120 | static struct task_struct *writer_task; | |
b772e1dd | 121 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
122 | static struct task_struct **reader_tasks; |
123 | static struct task_struct *stats_task; | |
d84f5203 | 124 | static struct task_struct *shuffler_task; |
d120f65f | 125 | static struct task_struct *stutter_task; |
bf66f18e | 126 | static struct task_struct *fqs_task; |
8e8be45e | 127 | static struct task_struct *boost_tasks[NR_CPUS]; |
d5f546d8 | 128 | static struct task_struct *shutdown_task; |
b58bdcca PM |
129 | #ifdef CONFIG_HOTPLUG_CPU |
130 | static struct task_struct *onoff_task; | |
131 | #endif /* #ifdef CONFIG_HOTPLUG_CPU */ | |
a241ec65 PM |
132 | |
133 | #define RCU_TORTURE_PIPE_LEN 10 | |
134 | ||
135 | struct rcu_torture { | |
136 | struct rcu_head rtort_rcu; | |
137 | int rtort_pipe_count; | |
138 | struct list_head rtort_free; | |
996417d2 | 139 | int rtort_mbtest; |
a241ec65 PM |
140 | }; |
141 | ||
a241ec65 | 142 | static LIST_HEAD(rcu_torture_freelist); |
0ddea0ea | 143 | static struct rcu_torture __rcu *rcu_torture_current; |
4a298656 | 144 | static unsigned long rcu_torture_current_version; |
a241ec65 PM |
145 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
146 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
147 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
148 | { 0 }; | |
149 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
150 | { 0 }; | |
151 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
152 | static atomic_t n_rcu_torture_alloc; |
153 | static atomic_t n_rcu_torture_alloc_fail; | |
154 | static atomic_t n_rcu_torture_free; | |
155 | static atomic_t n_rcu_torture_mberror; | |
156 | static atomic_t n_rcu_torture_error; | |
8e8be45e PM |
157 | static long n_rcu_torture_boost_ktrerror; |
158 | static long n_rcu_torture_boost_rterror; | |
8e8be45e PM |
159 | static long n_rcu_torture_boost_failure; |
160 | static long n_rcu_torture_boosts; | |
a71fca58 | 161 | static long n_rcu_torture_timers; |
b58bdcca PM |
162 | static long n_offline_attempts; |
163 | static long n_offline_successes; | |
164 | static long n_online_attempts; | |
165 | static long n_online_successes; | |
e3033736 | 166 | static struct list_head rcu_torture_removed; |
73d0a4b1 | 167 | static cpumask_var_t shuffle_tmp_mask; |
a241ec65 | 168 | |
a71fca58 | 169 | static int stutter_pause_test; |
d120f65f | 170 | |
31a72bce PM |
171 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) |
172 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
173 | #else | |
174 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
175 | #endif | |
176 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
bb3bf705 PM |
177 | module_param(rcutorture_runnable, int, 0444); |
178 | MODULE_PARM_DESC(rcutorture_runnable, "Start rcutorture at boot"); | |
31a72bce | 179 | |
3acf4a9a | 180 | #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) |
8e8be45e | 181 | #define rcu_can_boost() 1 |
3acf4a9a | 182 | #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 183 | #define rcu_can_boost() 0 |
3acf4a9a | 184 | #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ |
8e8be45e | 185 | |
d5f546d8 | 186 | static unsigned long shutdown_time; /* jiffies to system shutdown. */ |
8e8be45e PM |
187 | static unsigned long boost_starttime; /* jiffies of next boost test start. */ |
188 | DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ | |
189 | /* and boost task create/destroy. */ | |
190 | ||
c9d557c1 PM |
191 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
192 | ||
193 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
194 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
195 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
196 | static int fullstop = FULLSTOP_RMMOD; | |
0ddea0ea PM |
197 | /* |
198 | * Protect fullstop transitions and spawning of kthreads. | |
199 | */ | |
200 | static DEFINE_MUTEX(fullstop_mutex); | |
343e9099 | 201 | |
d5f546d8 PM |
202 | /* Forward reference. */ |
203 | static void rcu_torture_cleanup(void); | |
204 | ||
343e9099 | 205 | /* |
c9d557c1 | 206 | * Detect and respond to a system shutdown. |
343e9099 PM |
207 | */ |
208 | static int | |
209 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
210 | unsigned long unused2, void *unused3) | |
211 | { | |
c59ab97e | 212 | mutex_lock(&fullstop_mutex); |
c9d557c1 | 213 | if (fullstop == FULLSTOP_DONTSTOP) |
c59ab97e | 214 | fullstop = FULLSTOP_SHUTDOWN; |
c9d557c1 PM |
215 | else |
216 | printk(KERN_WARNING /* but going down anyway, so... */ | |
217 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
c59ab97e | 218 | mutex_unlock(&fullstop_mutex); |
343e9099 PM |
219 | return NOTIFY_DONE; |
220 | } | |
221 | ||
c9d557c1 PM |
222 | /* |
223 | * Absorb kthreads into a kernel function that won't return, so that | |
224 | * they won't ever access module text or data again. | |
225 | */ | |
226 | static void rcutorture_shutdown_absorb(char *title) | |
227 | { | |
228 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
229 | printk(KERN_NOTICE | |
230 | "rcutorture thread %s parking due to system shutdown\n", | |
231 | title); | |
232 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
233 | } | |
234 | } | |
235 | ||
a241ec65 PM |
236 | /* |
237 | * Allocate an element from the rcu_tortures pool. | |
238 | */ | |
97a41e26 | 239 | static struct rcu_torture * |
a241ec65 PM |
240 | rcu_torture_alloc(void) |
241 | { | |
242 | struct list_head *p; | |
243 | ||
adac1665 | 244 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
245 | if (list_empty(&rcu_torture_freelist)) { |
246 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 247 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
248 | return NULL; |
249 | } | |
250 | atomic_inc(&n_rcu_torture_alloc); | |
251 | p = rcu_torture_freelist.next; | |
252 | list_del_init(p); | |
adac1665 | 253 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
254 | return container_of(p, struct rcu_torture, rtort_free); |
255 | } | |
256 | ||
257 | /* | |
258 | * Free an element to the rcu_tortures pool. | |
259 | */ | |
260 | static void | |
261 | rcu_torture_free(struct rcu_torture *p) | |
262 | { | |
263 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 264 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 265 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 266 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
267 | } |
268 | ||
a241ec65 PM |
269 | struct rcu_random_state { |
270 | unsigned long rrs_state; | |
75cfef32 | 271 | long rrs_count; |
a241ec65 PM |
272 | }; |
273 | ||
274 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
275 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
276 | #define RCU_RANDOM_REFRESH 10000 | |
277 | ||
278 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
279 | ||
280 | /* | |
281 | * Crude but fast random-number generator. Uses a linear congruential | |
c17ac855 | 282 | * generator, with occasional help from cpu_clock(). |
a241ec65 | 283 | */ |
75cfef32 | 284 | static unsigned long |
a241ec65 PM |
285 | rcu_random(struct rcu_random_state *rrsp) |
286 | { | |
a241ec65 | 287 | if (--rrsp->rrs_count < 0) { |
c676329a | 288 | rrsp->rrs_state += (unsigned long)local_clock(); |
a241ec65 PM |
289 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
290 | } | |
291 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
292 | return swahw32(rrsp->rrs_state); | |
293 | } | |
294 | ||
d120f65f | 295 | static void |
c9d557c1 | 296 | rcu_stutter_wait(char *title) |
d120f65f | 297 | { |
c9d557c1 | 298 | while (stutter_pause_test || !rcutorture_runnable) { |
e3d7be27 PM |
299 | if (rcutorture_runnable) |
300 | schedule_timeout_interruptible(1); | |
301 | else | |
3ccf79f4 | 302 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
c9d557c1 | 303 | rcutorture_shutdown_absorb(title); |
343e9099 | 304 | } |
d120f65f PM |
305 | } |
306 | ||
72e9bb54 PM |
307 | /* |
308 | * Operations vector for selecting different types of tests. | |
309 | */ | |
310 | ||
311 | struct rcu_torture_ops { | |
312 | void (*init)(void); | |
313 | void (*cleanup)(void); | |
314 | int (*readlock)(void); | |
0acc512c | 315 | void (*read_delay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
316 | void (*readunlock)(int idx); |
317 | int (*completed)(void); | |
0acc512c | 318 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 319 | void (*sync)(void); |
2326974d | 320 | void (*cb_barrier)(void); |
bf66f18e | 321 | void (*fqs)(void); |
72e9bb54 | 322 | int (*stats)(char *page); |
0acc512c | 323 | int irq_capable; |
8e8be45e | 324 | int can_boost; |
72e9bb54 PM |
325 | char *name; |
326 | }; | |
a71fca58 PM |
327 | |
328 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
329 | |
330 | /* | |
331 | * Definitions for rcu torture testing. | |
332 | */ | |
333 | ||
a49a4af7 | 334 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
335 | { |
336 | rcu_read_lock(); | |
337 | return 0; | |
338 | } | |
339 | ||
b2896d2e PM |
340 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
341 | { | |
b8d57a76 JT |
342 | const unsigned long shortdelay_us = 200; |
343 | const unsigned long longdelay_ms = 50; | |
b2896d2e | 344 | |
b8d57a76 JT |
345 | /* We want a short delay sometimes to make a reader delay the grace |
346 | * period, and we want a long delay occasionally to trigger | |
347 | * force_quiescent_state. */ | |
b2896d2e | 348 | |
b8d57a76 JT |
349 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) |
350 | mdelay(longdelay_ms); | |
351 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
352 | udelay(shortdelay_us); | |
e546f485 LJ |
353 | #ifdef CONFIG_PREEMPT |
354 | if (!preempt_count() && !(rcu_random(rrsp) % (nrealreaders * 20000))) | |
355 | preempt_schedule(); /* No QS if preempt_disable() in effect */ | |
356 | #endif | |
b2896d2e PM |
357 | } |
358 | ||
a49a4af7 | 359 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
360 | { |
361 | rcu_read_unlock(); | |
362 | } | |
363 | ||
364 | static int rcu_torture_completed(void) | |
365 | { | |
366 | return rcu_batches_completed(); | |
367 | } | |
368 | ||
369 | static void | |
370 | rcu_torture_cb(struct rcu_head *p) | |
371 | { | |
372 | int i; | |
373 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
374 | ||
c9d557c1 | 375 | if (fullstop != FULLSTOP_DONTSTOP) { |
72e9bb54 PM |
376 | /* Test is ending, just drop callbacks on the floor. */ |
377 | /* The next initialization will pick up the pieces. */ | |
378 | return; | |
379 | } | |
380 | i = rp->rtort_pipe_count; | |
381 | if (i > RCU_TORTURE_PIPE_LEN) | |
382 | i = RCU_TORTURE_PIPE_LEN; | |
383 | atomic_inc(&rcu_torture_wcount[i]); | |
384 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
385 | rp->rtort_mbtest = 0; | |
386 | rcu_torture_free(rp); | |
387 | } else | |
0acc512c | 388 | cur_ops->deferred_free(rp); |
72e9bb54 PM |
389 | } |
390 | ||
d9a3da06 PM |
391 | static int rcu_no_completed(void) |
392 | { | |
393 | return 0; | |
394 | } | |
395 | ||
72e9bb54 PM |
396 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
397 | { | |
398 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
399 | } | |
400 | ||
401 | static struct rcu_torture_ops rcu_ops = { | |
0acc512c PM |
402 | .init = NULL, |
403 | .cleanup = NULL, | |
404 | .readlock = rcu_torture_read_lock, | |
405 | .read_delay = rcu_read_delay, | |
406 | .readunlock = rcu_torture_read_unlock, | |
407 | .completed = rcu_torture_completed, | |
408 | .deferred_free = rcu_torture_deferred_free, | |
409 | .sync = synchronize_rcu, | |
410 | .cb_barrier = rcu_barrier, | |
bf66f18e | 411 | .fqs = rcu_force_quiescent_state, |
0acc512c | 412 | .stats = NULL, |
a71fca58 | 413 | .irq_capable = 1, |
8e8be45e | 414 | .can_boost = rcu_can_boost(), |
a71fca58 | 415 | .name = "rcu" |
72e9bb54 PM |
416 | }; |
417 | ||
e3033736 JT |
418 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) |
419 | { | |
420 | int i; | |
421 | struct rcu_torture *rp; | |
422 | struct rcu_torture *rp1; | |
423 | ||
424 | cur_ops->sync(); | |
425 | list_add(&p->rtort_free, &rcu_torture_removed); | |
426 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
427 | i = rp->rtort_pipe_count; | |
428 | if (i > RCU_TORTURE_PIPE_LEN) | |
429 | i = RCU_TORTURE_PIPE_LEN; | |
430 | atomic_inc(&rcu_torture_wcount[i]); | |
431 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
432 | rp->rtort_mbtest = 0; | |
433 | list_del(&rp->rtort_free); | |
434 | rcu_torture_free(rp); | |
435 | } | |
436 | } | |
437 | } | |
438 | ||
439 | static void rcu_sync_torture_init(void) | |
440 | { | |
441 | INIT_LIST_HEAD(&rcu_torture_removed); | |
442 | } | |
443 | ||
20d2e428 | 444 | static struct rcu_torture_ops rcu_sync_ops = { |
0acc512c PM |
445 | .init = rcu_sync_torture_init, |
446 | .cleanup = NULL, | |
447 | .readlock = rcu_torture_read_lock, | |
448 | .read_delay = rcu_read_delay, | |
449 | .readunlock = rcu_torture_read_unlock, | |
450 | .completed = rcu_torture_completed, | |
451 | .deferred_free = rcu_sync_torture_deferred_free, | |
452 | .sync = synchronize_rcu, | |
453 | .cb_barrier = NULL, | |
bf66f18e | 454 | .fqs = rcu_force_quiescent_state, |
0acc512c PM |
455 | .stats = NULL, |
456 | .irq_capable = 1, | |
8e8be45e | 457 | .can_boost = rcu_can_boost(), |
0acc512c | 458 | .name = "rcu_sync" |
20d2e428 JT |
459 | }; |
460 | ||
d9a3da06 PM |
461 | static struct rcu_torture_ops rcu_expedited_ops = { |
462 | .init = rcu_sync_torture_init, | |
463 | .cleanup = NULL, | |
464 | .readlock = rcu_torture_read_lock, | |
465 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
466 | .readunlock = rcu_torture_read_unlock, | |
467 | .completed = rcu_no_completed, | |
468 | .deferred_free = rcu_sync_torture_deferred_free, | |
469 | .sync = synchronize_rcu_expedited, | |
470 | .cb_barrier = NULL, | |
bf66f18e | 471 | .fqs = rcu_force_quiescent_state, |
d9a3da06 PM |
472 | .stats = NULL, |
473 | .irq_capable = 1, | |
8e8be45e | 474 | .can_boost = rcu_can_boost(), |
d9a3da06 PM |
475 | .name = "rcu_expedited" |
476 | }; | |
477 | ||
c32e0660 PM |
478 | /* |
479 | * Definitions for rcu_bh torture testing. | |
480 | */ | |
481 | ||
a49a4af7 | 482 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
483 | { |
484 | rcu_read_lock_bh(); | |
485 | return 0; | |
486 | } | |
487 | ||
a49a4af7 | 488 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
489 | { |
490 | rcu_read_unlock_bh(); | |
491 | } | |
492 | ||
493 | static int rcu_bh_torture_completed(void) | |
494 | { | |
495 | return rcu_batches_completed_bh(); | |
496 | } | |
497 | ||
498 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
499 | { | |
500 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
501 | } | |
502 | ||
503 | static struct rcu_torture_ops rcu_bh_ops = { | |
0acc512c PM |
504 | .init = NULL, |
505 | .cleanup = NULL, | |
506 | .readlock = rcu_bh_torture_read_lock, | |
507 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
508 | .readunlock = rcu_bh_torture_read_unlock, | |
509 | .completed = rcu_bh_torture_completed, | |
510 | .deferred_free = rcu_bh_torture_deferred_free, | |
bdf2a436 | 511 | .sync = synchronize_rcu_bh, |
0acc512c | 512 | .cb_barrier = rcu_barrier_bh, |
bf66f18e | 513 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
514 | .stats = NULL, |
515 | .irq_capable = 1, | |
516 | .name = "rcu_bh" | |
c32e0660 PM |
517 | }; |
518 | ||
11a14701 | 519 | static struct rcu_torture_ops rcu_bh_sync_ops = { |
0acc512c PM |
520 | .init = rcu_sync_torture_init, |
521 | .cleanup = NULL, | |
522 | .readlock = rcu_bh_torture_read_lock, | |
523 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
524 | .readunlock = rcu_bh_torture_read_unlock, | |
525 | .completed = rcu_bh_torture_completed, | |
526 | .deferred_free = rcu_sync_torture_deferred_free, | |
bdf2a436 | 527 | .sync = synchronize_rcu_bh, |
0acc512c | 528 | .cb_barrier = NULL, |
bf66f18e | 529 | .fqs = rcu_bh_force_quiescent_state, |
0acc512c PM |
530 | .stats = NULL, |
531 | .irq_capable = 1, | |
532 | .name = "rcu_bh_sync" | |
11a14701 JT |
533 | }; |
534 | ||
bdf2a436 PM |
535 | static struct rcu_torture_ops rcu_bh_expedited_ops = { |
536 | .init = rcu_sync_torture_init, | |
537 | .cleanup = NULL, | |
538 | .readlock = rcu_bh_torture_read_lock, | |
539 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
540 | .readunlock = rcu_bh_torture_read_unlock, | |
541 | .completed = rcu_bh_torture_completed, | |
542 | .deferred_free = rcu_sync_torture_deferred_free, | |
543 | .sync = synchronize_rcu_bh_expedited, | |
544 | .cb_barrier = NULL, | |
545 | .fqs = rcu_bh_force_quiescent_state, | |
546 | .stats = NULL, | |
547 | .irq_capable = 1, | |
548 | .name = "rcu_bh_expedited" | |
549 | }; | |
550 | ||
b2896d2e PM |
551 | /* |
552 | * Definitions for srcu torture testing. | |
553 | */ | |
554 | ||
555 | static struct srcu_struct srcu_ctl; | |
b2896d2e PM |
556 | |
557 | static void srcu_torture_init(void) | |
558 | { | |
559 | init_srcu_struct(&srcu_ctl); | |
e3033736 | 560 | rcu_sync_torture_init(); |
b2896d2e PM |
561 | } |
562 | ||
563 | static void srcu_torture_cleanup(void) | |
564 | { | |
565 | synchronize_srcu(&srcu_ctl); | |
566 | cleanup_srcu_struct(&srcu_ctl); | |
567 | } | |
568 | ||
012d3ca8 | 569 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
570 | { |
571 | return srcu_read_lock(&srcu_ctl); | |
572 | } | |
573 | ||
574 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
575 | { | |
576 | long delay; | |
577 | const long uspertick = 1000000 / HZ; | |
578 | const long longdelay = 10; | |
579 | ||
580 | /* We want there to be long-running readers, but not all the time. */ | |
581 | ||
582 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
583 | if (!delay) | |
584 | schedule_timeout_interruptible(longdelay); | |
e546f485 LJ |
585 | else |
586 | rcu_read_delay(rrsp); | |
b2896d2e PM |
587 | } |
588 | ||
012d3ca8 | 589 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
590 | { |
591 | srcu_read_unlock(&srcu_ctl, idx); | |
592 | } | |
593 | ||
594 | static int srcu_torture_completed(void) | |
595 | { | |
596 | return srcu_batches_completed(&srcu_ctl); | |
597 | } | |
598 | ||
b772e1dd JT |
599 | static void srcu_torture_synchronize(void) |
600 | { | |
601 | synchronize_srcu(&srcu_ctl); | |
602 | } | |
603 | ||
b2896d2e PM |
604 | static int srcu_torture_stats(char *page) |
605 | { | |
606 | int cnt = 0; | |
607 | int cpu; | |
608 | int idx = srcu_ctl.completed & 0x1; | |
609 | ||
610 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
611 | torture_type, TORTURE_FLAG, idx); | |
612 | for_each_possible_cpu(cpu) { | |
613 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
614 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
615 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
616 | } | |
617 | cnt += sprintf(&page[cnt], "\n"); | |
618 | return cnt; | |
619 | } | |
620 | ||
621 | static struct rcu_torture_ops srcu_ops = { | |
0acc512c PM |
622 | .init = srcu_torture_init, |
623 | .cleanup = srcu_torture_cleanup, | |
624 | .readlock = srcu_torture_read_lock, | |
625 | .read_delay = srcu_read_delay, | |
626 | .readunlock = srcu_torture_read_unlock, | |
627 | .completed = srcu_torture_completed, | |
628 | .deferred_free = rcu_sync_torture_deferred_free, | |
629 | .sync = srcu_torture_synchronize, | |
630 | .cb_barrier = NULL, | |
631 | .stats = srcu_torture_stats, | |
632 | .name = "srcu" | |
b2896d2e PM |
633 | }; |
634 | ||
804bb837 PM |
635 | static void srcu_torture_synchronize_expedited(void) |
636 | { | |
637 | synchronize_srcu_expedited(&srcu_ctl); | |
638 | } | |
639 | ||
640 | static struct rcu_torture_ops srcu_expedited_ops = { | |
641 | .init = srcu_torture_init, | |
642 | .cleanup = srcu_torture_cleanup, | |
643 | .readlock = srcu_torture_read_lock, | |
644 | .read_delay = srcu_read_delay, | |
645 | .readunlock = srcu_torture_read_unlock, | |
646 | .completed = srcu_torture_completed, | |
647 | .deferred_free = rcu_sync_torture_deferred_free, | |
648 | .sync = srcu_torture_synchronize_expedited, | |
649 | .cb_barrier = NULL, | |
650 | .stats = srcu_torture_stats, | |
651 | .name = "srcu_expedited" | |
652 | }; | |
653 | ||
4b6c2cca JT |
654 | /* |
655 | * Definitions for sched torture testing. | |
656 | */ | |
657 | ||
658 | static int sched_torture_read_lock(void) | |
659 | { | |
660 | preempt_disable(); | |
661 | return 0; | |
662 | } | |
663 | ||
664 | static void sched_torture_read_unlock(int idx) | |
665 | { | |
666 | preempt_enable(); | |
667 | } | |
668 | ||
2326974d PM |
669 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) |
670 | { | |
671 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
672 | } | |
673 | ||
4b6c2cca | 674 | static struct rcu_torture_ops sched_ops = { |
0acc512c PM |
675 | .init = rcu_sync_torture_init, |
676 | .cleanup = NULL, | |
677 | .readlock = sched_torture_read_lock, | |
678 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
679 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 680 | .completed = rcu_no_completed, |
0acc512c | 681 | .deferred_free = rcu_sched_torture_deferred_free, |
bdf2a436 | 682 | .sync = synchronize_sched, |
0acc512c | 683 | .cb_barrier = rcu_barrier_sched, |
bf66f18e | 684 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
685 | .stats = NULL, |
686 | .irq_capable = 1, | |
687 | .name = "sched" | |
4b6c2cca JT |
688 | }; |
689 | ||
804bb837 | 690 | static struct rcu_torture_ops sched_sync_ops = { |
0acc512c PM |
691 | .init = rcu_sync_torture_init, |
692 | .cleanup = NULL, | |
693 | .readlock = sched_torture_read_lock, | |
694 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
695 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 696 | .completed = rcu_no_completed, |
0acc512c | 697 | .deferred_free = rcu_sync_torture_deferred_free, |
bdf2a436 | 698 | .sync = synchronize_sched, |
0acc512c | 699 | .cb_barrier = NULL, |
bf66f18e | 700 | .fqs = rcu_sched_force_quiescent_state, |
0acc512c PM |
701 | .stats = NULL, |
702 | .name = "sched_sync" | |
703 | }; | |
704 | ||
0acc512c PM |
705 | static struct rcu_torture_ops sched_expedited_ops = { |
706 | .init = rcu_sync_torture_init, | |
707 | .cleanup = NULL, | |
708 | .readlock = sched_torture_read_lock, | |
709 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
710 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 711 | .completed = rcu_no_completed, |
0acc512c PM |
712 | .deferred_free = rcu_sync_torture_deferred_free, |
713 | .sync = synchronize_sched_expedited, | |
714 | .cb_barrier = NULL, | |
bf66f18e | 715 | .fqs = rcu_sched_force_quiescent_state, |
969c7921 | 716 | .stats = NULL, |
0acc512c PM |
717 | .irq_capable = 1, |
718 | .name = "sched_expedited" | |
2326974d PM |
719 | }; |
720 | ||
8e8be45e PM |
721 | /* |
722 | * RCU torture priority-boost testing. Runs one real-time thread per | |
723 | * CPU for moderate bursts, repeatedly registering RCU callbacks and | |
724 | * spinning waiting for them to be invoked. If a given callback takes | |
725 | * too long to be invoked, we assume that priority inversion has occurred. | |
726 | */ | |
727 | ||
728 | struct rcu_boost_inflight { | |
729 | struct rcu_head rcu; | |
730 | int inflight; | |
731 | }; | |
732 | ||
733 | static void rcu_torture_boost_cb(struct rcu_head *head) | |
734 | { | |
735 | struct rcu_boost_inflight *rbip = | |
736 | container_of(head, struct rcu_boost_inflight, rcu); | |
737 | ||
738 | smp_mb(); /* Ensure RCU-core accesses precede clearing ->inflight */ | |
739 | rbip->inflight = 0; | |
740 | } | |
741 | ||
742 | static int rcu_torture_boost(void *arg) | |
743 | { | |
744 | unsigned long call_rcu_time; | |
745 | unsigned long endtime; | |
746 | unsigned long oldstarttime; | |
747 | struct rcu_boost_inflight rbi = { .inflight = 0 }; | |
748 | struct sched_param sp; | |
749 | ||
750 | VERBOSE_PRINTK_STRING("rcu_torture_boost started"); | |
751 | ||
752 | /* Set real-time priority. */ | |
753 | sp.sched_priority = 1; | |
754 | if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { | |
755 | VERBOSE_PRINTK_STRING("rcu_torture_boost RT prio failed!"); | |
756 | n_rcu_torture_boost_rterror++; | |
757 | } | |
758 | ||
561190e3 | 759 | init_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
760 | /* Each pass through the following loop does one boost-test cycle. */ |
761 | do { | |
762 | /* Wait for the next test interval. */ | |
763 | oldstarttime = boost_starttime; | |
93898fb1 | 764 | while (ULONG_CMP_LT(jiffies, oldstarttime)) { |
8e8be45e PM |
765 | schedule_timeout_uninterruptible(1); |
766 | rcu_stutter_wait("rcu_torture_boost"); | |
767 | if (kthread_should_stop() || | |
768 | fullstop != FULLSTOP_DONTSTOP) | |
769 | goto checkwait; | |
770 | } | |
771 | ||
772 | /* Do one boost-test interval. */ | |
773 | endtime = oldstarttime + test_boost_duration * HZ; | |
774 | call_rcu_time = jiffies; | |
93898fb1 | 775 | while (ULONG_CMP_LT(jiffies, endtime)) { |
8e8be45e PM |
776 | /* If we don't have a callback in flight, post one. */ |
777 | if (!rbi.inflight) { | |
778 | smp_mb(); /* RCU core before ->inflight = 1. */ | |
779 | rbi.inflight = 1; | |
780 | call_rcu(&rbi.rcu, rcu_torture_boost_cb); | |
781 | if (jiffies - call_rcu_time > | |
782 | test_boost_duration * HZ - HZ / 2) { | |
783 | VERBOSE_PRINTK_STRING("rcu_torture_boost boosting failed"); | |
784 | n_rcu_torture_boost_failure++; | |
785 | } | |
786 | call_rcu_time = jiffies; | |
787 | } | |
788 | cond_resched(); | |
789 | rcu_stutter_wait("rcu_torture_boost"); | |
790 | if (kthread_should_stop() || | |
791 | fullstop != FULLSTOP_DONTSTOP) | |
792 | goto checkwait; | |
793 | } | |
794 | ||
795 | /* | |
796 | * Set the start time of the next test interval. | |
797 | * Yes, this is vulnerable to long delays, but such | |
798 | * delays simply cause a false negative for the next | |
799 | * interval. Besides, we are running at RT priority, | |
800 | * so delays should be relatively rare. | |
801 | */ | |
ab8f11e5 PM |
802 | while (oldstarttime == boost_starttime && |
803 | !kthread_should_stop()) { | |
8e8be45e PM |
804 | if (mutex_trylock(&boost_mutex)) { |
805 | boost_starttime = jiffies + | |
806 | test_boost_interval * HZ; | |
807 | n_rcu_torture_boosts++; | |
808 | mutex_unlock(&boost_mutex); | |
809 | break; | |
810 | } | |
811 | schedule_timeout_uninterruptible(1); | |
812 | } | |
813 | ||
814 | /* Go do the stutter. */ | |
815 | checkwait: rcu_stutter_wait("rcu_torture_boost"); | |
816 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
817 | ||
818 | /* Clean up and exit. */ | |
819 | VERBOSE_PRINTK_STRING("rcu_torture_boost task stopping"); | |
820 | rcutorture_shutdown_absorb("rcu_torture_boost"); | |
821 | while (!kthread_should_stop() || rbi.inflight) | |
822 | schedule_timeout_uninterruptible(1); | |
823 | smp_mb(); /* order accesses to ->inflight before stack-frame death. */ | |
9d68197c | 824 | destroy_rcu_head_on_stack(&rbi.rcu); |
8e8be45e PM |
825 | return 0; |
826 | } | |
827 | ||
bf66f18e PM |
828 | /* |
829 | * RCU torture force-quiescent-state kthread. Repeatedly induces | |
830 | * bursts of calls to force_quiescent_state(), increasing the probability | |
831 | * of occurrence of some important types of race conditions. | |
832 | */ | |
833 | static int | |
834 | rcu_torture_fqs(void *arg) | |
835 | { | |
836 | unsigned long fqs_resume_time; | |
837 | int fqs_burst_remaining; | |
838 | ||
839 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task started"); | |
840 | do { | |
841 | fqs_resume_time = jiffies + fqs_stutter * HZ; | |
93898fb1 PM |
842 | while (ULONG_CMP_LT(jiffies, fqs_resume_time) && |
843 | !kthread_should_stop()) { | |
bf66f18e PM |
844 | schedule_timeout_interruptible(1); |
845 | } | |
846 | fqs_burst_remaining = fqs_duration; | |
93898fb1 PM |
847 | while (fqs_burst_remaining > 0 && |
848 | !kthread_should_stop()) { | |
bf66f18e PM |
849 | cur_ops->fqs(); |
850 | udelay(fqs_holdoff); | |
851 | fqs_burst_remaining -= fqs_holdoff; | |
852 | } | |
853 | rcu_stutter_wait("rcu_torture_fqs"); | |
854 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
855 | VERBOSE_PRINTK_STRING("rcu_torture_fqs task stopping"); | |
856 | rcutorture_shutdown_absorb("rcu_torture_fqs"); | |
857 | while (!kthread_should_stop()) | |
858 | schedule_timeout_uninterruptible(1); | |
859 | return 0; | |
860 | } | |
861 | ||
a241ec65 PM |
862 | /* |
863 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
864 | * for that pointed to by rcu_torture_current, freeing the old structure | |
865 | * after a series of grace periods (the "pipeline"). | |
866 | */ | |
867 | static int | |
868 | rcu_torture_writer(void *arg) | |
869 | { | |
870 | int i; | |
871 | long oldbatch = rcu_batches_completed(); | |
872 | struct rcu_torture *rp; | |
873 | struct rcu_torture *old_rp; | |
874 | static DEFINE_RCU_RANDOM(rand); | |
875 | ||
876 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
877 | set_user_nice(current, 19); |
878 | ||
a241ec65 PM |
879 | do { |
880 | schedule_timeout_uninterruptible(1); | |
a71fca58 PM |
881 | rp = rcu_torture_alloc(); |
882 | if (rp == NULL) | |
a241ec65 PM |
883 | continue; |
884 | rp->rtort_pipe_count = 0; | |
885 | udelay(rcu_random(&rand) & 0x3ff); | |
0ddea0ea PM |
886 | old_rp = rcu_dereference_check(rcu_torture_current, |
887 | current == writer_task); | |
996417d2 | 888 | rp->rtort_mbtest = 1; |
a241ec65 | 889 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 890 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 891 | if (old_rp) { |
a241ec65 PM |
892 | i = old_rp->rtort_pipe_count; |
893 | if (i > RCU_TORTURE_PIPE_LEN) | |
894 | i = RCU_TORTURE_PIPE_LEN; | |
895 | atomic_inc(&rcu_torture_wcount[i]); | |
896 | old_rp->rtort_pipe_count++; | |
0acc512c | 897 | cur_ops->deferred_free(old_rp); |
a241ec65 | 898 | } |
4a298656 | 899 | rcutorture_record_progress(++rcu_torture_current_version); |
72e9bb54 | 900 | oldbatch = cur_ops->completed(); |
c9d557c1 PM |
901 | rcu_stutter_wait("rcu_torture_writer"); |
902 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 903 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
c9d557c1 PM |
904 | rcutorture_shutdown_absorb("rcu_torture_writer"); |
905 | while (!kthread_should_stop()) | |
a241ec65 PM |
906 | schedule_timeout_uninterruptible(1); |
907 | return 0; | |
908 | } | |
909 | ||
b772e1dd JT |
910 | /* |
911 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
912 | * delay between calls. | |
913 | */ | |
914 | static int | |
915 | rcu_torture_fakewriter(void *arg) | |
916 | { | |
917 | DEFINE_RCU_RANDOM(rand); | |
918 | ||
919 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
920 | set_user_nice(current, 19); | |
921 | ||
922 | do { | |
923 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
924 | udelay(rcu_random(&rand) & 0x3ff); | |
925 | cur_ops->sync(); | |
c9d557c1 PM |
926 | rcu_stutter_wait("rcu_torture_fakewriter"); |
927 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
b772e1dd JT |
928 | |
929 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
c9d557c1 PM |
930 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); |
931 | while (!kthread_should_stop()) | |
b772e1dd JT |
932 | schedule_timeout_uninterruptible(1); |
933 | return 0; | |
934 | } | |
935 | ||
91afaf30 PM |
936 | void rcutorture_trace_dump(void) |
937 | { | |
938 | static atomic_t beenhere = ATOMIC_INIT(0); | |
939 | ||
940 | if (atomic_read(&beenhere)) | |
941 | return; | |
942 | if (atomic_xchg(&beenhere, 1) != 0) | |
943 | return; | |
944 | do_trace_rcu_torture_read(cur_ops->name, (struct rcu_head *)~0UL); | |
945 | ftrace_dump(DUMP_ALL); | |
946 | } | |
947 | ||
0729fbf3 PM |
948 | /* |
949 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
950 | * incrementing the corresponding element of the pipeline array. The | |
951 | * counter in the element should never be greater than 1, otherwise, the | |
952 | * RCU implementation is broken. | |
953 | */ | |
954 | static void rcu_torture_timer(unsigned long unused) | |
955 | { | |
956 | int idx; | |
957 | int completed; | |
958 | static DEFINE_RCU_RANDOM(rand); | |
959 | static DEFINE_SPINLOCK(rand_lock); | |
960 | struct rcu_torture *p; | |
961 | int pipe_count; | |
962 | ||
963 | idx = cur_ops->readlock(); | |
964 | completed = cur_ops->completed(); | |
632ee200 | 965 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
966 | rcu_read_lock_bh_held() || |
967 | rcu_read_lock_sched_held() || | |
968 | srcu_read_lock_held(&srcu_ctl)); | |
91afaf30 | 969 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); |
0729fbf3 PM |
970 | if (p == NULL) { |
971 | /* Leave because rcu_torture_writer is not yet underway */ | |
972 | cur_ops->readunlock(idx); | |
973 | return; | |
974 | } | |
975 | if (p->rtort_mbtest == 0) | |
976 | atomic_inc(&n_rcu_torture_mberror); | |
977 | spin_lock(&rand_lock); | |
0acc512c | 978 | cur_ops->read_delay(&rand); |
0729fbf3 PM |
979 | n_rcu_torture_timers++; |
980 | spin_unlock(&rand_lock); | |
981 | preempt_disable(); | |
982 | pipe_count = p->rtort_pipe_count; | |
983 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
984 | /* Should not happen, but... */ | |
985 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
986 | } | |
91afaf30 PM |
987 | if (pipe_count > 1) |
988 | rcutorture_trace_dump(); | |
dd17c8f7 | 989 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
0729fbf3 PM |
990 | completed = cur_ops->completed() - completed; |
991 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
992 | /* Should not happen, but... */ | |
993 | completed = RCU_TORTURE_PIPE_LEN; | |
994 | } | |
dd17c8f7 | 995 | __this_cpu_inc(rcu_torture_batch[completed]); |
0729fbf3 PM |
996 | preempt_enable(); |
997 | cur_ops->readunlock(idx); | |
998 | } | |
999 | ||
a241ec65 PM |
1000 | /* |
1001 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
1002 | * incrementing the corresponding element of the pipeline array. The | |
1003 | * counter in the element should never be greater than 1, otherwise, the | |
1004 | * RCU implementation is broken. | |
1005 | */ | |
1006 | static int | |
1007 | rcu_torture_reader(void *arg) | |
1008 | { | |
1009 | int completed; | |
72e9bb54 | 1010 | int idx; |
a241ec65 PM |
1011 | DEFINE_RCU_RANDOM(rand); |
1012 | struct rcu_torture *p; | |
1013 | int pipe_count; | |
0729fbf3 | 1014 | struct timer_list t; |
a241ec65 PM |
1015 | |
1016 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 1017 | set_user_nice(current, 19); |
0acc512c | 1018 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 1019 | setup_timer_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 1020 | |
a241ec65 | 1021 | do { |
0acc512c | 1022 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 | 1023 | if (!timer_pending(&t)) |
6155fec9 | 1024 | mod_timer(&t, jiffies + 1); |
0729fbf3 | 1025 | } |
72e9bb54 PM |
1026 | idx = cur_ops->readlock(); |
1027 | completed = cur_ops->completed(); | |
632ee200 | 1028 | p = rcu_dereference_check(rcu_torture_current, |
632ee200 PM |
1029 | rcu_read_lock_bh_held() || |
1030 | rcu_read_lock_sched_held() || | |
1031 | srcu_read_lock_held(&srcu_ctl)); | |
91afaf30 | 1032 | do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu); |
a241ec65 PM |
1033 | if (p == NULL) { |
1034 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 1035 | cur_ops->readunlock(idx); |
a241ec65 PM |
1036 | schedule_timeout_interruptible(HZ); |
1037 | continue; | |
1038 | } | |
996417d2 PM |
1039 | if (p->rtort_mbtest == 0) |
1040 | atomic_inc(&n_rcu_torture_mberror); | |
0acc512c | 1041 | cur_ops->read_delay(&rand); |
a241ec65 PM |
1042 | preempt_disable(); |
1043 | pipe_count = p->rtort_pipe_count; | |
1044 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
1045 | /* Should not happen, but... */ | |
1046 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
1047 | } | |
91afaf30 PM |
1048 | if (pipe_count > 1) |
1049 | rcutorture_trace_dump(); | |
dd17c8f7 | 1050 | __this_cpu_inc(rcu_torture_count[pipe_count]); |
72e9bb54 | 1051 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
1052 | if (completed > RCU_TORTURE_PIPE_LEN) { |
1053 | /* Should not happen, but... */ | |
1054 | completed = RCU_TORTURE_PIPE_LEN; | |
1055 | } | |
dd17c8f7 | 1056 | __this_cpu_inc(rcu_torture_batch[completed]); |
a241ec65 | 1057 | preempt_enable(); |
72e9bb54 | 1058 | cur_ops->readunlock(idx); |
a241ec65 | 1059 | schedule(); |
c9d557c1 PM |
1060 | rcu_stutter_wait("rcu_torture_reader"); |
1061 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 1062 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
c9d557c1 | 1063 | rcutorture_shutdown_absorb("rcu_torture_reader"); |
0acc512c | 1064 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 1065 | del_timer_sync(&t); |
c9d557c1 | 1066 | while (!kthread_should_stop()) |
a241ec65 PM |
1067 | schedule_timeout_uninterruptible(1); |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | /* | |
1072 | * Create an RCU-torture statistics message in the specified buffer. | |
1073 | */ | |
1074 | static int | |
1075 | rcu_torture_printk(char *page) | |
1076 | { | |
1077 | int cnt = 0; | |
1078 | int cpu; | |
1079 | int i; | |
1080 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1081 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
1082 | ||
0a945022 | 1083 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1084 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1085 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
1086 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
1087 | } | |
1088 | } | |
1089 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
1090 | if (pipesummary[i] != 0) | |
1091 | break; | |
1092 | } | |
72e9bb54 | 1093 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 1094 | cnt += sprintf(&page[cnt], |
4a298656 | 1095 | "rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d " |
67b98dba | 1096 | "rtmbe: %d rtbke: %ld rtbre: %ld " |
b58bdcca PM |
1097 | "rtbf: %ld rtb: %ld nt: %ld " |
1098 | "onoff: %ld/%ld:%ld/%ld", | |
a241ec65 PM |
1099 | rcu_torture_current, |
1100 | rcu_torture_current_version, | |
1101 | list_empty(&rcu_torture_freelist), | |
1102 | atomic_read(&n_rcu_torture_alloc), | |
1103 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 | 1104 | atomic_read(&n_rcu_torture_free), |
0729fbf3 | 1105 | atomic_read(&n_rcu_torture_mberror), |
8e8be45e PM |
1106 | n_rcu_torture_boost_ktrerror, |
1107 | n_rcu_torture_boost_rterror, | |
8e8be45e PM |
1108 | n_rcu_torture_boost_failure, |
1109 | n_rcu_torture_boosts, | |
b58bdcca PM |
1110 | n_rcu_torture_timers, |
1111 | n_online_successes, | |
1112 | n_online_attempts, | |
1113 | n_offline_successes, | |
1114 | n_offline_attempts); | |
8e8be45e PM |
1115 | if (atomic_read(&n_rcu_torture_mberror) != 0 || |
1116 | n_rcu_torture_boost_ktrerror != 0 || | |
1117 | n_rcu_torture_boost_rterror != 0 || | |
8e8be45e | 1118 | n_rcu_torture_boost_failure != 0) |
996417d2 | 1119 | cnt += sprintf(&page[cnt], " !!!"); |
72e9bb54 | 1120 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 1121 | if (i > 1) { |
a241ec65 | 1122 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 | 1123 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 1124 | WARN_ON_ONCE(1); |
996417d2 | 1125 | } |
a241ec65 PM |
1126 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
1127 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
1128 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 1129 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 1130 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 1131 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 1132 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 1133 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
1134 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
1135 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
1136 | cnt += sprintf(&page[cnt], " %d", | |
1137 | atomic_read(&rcu_torture_wcount[i])); | |
1138 | } | |
1139 | cnt += sprintf(&page[cnt], "\n"); | |
c8e5b163 | 1140 | if (cur_ops->stats) |
72e9bb54 | 1141 | cnt += cur_ops->stats(&page[cnt]); |
a241ec65 PM |
1142 | return cnt; |
1143 | } | |
1144 | ||
1145 | /* | |
1146 | * Print torture statistics. Caller must ensure that there is only | |
1147 | * one call to this function at a given time!!! This is normally | |
1148 | * accomplished by relying on the module system to only have one copy | |
1149 | * of the module loaded, and then by giving the rcu_torture_stats | |
1150 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
1151 | * thread is not running). | |
1152 | */ | |
1153 | static void | |
1154 | rcu_torture_stats_print(void) | |
1155 | { | |
1156 | int cnt; | |
1157 | ||
1158 | cnt = rcu_torture_printk(printk_buf); | |
1159 | printk(KERN_ALERT "%s", printk_buf); | |
1160 | } | |
1161 | ||
1162 | /* | |
1163 | * Periodically prints torture statistics, if periodic statistics printing | |
1164 | * was specified via the stat_interval module parameter. | |
1165 | * | |
1166 | * No need to worry about fullstop here, since this one doesn't reference | |
1167 | * volatile state or register callbacks. | |
1168 | */ | |
1169 | static int | |
1170 | rcu_torture_stats(void *arg) | |
1171 | { | |
1172 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
1173 | do { | |
1174 | schedule_timeout_interruptible(stat_interval * HZ); | |
1175 | rcu_torture_stats_print(); | |
c9d557c1 PM |
1176 | rcutorture_shutdown_absorb("rcu_torture_stats"); |
1177 | } while (!kthread_should_stop()); | |
a241ec65 PM |
1178 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
1179 | return 0; | |
1180 | } | |
1181 | ||
d84f5203 SV |
1182 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
1183 | ||
1184 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
1185 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
1186 | */ | |
b2896d2e | 1187 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 | 1188 | { |
d84f5203 SV |
1189 | int i; |
1190 | ||
73d0a4b1 | 1191 | cpumask_setall(shuffle_tmp_mask); |
86ef5c9a | 1192 | get_online_cpus(); |
d84f5203 SV |
1193 | |
1194 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
c9d557c1 PM |
1195 | if (num_online_cpus() == 1) { |
1196 | put_online_cpus(); | |
1197 | return; | |
1198 | } | |
d84f5203 SV |
1199 | |
1200 | if (rcu_idle_cpu != -1) | |
73d0a4b1 | 1201 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); |
d84f5203 | 1202 | |
73d0a4b1 | 1203 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); |
d84f5203 | 1204 | |
c8e5b163 | 1205 | if (reader_tasks) { |
d84f5203 SV |
1206 | for (i = 0; i < nrealreaders; i++) |
1207 | if (reader_tasks[i]) | |
f70316da | 1208 | set_cpus_allowed_ptr(reader_tasks[i], |
73d0a4b1 | 1209 | shuffle_tmp_mask); |
d84f5203 SV |
1210 | } |
1211 | ||
c8e5b163 | 1212 | if (fakewriter_tasks) { |
b772e1dd JT |
1213 | for (i = 0; i < nfakewriters; i++) |
1214 | if (fakewriter_tasks[i]) | |
f70316da | 1215 | set_cpus_allowed_ptr(fakewriter_tasks[i], |
73d0a4b1 | 1216 | shuffle_tmp_mask); |
b772e1dd JT |
1217 | } |
1218 | ||
d84f5203 | 1219 | if (writer_task) |
73d0a4b1 | 1220 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); |
d84f5203 SV |
1221 | |
1222 | if (stats_task) | |
73d0a4b1 | 1223 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); |
d84f5203 SV |
1224 | |
1225 | if (rcu_idle_cpu == -1) | |
1226 | rcu_idle_cpu = num_online_cpus() - 1; | |
1227 | else | |
1228 | rcu_idle_cpu--; | |
1229 | ||
86ef5c9a | 1230 | put_online_cpus(); |
d84f5203 SV |
1231 | } |
1232 | ||
1233 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
1234 | * system to become idle at a time and cut off its timer ticks. This is meant | |
1235 | * to test the support for such tickless idle CPU in RCU. | |
1236 | */ | |
1237 | static int | |
1238 | rcu_torture_shuffle(void *arg) | |
1239 | { | |
1240 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
1241 | do { | |
1242 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1243 | rcu_torture_shuffle_tasks(); | |
c9d557c1 PM |
1244 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); |
1245 | } while (!kthread_should_stop()); | |
d84f5203 SV |
1246 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
1247 | return 0; | |
1248 | } | |
1249 | ||
d120f65f PM |
1250 | /* Cause the rcutorture test to "stutter", starting and stopping all |
1251 | * threads periodically. | |
1252 | */ | |
1253 | static int | |
1254 | rcu_torture_stutter(void *arg) | |
1255 | { | |
1256 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1257 | do { | |
1258 | schedule_timeout_interruptible(stutter * HZ); | |
1259 | stutter_pause_test = 1; | |
c9d557c1 | 1260 | if (!kthread_should_stop()) |
d120f65f PM |
1261 | schedule_timeout_interruptible(stutter * HZ); |
1262 | stutter_pause_test = 0; | |
c9d557c1 PM |
1263 | rcutorture_shutdown_absorb("rcu_torture_stutter"); |
1264 | } while (!kthread_should_stop()); | |
d120f65f PM |
1265 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); |
1266 | return 0; | |
1267 | } | |
1268 | ||
95c38322 | 1269 | static inline void |
8e8be45e | 1270 | rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag) |
95c38322 | 1271 | { |
b772e1dd JT |
1272 | printk(KERN_ALERT "%s" TORTURE_FLAG |
1273 | "--- %s: nreaders=%d nfakewriters=%d " | |
95c38322 | 1274 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
bf66f18e | 1275 | "shuffle_interval=%d stutter=%d irqreader=%d " |
8e8be45e PM |
1276 | "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " |
1277 | "test_boost=%d/%d test_boost_interval=%d " | |
b58bdcca PM |
1278 | "test_boost_duration=%d shutdown_secs=%d " |
1279 | "onoff_interval=%d\n", | |
b772e1dd | 1280 | torture_type, tag, nrealreaders, nfakewriters, |
d120f65f | 1281 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, |
8e8be45e PM |
1282 | stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, |
1283 | test_boost, cur_ops->can_boost, | |
b58bdcca PM |
1284 | test_boost_interval, test_boost_duration, shutdown_secs, |
1285 | onoff_interval); | |
95c38322 PM |
1286 | } |
1287 | ||
8e8be45e | 1288 | static struct notifier_block rcutorture_shutdown_nb = { |
343e9099 PM |
1289 | .notifier_call = rcutorture_shutdown_notify, |
1290 | }; | |
1291 | ||
8e8be45e PM |
1292 | static void rcutorture_booster_cleanup(int cpu) |
1293 | { | |
1294 | struct task_struct *t; | |
1295 | ||
1296 | if (boost_tasks[cpu] == NULL) | |
1297 | return; | |
1298 | mutex_lock(&boost_mutex); | |
1299 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_boost task"); | |
1300 | t = boost_tasks[cpu]; | |
1301 | boost_tasks[cpu] = NULL; | |
1302 | mutex_unlock(&boost_mutex); | |
1303 | ||
1304 | /* This must be outside of the mutex, otherwise deadlock! */ | |
1305 | kthread_stop(t); | |
1306 | } | |
1307 | ||
1308 | static int rcutorture_booster_init(int cpu) | |
1309 | { | |
1310 | int retval; | |
1311 | ||
1312 | if (boost_tasks[cpu] != NULL) | |
1313 | return 0; /* Already created, nothing more to do. */ | |
1314 | ||
1315 | /* Don't allow time recalculation while creating a new task. */ | |
1316 | mutex_lock(&boost_mutex); | |
1317 | VERBOSE_PRINTK_STRING("Creating rcu_torture_boost task"); | |
1f288094 ED |
1318 | boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, |
1319 | cpu_to_node(cpu), | |
1320 | "rcu_torture_boost"); | |
8e8be45e PM |
1321 | if (IS_ERR(boost_tasks[cpu])) { |
1322 | retval = PTR_ERR(boost_tasks[cpu]); | |
1323 | VERBOSE_PRINTK_STRING("rcu_torture_boost task create failed"); | |
1324 | n_rcu_torture_boost_ktrerror++; | |
1325 | boost_tasks[cpu] = NULL; | |
1326 | mutex_unlock(&boost_mutex); | |
1327 | return retval; | |
1328 | } | |
1329 | kthread_bind(boost_tasks[cpu], cpu); | |
1330 | wake_up_process(boost_tasks[cpu]); | |
1331 | mutex_unlock(&boost_mutex); | |
1332 | return 0; | |
1333 | } | |
1334 | ||
d5f546d8 PM |
1335 | /* |
1336 | * Cause the rcutorture test to shutdown the system after the test has | |
1337 | * run for the time specified by the shutdown_secs module parameter. | |
1338 | */ | |
1339 | static int | |
1340 | rcu_torture_shutdown(void *arg) | |
1341 | { | |
1342 | long delta; | |
1343 | unsigned long jiffies_snap; | |
1344 | ||
1345 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started"); | |
1346 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1347 | while (ULONG_CMP_LT(jiffies_snap, shutdown_time) && | |
1348 | !kthread_should_stop()) { | |
1349 | delta = shutdown_time - jiffies_snap; | |
1350 | if (verbose) | |
1351 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1352 | "rcu_torture_shutdown task: %lu " | |
1353 | "jiffies remaining\n", | |
1354 | torture_type, delta); | |
1355 | schedule_timeout_interruptible(delta); | |
1356 | jiffies_snap = ACCESS_ONCE(jiffies); | |
1357 | } | |
b58bdcca | 1358 | if (kthread_should_stop()) { |
d5f546d8 PM |
1359 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping"); |
1360 | return 0; | |
1361 | } | |
1362 | ||
1363 | /* OK, shut down the system. */ | |
1364 | ||
1365 | VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system"); | |
1366 | shutdown_task = NULL; /* Avoid self-kill deadlock. */ | |
1367 | rcu_torture_cleanup(); /* Get the success/failure message. */ | |
1368 | kernel_power_off(); /* Shut down the system. */ | |
1369 | return 0; | |
1370 | } | |
1371 | ||
b58bdcca PM |
1372 | #ifdef CONFIG_HOTPLUG_CPU |
1373 | ||
1374 | /* | |
1375 | * Execute random CPU-hotplug operations at the interval specified | |
1376 | * by the onoff_interval. | |
1377 | */ | |
1378 | static int | |
1379 | rcu_torture_onoff(void *arg) | |
1380 | { | |
1381 | int cpu; | |
1382 | int maxcpu = -1; | |
1383 | DEFINE_RCU_RANDOM(rand); | |
1384 | ||
1385 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task started"); | |
1386 | for_each_online_cpu(cpu) | |
1387 | maxcpu = cpu; | |
1388 | WARN_ON(maxcpu < 0); | |
1389 | while (!kthread_should_stop()) { | |
1390 | cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1); | |
f220242a | 1391 | if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) { |
b58bdcca PM |
1392 | if (verbose) |
1393 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1394 | "rcu_torture_onoff task: offlining %d\n", | |
1395 | torture_type, cpu); | |
1396 | n_offline_attempts++; | |
1397 | if (cpu_down(cpu) == 0) { | |
1398 | if (verbose) | |
1399 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1400 | "rcu_torture_onoff task: " | |
1401 | "offlined %d\n", | |
1402 | torture_type, cpu); | |
1403 | n_offline_successes++; | |
1404 | } | |
f220242a | 1405 | } else if (cpu_is_hotpluggable(cpu)) { |
b58bdcca PM |
1406 | if (verbose) |
1407 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1408 | "rcu_torture_onoff task: onlining %d\n", | |
1409 | torture_type, cpu); | |
1410 | n_online_attempts++; | |
1411 | if (cpu_up(cpu) == 0) { | |
1412 | if (verbose) | |
1413 | printk(KERN_ALERT "%s" TORTURE_FLAG | |
1414 | "rcu_torture_onoff task: " | |
1415 | "onlined %d\n", | |
1416 | torture_type, cpu); | |
1417 | n_online_successes++; | |
1418 | } | |
1419 | } | |
1420 | schedule_timeout_interruptible(onoff_interval * HZ); | |
1421 | } | |
1422 | VERBOSE_PRINTK_STRING("rcu_torture_onoff task stopping"); | |
1423 | return 0; | |
1424 | } | |
1425 | ||
1426 | static int | |
1427 | rcu_torture_onoff_init(void) | |
1428 | { | |
1429 | if (onoff_interval <= 0) | |
1430 | return 0; | |
1431 | onoff_task = kthread_run(rcu_torture_onoff, NULL, "rcu_torture_onoff"); | |
1432 | if (IS_ERR(onoff_task)) { | |
1433 | onoff_task = NULL; | |
1434 | return PTR_ERR(onoff_task); | |
1435 | } | |
1436 | return 0; | |
1437 | } | |
1438 | ||
1439 | static void rcu_torture_onoff_cleanup(void) | |
1440 | { | |
1441 | if (onoff_task == NULL) | |
1442 | return; | |
1443 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_onoff task"); | |
1444 | kthread_stop(onoff_task); | |
1445 | } | |
1446 | ||
1447 | #else /* #ifdef CONFIG_HOTPLUG_CPU */ | |
1448 | ||
1449 | static void | |
1450 | rcu_torture_onoff_init(void) | |
1451 | { | |
1452 | } | |
1453 | ||
1454 | static void rcu_torture_onoff_cleanup(void) | |
1455 | { | |
1456 | } | |
1457 | ||
1458 | #endif /* #else #ifdef CONFIG_HOTPLUG_CPU */ | |
1459 | ||
8e8be45e PM |
1460 | static int rcutorture_cpu_notify(struct notifier_block *self, |
1461 | unsigned long action, void *hcpu) | |
1462 | { | |
1463 | long cpu = (long)hcpu; | |
1464 | ||
1465 | switch (action) { | |
1466 | case CPU_ONLINE: | |
1467 | case CPU_DOWN_FAILED: | |
1468 | (void)rcutorture_booster_init(cpu); | |
1469 | break; | |
1470 | case CPU_DOWN_PREPARE: | |
1471 | rcutorture_booster_cleanup(cpu); | |
1472 | break; | |
1473 | default: | |
1474 | break; | |
1475 | } | |
1476 | return NOTIFY_OK; | |
1477 | } | |
1478 | ||
1479 | static struct notifier_block rcutorture_cpu_nb = { | |
1480 | .notifier_call = rcutorture_cpu_notify, | |
1481 | }; | |
1482 | ||
a241ec65 PM |
1483 | static void |
1484 | rcu_torture_cleanup(void) | |
1485 | { | |
1486 | int i; | |
1487 | ||
343e9099 | 1488 | mutex_lock(&fullstop_mutex); |
4a298656 | 1489 | rcutorture_record_test_transition(); |
c9d557c1 PM |
1490 | if (fullstop == FULLSTOP_SHUTDOWN) { |
1491 | printk(KERN_WARNING /* but going down anyway, so... */ | |
1492 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
343e9099 | 1493 | mutex_unlock(&fullstop_mutex); |
c9d557c1 | 1494 | schedule_timeout_uninterruptible(10); |
343e9099 PM |
1495 | if (cur_ops->cb_barrier != NULL) |
1496 | cur_ops->cb_barrier(); | |
1497 | return; | |
1498 | } | |
c9d557c1 | 1499 | fullstop = FULLSTOP_RMMOD; |
343e9099 | 1500 | mutex_unlock(&fullstop_mutex); |
8e8be45e | 1501 | unregister_reboot_notifier(&rcutorture_shutdown_nb); |
d120f65f PM |
1502 | if (stutter_task) { |
1503 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1504 | kthread_stop(stutter_task); | |
1505 | } | |
1506 | stutter_task = NULL; | |
c8e5b163 | 1507 | if (shuffler_task) { |
d84f5203 SV |
1508 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
1509 | kthread_stop(shuffler_task); | |
73d0a4b1 | 1510 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1511 | } |
1512 | shuffler_task = NULL; | |
1513 | ||
c8e5b163 | 1514 | if (writer_task) { |
a241ec65 PM |
1515 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
1516 | kthread_stop(writer_task); | |
1517 | } | |
1518 | writer_task = NULL; | |
1519 | ||
c8e5b163 | 1520 | if (reader_tasks) { |
a241ec65 | 1521 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 1522 | if (reader_tasks[i]) { |
a241ec65 PM |
1523 | VERBOSE_PRINTK_STRING( |
1524 | "Stopping rcu_torture_reader task"); | |
1525 | kthread_stop(reader_tasks[i]); | |
1526 | } | |
1527 | reader_tasks[i] = NULL; | |
1528 | } | |
1529 | kfree(reader_tasks); | |
1530 | reader_tasks = NULL; | |
1531 | } | |
1532 | rcu_torture_current = NULL; | |
1533 | ||
c8e5b163 | 1534 | if (fakewriter_tasks) { |
b772e1dd | 1535 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 1536 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
1537 | VERBOSE_PRINTK_STRING( |
1538 | "Stopping rcu_torture_fakewriter task"); | |
1539 | kthread_stop(fakewriter_tasks[i]); | |
1540 | } | |
1541 | fakewriter_tasks[i] = NULL; | |
1542 | } | |
1543 | kfree(fakewriter_tasks); | |
1544 | fakewriter_tasks = NULL; | |
1545 | } | |
1546 | ||
c8e5b163 | 1547 | if (stats_task) { |
a241ec65 PM |
1548 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
1549 | kthread_stop(stats_task); | |
1550 | } | |
1551 | stats_task = NULL; | |
1552 | ||
bf66f18e PM |
1553 | if (fqs_task) { |
1554 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_fqs task"); | |
1555 | kthread_stop(fqs_task); | |
1556 | } | |
1557 | fqs_task = NULL; | |
8e8be45e PM |
1558 | if ((test_boost == 1 && cur_ops->can_boost) || |
1559 | test_boost == 2) { | |
1560 | unregister_cpu_notifier(&rcutorture_cpu_nb); | |
1561 | for_each_possible_cpu(i) | |
1562 | rcutorture_booster_cleanup(i); | |
1563 | } | |
d5f546d8 PM |
1564 | if (shutdown_task != NULL) { |
1565 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task"); | |
1566 | kthread_stop(shutdown_task); | |
1567 | } | |
b58bdcca | 1568 | rcu_torture_onoff_cleanup(); |
bf66f18e | 1569 | |
a241ec65 | 1570 | /* Wait for all RCU callbacks to fire. */ |
2326974d PM |
1571 | |
1572 | if (cur_ops->cb_barrier != NULL) | |
1573 | cur_ops->cb_barrier(); | |
a241ec65 | 1574 | |
a241ec65 | 1575 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 1576 | |
c8e5b163 | 1577 | if (cur_ops->cleanup) |
72e9bb54 | 1578 | cur_ops->cleanup(); |
95c38322 | 1579 | if (atomic_read(&n_rcu_torture_error)) |
8e8be45e | 1580 | rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); |
95c38322 | 1581 | else |
8e8be45e | 1582 | rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); |
a241ec65 PM |
1583 | } |
1584 | ||
6f8bc500 | 1585 | static int __init |
a241ec65 PM |
1586 | rcu_torture_init(void) |
1587 | { | |
1588 | int i; | |
1589 | int cpu; | |
1590 | int firsterr = 0; | |
ade5fb81 | 1591 | static struct rcu_torture_ops *torture_ops[] = |
d9a3da06 | 1592 | { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops, |
bdf2a436 | 1593 | &rcu_bh_ops, &rcu_bh_sync_ops, &rcu_bh_expedited_ops, |
804bb837 PM |
1594 | &srcu_ops, &srcu_expedited_ops, |
1595 | &sched_ops, &sched_sync_ops, &sched_expedited_ops, }; | |
a241ec65 | 1596 | |
343e9099 PM |
1597 | mutex_lock(&fullstop_mutex); |
1598 | ||
a241ec65 | 1599 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 1600 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 1601 | cur_ops = torture_ops[i]; |
ade5fb81 | 1602 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 1603 | break; |
72e9bb54 | 1604 | } |
ade5fb81 | 1605 | if (i == ARRAY_SIZE(torture_ops)) { |
cf886c44 | 1606 | printk(KERN_ALERT "rcu-torture: invalid torture type: \"%s\"\n", |
72e9bb54 | 1607 | torture_type); |
cf886c44 PM |
1608 | printk(KERN_ALERT "rcu-torture types:"); |
1609 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
1610 | printk(KERN_ALERT " %s", torture_ops[i]->name); | |
1611 | printk(KERN_ALERT "\n"); | |
343e9099 | 1612 | mutex_unlock(&fullstop_mutex); |
a71fca58 | 1613 | return -EINVAL; |
72e9bb54 | 1614 | } |
bf66f18e PM |
1615 | if (cur_ops->fqs == NULL && fqs_duration != 0) { |
1616 | printk(KERN_ALERT "rcu-torture: ->fqs NULL and non-zero " | |
1617 | "fqs_duration, fqs disabled.\n"); | |
1618 | fqs_duration = 0; | |
1619 | } | |
c8e5b163 | 1620 | if (cur_ops->init) |
72e9bb54 PM |
1621 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
1622 | ||
a241ec65 PM |
1623 | if (nreaders >= 0) |
1624 | nrealreaders = nreaders; | |
1625 | else | |
1626 | nrealreaders = 2 * num_online_cpus(); | |
8e8be45e | 1627 | rcu_torture_print_module_parms(cur_ops, "Start of test"); |
c9d557c1 | 1628 | fullstop = FULLSTOP_DONTSTOP; |
a241ec65 PM |
1629 | |
1630 | /* Set up the freelist. */ | |
1631 | ||
1632 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 1633 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 1634 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
1635 | list_add_tail(&rcu_tortures[i].rtort_free, |
1636 | &rcu_torture_freelist); | |
1637 | } | |
1638 | ||
1639 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1640 | ||
1641 | rcu_torture_current = NULL; | |
1642 | rcu_torture_current_version = 0; | |
1643 | atomic_set(&n_rcu_torture_alloc, 0); | |
1644 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1645 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
1646 | atomic_set(&n_rcu_torture_mberror, 0); |
1647 | atomic_set(&n_rcu_torture_error, 0); | |
8e8be45e PM |
1648 | n_rcu_torture_boost_ktrerror = 0; |
1649 | n_rcu_torture_boost_rterror = 0; | |
8e8be45e PM |
1650 | n_rcu_torture_boost_failure = 0; |
1651 | n_rcu_torture_boosts = 0; | |
a241ec65 PM |
1652 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
1653 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 1654 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1655 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1656 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1657 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1658 | } | |
1659 | } | |
1660 | ||
1661 | /* Start up the kthreads. */ | |
1662 | ||
1663 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
1664 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
1665 | "rcu_torture_writer"); | |
1666 | if (IS_ERR(writer_task)) { | |
1667 | firsterr = PTR_ERR(writer_task); | |
1668 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1669 | writer_task = NULL; | |
1670 | goto unwind; | |
1671 | } | |
b772e1dd | 1672 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
a71fca58 | 1673 | GFP_KERNEL); |
b772e1dd JT |
1674 | if (fakewriter_tasks == NULL) { |
1675 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1676 | firsterr = -ENOMEM; | |
1677 | goto unwind; | |
1678 | } | |
1679 | for (i = 0; i < nfakewriters; i++) { | |
1680 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
1681 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
a71fca58 | 1682 | "rcu_torture_fakewriter"); |
b772e1dd JT |
1683 | if (IS_ERR(fakewriter_tasks[i])) { |
1684 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
1685 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
1686 | fakewriter_tasks[i] = NULL; | |
1687 | goto unwind; | |
1688 | } | |
1689 | } | |
2860aaba | 1690 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
1691 | GFP_KERNEL); |
1692 | if (reader_tasks == NULL) { | |
1693 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1694 | firsterr = -ENOMEM; | |
1695 | goto unwind; | |
1696 | } | |
1697 | for (i = 0; i < nrealreaders; i++) { | |
1698 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
1699 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
1700 | "rcu_torture_reader"); | |
1701 | if (IS_ERR(reader_tasks[i])) { | |
1702 | firsterr = PTR_ERR(reader_tasks[i]); | |
1703 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
1704 | reader_tasks[i] = NULL; | |
1705 | goto unwind; | |
1706 | } | |
1707 | } | |
1708 | if (stat_interval > 0) { | |
1709 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
1710 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
1711 | "rcu_torture_stats"); | |
1712 | if (IS_ERR(stats_task)) { | |
1713 | firsterr = PTR_ERR(stats_task); | |
1714 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
1715 | stats_task = NULL; | |
1716 | goto unwind; | |
1717 | } | |
1718 | } | |
d84f5203 SV |
1719 | if (test_no_idle_hz) { |
1720 | rcu_idle_cpu = num_online_cpus() - 1; | |
73d0a4b1 RR |
1721 | |
1722 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
1723 | firsterr = -ENOMEM; | |
1724 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
1725 | goto unwind; | |
1726 | } | |
1727 | ||
d84f5203 SV |
1728 | /* Create the shuffler thread */ |
1729 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
1730 | "rcu_torture_shuffle"); | |
1731 | if (IS_ERR(shuffler_task)) { | |
73d0a4b1 | 1732 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1733 | firsterr = PTR_ERR(shuffler_task); |
1734 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
1735 | shuffler_task = NULL; | |
1736 | goto unwind; | |
1737 | } | |
1738 | } | |
d120f65f PM |
1739 | if (stutter < 0) |
1740 | stutter = 0; | |
1741 | if (stutter) { | |
1742 | /* Create the stutter thread */ | |
1743 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
1744 | "rcu_torture_stutter"); | |
1745 | if (IS_ERR(stutter_task)) { | |
1746 | firsterr = PTR_ERR(stutter_task); | |
1747 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
1748 | stutter_task = NULL; | |
1749 | goto unwind; | |
1750 | } | |
1751 | } | |
bf66f18e PM |
1752 | if (fqs_duration < 0) |
1753 | fqs_duration = 0; | |
1754 | if (fqs_duration) { | |
1755 | /* Create the stutter thread */ | |
1756 | fqs_task = kthread_run(rcu_torture_fqs, NULL, | |
1757 | "rcu_torture_fqs"); | |
1758 | if (IS_ERR(fqs_task)) { | |
1759 | firsterr = PTR_ERR(fqs_task); | |
1760 | VERBOSE_PRINTK_ERRSTRING("Failed to create fqs"); | |
1761 | fqs_task = NULL; | |
1762 | goto unwind; | |
1763 | } | |
1764 | } | |
8e8be45e PM |
1765 | if (test_boost_interval < 1) |
1766 | test_boost_interval = 1; | |
1767 | if (test_boost_duration < 2) | |
1768 | test_boost_duration = 2; | |
1769 | if ((test_boost == 1 && cur_ops->can_boost) || | |
1770 | test_boost == 2) { | |
1771 | int retval; | |
1772 | ||
1773 | boost_starttime = jiffies + test_boost_interval * HZ; | |
1774 | register_cpu_notifier(&rcutorture_cpu_nb); | |
1775 | for_each_possible_cpu(i) { | |
1776 | if (cpu_is_offline(i)) | |
1777 | continue; /* Heuristic: CPU can go offline. */ | |
1778 | retval = rcutorture_booster_init(i); | |
1779 | if (retval < 0) { | |
1780 | firsterr = retval; | |
1781 | goto unwind; | |
1782 | } | |
1783 | } | |
1784 | } | |
d5f546d8 PM |
1785 | if (shutdown_secs > 0) { |
1786 | shutdown_time = jiffies + shutdown_secs * HZ; | |
1787 | shutdown_task = kthread_run(rcu_torture_shutdown, NULL, | |
1788 | "rcu_torture_shutdown"); | |
1789 | if (IS_ERR(shutdown_task)) { | |
1790 | firsterr = PTR_ERR(shutdown_task); | |
1791 | VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown"); | |
1792 | shutdown_task = NULL; | |
1793 | goto unwind; | |
1794 | } | |
1795 | } | |
b58bdcca | 1796 | rcu_torture_onoff_init(); |
8e8be45e | 1797 | register_reboot_notifier(&rcutorture_shutdown_nb); |
4a298656 | 1798 | rcutorture_record_test_transition(); |
343e9099 | 1799 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
1800 | return 0; |
1801 | ||
1802 | unwind: | |
343e9099 | 1803 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
1804 | rcu_torture_cleanup(); |
1805 | return firsterr; | |
1806 | } | |
1807 | ||
1808 | module_init(rcu_torture_init); | |
1809 | module_exit(rcu_torture_cleanup); |