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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). */ |
20d2e428 | 64 | static char *torture_type = "rcu"; /* What RCU implementation to torture. */ |
a241ec65 | 65 | |
d6ad6711 | 66 | module_param(nreaders, int, 0444); |
a241ec65 | 67 | MODULE_PARM_DESC(nreaders, "Number of RCU reader threads"); |
d6ad6711 | 68 | module_param(nfakewriters, int, 0444); |
b772e1dd | 69 | MODULE_PARM_DESC(nfakewriters, "Number of RCU fake writer threads"); |
d6ad6711 | 70 | module_param(stat_interval, int, 0444); |
a241ec65 | 71 | MODULE_PARM_DESC(stat_interval, "Number of seconds between stats printk()s"); |
d6ad6711 | 72 | module_param(verbose, bool, 0444); |
a241ec65 | 73 | MODULE_PARM_DESC(verbose, "Enable verbose debugging printk()s"); |
d6ad6711 | 74 | module_param(test_no_idle_hz, bool, 0444); |
d84f5203 | 75 | MODULE_PARM_DESC(test_no_idle_hz, "Test support for tickless idle CPUs"); |
d6ad6711 | 76 | module_param(shuffle_interval, int, 0444); |
d84f5203 | 77 | MODULE_PARM_DESC(shuffle_interval, "Number of seconds between shuffles"); |
d120f65f PM |
78 | module_param(stutter, int, 0444); |
79 | MODULE_PARM_DESC(stutter, "Number of seconds to run/halt test"); | |
0729fbf3 PM |
80 | module_param(irqreader, int, 0444); |
81 | MODULE_PARM_DESC(irqreader, "Allow RCU readers from irq handlers"); | |
d6ad6711 | 82 | module_param(torture_type, charp, 0444); |
b2896d2e | 83 | MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, srcu)"); |
72e9bb54 PM |
84 | |
85 | #define TORTURE_FLAG "-torture:" | |
a241ec65 | 86 | #define PRINTK_STRING(s) \ |
72e9bb54 | 87 | do { printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 88 | #define VERBOSE_PRINTK_STRING(s) \ |
72e9bb54 | 89 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG s "\n", torture_type); } while (0) |
a241ec65 | 90 | #define VERBOSE_PRINTK_ERRSTRING(s) \ |
72e9bb54 | 91 | do { if (verbose) printk(KERN_ALERT "%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0) |
a241ec65 PM |
92 | |
93 | static char printk_buf[4096]; | |
94 | ||
95 | static int nrealreaders; | |
96 | static struct task_struct *writer_task; | |
b772e1dd | 97 | static struct task_struct **fakewriter_tasks; |
a241ec65 PM |
98 | static struct task_struct **reader_tasks; |
99 | static struct task_struct *stats_task; | |
d84f5203 | 100 | static struct task_struct *shuffler_task; |
d120f65f | 101 | static struct task_struct *stutter_task; |
a241ec65 PM |
102 | |
103 | #define RCU_TORTURE_PIPE_LEN 10 | |
104 | ||
105 | struct rcu_torture { | |
106 | struct rcu_head rtort_rcu; | |
107 | int rtort_pipe_count; | |
108 | struct list_head rtort_free; | |
996417d2 | 109 | int rtort_mbtest; |
a241ec65 PM |
110 | }; |
111 | ||
a241ec65 | 112 | static LIST_HEAD(rcu_torture_freelist); |
a71fca58 PM |
113 | static struct rcu_torture *rcu_torture_current; |
114 | static long rcu_torture_current_version; | |
a241ec65 PM |
115 | static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; |
116 | static DEFINE_SPINLOCK(rcu_torture_lock); | |
117 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count) = | |
118 | { 0 }; | |
119 | static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch) = | |
120 | { 0 }; | |
121 | static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; | |
b2896d2e PM |
122 | static atomic_t n_rcu_torture_alloc; |
123 | static atomic_t n_rcu_torture_alloc_fail; | |
124 | static atomic_t n_rcu_torture_free; | |
125 | static atomic_t n_rcu_torture_mberror; | |
126 | static atomic_t n_rcu_torture_error; | |
a71fca58 | 127 | static long n_rcu_torture_timers; |
e3033736 | 128 | static struct list_head rcu_torture_removed; |
73d0a4b1 | 129 | static cpumask_var_t shuffle_tmp_mask; |
a241ec65 | 130 | |
a71fca58 | 131 | static int stutter_pause_test; |
d120f65f | 132 | |
31a72bce PM |
133 | #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE) |
134 | #define RCUTORTURE_RUNNABLE_INIT 1 | |
135 | #else | |
136 | #define RCUTORTURE_RUNNABLE_INIT 0 | |
137 | #endif | |
138 | int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT; | |
139 | ||
c9d557c1 PM |
140 | /* Mediate rmmod and system shutdown. Concurrent rmmod & shutdown illegal! */ |
141 | ||
142 | #define FULLSTOP_DONTSTOP 0 /* Normal operation. */ | |
143 | #define FULLSTOP_SHUTDOWN 1 /* System shutdown with rcutorture running. */ | |
144 | #define FULLSTOP_RMMOD 2 /* Normal rmmod of rcutorture. */ | |
145 | static int fullstop = FULLSTOP_RMMOD; | |
146 | DEFINE_MUTEX(fullstop_mutex); /* Protect fullstop transitions and spawning */ | |
147 | /* of kthreads. */ | |
343e9099 PM |
148 | |
149 | /* | |
c9d557c1 | 150 | * Detect and respond to a system shutdown. |
343e9099 PM |
151 | */ |
152 | static int | |
153 | rcutorture_shutdown_notify(struct notifier_block *unused1, | |
154 | unsigned long unused2, void *unused3) | |
155 | { | |
c59ab97e | 156 | mutex_lock(&fullstop_mutex); |
c9d557c1 | 157 | if (fullstop == FULLSTOP_DONTSTOP) |
c59ab97e | 158 | fullstop = FULLSTOP_SHUTDOWN; |
c9d557c1 PM |
159 | else |
160 | printk(KERN_WARNING /* but going down anyway, so... */ | |
161 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
c59ab97e | 162 | mutex_unlock(&fullstop_mutex); |
343e9099 PM |
163 | return NOTIFY_DONE; |
164 | } | |
165 | ||
c9d557c1 PM |
166 | /* |
167 | * Absorb kthreads into a kernel function that won't return, so that | |
168 | * they won't ever access module text or data again. | |
169 | */ | |
170 | static void rcutorture_shutdown_absorb(char *title) | |
171 | { | |
172 | if (ACCESS_ONCE(fullstop) == FULLSTOP_SHUTDOWN) { | |
173 | printk(KERN_NOTICE | |
174 | "rcutorture thread %s parking due to system shutdown\n", | |
175 | title); | |
176 | schedule_timeout_uninterruptible(MAX_SCHEDULE_TIMEOUT); | |
177 | } | |
178 | } | |
179 | ||
a241ec65 PM |
180 | /* |
181 | * Allocate an element from the rcu_tortures pool. | |
182 | */ | |
97a41e26 | 183 | static struct rcu_torture * |
a241ec65 PM |
184 | rcu_torture_alloc(void) |
185 | { | |
186 | struct list_head *p; | |
187 | ||
adac1665 | 188 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 PM |
189 | if (list_empty(&rcu_torture_freelist)) { |
190 | atomic_inc(&n_rcu_torture_alloc_fail); | |
adac1665 | 191 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
192 | return NULL; |
193 | } | |
194 | atomic_inc(&n_rcu_torture_alloc); | |
195 | p = rcu_torture_freelist.next; | |
196 | list_del_init(p); | |
adac1665 | 197 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
198 | return container_of(p, struct rcu_torture, rtort_free); |
199 | } | |
200 | ||
201 | /* | |
202 | * Free an element to the rcu_tortures pool. | |
203 | */ | |
204 | static void | |
205 | rcu_torture_free(struct rcu_torture *p) | |
206 | { | |
207 | atomic_inc(&n_rcu_torture_free); | |
adac1665 | 208 | spin_lock_bh(&rcu_torture_lock); |
a241ec65 | 209 | list_add_tail(&p->rtort_free, &rcu_torture_freelist); |
adac1665 | 210 | spin_unlock_bh(&rcu_torture_lock); |
a241ec65 PM |
211 | } |
212 | ||
a241ec65 PM |
213 | struct rcu_random_state { |
214 | unsigned long rrs_state; | |
75cfef32 | 215 | long rrs_count; |
a241ec65 PM |
216 | }; |
217 | ||
218 | #define RCU_RANDOM_MULT 39916801 /* prime */ | |
219 | #define RCU_RANDOM_ADD 479001701 /* prime */ | |
220 | #define RCU_RANDOM_REFRESH 10000 | |
221 | ||
222 | #define DEFINE_RCU_RANDOM(name) struct rcu_random_state name = { 0, 0 } | |
223 | ||
224 | /* | |
225 | * Crude but fast random-number generator. Uses a linear congruential | |
c17ac855 | 226 | * generator, with occasional help from cpu_clock(). |
a241ec65 | 227 | */ |
75cfef32 | 228 | static unsigned long |
a241ec65 PM |
229 | rcu_random(struct rcu_random_state *rrsp) |
230 | { | |
a241ec65 | 231 | if (--rrsp->rrs_count < 0) { |
c17ac855 PM |
232 | rrsp->rrs_state += |
233 | (unsigned long)cpu_clock(raw_smp_processor_id()); | |
a241ec65 PM |
234 | rrsp->rrs_count = RCU_RANDOM_REFRESH; |
235 | } | |
236 | rrsp->rrs_state = rrsp->rrs_state * RCU_RANDOM_MULT + RCU_RANDOM_ADD; | |
237 | return swahw32(rrsp->rrs_state); | |
238 | } | |
239 | ||
d120f65f | 240 | static void |
c9d557c1 | 241 | rcu_stutter_wait(char *title) |
d120f65f | 242 | { |
c9d557c1 | 243 | while (stutter_pause_test || !rcutorture_runnable) { |
e3d7be27 PM |
244 | if (rcutorture_runnable) |
245 | schedule_timeout_interruptible(1); | |
246 | else | |
3ccf79f4 | 247 | schedule_timeout_interruptible(round_jiffies_relative(HZ)); |
c9d557c1 | 248 | rcutorture_shutdown_absorb(title); |
343e9099 | 249 | } |
d120f65f PM |
250 | } |
251 | ||
72e9bb54 PM |
252 | /* |
253 | * Operations vector for selecting different types of tests. | |
254 | */ | |
255 | ||
256 | struct rcu_torture_ops { | |
257 | void (*init)(void); | |
258 | void (*cleanup)(void); | |
259 | int (*readlock)(void); | |
0acc512c | 260 | void (*read_delay)(struct rcu_random_state *rrsp); |
72e9bb54 PM |
261 | void (*readunlock)(int idx); |
262 | int (*completed)(void); | |
0acc512c | 263 | void (*deferred_free)(struct rcu_torture *p); |
b772e1dd | 264 | void (*sync)(void); |
2326974d | 265 | void (*cb_barrier)(void); |
72e9bb54 | 266 | int (*stats)(char *page); |
0acc512c | 267 | int irq_capable; |
72e9bb54 PM |
268 | char *name; |
269 | }; | |
a71fca58 PM |
270 | |
271 | static struct rcu_torture_ops *cur_ops; | |
72e9bb54 PM |
272 | |
273 | /* | |
274 | * Definitions for rcu torture testing. | |
275 | */ | |
276 | ||
a49a4af7 | 277 | static int rcu_torture_read_lock(void) __acquires(RCU) |
72e9bb54 PM |
278 | { |
279 | rcu_read_lock(); | |
280 | return 0; | |
281 | } | |
282 | ||
b2896d2e PM |
283 | static void rcu_read_delay(struct rcu_random_state *rrsp) |
284 | { | |
b8d57a76 JT |
285 | const unsigned long shortdelay_us = 200; |
286 | const unsigned long longdelay_ms = 50; | |
b2896d2e | 287 | |
b8d57a76 JT |
288 | /* We want a short delay sometimes to make a reader delay the grace |
289 | * period, and we want a long delay occasionally to trigger | |
290 | * force_quiescent_state. */ | |
b2896d2e | 291 | |
b8d57a76 JT |
292 | if (!(rcu_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) |
293 | mdelay(longdelay_ms); | |
294 | if (!(rcu_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) | |
295 | udelay(shortdelay_us); | |
b2896d2e PM |
296 | } |
297 | ||
a49a4af7 | 298 | static void rcu_torture_read_unlock(int idx) __releases(RCU) |
72e9bb54 PM |
299 | { |
300 | rcu_read_unlock(); | |
301 | } | |
302 | ||
303 | static int rcu_torture_completed(void) | |
304 | { | |
305 | return rcu_batches_completed(); | |
306 | } | |
307 | ||
308 | static void | |
309 | rcu_torture_cb(struct rcu_head *p) | |
310 | { | |
311 | int i; | |
312 | struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); | |
313 | ||
c9d557c1 | 314 | if (fullstop != FULLSTOP_DONTSTOP) { |
72e9bb54 PM |
315 | /* Test is ending, just drop callbacks on the floor. */ |
316 | /* The next initialization will pick up the pieces. */ | |
317 | return; | |
318 | } | |
319 | i = rp->rtort_pipe_count; | |
320 | if (i > RCU_TORTURE_PIPE_LEN) | |
321 | i = RCU_TORTURE_PIPE_LEN; | |
322 | atomic_inc(&rcu_torture_wcount[i]); | |
323 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
324 | rp->rtort_mbtest = 0; | |
325 | rcu_torture_free(rp); | |
326 | } else | |
0acc512c | 327 | cur_ops->deferred_free(rp); |
72e9bb54 PM |
328 | } |
329 | ||
d9a3da06 PM |
330 | static int rcu_no_completed(void) |
331 | { | |
332 | return 0; | |
333 | } | |
334 | ||
72e9bb54 PM |
335 | static void rcu_torture_deferred_free(struct rcu_torture *p) |
336 | { | |
337 | call_rcu(&p->rtort_rcu, rcu_torture_cb); | |
338 | } | |
339 | ||
340 | static struct rcu_torture_ops rcu_ops = { | |
0acc512c PM |
341 | .init = NULL, |
342 | .cleanup = NULL, | |
343 | .readlock = rcu_torture_read_lock, | |
344 | .read_delay = rcu_read_delay, | |
345 | .readunlock = rcu_torture_read_unlock, | |
346 | .completed = rcu_torture_completed, | |
347 | .deferred_free = rcu_torture_deferred_free, | |
348 | .sync = synchronize_rcu, | |
349 | .cb_barrier = rcu_barrier, | |
350 | .stats = NULL, | |
a71fca58 PM |
351 | .irq_capable = 1, |
352 | .name = "rcu" | |
72e9bb54 PM |
353 | }; |
354 | ||
e3033736 JT |
355 | static void rcu_sync_torture_deferred_free(struct rcu_torture *p) |
356 | { | |
357 | int i; | |
358 | struct rcu_torture *rp; | |
359 | struct rcu_torture *rp1; | |
360 | ||
361 | cur_ops->sync(); | |
362 | list_add(&p->rtort_free, &rcu_torture_removed); | |
363 | list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { | |
364 | i = rp->rtort_pipe_count; | |
365 | if (i > RCU_TORTURE_PIPE_LEN) | |
366 | i = RCU_TORTURE_PIPE_LEN; | |
367 | atomic_inc(&rcu_torture_wcount[i]); | |
368 | if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { | |
369 | rp->rtort_mbtest = 0; | |
370 | list_del(&rp->rtort_free); | |
371 | rcu_torture_free(rp); | |
372 | } | |
373 | } | |
374 | } | |
375 | ||
376 | static void rcu_sync_torture_init(void) | |
377 | { | |
378 | INIT_LIST_HEAD(&rcu_torture_removed); | |
379 | } | |
380 | ||
20d2e428 | 381 | static struct rcu_torture_ops rcu_sync_ops = { |
0acc512c PM |
382 | .init = rcu_sync_torture_init, |
383 | .cleanup = NULL, | |
384 | .readlock = rcu_torture_read_lock, | |
385 | .read_delay = rcu_read_delay, | |
386 | .readunlock = rcu_torture_read_unlock, | |
387 | .completed = rcu_torture_completed, | |
388 | .deferred_free = rcu_sync_torture_deferred_free, | |
389 | .sync = synchronize_rcu, | |
390 | .cb_barrier = NULL, | |
391 | .stats = NULL, | |
392 | .irq_capable = 1, | |
393 | .name = "rcu_sync" | |
20d2e428 JT |
394 | }; |
395 | ||
d9a3da06 PM |
396 | static struct rcu_torture_ops rcu_expedited_ops = { |
397 | .init = rcu_sync_torture_init, | |
398 | .cleanup = NULL, | |
399 | .readlock = rcu_torture_read_lock, | |
400 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
401 | .readunlock = rcu_torture_read_unlock, | |
402 | .completed = rcu_no_completed, | |
403 | .deferred_free = rcu_sync_torture_deferred_free, | |
404 | .sync = synchronize_rcu_expedited, | |
405 | .cb_barrier = NULL, | |
406 | .stats = NULL, | |
407 | .irq_capable = 1, | |
408 | .name = "rcu_expedited" | |
409 | }; | |
410 | ||
c32e0660 PM |
411 | /* |
412 | * Definitions for rcu_bh torture testing. | |
413 | */ | |
414 | ||
a49a4af7 | 415 | static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) |
c32e0660 PM |
416 | { |
417 | rcu_read_lock_bh(); | |
418 | return 0; | |
419 | } | |
420 | ||
a49a4af7 | 421 | static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) |
c32e0660 PM |
422 | { |
423 | rcu_read_unlock_bh(); | |
424 | } | |
425 | ||
426 | static int rcu_bh_torture_completed(void) | |
427 | { | |
428 | return rcu_batches_completed_bh(); | |
429 | } | |
430 | ||
431 | static void rcu_bh_torture_deferred_free(struct rcu_torture *p) | |
432 | { | |
433 | call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); | |
434 | } | |
435 | ||
b772e1dd JT |
436 | struct rcu_bh_torture_synchronize { |
437 | struct rcu_head head; | |
438 | struct completion completion; | |
439 | }; | |
440 | ||
441 | static void rcu_bh_torture_wakeme_after_cb(struct rcu_head *head) | |
442 | { | |
443 | struct rcu_bh_torture_synchronize *rcu; | |
444 | ||
445 | rcu = container_of(head, struct rcu_bh_torture_synchronize, head); | |
446 | complete(&rcu->completion); | |
447 | } | |
448 | ||
449 | static void rcu_bh_torture_synchronize(void) | |
450 | { | |
451 | struct rcu_bh_torture_synchronize rcu; | |
452 | ||
453 | init_completion(&rcu.completion); | |
454 | call_rcu_bh(&rcu.head, rcu_bh_torture_wakeme_after_cb); | |
455 | wait_for_completion(&rcu.completion); | |
456 | } | |
457 | ||
c32e0660 | 458 | static struct rcu_torture_ops rcu_bh_ops = { |
0acc512c PM |
459 | .init = NULL, |
460 | .cleanup = NULL, | |
461 | .readlock = rcu_bh_torture_read_lock, | |
462 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
463 | .readunlock = rcu_bh_torture_read_unlock, | |
464 | .completed = rcu_bh_torture_completed, | |
465 | .deferred_free = rcu_bh_torture_deferred_free, | |
466 | .sync = rcu_bh_torture_synchronize, | |
467 | .cb_barrier = rcu_barrier_bh, | |
468 | .stats = NULL, | |
469 | .irq_capable = 1, | |
470 | .name = "rcu_bh" | |
c32e0660 PM |
471 | }; |
472 | ||
11a14701 | 473 | static struct rcu_torture_ops rcu_bh_sync_ops = { |
0acc512c PM |
474 | .init = rcu_sync_torture_init, |
475 | .cleanup = NULL, | |
476 | .readlock = rcu_bh_torture_read_lock, | |
477 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
478 | .readunlock = rcu_bh_torture_read_unlock, | |
479 | .completed = rcu_bh_torture_completed, | |
480 | .deferred_free = rcu_sync_torture_deferred_free, | |
481 | .sync = rcu_bh_torture_synchronize, | |
482 | .cb_barrier = NULL, | |
483 | .stats = NULL, | |
484 | .irq_capable = 1, | |
485 | .name = "rcu_bh_sync" | |
11a14701 JT |
486 | }; |
487 | ||
b2896d2e PM |
488 | /* |
489 | * Definitions for srcu torture testing. | |
490 | */ | |
491 | ||
492 | static struct srcu_struct srcu_ctl; | |
b2896d2e PM |
493 | |
494 | static void srcu_torture_init(void) | |
495 | { | |
496 | init_srcu_struct(&srcu_ctl); | |
e3033736 | 497 | rcu_sync_torture_init(); |
b2896d2e PM |
498 | } |
499 | ||
500 | static void srcu_torture_cleanup(void) | |
501 | { | |
502 | synchronize_srcu(&srcu_ctl); | |
503 | cleanup_srcu_struct(&srcu_ctl); | |
504 | } | |
505 | ||
012d3ca8 | 506 | static int srcu_torture_read_lock(void) __acquires(&srcu_ctl) |
b2896d2e PM |
507 | { |
508 | return srcu_read_lock(&srcu_ctl); | |
509 | } | |
510 | ||
511 | static void srcu_read_delay(struct rcu_random_state *rrsp) | |
512 | { | |
513 | long delay; | |
514 | const long uspertick = 1000000 / HZ; | |
515 | const long longdelay = 10; | |
516 | ||
517 | /* We want there to be long-running readers, but not all the time. */ | |
518 | ||
519 | delay = rcu_random(rrsp) % (nrealreaders * 2 * longdelay * uspertick); | |
520 | if (!delay) | |
521 | schedule_timeout_interruptible(longdelay); | |
522 | } | |
523 | ||
012d3ca8 | 524 | static void srcu_torture_read_unlock(int idx) __releases(&srcu_ctl) |
b2896d2e PM |
525 | { |
526 | srcu_read_unlock(&srcu_ctl, idx); | |
527 | } | |
528 | ||
529 | static int srcu_torture_completed(void) | |
530 | { | |
531 | return srcu_batches_completed(&srcu_ctl); | |
532 | } | |
533 | ||
b772e1dd JT |
534 | static void srcu_torture_synchronize(void) |
535 | { | |
536 | synchronize_srcu(&srcu_ctl); | |
537 | } | |
538 | ||
b2896d2e PM |
539 | static int srcu_torture_stats(char *page) |
540 | { | |
541 | int cnt = 0; | |
542 | int cpu; | |
543 | int idx = srcu_ctl.completed & 0x1; | |
544 | ||
545 | cnt += sprintf(&page[cnt], "%s%s per-CPU(idx=%d):", | |
546 | torture_type, TORTURE_FLAG, idx); | |
547 | for_each_possible_cpu(cpu) { | |
548 | cnt += sprintf(&page[cnt], " %d(%d,%d)", cpu, | |
549 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[!idx], | |
550 | per_cpu_ptr(srcu_ctl.per_cpu_ref, cpu)->c[idx]); | |
551 | } | |
552 | cnt += sprintf(&page[cnt], "\n"); | |
553 | return cnt; | |
554 | } | |
555 | ||
556 | static struct rcu_torture_ops srcu_ops = { | |
0acc512c PM |
557 | .init = srcu_torture_init, |
558 | .cleanup = srcu_torture_cleanup, | |
559 | .readlock = srcu_torture_read_lock, | |
560 | .read_delay = srcu_read_delay, | |
561 | .readunlock = srcu_torture_read_unlock, | |
562 | .completed = srcu_torture_completed, | |
563 | .deferred_free = rcu_sync_torture_deferred_free, | |
564 | .sync = srcu_torture_synchronize, | |
565 | .cb_barrier = NULL, | |
566 | .stats = srcu_torture_stats, | |
567 | .name = "srcu" | |
b2896d2e PM |
568 | }; |
569 | ||
804bb837 PM |
570 | static void srcu_torture_synchronize_expedited(void) |
571 | { | |
572 | synchronize_srcu_expedited(&srcu_ctl); | |
573 | } | |
574 | ||
575 | static struct rcu_torture_ops srcu_expedited_ops = { | |
576 | .init = srcu_torture_init, | |
577 | .cleanup = srcu_torture_cleanup, | |
578 | .readlock = srcu_torture_read_lock, | |
579 | .read_delay = srcu_read_delay, | |
580 | .readunlock = srcu_torture_read_unlock, | |
581 | .completed = srcu_torture_completed, | |
582 | .deferred_free = rcu_sync_torture_deferred_free, | |
583 | .sync = srcu_torture_synchronize_expedited, | |
584 | .cb_barrier = NULL, | |
585 | .stats = srcu_torture_stats, | |
586 | .name = "srcu_expedited" | |
587 | }; | |
588 | ||
4b6c2cca JT |
589 | /* |
590 | * Definitions for sched torture testing. | |
591 | */ | |
592 | ||
593 | static int sched_torture_read_lock(void) | |
594 | { | |
595 | preempt_disable(); | |
596 | return 0; | |
597 | } | |
598 | ||
599 | static void sched_torture_read_unlock(int idx) | |
600 | { | |
601 | preempt_enable(); | |
602 | } | |
603 | ||
2326974d PM |
604 | static void rcu_sched_torture_deferred_free(struct rcu_torture *p) |
605 | { | |
606 | call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); | |
607 | } | |
608 | ||
4b6c2cca JT |
609 | static void sched_torture_synchronize(void) |
610 | { | |
611 | synchronize_sched(); | |
612 | } | |
613 | ||
614 | static struct rcu_torture_ops sched_ops = { | |
0acc512c PM |
615 | .init = rcu_sync_torture_init, |
616 | .cleanup = NULL, | |
617 | .readlock = sched_torture_read_lock, | |
618 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
619 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 620 | .completed = rcu_no_completed, |
0acc512c PM |
621 | .deferred_free = rcu_sched_torture_deferred_free, |
622 | .sync = sched_torture_synchronize, | |
623 | .cb_barrier = rcu_barrier_sched, | |
624 | .stats = NULL, | |
625 | .irq_capable = 1, | |
626 | .name = "sched" | |
4b6c2cca JT |
627 | }; |
628 | ||
804bb837 | 629 | static struct rcu_torture_ops sched_sync_ops = { |
0acc512c PM |
630 | .init = rcu_sync_torture_init, |
631 | .cleanup = NULL, | |
632 | .readlock = sched_torture_read_lock, | |
633 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
634 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 635 | .completed = rcu_no_completed, |
0acc512c PM |
636 | .deferred_free = rcu_sync_torture_deferred_free, |
637 | .sync = sched_torture_synchronize, | |
638 | .cb_barrier = NULL, | |
639 | .stats = NULL, | |
640 | .name = "sched_sync" | |
641 | }; | |
642 | ||
0acc512c PM |
643 | static struct rcu_torture_ops sched_expedited_ops = { |
644 | .init = rcu_sync_torture_init, | |
645 | .cleanup = NULL, | |
646 | .readlock = sched_torture_read_lock, | |
647 | .read_delay = rcu_read_delay, /* just reuse rcu's version. */ | |
648 | .readunlock = sched_torture_read_unlock, | |
d9a3da06 | 649 | .completed = rcu_no_completed, |
0acc512c PM |
650 | .deferred_free = rcu_sync_torture_deferred_free, |
651 | .sync = synchronize_sched_expedited, | |
652 | .cb_barrier = NULL, | |
653 | .stats = rcu_expedited_torture_stats, | |
654 | .irq_capable = 1, | |
655 | .name = "sched_expedited" | |
2326974d PM |
656 | }; |
657 | ||
a241ec65 PM |
658 | /* |
659 | * RCU torture writer kthread. Repeatedly substitutes a new structure | |
660 | * for that pointed to by rcu_torture_current, freeing the old structure | |
661 | * after a series of grace periods (the "pipeline"). | |
662 | */ | |
663 | static int | |
664 | rcu_torture_writer(void *arg) | |
665 | { | |
666 | int i; | |
667 | long oldbatch = rcu_batches_completed(); | |
668 | struct rcu_torture *rp; | |
669 | struct rcu_torture *old_rp; | |
670 | static DEFINE_RCU_RANDOM(rand); | |
671 | ||
672 | VERBOSE_PRINTK_STRING("rcu_torture_writer task started"); | |
dbdf65b1 IM |
673 | set_user_nice(current, 19); |
674 | ||
a241ec65 PM |
675 | do { |
676 | schedule_timeout_uninterruptible(1); | |
a71fca58 PM |
677 | rp = rcu_torture_alloc(); |
678 | if (rp == NULL) | |
a241ec65 PM |
679 | continue; |
680 | rp->rtort_pipe_count = 0; | |
681 | udelay(rcu_random(&rand) & 0x3ff); | |
682 | old_rp = rcu_torture_current; | |
996417d2 | 683 | rp->rtort_mbtest = 1; |
a241ec65 | 684 | rcu_assign_pointer(rcu_torture_current, rp); |
9b2619af | 685 | smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ |
c8e5b163 | 686 | if (old_rp) { |
a241ec65 PM |
687 | i = old_rp->rtort_pipe_count; |
688 | if (i > RCU_TORTURE_PIPE_LEN) | |
689 | i = RCU_TORTURE_PIPE_LEN; | |
690 | atomic_inc(&rcu_torture_wcount[i]); | |
691 | old_rp->rtort_pipe_count++; | |
0acc512c | 692 | cur_ops->deferred_free(old_rp); |
a241ec65 PM |
693 | } |
694 | rcu_torture_current_version++; | |
72e9bb54 | 695 | oldbatch = cur_ops->completed(); |
c9d557c1 PM |
696 | rcu_stutter_wait("rcu_torture_writer"); |
697 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 698 | VERBOSE_PRINTK_STRING("rcu_torture_writer task stopping"); |
c9d557c1 PM |
699 | rcutorture_shutdown_absorb("rcu_torture_writer"); |
700 | while (!kthread_should_stop()) | |
a241ec65 PM |
701 | schedule_timeout_uninterruptible(1); |
702 | return 0; | |
703 | } | |
704 | ||
b772e1dd JT |
705 | /* |
706 | * RCU torture fake writer kthread. Repeatedly calls sync, with a random | |
707 | * delay between calls. | |
708 | */ | |
709 | static int | |
710 | rcu_torture_fakewriter(void *arg) | |
711 | { | |
712 | DEFINE_RCU_RANDOM(rand); | |
713 | ||
714 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task started"); | |
715 | set_user_nice(current, 19); | |
716 | ||
717 | do { | |
718 | schedule_timeout_uninterruptible(1 + rcu_random(&rand)%10); | |
719 | udelay(rcu_random(&rand) & 0x3ff); | |
720 | cur_ops->sync(); | |
c9d557c1 PM |
721 | rcu_stutter_wait("rcu_torture_fakewriter"); |
722 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
b772e1dd JT |
723 | |
724 | VERBOSE_PRINTK_STRING("rcu_torture_fakewriter task stopping"); | |
c9d557c1 PM |
725 | rcutorture_shutdown_absorb("rcu_torture_fakewriter"); |
726 | while (!kthread_should_stop()) | |
b772e1dd JT |
727 | schedule_timeout_uninterruptible(1); |
728 | return 0; | |
729 | } | |
730 | ||
0729fbf3 PM |
731 | /* |
732 | * RCU torture reader from timer handler. Dereferences rcu_torture_current, | |
733 | * incrementing the corresponding element of the pipeline array. The | |
734 | * counter in the element should never be greater than 1, otherwise, the | |
735 | * RCU implementation is broken. | |
736 | */ | |
737 | static void rcu_torture_timer(unsigned long unused) | |
738 | { | |
739 | int idx; | |
740 | int completed; | |
741 | static DEFINE_RCU_RANDOM(rand); | |
742 | static DEFINE_SPINLOCK(rand_lock); | |
743 | struct rcu_torture *p; | |
744 | int pipe_count; | |
745 | ||
746 | idx = cur_ops->readlock(); | |
747 | completed = cur_ops->completed(); | |
748 | p = rcu_dereference(rcu_torture_current); | |
749 | if (p == NULL) { | |
750 | /* Leave because rcu_torture_writer is not yet underway */ | |
751 | cur_ops->readunlock(idx); | |
752 | return; | |
753 | } | |
754 | if (p->rtort_mbtest == 0) | |
755 | atomic_inc(&n_rcu_torture_mberror); | |
756 | spin_lock(&rand_lock); | |
0acc512c | 757 | cur_ops->read_delay(&rand); |
0729fbf3 PM |
758 | n_rcu_torture_timers++; |
759 | spin_unlock(&rand_lock); | |
760 | preempt_disable(); | |
761 | pipe_count = p->rtort_pipe_count; | |
762 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
763 | /* Should not happen, but... */ | |
764 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
765 | } | |
e800879d | 766 | __this_cpu_inc(per_cpu_var(rcu_torture_count)[pipe_count]); |
0729fbf3 PM |
767 | completed = cur_ops->completed() - completed; |
768 | if (completed > RCU_TORTURE_PIPE_LEN) { | |
769 | /* Should not happen, but... */ | |
770 | completed = RCU_TORTURE_PIPE_LEN; | |
771 | } | |
e800879d | 772 | __this_cpu_inc(per_cpu_var(rcu_torture_batch)[completed]); |
0729fbf3 PM |
773 | preempt_enable(); |
774 | cur_ops->readunlock(idx); | |
775 | } | |
776 | ||
a241ec65 PM |
777 | /* |
778 | * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, | |
779 | * incrementing the corresponding element of the pipeline array. The | |
780 | * counter in the element should never be greater than 1, otherwise, the | |
781 | * RCU implementation is broken. | |
782 | */ | |
783 | static int | |
784 | rcu_torture_reader(void *arg) | |
785 | { | |
786 | int completed; | |
72e9bb54 | 787 | int idx; |
a241ec65 PM |
788 | DEFINE_RCU_RANDOM(rand); |
789 | struct rcu_torture *p; | |
790 | int pipe_count; | |
0729fbf3 | 791 | struct timer_list t; |
a241ec65 PM |
792 | |
793 | VERBOSE_PRINTK_STRING("rcu_torture_reader task started"); | |
dbdf65b1 | 794 | set_user_nice(current, 19); |
0acc512c | 795 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 796 | setup_timer_on_stack(&t, rcu_torture_timer, 0); |
dbdf65b1 | 797 | |
a241ec65 | 798 | do { |
0acc512c | 799 | if (irqreader && cur_ops->irq_capable) { |
0729fbf3 PM |
800 | if (!timer_pending(&t)) |
801 | mod_timer(&t, 1); | |
802 | } | |
72e9bb54 PM |
803 | idx = cur_ops->readlock(); |
804 | completed = cur_ops->completed(); | |
a241ec65 PM |
805 | p = rcu_dereference(rcu_torture_current); |
806 | if (p == NULL) { | |
807 | /* Wait for rcu_torture_writer to get underway */ | |
72e9bb54 | 808 | cur_ops->readunlock(idx); |
a241ec65 PM |
809 | schedule_timeout_interruptible(HZ); |
810 | continue; | |
811 | } | |
996417d2 PM |
812 | if (p->rtort_mbtest == 0) |
813 | atomic_inc(&n_rcu_torture_mberror); | |
0acc512c | 814 | cur_ops->read_delay(&rand); |
a241ec65 PM |
815 | preempt_disable(); |
816 | pipe_count = p->rtort_pipe_count; | |
817 | if (pipe_count > RCU_TORTURE_PIPE_LEN) { | |
818 | /* Should not happen, but... */ | |
819 | pipe_count = RCU_TORTURE_PIPE_LEN; | |
820 | } | |
e800879d | 821 | __this_cpu_inc(per_cpu_var(rcu_torture_count)[pipe_count]); |
72e9bb54 | 822 | completed = cur_ops->completed() - completed; |
a241ec65 PM |
823 | if (completed > RCU_TORTURE_PIPE_LEN) { |
824 | /* Should not happen, but... */ | |
825 | completed = RCU_TORTURE_PIPE_LEN; | |
826 | } | |
e800879d | 827 | __this_cpu_inc(per_cpu_var(rcu_torture_batch)[completed]); |
a241ec65 | 828 | preempt_enable(); |
72e9bb54 | 829 | cur_ops->readunlock(idx); |
a241ec65 | 830 | schedule(); |
c9d557c1 PM |
831 | rcu_stutter_wait("rcu_torture_reader"); |
832 | } while (!kthread_should_stop() && fullstop == FULLSTOP_DONTSTOP); | |
a241ec65 | 833 | VERBOSE_PRINTK_STRING("rcu_torture_reader task stopping"); |
c9d557c1 | 834 | rcutorture_shutdown_absorb("rcu_torture_reader"); |
0acc512c | 835 | if (irqreader && cur_ops->irq_capable) |
0729fbf3 | 836 | del_timer_sync(&t); |
c9d557c1 | 837 | while (!kthread_should_stop()) |
a241ec65 PM |
838 | schedule_timeout_uninterruptible(1); |
839 | return 0; | |
840 | } | |
841 | ||
842 | /* | |
843 | * Create an RCU-torture statistics message in the specified buffer. | |
844 | */ | |
845 | static int | |
846 | rcu_torture_printk(char *page) | |
847 | { | |
848 | int cnt = 0; | |
849 | int cpu; | |
850 | int i; | |
851 | long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
852 | long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; | |
853 | ||
0a945022 | 854 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
855 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
856 | pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; | |
857 | batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; | |
858 | } | |
859 | } | |
860 | for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { | |
861 | if (pipesummary[i] != 0) | |
862 | break; | |
863 | } | |
72e9bb54 | 864 | cnt += sprintf(&page[cnt], "%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 865 | cnt += sprintf(&page[cnt], |
996417d2 | 866 | "rtc: %p ver: %ld tfle: %d rta: %d rtaf: %d rtf: %d " |
0729fbf3 | 867 | "rtmbe: %d nt: %ld", |
a241ec65 PM |
868 | rcu_torture_current, |
869 | rcu_torture_current_version, | |
870 | list_empty(&rcu_torture_freelist), | |
871 | atomic_read(&n_rcu_torture_alloc), | |
872 | atomic_read(&n_rcu_torture_alloc_fail), | |
996417d2 | 873 | atomic_read(&n_rcu_torture_free), |
0729fbf3 PM |
874 | atomic_read(&n_rcu_torture_mberror), |
875 | n_rcu_torture_timers); | |
996417d2 PM |
876 | if (atomic_read(&n_rcu_torture_mberror) != 0) |
877 | cnt += sprintf(&page[cnt], " !!!"); | |
72e9bb54 | 878 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
996417d2 | 879 | if (i > 1) { |
a241ec65 | 880 | cnt += sprintf(&page[cnt], "!!! "); |
996417d2 | 881 | atomic_inc(&n_rcu_torture_error); |
5af970a4 | 882 | WARN_ON_ONCE(1); |
996417d2 | 883 | } |
a241ec65 PM |
884 | cnt += sprintf(&page[cnt], "Reader Pipe: "); |
885 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) | |
886 | cnt += sprintf(&page[cnt], " %ld", pipesummary[i]); | |
72e9bb54 | 887 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 | 888 | cnt += sprintf(&page[cnt], "Reader Batch: "); |
72e9bb54 | 889 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
a241ec65 | 890 | cnt += sprintf(&page[cnt], " %ld", batchsummary[i]); |
72e9bb54 | 891 | cnt += sprintf(&page[cnt], "\n%s%s ", torture_type, TORTURE_FLAG); |
a241ec65 PM |
892 | cnt += sprintf(&page[cnt], "Free-Block Circulation: "); |
893 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { | |
894 | cnt += sprintf(&page[cnt], " %d", | |
895 | atomic_read(&rcu_torture_wcount[i])); | |
896 | } | |
897 | cnt += sprintf(&page[cnt], "\n"); | |
c8e5b163 | 898 | if (cur_ops->stats) |
72e9bb54 | 899 | cnt += cur_ops->stats(&page[cnt]); |
a241ec65 PM |
900 | return cnt; |
901 | } | |
902 | ||
903 | /* | |
904 | * Print torture statistics. Caller must ensure that there is only | |
905 | * one call to this function at a given time!!! This is normally | |
906 | * accomplished by relying on the module system to only have one copy | |
907 | * of the module loaded, and then by giving the rcu_torture_stats | |
908 | * kthread full control (or the init/cleanup functions when rcu_torture_stats | |
909 | * thread is not running). | |
910 | */ | |
911 | static void | |
912 | rcu_torture_stats_print(void) | |
913 | { | |
914 | int cnt; | |
915 | ||
916 | cnt = rcu_torture_printk(printk_buf); | |
917 | printk(KERN_ALERT "%s", printk_buf); | |
918 | } | |
919 | ||
920 | /* | |
921 | * Periodically prints torture statistics, if periodic statistics printing | |
922 | * was specified via the stat_interval module parameter. | |
923 | * | |
924 | * No need to worry about fullstop here, since this one doesn't reference | |
925 | * volatile state or register callbacks. | |
926 | */ | |
927 | static int | |
928 | rcu_torture_stats(void *arg) | |
929 | { | |
930 | VERBOSE_PRINTK_STRING("rcu_torture_stats task started"); | |
931 | do { | |
932 | schedule_timeout_interruptible(stat_interval * HZ); | |
933 | rcu_torture_stats_print(); | |
c9d557c1 PM |
934 | rcutorture_shutdown_absorb("rcu_torture_stats"); |
935 | } while (!kthread_should_stop()); | |
a241ec65 PM |
936 | VERBOSE_PRINTK_STRING("rcu_torture_stats task stopping"); |
937 | return 0; | |
938 | } | |
939 | ||
d84f5203 SV |
940 | static int rcu_idle_cpu; /* Force all torture tasks off this CPU */ |
941 | ||
942 | /* Shuffle tasks such that we allow @rcu_idle_cpu to become idle. A special case | |
943 | * is when @rcu_idle_cpu = -1, when we allow the tasks to run on all CPUs. | |
944 | */ | |
b2896d2e | 945 | static void rcu_torture_shuffle_tasks(void) |
d84f5203 | 946 | { |
d84f5203 SV |
947 | int i; |
948 | ||
73d0a4b1 | 949 | cpumask_setall(shuffle_tmp_mask); |
86ef5c9a | 950 | get_online_cpus(); |
d84f5203 SV |
951 | |
952 | /* No point in shuffling if there is only one online CPU (ex: UP) */ | |
c9d557c1 PM |
953 | if (num_online_cpus() == 1) { |
954 | put_online_cpus(); | |
955 | return; | |
956 | } | |
d84f5203 SV |
957 | |
958 | if (rcu_idle_cpu != -1) | |
73d0a4b1 | 959 | cpumask_clear_cpu(rcu_idle_cpu, shuffle_tmp_mask); |
d84f5203 | 960 | |
73d0a4b1 | 961 | set_cpus_allowed_ptr(current, shuffle_tmp_mask); |
d84f5203 | 962 | |
c8e5b163 | 963 | if (reader_tasks) { |
d84f5203 SV |
964 | for (i = 0; i < nrealreaders; i++) |
965 | if (reader_tasks[i]) | |
f70316da | 966 | set_cpus_allowed_ptr(reader_tasks[i], |
73d0a4b1 | 967 | shuffle_tmp_mask); |
d84f5203 SV |
968 | } |
969 | ||
c8e5b163 | 970 | if (fakewriter_tasks) { |
b772e1dd JT |
971 | for (i = 0; i < nfakewriters; i++) |
972 | if (fakewriter_tasks[i]) | |
f70316da | 973 | set_cpus_allowed_ptr(fakewriter_tasks[i], |
73d0a4b1 | 974 | shuffle_tmp_mask); |
b772e1dd JT |
975 | } |
976 | ||
d84f5203 | 977 | if (writer_task) |
73d0a4b1 | 978 | set_cpus_allowed_ptr(writer_task, shuffle_tmp_mask); |
d84f5203 SV |
979 | |
980 | if (stats_task) | |
73d0a4b1 | 981 | set_cpus_allowed_ptr(stats_task, shuffle_tmp_mask); |
d84f5203 SV |
982 | |
983 | if (rcu_idle_cpu == -1) | |
984 | rcu_idle_cpu = num_online_cpus() - 1; | |
985 | else | |
986 | rcu_idle_cpu--; | |
987 | ||
86ef5c9a | 988 | put_online_cpus(); |
d84f5203 SV |
989 | } |
990 | ||
991 | /* Shuffle tasks across CPUs, with the intent of allowing each CPU in the | |
992 | * system to become idle at a time and cut off its timer ticks. This is meant | |
993 | * to test the support for such tickless idle CPU in RCU. | |
994 | */ | |
995 | static int | |
996 | rcu_torture_shuffle(void *arg) | |
997 | { | |
998 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task started"); | |
999 | do { | |
1000 | schedule_timeout_interruptible(shuffle_interval * HZ); | |
1001 | rcu_torture_shuffle_tasks(); | |
c9d557c1 PM |
1002 | rcutorture_shutdown_absorb("rcu_torture_shuffle"); |
1003 | } while (!kthread_should_stop()); | |
d84f5203 SV |
1004 | VERBOSE_PRINTK_STRING("rcu_torture_shuffle task stopping"); |
1005 | return 0; | |
1006 | } | |
1007 | ||
d120f65f PM |
1008 | /* Cause the rcutorture test to "stutter", starting and stopping all |
1009 | * threads periodically. | |
1010 | */ | |
1011 | static int | |
1012 | rcu_torture_stutter(void *arg) | |
1013 | { | |
1014 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task started"); | |
1015 | do { | |
1016 | schedule_timeout_interruptible(stutter * HZ); | |
1017 | stutter_pause_test = 1; | |
c9d557c1 | 1018 | if (!kthread_should_stop()) |
d120f65f PM |
1019 | schedule_timeout_interruptible(stutter * HZ); |
1020 | stutter_pause_test = 0; | |
c9d557c1 PM |
1021 | rcutorture_shutdown_absorb("rcu_torture_stutter"); |
1022 | } while (!kthread_should_stop()); | |
d120f65f PM |
1023 | VERBOSE_PRINTK_STRING("rcu_torture_stutter task stopping"); |
1024 | return 0; | |
1025 | } | |
1026 | ||
95c38322 PM |
1027 | static inline void |
1028 | rcu_torture_print_module_parms(char *tag) | |
1029 | { | |
b772e1dd JT |
1030 | printk(KERN_ALERT "%s" TORTURE_FLAG |
1031 | "--- %s: nreaders=%d nfakewriters=%d " | |
95c38322 | 1032 | "stat_interval=%d verbose=%d test_no_idle_hz=%d " |
0729fbf3 | 1033 | "shuffle_interval=%d stutter=%d irqreader=%d\n", |
b772e1dd | 1034 | torture_type, tag, nrealreaders, nfakewriters, |
d120f65f | 1035 | stat_interval, verbose, test_no_idle_hz, shuffle_interval, |
0729fbf3 | 1036 | stutter, irqreader); |
95c38322 PM |
1037 | } |
1038 | ||
343e9099 PM |
1039 | static struct notifier_block rcutorture_nb = { |
1040 | .notifier_call = rcutorture_shutdown_notify, | |
1041 | }; | |
1042 | ||
a241ec65 PM |
1043 | static void |
1044 | rcu_torture_cleanup(void) | |
1045 | { | |
1046 | int i; | |
1047 | ||
343e9099 | 1048 | mutex_lock(&fullstop_mutex); |
c9d557c1 PM |
1049 | if (fullstop == FULLSTOP_SHUTDOWN) { |
1050 | printk(KERN_WARNING /* but going down anyway, so... */ | |
1051 | "Concurrent 'rmmod rcutorture' and shutdown illegal!\n"); | |
343e9099 | 1052 | mutex_unlock(&fullstop_mutex); |
c9d557c1 | 1053 | schedule_timeout_uninterruptible(10); |
343e9099 PM |
1054 | if (cur_ops->cb_barrier != NULL) |
1055 | cur_ops->cb_barrier(); | |
1056 | return; | |
1057 | } | |
c9d557c1 | 1058 | fullstop = FULLSTOP_RMMOD; |
343e9099 PM |
1059 | mutex_unlock(&fullstop_mutex); |
1060 | unregister_reboot_notifier(&rcutorture_nb); | |
d120f65f PM |
1061 | if (stutter_task) { |
1062 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stutter task"); | |
1063 | kthread_stop(stutter_task); | |
1064 | } | |
1065 | stutter_task = NULL; | |
c8e5b163 | 1066 | if (shuffler_task) { |
d84f5203 SV |
1067 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); |
1068 | kthread_stop(shuffler_task); | |
73d0a4b1 | 1069 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1070 | } |
1071 | shuffler_task = NULL; | |
1072 | ||
c8e5b163 | 1073 | if (writer_task) { |
a241ec65 PM |
1074 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); |
1075 | kthread_stop(writer_task); | |
1076 | } | |
1077 | writer_task = NULL; | |
1078 | ||
c8e5b163 | 1079 | if (reader_tasks) { |
a241ec65 | 1080 | for (i = 0; i < nrealreaders; i++) { |
c8e5b163 | 1081 | if (reader_tasks[i]) { |
a241ec65 PM |
1082 | VERBOSE_PRINTK_STRING( |
1083 | "Stopping rcu_torture_reader task"); | |
1084 | kthread_stop(reader_tasks[i]); | |
1085 | } | |
1086 | reader_tasks[i] = NULL; | |
1087 | } | |
1088 | kfree(reader_tasks); | |
1089 | reader_tasks = NULL; | |
1090 | } | |
1091 | rcu_torture_current = NULL; | |
1092 | ||
c8e5b163 | 1093 | if (fakewriter_tasks) { |
b772e1dd | 1094 | for (i = 0; i < nfakewriters; i++) { |
c8e5b163 | 1095 | if (fakewriter_tasks[i]) { |
b772e1dd JT |
1096 | VERBOSE_PRINTK_STRING( |
1097 | "Stopping rcu_torture_fakewriter task"); | |
1098 | kthread_stop(fakewriter_tasks[i]); | |
1099 | } | |
1100 | fakewriter_tasks[i] = NULL; | |
1101 | } | |
1102 | kfree(fakewriter_tasks); | |
1103 | fakewriter_tasks = NULL; | |
1104 | } | |
1105 | ||
c8e5b163 | 1106 | if (stats_task) { |
a241ec65 PM |
1107 | VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); |
1108 | kthread_stop(stats_task); | |
1109 | } | |
1110 | stats_task = NULL; | |
1111 | ||
1112 | /* Wait for all RCU callbacks to fire. */ | |
2326974d PM |
1113 | |
1114 | if (cur_ops->cb_barrier != NULL) | |
1115 | cur_ops->cb_barrier(); | |
a241ec65 | 1116 | |
a241ec65 | 1117 | rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ |
72e9bb54 | 1118 | |
c8e5b163 | 1119 | if (cur_ops->cleanup) |
72e9bb54 | 1120 | cur_ops->cleanup(); |
95c38322 PM |
1121 | if (atomic_read(&n_rcu_torture_error)) |
1122 | rcu_torture_print_module_parms("End of test: FAILURE"); | |
1123 | else | |
1124 | rcu_torture_print_module_parms("End of test: SUCCESS"); | |
a241ec65 PM |
1125 | } |
1126 | ||
6f8bc500 | 1127 | static int __init |
a241ec65 PM |
1128 | rcu_torture_init(void) |
1129 | { | |
1130 | int i; | |
1131 | int cpu; | |
1132 | int firsterr = 0; | |
ade5fb81 | 1133 | static struct rcu_torture_ops *torture_ops[] = |
d9a3da06 PM |
1134 | { &rcu_ops, &rcu_sync_ops, &rcu_expedited_ops, |
1135 | &rcu_bh_ops, &rcu_bh_sync_ops, | |
804bb837 PM |
1136 | &srcu_ops, &srcu_expedited_ops, |
1137 | &sched_ops, &sched_sync_ops, &sched_expedited_ops, }; | |
a241ec65 | 1138 | |
343e9099 PM |
1139 | mutex_lock(&fullstop_mutex); |
1140 | ||
a241ec65 | 1141 | /* Process args and tell the world that the torturer is on the job. */ |
ade5fb81 | 1142 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { |
72e9bb54 | 1143 | cur_ops = torture_ops[i]; |
ade5fb81 | 1144 | if (strcmp(torture_type, cur_ops->name) == 0) |
72e9bb54 | 1145 | break; |
72e9bb54 | 1146 | } |
ade5fb81 | 1147 | if (i == ARRAY_SIZE(torture_ops)) { |
cf886c44 | 1148 | printk(KERN_ALERT "rcu-torture: invalid torture type: \"%s\"\n", |
72e9bb54 | 1149 | torture_type); |
cf886c44 PM |
1150 | printk(KERN_ALERT "rcu-torture types:"); |
1151 | for (i = 0; i < ARRAY_SIZE(torture_ops); i++) | |
1152 | printk(KERN_ALERT " %s", torture_ops[i]->name); | |
1153 | printk(KERN_ALERT "\n"); | |
343e9099 | 1154 | mutex_unlock(&fullstop_mutex); |
a71fca58 | 1155 | return -EINVAL; |
72e9bb54 | 1156 | } |
c8e5b163 | 1157 | if (cur_ops->init) |
72e9bb54 PM |
1158 | cur_ops->init(); /* no "goto unwind" prior to this point!!! */ |
1159 | ||
a241ec65 PM |
1160 | if (nreaders >= 0) |
1161 | nrealreaders = nreaders; | |
1162 | else | |
1163 | nrealreaders = 2 * num_online_cpus(); | |
95c38322 | 1164 | rcu_torture_print_module_parms("Start of test"); |
c9d557c1 | 1165 | fullstop = FULLSTOP_DONTSTOP; |
a241ec65 PM |
1166 | |
1167 | /* Set up the freelist. */ | |
1168 | ||
1169 | INIT_LIST_HEAD(&rcu_torture_freelist); | |
788e770e | 1170 | for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { |
996417d2 | 1171 | rcu_tortures[i].rtort_mbtest = 0; |
a241ec65 PM |
1172 | list_add_tail(&rcu_tortures[i].rtort_free, |
1173 | &rcu_torture_freelist); | |
1174 | } | |
1175 | ||
1176 | /* Initialize the statistics so that each run gets its own numbers. */ | |
1177 | ||
1178 | rcu_torture_current = NULL; | |
1179 | rcu_torture_current_version = 0; | |
1180 | atomic_set(&n_rcu_torture_alloc, 0); | |
1181 | atomic_set(&n_rcu_torture_alloc_fail, 0); | |
1182 | atomic_set(&n_rcu_torture_free, 0); | |
996417d2 PM |
1183 | atomic_set(&n_rcu_torture_mberror, 0); |
1184 | atomic_set(&n_rcu_torture_error, 0); | |
a241ec65 PM |
1185 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) |
1186 | atomic_set(&rcu_torture_wcount[i], 0); | |
0a945022 | 1187 | for_each_possible_cpu(cpu) { |
a241ec65 PM |
1188 | for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { |
1189 | per_cpu(rcu_torture_count, cpu)[i] = 0; | |
1190 | per_cpu(rcu_torture_batch, cpu)[i] = 0; | |
1191 | } | |
1192 | } | |
1193 | ||
1194 | /* Start up the kthreads. */ | |
1195 | ||
1196 | VERBOSE_PRINTK_STRING("Creating rcu_torture_writer task"); | |
1197 | writer_task = kthread_run(rcu_torture_writer, NULL, | |
1198 | "rcu_torture_writer"); | |
1199 | if (IS_ERR(writer_task)) { | |
1200 | firsterr = PTR_ERR(writer_task); | |
1201 | VERBOSE_PRINTK_ERRSTRING("Failed to create writer"); | |
1202 | writer_task = NULL; | |
1203 | goto unwind; | |
1204 | } | |
b772e1dd | 1205 | fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]), |
a71fca58 | 1206 | GFP_KERNEL); |
b772e1dd JT |
1207 | if (fakewriter_tasks == NULL) { |
1208 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1209 | firsterr = -ENOMEM; | |
1210 | goto unwind; | |
1211 | } | |
1212 | for (i = 0; i < nfakewriters; i++) { | |
1213 | VERBOSE_PRINTK_STRING("Creating rcu_torture_fakewriter task"); | |
1214 | fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL, | |
a71fca58 | 1215 | "rcu_torture_fakewriter"); |
b772e1dd JT |
1216 | if (IS_ERR(fakewriter_tasks[i])) { |
1217 | firsterr = PTR_ERR(fakewriter_tasks[i]); | |
1218 | VERBOSE_PRINTK_ERRSTRING("Failed to create fakewriter"); | |
1219 | fakewriter_tasks[i] = NULL; | |
1220 | goto unwind; | |
1221 | } | |
1222 | } | |
2860aaba | 1223 | reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), |
a241ec65 PM |
1224 | GFP_KERNEL); |
1225 | if (reader_tasks == NULL) { | |
1226 | VERBOSE_PRINTK_ERRSTRING("out of memory"); | |
1227 | firsterr = -ENOMEM; | |
1228 | goto unwind; | |
1229 | } | |
1230 | for (i = 0; i < nrealreaders; i++) { | |
1231 | VERBOSE_PRINTK_STRING("Creating rcu_torture_reader task"); | |
1232 | reader_tasks[i] = kthread_run(rcu_torture_reader, NULL, | |
1233 | "rcu_torture_reader"); | |
1234 | if (IS_ERR(reader_tasks[i])) { | |
1235 | firsterr = PTR_ERR(reader_tasks[i]); | |
1236 | VERBOSE_PRINTK_ERRSTRING("Failed to create reader"); | |
1237 | reader_tasks[i] = NULL; | |
1238 | goto unwind; | |
1239 | } | |
1240 | } | |
1241 | if (stat_interval > 0) { | |
1242 | VERBOSE_PRINTK_STRING("Creating rcu_torture_stats task"); | |
1243 | stats_task = kthread_run(rcu_torture_stats, NULL, | |
1244 | "rcu_torture_stats"); | |
1245 | if (IS_ERR(stats_task)) { | |
1246 | firsterr = PTR_ERR(stats_task); | |
1247 | VERBOSE_PRINTK_ERRSTRING("Failed to create stats"); | |
1248 | stats_task = NULL; | |
1249 | goto unwind; | |
1250 | } | |
1251 | } | |
d84f5203 SV |
1252 | if (test_no_idle_hz) { |
1253 | rcu_idle_cpu = num_online_cpus() - 1; | |
73d0a4b1 RR |
1254 | |
1255 | if (!alloc_cpumask_var(&shuffle_tmp_mask, GFP_KERNEL)) { | |
1256 | firsterr = -ENOMEM; | |
1257 | VERBOSE_PRINTK_ERRSTRING("Failed to alloc mask"); | |
1258 | goto unwind; | |
1259 | } | |
1260 | ||
d84f5203 SV |
1261 | /* Create the shuffler thread */ |
1262 | shuffler_task = kthread_run(rcu_torture_shuffle, NULL, | |
1263 | "rcu_torture_shuffle"); | |
1264 | if (IS_ERR(shuffler_task)) { | |
73d0a4b1 | 1265 | free_cpumask_var(shuffle_tmp_mask); |
d84f5203 SV |
1266 | firsterr = PTR_ERR(shuffler_task); |
1267 | VERBOSE_PRINTK_ERRSTRING("Failed to create shuffler"); | |
1268 | shuffler_task = NULL; | |
1269 | goto unwind; | |
1270 | } | |
1271 | } | |
d120f65f PM |
1272 | if (stutter < 0) |
1273 | stutter = 0; | |
1274 | if (stutter) { | |
1275 | /* Create the stutter thread */ | |
1276 | stutter_task = kthread_run(rcu_torture_stutter, NULL, | |
1277 | "rcu_torture_stutter"); | |
1278 | if (IS_ERR(stutter_task)) { | |
1279 | firsterr = PTR_ERR(stutter_task); | |
1280 | VERBOSE_PRINTK_ERRSTRING("Failed to create stutter"); | |
1281 | stutter_task = NULL; | |
1282 | goto unwind; | |
1283 | } | |
1284 | } | |
343e9099 PM |
1285 | register_reboot_notifier(&rcutorture_nb); |
1286 | mutex_unlock(&fullstop_mutex); | |
a241ec65 PM |
1287 | return 0; |
1288 | ||
1289 | unwind: | |
343e9099 | 1290 | mutex_unlock(&fullstop_mutex); |
a241ec65 PM |
1291 | rcu_torture_cleanup(); |
1292 | return firsterr; | |
1293 | } | |
1294 | ||
1295 | module_init(rcu_torture_init); | |
1296 | module_exit(rcu_torture_cleanup); |