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userns: Make map_id_down a wrapper for map_id_range_down
[cris-mirror.git] / kernel / rcu / rcutorture.c
blob45f2ffbc1e78ed587d26d6764cb8d1aba0f6f2d8
1 /*
2 * Read-Copy Update module-based torture test facility
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, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
17 *
18 * Copyright (C) IBM Corporation, 2005, 2006
19 *
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Josh Triplett <josh@joshtriplett.org>
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/signal.h>
36 #include <uapi/linux/sched/types.h>
37 #include <linux/atomic.h>
38 #include <linux/bitops.h>
39 #include <linux/completion.h>
40 #include <linux/moduleparam.h>
41 #include <linux/percpu.h>
42 #include <linux/notifier.h>
43 #include <linux/reboot.h>
44 #include <linux/freezer.h>
45 #include <linux/cpu.h>
46 #include <linux/delay.h>
47 #include <linux/stat.h>
48 #include <linux/srcu.h>
49 #include <linux/slab.h>
50 #include <linux/trace_clock.h>
51 #include <asm/byteorder.h>
52 #include <linux/torture.h>
53 #include <linux/vmalloc.h>
54
55 #include "rcu.h"
56
57 MODULE_LICENSE("GPL");
58 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
59
60
61 torture_param(int, cbflood_inter_holdoff, HZ,
62 "Holdoff between floods (jiffies)");
63 torture_param(int, cbflood_intra_holdoff, 1,
64 "Holdoff between bursts (jiffies)");
65 torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable");
66 torture_param(int, cbflood_n_per_burst, 20000,
67 "# callbacks per burst in flood");
68 torture_param(int, fqs_duration, 0,
69 "Duration of fqs bursts (us), 0 to disable");
70 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
71 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
72 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
73 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
74 torture_param(bool, gp_normal, false,
75 "Use normal (non-expedited) GP wait primitives");
76 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
77 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
78 torture_param(int, n_barrier_cbs, 0,
79 "# of callbacks/kthreads for barrier testing");
80 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
81 torture_param(int, nreaders, -1, "Number of RCU reader threads");
82 torture_param(int, object_debug, 0,
83 "Enable debug-object double call_rcu() testing");
84 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
85 torture_param(int, onoff_interval, 0,
86 "Time between CPU hotplugs (s), 0=disable");
87 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
88 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
89 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
90 torture_param(int, stall_cpu_holdoff, 10,
91 "Time to wait before starting stall (s).");
92 torture_param(int, stat_interval, 60,
93 "Number of seconds between stats printk()s");
94 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
95 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
96 torture_param(int, test_boost_duration, 4,
97 "Duration of each boost test, seconds.");
98 torture_param(int, test_boost_interval, 7,
99 "Interval between boost tests, seconds.");
100 torture_param(bool, test_no_idle_hz, true,
101 "Test support for tickless idle CPUs");
102 torture_param(bool, verbose, true,
103 "Enable verbose debugging printk()s");
104
105 static char *torture_type = "rcu";
106 module_param(torture_type, charp, 0444);
107 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
108
109 static int nrealreaders;
110 static int ncbflooders;
111 static struct task_struct *writer_task;
112 static struct task_struct **fakewriter_tasks;
113 static struct task_struct **reader_tasks;
114 static struct task_struct *stats_task;
115 static struct task_struct **cbflood_task;
116 static struct task_struct *fqs_task;
117 static struct task_struct *boost_tasks[NR_CPUS];
118 static struct task_struct *stall_task;
119 static struct task_struct **barrier_cbs_tasks;
120 static struct task_struct *barrier_task;
121
122 #define RCU_TORTURE_PIPE_LEN 10
123
124 struct rcu_torture {
125 struct rcu_head rtort_rcu;
126 int rtort_pipe_count;
127 struct list_head rtort_free;
128 int rtort_mbtest;
129 };
130
131 static LIST_HEAD(rcu_torture_freelist);
132 static struct rcu_torture __rcu *rcu_torture_current;
133 static unsigned long rcu_torture_current_version;
134 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
135 static DEFINE_SPINLOCK(rcu_torture_lock);
136 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
137 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
138 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
139 static atomic_t n_rcu_torture_alloc;
140 static atomic_t n_rcu_torture_alloc_fail;
141 static atomic_t n_rcu_torture_free;
142 static atomic_t n_rcu_torture_mberror;
143 static atomic_t n_rcu_torture_error;
144 static long n_rcu_torture_barrier_error;
145 static long n_rcu_torture_boost_ktrerror;
146 static long n_rcu_torture_boost_rterror;
147 static long n_rcu_torture_boost_failure;
148 static long n_rcu_torture_boosts;
149 static long n_rcu_torture_timers;
150 static long n_barrier_attempts;
151 static long n_barrier_successes;
152 static atomic_long_t n_cbfloods;
153 static struct list_head rcu_torture_removed;
154
155 static int rcu_torture_writer_state;
156 #define RTWS_FIXED_DELAY 0
157 #define RTWS_DELAY 1
158 #define RTWS_REPLACE 2
159 #define RTWS_DEF_FREE 3
160 #define RTWS_EXP_SYNC 4
161 #define RTWS_COND_GET 5
162 #define RTWS_COND_SYNC 6
163 #define RTWS_SYNC 7
164 #define RTWS_STUTTER 8
165 #define RTWS_STOPPING 9
166 static const char * const rcu_torture_writer_state_names[] = {
167 "RTWS_FIXED_DELAY",
168 "RTWS_DELAY",
169 "RTWS_REPLACE",
170 "RTWS_DEF_FREE",
171 "RTWS_EXP_SYNC",
172 "RTWS_COND_GET",
173 "RTWS_COND_SYNC",
174 "RTWS_SYNC",
175 "RTWS_STUTTER",
176 "RTWS_STOPPING",
177 };
178
179 static const char *rcu_torture_writer_state_getname(void)
180 {
181 unsigned int i = READ_ONCE(rcu_torture_writer_state);
182
183 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
184 return "???";
185 return rcu_torture_writer_state_names[i];
186 }
187
188 static int torture_runnable = IS_ENABLED(MODULE);
189 module_param(torture_runnable, int, 0444);
190 MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot");
191
192 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
193 #define rcu_can_boost() 1
194 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
195 #define rcu_can_boost() 0
196 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
197
198 #ifdef CONFIG_RCU_TRACE
199 static u64 notrace rcu_trace_clock_local(void)
200 {
201 u64 ts = trace_clock_local();
202
203 (void)do_div(ts, NSEC_PER_USEC);
204 return ts;
205 }
206 #else /* #ifdef CONFIG_RCU_TRACE */
207 static u64 notrace rcu_trace_clock_local(void)
208 {
209 return 0ULL;
210 }
211 #endif /* #else #ifdef CONFIG_RCU_TRACE */
212
213 static unsigned long boost_starttime; /* jiffies of next boost test start. */
214 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
215 /* and boost task create/destroy. */
216 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
217 static bool barrier_phase; /* Test phase. */
218 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
219 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
220 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
221
222 /*
223 * Allocate an element from the rcu_tortures pool.
224 */
225 static struct rcu_torture *
226 rcu_torture_alloc(void)
227 {
228 struct list_head *p;
229
230 spin_lock_bh(&rcu_torture_lock);
231 if (list_empty(&rcu_torture_freelist)) {
232 atomic_inc(&n_rcu_torture_alloc_fail);
233 spin_unlock_bh(&rcu_torture_lock);
234 return NULL;
235 }
236 atomic_inc(&n_rcu_torture_alloc);
237 p = rcu_torture_freelist.next;
238 list_del_init(p);
239 spin_unlock_bh(&rcu_torture_lock);
240 return container_of(p, struct rcu_torture, rtort_free);
241 }
242
243 /*
244 * Free an element to the rcu_tortures pool.
245 */
246 static void
247 rcu_torture_free(struct rcu_torture *p)
248 {
249 atomic_inc(&n_rcu_torture_free);
250 spin_lock_bh(&rcu_torture_lock);
251 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
252 spin_unlock_bh(&rcu_torture_lock);
253 }
254
255 /*
256 * Operations vector for selecting different types of tests.
257 */
258
259 struct rcu_torture_ops {
260 int ttype;
261 void (*init)(void);
262 void (*cleanup)(void);
263 int (*readlock)(void);
264 void (*read_delay)(struct torture_random_state *rrsp);
265 void (*readunlock)(int idx);
266 unsigned long (*started)(void);
267 unsigned long (*completed)(void);
268 void (*deferred_free)(struct rcu_torture *p);
269 void (*sync)(void);
270 void (*exp_sync)(void);
271 unsigned long (*get_state)(void);
272 void (*cond_sync)(unsigned long oldstate);
273 call_rcu_func_t call;
274 void (*cb_barrier)(void);
275 void (*fqs)(void);
276 void (*stats)(void);
277 int irq_capable;
278 int can_boost;
279 const char *name;
280 };
281
282 static struct rcu_torture_ops *cur_ops;
283
284 /*
285 * Definitions for rcu torture testing.
286 */
287
288 static int rcu_torture_read_lock(void) __acquires(RCU)
289 {
290 rcu_read_lock();
291 return 0;
292 }
293
294 static void rcu_read_delay(struct torture_random_state *rrsp)
295 {
296 unsigned long started;
297 unsigned long completed;
298 const unsigned long shortdelay_us = 200;
299 const unsigned long longdelay_ms = 50;
300 unsigned long long ts;
301
302 /* We want a short delay sometimes to make a reader delay the grace
303 * period, and we want a long delay occasionally to trigger
304 * force_quiescent_state. */
305
306 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
307 started = cur_ops->completed();
308 ts = rcu_trace_clock_local();
309 mdelay(longdelay_ms);
310 completed = cur_ops->completed();
311 do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
312 started, completed);
313 }
314 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
315 udelay(shortdelay_us);
316 #ifdef CONFIG_PREEMPT
317 if (!preempt_count() &&
318 !(torture_random(rrsp) % (nrealreaders * 20000)))
319 preempt_schedule(); /* No QS if preempt_disable() in effect */
320 #endif
321 }
322
323 static void rcu_torture_read_unlock(int idx) __releases(RCU)
324 {
325 rcu_read_unlock();
326 }
327
328 /*
329 * Update callback in the pipe. This should be invoked after a grace period.
330 */
331 static bool
332 rcu_torture_pipe_update_one(struct rcu_torture *rp)
333 {
334 int i;
335
336 i = rp->rtort_pipe_count;
337 if (i > RCU_TORTURE_PIPE_LEN)
338 i = RCU_TORTURE_PIPE_LEN;
339 atomic_inc(&rcu_torture_wcount[i]);
340 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
341 rp->rtort_mbtest = 0;
342 return true;
343 }
344 return false;
345 }
346
347 /*
348 * Update all callbacks in the pipe. Suitable for synchronous grace-period
349 * primitives.
350 */
351 static void
352 rcu_torture_pipe_update(struct rcu_torture *old_rp)
353 {
354 struct rcu_torture *rp;
355 struct rcu_torture *rp1;
356
357 if (old_rp)
358 list_add(&old_rp->rtort_free, &rcu_torture_removed);
359 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
360 if (rcu_torture_pipe_update_one(rp)) {
361 list_del(&rp->rtort_free);
362 rcu_torture_free(rp);
363 }
364 }
365 }
366
367 static void
368 rcu_torture_cb(struct rcu_head *p)
369 {
370 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
371
372 if (torture_must_stop_irq()) {
373 /* Test is ending, just drop callbacks on the floor. */
374 /* The next initialization will pick up the pieces. */
375 return;
376 }
377 if (rcu_torture_pipe_update_one(rp))
378 rcu_torture_free(rp);
379 else
380 cur_ops->deferred_free(rp);
381 }
382
383 static unsigned long rcu_no_completed(void)
384 {
385 return 0;
386 }
387
388 static void rcu_torture_deferred_free(struct rcu_torture *p)
389 {
390 call_rcu(&p->rtort_rcu, rcu_torture_cb);
391 }
392
393 static void rcu_sync_torture_init(void)
394 {
395 INIT_LIST_HEAD(&rcu_torture_removed);
396 }
397
398 static struct rcu_torture_ops rcu_ops = {
399 .ttype = RCU_FLAVOR,
400 .init = rcu_sync_torture_init,
401 .readlock = rcu_torture_read_lock,
402 .read_delay = rcu_read_delay,
403 .readunlock = rcu_torture_read_unlock,
404 .started = rcu_batches_started,
405 .completed = rcu_batches_completed,
406 .deferred_free = rcu_torture_deferred_free,
407 .sync = synchronize_rcu,
408 .exp_sync = synchronize_rcu_expedited,
409 .get_state = get_state_synchronize_rcu,
410 .cond_sync = cond_synchronize_rcu,
411 .call = call_rcu,
412 .cb_barrier = rcu_barrier,
413 .fqs = rcu_force_quiescent_state,
414 .stats = NULL,
415 .irq_capable = 1,
416 .can_boost = rcu_can_boost(),
417 .name = "rcu"
418 };
419
420 /*
421 * Definitions for rcu_bh torture testing.
422 */
423
424 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
425 {
426 rcu_read_lock_bh();
427 return 0;
428 }
429
430 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
431 {
432 rcu_read_unlock_bh();
433 }
434
435 static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
436 {
437 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
438 }
439
440 static struct rcu_torture_ops rcu_bh_ops = {
441 .ttype = RCU_BH_FLAVOR,
442 .init = rcu_sync_torture_init,
443 .readlock = rcu_bh_torture_read_lock,
444 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
445 .readunlock = rcu_bh_torture_read_unlock,
446 .started = rcu_batches_started_bh,
447 .completed = rcu_batches_completed_bh,
448 .deferred_free = rcu_bh_torture_deferred_free,
449 .sync = synchronize_rcu_bh,
450 .exp_sync = synchronize_rcu_bh_expedited,
451 .call = call_rcu_bh,
452 .cb_barrier = rcu_barrier_bh,
453 .fqs = rcu_bh_force_quiescent_state,
454 .stats = NULL,
455 .irq_capable = 1,
456 .name = "rcu_bh"
457 };
458
459 /*
460 * Don't even think about trying any of these in real life!!!
461 * The names includes "busted", and they really means it!
462 * The only purpose of these functions is to provide a buggy RCU
463 * implementation to make sure that rcutorture correctly emits
464 * buggy-RCU error messages.
465 */
466 static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
467 {
468 /* This is a deliberate bug for testing purposes only! */
469 rcu_torture_cb(&p->rtort_rcu);
470 }
471
472 static void synchronize_rcu_busted(void)
473 {
474 /* This is a deliberate bug for testing purposes only! */
475 }
476
477 static void
478 call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
479 {
480 /* This is a deliberate bug for testing purposes only! */
481 func(head);
482 }
483
484 static struct rcu_torture_ops rcu_busted_ops = {
485 .ttype = INVALID_RCU_FLAVOR,
486 .init = rcu_sync_torture_init,
487 .readlock = rcu_torture_read_lock,
488 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
489 .readunlock = rcu_torture_read_unlock,
490 .started = rcu_no_completed,
491 .completed = rcu_no_completed,
492 .deferred_free = rcu_busted_torture_deferred_free,
493 .sync = synchronize_rcu_busted,
494 .exp_sync = synchronize_rcu_busted,
495 .call = call_rcu_busted,
496 .cb_barrier = NULL,
497 .fqs = NULL,
498 .stats = NULL,
499 .irq_capable = 1,
500 .name = "busted"
501 };
502
503 /*
504 * Definitions for srcu torture testing.
505 */
506
507 DEFINE_STATIC_SRCU(srcu_ctl);
508 static struct srcu_struct srcu_ctld;
509 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
510
511 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
512 {
513 return srcu_read_lock(srcu_ctlp);
514 }
515
516 static void srcu_read_delay(struct torture_random_state *rrsp)
517 {
518 long delay;
519 const long uspertick = 1000000 / HZ;
520 const long longdelay = 10;
521
522 /* We want there to be long-running readers, but not all the time. */
523
524 delay = torture_random(rrsp) %
525 (nrealreaders * 2 * longdelay * uspertick);
526 if (!delay && in_task())
527 schedule_timeout_interruptible(longdelay);
528 else
529 rcu_read_delay(rrsp);
530 }
531
532 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
533 {
534 srcu_read_unlock(srcu_ctlp, idx);
535 }
536
537 static unsigned long srcu_torture_completed(void)
538 {
539 return srcu_batches_completed(srcu_ctlp);
540 }
541
542 static void srcu_torture_deferred_free(struct rcu_torture *rp)
543 {
544 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
545 }
546
547 static void srcu_torture_synchronize(void)
548 {
549 synchronize_srcu(srcu_ctlp);
550 }
551
552 static void srcu_torture_call(struct rcu_head *head,
553 rcu_callback_t func)
554 {
555 call_srcu(srcu_ctlp, head, func);
556 }
557
558 static void srcu_torture_barrier(void)
559 {
560 srcu_barrier(srcu_ctlp);
561 }
562
563 static void srcu_torture_stats(void)
564 {
565 srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG);
566 }
567
568 static void srcu_torture_synchronize_expedited(void)
569 {
570 synchronize_srcu_expedited(srcu_ctlp);
571 }
572
573 static struct rcu_torture_ops srcu_ops = {
574 .ttype = SRCU_FLAVOR,
575 .init = rcu_sync_torture_init,
576 .readlock = srcu_torture_read_lock,
577 .read_delay = srcu_read_delay,
578 .readunlock = srcu_torture_read_unlock,
579 .started = NULL,
580 .completed = srcu_torture_completed,
581 .deferred_free = srcu_torture_deferred_free,
582 .sync = srcu_torture_synchronize,
583 .exp_sync = srcu_torture_synchronize_expedited,
584 .call = srcu_torture_call,
585 .cb_barrier = srcu_torture_barrier,
586 .stats = srcu_torture_stats,
587 .irq_capable = 1,
588 .name = "srcu"
589 };
590
591 static void srcu_torture_init(void)
592 {
593 rcu_sync_torture_init();
594 WARN_ON(init_srcu_struct(&srcu_ctld));
595 srcu_ctlp = &srcu_ctld;
596 }
597
598 static void srcu_torture_cleanup(void)
599 {
600 cleanup_srcu_struct(&srcu_ctld);
601 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
602 }
603
604 /* As above, but dynamically allocated. */
605 static struct rcu_torture_ops srcud_ops = {
606 .ttype = SRCU_FLAVOR,
607 .init = srcu_torture_init,
608 .cleanup = srcu_torture_cleanup,
609 .readlock = srcu_torture_read_lock,
610 .read_delay = srcu_read_delay,
611 .readunlock = srcu_torture_read_unlock,
612 .started = NULL,
613 .completed = srcu_torture_completed,
614 .deferred_free = srcu_torture_deferred_free,
615 .sync = srcu_torture_synchronize,
616 .exp_sync = srcu_torture_synchronize_expedited,
617 .call = srcu_torture_call,
618 .cb_barrier = srcu_torture_barrier,
619 .stats = srcu_torture_stats,
620 .irq_capable = 1,
621 .name = "srcud"
622 };
623
624 /*
625 * Definitions for sched torture testing.
626 */
627
628 static int sched_torture_read_lock(void)
629 {
630 preempt_disable();
631 return 0;
632 }
633
634 static void sched_torture_read_unlock(int idx)
635 {
636 preempt_enable();
637 }
638
639 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
640 {
641 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
642 }
643
644 static struct rcu_torture_ops sched_ops = {
645 .ttype = RCU_SCHED_FLAVOR,
646 .init = rcu_sync_torture_init,
647 .readlock = sched_torture_read_lock,
648 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
649 .readunlock = sched_torture_read_unlock,
650 .started = rcu_batches_started_sched,
651 .completed = rcu_batches_completed_sched,
652 .deferred_free = rcu_sched_torture_deferred_free,
653 .sync = synchronize_sched,
654 .exp_sync = synchronize_sched_expedited,
655 .get_state = get_state_synchronize_sched,
656 .cond_sync = cond_synchronize_sched,
657 .call = call_rcu_sched,
658 .cb_barrier = rcu_barrier_sched,
659 .fqs = rcu_sched_force_quiescent_state,
660 .stats = NULL,
661 .irq_capable = 1,
662 .name = "sched"
663 };
664
665 /*
666 * Definitions for RCU-tasks torture testing.
667 */
668
669 static int tasks_torture_read_lock(void)
670 {
671 return 0;
672 }
673
674 static void tasks_torture_read_unlock(int idx)
675 {
676 }
677
678 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
679 {
680 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
681 }
682
683 static struct rcu_torture_ops tasks_ops = {
684 .ttype = RCU_TASKS_FLAVOR,
685 .init = rcu_sync_torture_init,
686 .readlock = tasks_torture_read_lock,
687 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
688 .readunlock = tasks_torture_read_unlock,
689 .started = rcu_no_completed,
690 .completed = rcu_no_completed,
691 .deferred_free = rcu_tasks_torture_deferred_free,
692 .sync = synchronize_rcu_tasks,
693 .exp_sync = synchronize_rcu_tasks,
694 .call = call_rcu_tasks,
695 .cb_barrier = rcu_barrier_tasks,
696 .fqs = NULL,
697 .stats = NULL,
698 .irq_capable = 1,
699 .name = "tasks"
700 };
701
702 static bool __maybe_unused torturing_tasks(void)
703 {
704 return cur_ops == &tasks_ops;
705 }
706
707 /*
708 * RCU torture priority-boost testing. Runs one real-time thread per
709 * CPU for moderate bursts, repeatedly registering RCU callbacks and
710 * spinning waiting for them to be invoked. If a given callback takes
711 * too long to be invoked, we assume that priority inversion has occurred.
712 */
713
714 struct rcu_boost_inflight {
715 struct rcu_head rcu;
716 int inflight;
717 };
718
719 static void rcu_torture_boost_cb(struct rcu_head *head)
720 {
721 struct rcu_boost_inflight *rbip =
722 container_of(head, struct rcu_boost_inflight, rcu);
723
724 /* Ensure RCU-core accesses precede clearing ->inflight */
725 smp_store_release(&rbip->inflight, 0);
726 }
727
728 static int rcu_torture_boost(void *arg)
729 {
730 unsigned long call_rcu_time;
731 unsigned long endtime;
732 unsigned long oldstarttime;
733 struct rcu_boost_inflight rbi = { .inflight = 0 };
734 struct sched_param sp;
735
736 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
737
738 /* Set real-time priority. */
739 sp.sched_priority = 1;
740 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
741 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
742 n_rcu_torture_boost_rterror++;
743 }
744
745 init_rcu_head_on_stack(&rbi.rcu);
746 /* Each pass through the following loop does one boost-test cycle. */
747 do {
748 /* Wait for the next test interval. */
749 oldstarttime = boost_starttime;
750 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
751 schedule_timeout_interruptible(oldstarttime - jiffies);
752 stutter_wait("rcu_torture_boost");
753 if (torture_must_stop())
754 goto checkwait;
755 }
756
757 /* Do one boost-test interval. */
758 endtime = oldstarttime + test_boost_duration * HZ;
759 call_rcu_time = jiffies;
760 while (ULONG_CMP_LT(jiffies, endtime)) {
761 /* If we don't have a callback in flight, post one. */
762 if (!smp_load_acquire(&rbi.inflight)) {
763 /* RCU core before ->inflight = 1. */
764 smp_store_release(&rbi.inflight, 1);
765 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
766 if (jiffies - call_rcu_time >
767 test_boost_duration * HZ - HZ / 2) {
768 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
769 n_rcu_torture_boost_failure++;
770 }
771 call_rcu_time = jiffies;
772 }
773 stutter_wait("rcu_torture_boost");
774 if (torture_must_stop())
775 goto checkwait;
776 }
777
778 /*
779 * Set the start time of the next test interval.
780 * Yes, this is vulnerable to long delays, but such
781 * delays simply cause a false negative for the next
782 * interval. Besides, we are running at RT priority,
783 * so delays should be relatively rare.
784 */
785 while (oldstarttime == boost_starttime &&
786 !kthread_should_stop()) {
787 if (mutex_trylock(&boost_mutex)) {
788 boost_starttime = jiffies +
789 test_boost_interval * HZ;
790 n_rcu_torture_boosts++;
791 mutex_unlock(&boost_mutex);
792 break;
793 }
794 schedule_timeout_uninterruptible(1);
795 }
796
797 /* Go do the stutter. */
798 checkwait: stutter_wait("rcu_torture_boost");
799 } while (!torture_must_stop());
800
801 /* Clean up and exit. */
802 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
803 torture_shutdown_absorb("rcu_torture_boost");
804 schedule_timeout_uninterruptible(1);
805 }
806 destroy_rcu_head_on_stack(&rbi.rcu);
807 torture_kthread_stopping("rcu_torture_boost");
808 return 0;
809 }
810
811 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
812 {
813 }
814
815 /*
816 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
817 * to call_rcu() or analogous, increasing the probability of occurrence
818 * of callback-overflow corner cases.
819 */
820 static int
821 rcu_torture_cbflood(void *arg)
822 {
823 int err = 1;
824 int i;
825 int j;
826 struct rcu_head *rhp;
827
828 if (cbflood_n_per_burst > 0 &&
829 cbflood_inter_holdoff > 0 &&
830 cbflood_intra_holdoff > 0 &&
831 cur_ops->call &&
832 cur_ops->cb_barrier) {
833 rhp = vmalloc(sizeof(*rhp) *
834 cbflood_n_burst * cbflood_n_per_burst);
835 err = !rhp;
836 }
837 if (err) {
838 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
839 goto wait_for_stop;
840 }
841 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
842 do {
843 schedule_timeout_interruptible(cbflood_inter_holdoff);
844 atomic_long_inc(&n_cbfloods);
845 WARN_ON(signal_pending(current));
846 for (i = 0; i < cbflood_n_burst; i++) {
847 for (j = 0; j < cbflood_n_per_burst; j++) {
848 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
849 rcu_torture_cbflood_cb);
850 }
851 schedule_timeout_interruptible(cbflood_intra_holdoff);
852 WARN_ON(signal_pending(current));
853 }
854 cur_ops->cb_barrier();
855 stutter_wait("rcu_torture_cbflood");
856 } while (!torture_must_stop());
857 vfree(rhp);
858 wait_for_stop:
859 torture_kthread_stopping("rcu_torture_cbflood");
860 return 0;
861 }
862
863 /*
864 * RCU torture force-quiescent-state kthread. Repeatedly induces
865 * bursts of calls to force_quiescent_state(), increasing the probability
866 * of occurrence of some important types of race conditions.
867 */
868 static int
869 rcu_torture_fqs(void *arg)
870 {
871 unsigned long fqs_resume_time;
872 int fqs_burst_remaining;
873
874 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
875 do {
876 fqs_resume_time = jiffies + fqs_stutter * HZ;
877 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
878 !kthread_should_stop()) {
879 schedule_timeout_interruptible(1);
880 }
881 fqs_burst_remaining = fqs_duration;
882 while (fqs_burst_remaining > 0 &&
883 !kthread_should_stop()) {
884 cur_ops->fqs();
885 udelay(fqs_holdoff);
886 fqs_burst_remaining -= fqs_holdoff;
887 }
888 stutter_wait("rcu_torture_fqs");
889 } while (!torture_must_stop());
890 torture_kthread_stopping("rcu_torture_fqs");
891 return 0;
892 }
893
894 /*
895 * RCU torture writer kthread. Repeatedly substitutes a new structure
896 * for that pointed to by rcu_torture_current, freeing the old structure
897 * after a series of grace periods (the "pipeline").
898 */
899 static int
900 rcu_torture_writer(void *arg)
901 {
902 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
903 int expediting = 0;
904 unsigned long gp_snap;
905 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
906 bool gp_sync1 = gp_sync;
907 int i;
908 struct rcu_torture *rp;
909 struct rcu_torture *old_rp;
910 static DEFINE_TORTURE_RANDOM(rand);
911 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
912 RTWS_COND_GET, RTWS_SYNC };
913 int nsynctypes = 0;
914
915 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
916 if (!can_expedite) {
917 pr_alert("%s" TORTURE_FLAG
918 " GP expediting controlled from boot/sysfs for %s,\n",
919 torture_type, cur_ops->name);
920 pr_alert("%s" TORTURE_FLAG
921 " Disabled dynamic grace-period expediting.\n",
922 torture_type);
923 }
924
925 /* Initialize synctype[] array. If none set, take default. */
926 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
927 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
928 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
929 synctype[nsynctypes++] = RTWS_COND_GET;
930 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
931 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
932 if (gp_exp1 && cur_ops->exp_sync)
933 synctype[nsynctypes++] = RTWS_EXP_SYNC;
934 else if (gp_exp && !cur_ops->exp_sync)
935 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
936 if (gp_normal1 && cur_ops->deferred_free)
937 synctype[nsynctypes++] = RTWS_DEF_FREE;
938 else if (gp_normal && !cur_ops->deferred_free)
939 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
940 if (gp_sync1 && cur_ops->sync)
941 synctype[nsynctypes++] = RTWS_SYNC;
942 else if (gp_sync && !cur_ops->sync)
943 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
944 if (WARN_ONCE(nsynctypes == 0,
945 "rcu_torture_writer: No update-side primitives.\n")) {
946 /*
947 * No updates primitives, so don't try updating.
948 * The resulting test won't be testing much, hence the
949 * above WARN_ONCE().
950 */
951 rcu_torture_writer_state = RTWS_STOPPING;
952 torture_kthread_stopping("rcu_torture_writer");
953 }
954
955 do {
956 rcu_torture_writer_state = RTWS_FIXED_DELAY;
957 schedule_timeout_uninterruptible(1);
958 rp = rcu_torture_alloc();
959 if (rp == NULL)
960 continue;
961 rp->rtort_pipe_count = 0;
962 rcu_torture_writer_state = RTWS_DELAY;
963 udelay(torture_random(&rand) & 0x3ff);
964 rcu_torture_writer_state = RTWS_REPLACE;
965 old_rp = rcu_dereference_check(rcu_torture_current,
966 current == writer_task);
967 rp->rtort_mbtest = 1;
968 rcu_assign_pointer(rcu_torture_current, rp);
969 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
970 if (old_rp) {
971 i = old_rp->rtort_pipe_count;
972 if (i > RCU_TORTURE_PIPE_LEN)
973 i = RCU_TORTURE_PIPE_LEN;
974 atomic_inc(&rcu_torture_wcount[i]);
975 old_rp->rtort_pipe_count++;
976 switch (synctype[torture_random(&rand) % nsynctypes]) {
977 case RTWS_DEF_FREE:
978 rcu_torture_writer_state = RTWS_DEF_FREE;
979 cur_ops->deferred_free(old_rp);
980 break;
981 case RTWS_EXP_SYNC:
982 rcu_torture_writer_state = RTWS_EXP_SYNC;
983 cur_ops->exp_sync();
984 rcu_torture_pipe_update(old_rp);
985 break;
986 case RTWS_COND_GET:
987 rcu_torture_writer_state = RTWS_COND_GET;
988 gp_snap = cur_ops->get_state();
989 i = torture_random(&rand) % 16;
990 if (i != 0)
991 schedule_timeout_interruptible(i);
992 udelay(torture_random(&rand) % 1000);
993 rcu_torture_writer_state = RTWS_COND_SYNC;
994 cur_ops->cond_sync(gp_snap);
995 rcu_torture_pipe_update(old_rp);
996 break;
997 case RTWS_SYNC:
998 rcu_torture_writer_state = RTWS_SYNC;
999 cur_ops->sync();
1000 rcu_torture_pipe_update(old_rp);
1001 break;
1002 default:
1003 WARN_ON_ONCE(1);
1004 break;
1005 }
1006 }
1007 rcutorture_record_progress(++rcu_torture_current_version);
1008 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1009 if (can_expedite &&
1010 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1011 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1012 if (expediting >= 0)
1013 rcu_expedite_gp();
1014 else
1015 rcu_unexpedite_gp();
1016 if (++expediting > 3)
1017 expediting = -expediting;
1018 }
1019 rcu_torture_writer_state = RTWS_STUTTER;
1020 stutter_wait("rcu_torture_writer");
1021 } while (!torture_must_stop());
1022 /* Reset expediting back to unexpedited. */
1023 if (expediting > 0)
1024 expediting = -expediting;
1025 while (can_expedite && expediting++ < 0)
1026 rcu_unexpedite_gp();
1027 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1028 rcu_torture_writer_state = RTWS_STOPPING;
1029 torture_kthread_stopping("rcu_torture_writer");
1030 return 0;
1031 }
1032
1033 /*
1034 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1035 * delay between calls.
1036 */
1037 static int
1038 rcu_torture_fakewriter(void *arg)
1039 {
1040 DEFINE_TORTURE_RANDOM(rand);
1041
1042 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1043 set_user_nice(current, MAX_NICE);
1044
1045 do {
1046 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1047 udelay(torture_random(&rand) & 0x3ff);
1048 if (cur_ops->cb_barrier != NULL &&
1049 torture_random(&rand) % (nfakewriters * 8) == 0) {
1050 cur_ops->cb_barrier();
1051 } else if (gp_normal == gp_exp) {
1052 if (torture_random(&rand) & 0x80)
1053 cur_ops->sync();
1054 else
1055 cur_ops->exp_sync();
1056 } else if (gp_normal) {
1057 cur_ops->sync();
1058 } else {
1059 cur_ops->exp_sync();
1060 }
1061 stutter_wait("rcu_torture_fakewriter");
1062 } while (!torture_must_stop());
1063
1064 torture_kthread_stopping("rcu_torture_fakewriter");
1065 return 0;
1066 }
1067
1068 static void rcu_torture_timer_cb(struct rcu_head *rhp)
1069 {
1070 kfree(rhp);
1071 }
1072
1073 /*
1074 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1075 * incrementing the corresponding element of the pipeline array. The
1076 * counter in the element should never be greater than 1, otherwise, the
1077 * RCU implementation is broken.
1078 */
1079 static void rcu_torture_timer(unsigned long unused)
1080 {
1081 int idx;
1082 unsigned long started;
1083 unsigned long completed;
1084 static DEFINE_TORTURE_RANDOM(rand);
1085 static DEFINE_SPINLOCK(rand_lock);
1086 struct rcu_torture *p;
1087 int pipe_count;
1088 unsigned long long ts;
1089
1090 idx = cur_ops->readlock();
1091 if (cur_ops->started)
1092 started = cur_ops->started();
1093 else
1094 started = cur_ops->completed();
1095 ts = rcu_trace_clock_local();
1096 p = rcu_dereference_check(rcu_torture_current,
1097 rcu_read_lock_bh_held() ||
1098 rcu_read_lock_sched_held() ||
1099 srcu_read_lock_held(srcu_ctlp) ||
1100 torturing_tasks());
1101 if (p == NULL) {
1102 /* Leave because rcu_torture_writer is not yet underway */
1103 cur_ops->readunlock(idx);
1104 return;
1105 }
1106 if (p->rtort_mbtest == 0)
1107 atomic_inc(&n_rcu_torture_mberror);
1108 spin_lock(&rand_lock);
1109 cur_ops->read_delay(&rand);
1110 n_rcu_torture_timers++;
1111 spin_unlock(&rand_lock);
1112 preempt_disable();
1113 pipe_count = p->rtort_pipe_count;
1114 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1115 /* Should not happen, but... */
1116 pipe_count = RCU_TORTURE_PIPE_LEN;
1117 }
1118 completed = cur_ops->completed();
1119 if (pipe_count > 1) {
1120 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1121 started, completed);
1122 rcu_ftrace_dump(DUMP_ALL);
1123 }
1124 __this_cpu_inc(rcu_torture_count[pipe_count]);
1125 completed = completed - started;
1126 if (cur_ops->started)
1127 completed++;
1128 if (completed > RCU_TORTURE_PIPE_LEN) {
1129 /* Should not happen, but... */
1130 completed = RCU_TORTURE_PIPE_LEN;
1131 }
1132 __this_cpu_inc(rcu_torture_batch[completed]);
1133 preempt_enable();
1134 cur_ops->readunlock(idx);
1135
1136 /* Test call_rcu() invocation from interrupt handler. */
1137 if (cur_ops->call) {
1138 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
1139
1140 if (rhp)
1141 cur_ops->call(rhp, rcu_torture_timer_cb);
1142 }
1143 }
1144
1145 /*
1146 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1147 * incrementing the corresponding element of the pipeline array. The
1148 * counter in the element should never be greater than 1, otherwise, the
1149 * RCU implementation is broken.
1150 */
1151 static int
1152 rcu_torture_reader(void *arg)
1153 {
1154 unsigned long started;
1155 unsigned long completed;
1156 int idx;
1157 DEFINE_TORTURE_RANDOM(rand);
1158 struct rcu_torture *p;
1159 int pipe_count;
1160 struct timer_list t;
1161 unsigned long long ts;
1162
1163 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1164 set_user_nice(current, MAX_NICE);
1165 if (irqreader && cur_ops->irq_capable)
1166 setup_timer_on_stack(&t, rcu_torture_timer, 0);
1167
1168 do {
1169 if (irqreader && cur_ops->irq_capable) {
1170 if (!timer_pending(&t))
1171 mod_timer(&t, jiffies + 1);
1172 }
1173 idx = cur_ops->readlock();
1174 if (cur_ops->started)
1175 started = cur_ops->started();
1176 else
1177 started = cur_ops->completed();
1178 ts = rcu_trace_clock_local();
1179 p = rcu_dereference_check(rcu_torture_current,
1180 rcu_read_lock_bh_held() ||
1181 rcu_read_lock_sched_held() ||
1182 srcu_read_lock_held(srcu_ctlp) ||
1183 torturing_tasks());
1184 if (p == NULL) {
1185 /* Wait for rcu_torture_writer to get underway */
1186 cur_ops->readunlock(idx);
1187 schedule_timeout_interruptible(HZ);
1188 continue;
1189 }
1190 if (p->rtort_mbtest == 0)
1191 atomic_inc(&n_rcu_torture_mberror);
1192 cur_ops->read_delay(&rand);
1193 preempt_disable();
1194 pipe_count = p->rtort_pipe_count;
1195 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1196 /* Should not happen, but... */
1197 pipe_count = RCU_TORTURE_PIPE_LEN;
1198 }
1199 completed = cur_ops->completed();
1200 if (pipe_count > 1) {
1201 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1202 ts, started, completed);
1203 rcu_ftrace_dump(DUMP_ALL);
1204 }
1205 __this_cpu_inc(rcu_torture_count[pipe_count]);
1206 completed = completed - started;
1207 if (cur_ops->started)
1208 completed++;
1209 if (completed > RCU_TORTURE_PIPE_LEN) {
1210 /* Should not happen, but... */
1211 completed = RCU_TORTURE_PIPE_LEN;
1212 }
1213 __this_cpu_inc(rcu_torture_batch[completed]);
1214 preempt_enable();
1215 cur_ops->readunlock(idx);
1216 stutter_wait("rcu_torture_reader");
1217 } while (!torture_must_stop());
1218 if (irqreader && cur_ops->irq_capable) {
1219 del_timer_sync(&t);
1220 destroy_timer_on_stack(&t);
1221 }
1222 torture_kthread_stopping("rcu_torture_reader");
1223 return 0;
1224 }
1225
1226 /*
1227 * Print torture statistics. Caller must ensure that there is only
1228 * one call to this function at a given time!!! This is normally
1229 * accomplished by relying on the module system to only have one copy
1230 * of the module loaded, and then by giving the rcu_torture_stats
1231 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1232 * thread is not running).
1233 */
1234 static void
1235 rcu_torture_stats_print(void)
1236 {
1237 int cpu;
1238 int i;
1239 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1240 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1241 static unsigned long rtcv_snap = ULONG_MAX;
1242 struct task_struct *wtp;
1243
1244 for_each_possible_cpu(cpu) {
1245 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1246 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1247 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1248 }
1249 }
1250 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1251 if (pipesummary[i] != 0)
1252 break;
1253 }
1254
1255 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1256 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1257 rcu_torture_current,
1258 rcu_torture_current_version,
1259 list_empty(&rcu_torture_freelist),
1260 atomic_read(&n_rcu_torture_alloc),
1261 atomic_read(&n_rcu_torture_alloc_fail),
1262 atomic_read(&n_rcu_torture_free));
1263 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1264 atomic_read(&n_rcu_torture_mberror),
1265 n_rcu_torture_barrier_error,
1266 n_rcu_torture_boost_ktrerror,
1267 n_rcu_torture_boost_rterror);
1268 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1269 n_rcu_torture_boost_failure,
1270 n_rcu_torture_boosts,
1271 n_rcu_torture_timers);
1272 torture_onoff_stats();
1273 pr_cont("barrier: %ld/%ld:%ld ",
1274 n_barrier_successes,
1275 n_barrier_attempts,
1276 n_rcu_torture_barrier_error);
1277 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1278
1279 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1280 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1281 n_rcu_torture_barrier_error != 0 ||
1282 n_rcu_torture_boost_ktrerror != 0 ||
1283 n_rcu_torture_boost_rterror != 0 ||
1284 n_rcu_torture_boost_failure != 0 ||
1285 i > 1) {
1286 pr_cont("%s", "!!! ");
1287 atomic_inc(&n_rcu_torture_error);
1288 WARN_ON_ONCE(1);
1289 }
1290 pr_cont("Reader Pipe: ");
1291 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1292 pr_cont(" %ld", pipesummary[i]);
1293 pr_cont("\n");
1294
1295 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1296 pr_cont("Reader Batch: ");
1297 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1298 pr_cont(" %ld", batchsummary[i]);
1299 pr_cont("\n");
1300
1301 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1302 pr_cont("Free-Block Circulation: ");
1303 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1304 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1305 }
1306 pr_cont("\n");
1307
1308 if (cur_ops->stats)
1309 cur_ops->stats();
1310 if (rtcv_snap == rcu_torture_current_version &&
1311 rcu_torture_current != NULL) {
1312 int __maybe_unused flags = 0;
1313 unsigned long __maybe_unused gpnum = 0;
1314 unsigned long __maybe_unused completed = 0;
1315
1316 rcutorture_get_gp_data(cur_ops->ttype,
1317 &flags, &gpnum, &completed);
1318 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
1319 &flags, &gpnum, &completed);
1320 wtp = READ_ONCE(writer_task);
1321 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx cpu %d\n",
1322 rcu_torture_writer_state_getname(),
1323 rcu_torture_writer_state,
1324 gpnum, completed, flags,
1325 wtp == NULL ? ~0UL : wtp->state,
1326 wtp == NULL ? -1 : (int)task_cpu(wtp));
1327 show_rcu_gp_kthreads();
1328 rcu_ftrace_dump(DUMP_ALL);
1329 }
1330 rtcv_snap = rcu_torture_current_version;
1331 }
1332
1333 /*
1334 * Periodically prints torture statistics, if periodic statistics printing
1335 * was specified via the stat_interval module parameter.
1336 */
1337 static int
1338 rcu_torture_stats(void *arg)
1339 {
1340 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1341 do {
1342 schedule_timeout_interruptible(stat_interval * HZ);
1343 rcu_torture_stats_print();
1344 torture_shutdown_absorb("rcu_torture_stats");
1345 } while (!torture_must_stop());
1346 torture_kthread_stopping("rcu_torture_stats");
1347 return 0;
1348 }
1349
1350 static inline void
1351 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1352 {
1353 pr_alert("%s" TORTURE_FLAG
1354 "--- %s: nreaders=%d nfakewriters=%d "
1355 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1356 "shuffle_interval=%d stutter=%d irqreader=%d "
1357 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1358 "test_boost=%d/%d test_boost_interval=%d "
1359 "test_boost_duration=%d shutdown_secs=%d "
1360 "stall_cpu=%d stall_cpu_holdoff=%d "
1361 "n_barrier_cbs=%d "
1362 "onoff_interval=%d onoff_holdoff=%d\n",
1363 torture_type, tag, nrealreaders, nfakewriters,
1364 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1365 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1366 test_boost, cur_ops->can_boost,
1367 test_boost_interval, test_boost_duration, shutdown_secs,
1368 stall_cpu, stall_cpu_holdoff,
1369 n_barrier_cbs,
1370 onoff_interval, onoff_holdoff);
1371 }
1372
1373 static int rcutorture_booster_cleanup(unsigned int cpu)
1374 {
1375 struct task_struct *t;
1376
1377 if (boost_tasks[cpu] == NULL)
1378 return 0;
1379 mutex_lock(&boost_mutex);
1380 t = boost_tasks[cpu];
1381 boost_tasks[cpu] = NULL;
1382 mutex_unlock(&boost_mutex);
1383
1384 /* This must be outside of the mutex, otherwise deadlock! */
1385 torture_stop_kthread(rcu_torture_boost, t);
1386 return 0;
1387 }
1388
1389 static int rcutorture_booster_init(unsigned int cpu)
1390 {
1391 int retval;
1392
1393 if (boost_tasks[cpu] != NULL)
1394 return 0; /* Already created, nothing more to do. */
1395
1396 /* Don't allow time recalculation while creating a new task. */
1397 mutex_lock(&boost_mutex);
1398 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1399 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1400 cpu_to_node(cpu),
1401 "rcu_torture_boost");
1402 if (IS_ERR(boost_tasks[cpu])) {
1403 retval = PTR_ERR(boost_tasks[cpu]);
1404 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1405 n_rcu_torture_boost_ktrerror++;
1406 boost_tasks[cpu] = NULL;
1407 mutex_unlock(&boost_mutex);
1408 return retval;
1409 }
1410 kthread_bind(boost_tasks[cpu], cpu);
1411 wake_up_process(boost_tasks[cpu]);
1412 mutex_unlock(&boost_mutex);
1413 return 0;
1414 }
1415
1416 /*
1417 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1418 * induces a CPU stall for the time specified by stall_cpu.
1419 */
1420 static int rcu_torture_stall(void *args)
1421 {
1422 unsigned long stop_at;
1423
1424 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1425 if (stall_cpu_holdoff > 0) {
1426 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1427 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1428 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1429 }
1430 if (!kthread_should_stop()) {
1431 stop_at = get_seconds() + stall_cpu;
1432 /* RCU CPU stall is expected behavior in following code. */
1433 pr_alert("rcu_torture_stall start.\n");
1434 rcu_read_lock();
1435 preempt_disable();
1436 while (ULONG_CMP_LT(get_seconds(), stop_at))
1437 continue; /* Induce RCU CPU stall warning. */
1438 preempt_enable();
1439 rcu_read_unlock();
1440 pr_alert("rcu_torture_stall end.\n");
1441 }
1442 torture_shutdown_absorb("rcu_torture_stall");
1443 while (!kthread_should_stop())
1444 schedule_timeout_interruptible(10 * HZ);
1445 return 0;
1446 }
1447
1448 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1449 static int __init rcu_torture_stall_init(void)
1450 {
1451 if (stall_cpu <= 0)
1452 return 0;
1453 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1454 }
1455
1456 /* Callback function for RCU barrier testing. */
1457 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1458 {
1459 atomic_inc(&barrier_cbs_invoked);
1460 }
1461
1462 /* kthread function to register callbacks used to test RCU barriers. */
1463 static int rcu_torture_barrier_cbs(void *arg)
1464 {
1465 long myid = (long)arg;
1466 bool lastphase = 0;
1467 bool newphase;
1468 struct rcu_head rcu;
1469
1470 init_rcu_head_on_stack(&rcu);
1471 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1472 set_user_nice(current, MAX_NICE);
1473 do {
1474 wait_event(barrier_cbs_wq[myid],
1475 (newphase =
1476 smp_load_acquire(&barrier_phase)) != lastphase ||
1477 torture_must_stop());
1478 lastphase = newphase;
1479 if (torture_must_stop())
1480 break;
1481 /*
1482 * The above smp_load_acquire() ensures barrier_phase load
1483 * is ordered before the following ->call().
1484 */
1485 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1486 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1487 local_irq_enable();
1488 if (atomic_dec_and_test(&barrier_cbs_count))
1489 wake_up(&barrier_wq);
1490 } while (!torture_must_stop());
1491 if (cur_ops->cb_barrier != NULL)
1492 cur_ops->cb_barrier();
1493 destroy_rcu_head_on_stack(&rcu);
1494 torture_kthread_stopping("rcu_torture_barrier_cbs");
1495 return 0;
1496 }
1497
1498 /* kthread function to drive and coordinate RCU barrier testing. */
1499 static int rcu_torture_barrier(void *arg)
1500 {
1501 int i;
1502
1503 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1504 do {
1505 atomic_set(&barrier_cbs_invoked, 0);
1506 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1507 /* Ensure barrier_phase ordered after prior assignments. */
1508 smp_store_release(&barrier_phase, !barrier_phase);
1509 for (i = 0; i < n_barrier_cbs; i++)
1510 wake_up(&barrier_cbs_wq[i]);
1511 wait_event(barrier_wq,
1512 atomic_read(&barrier_cbs_count) == 0 ||
1513 torture_must_stop());
1514 if (torture_must_stop())
1515 break;
1516 n_barrier_attempts++;
1517 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1518 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1519 n_rcu_torture_barrier_error++;
1520 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1521 atomic_read(&barrier_cbs_invoked),
1522 n_barrier_cbs);
1523 WARN_ON_ONCE(1);
1524 }
1525 n_barrier_successes++;
1526 schedule_timeout_interruptible(HZ / 10);
1527 } while (!torture_must_stop());
1528 torture_kthread_stopping("rcu_torture_barrier");
1529 return 0;
1530 }
1531
1532 /* Initialize RCU barrier testing. */
1533 static int rcu_torture_barrier_init(void)
1534 {
1535 int i;
1536 int ret;
1537
1538 if (n_barrier_cbs <= 0)
1539 return 0;
1540 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1541 pr_alert("%s" TORTURE_FLAG
1542 " Call or barrier ops missing for %s,\n",
1543 torture_type, cur_ops->name);
1544 pr_alert("%s" TORTURE_FLAG
1545 " RCU barrier testing omitted from run.\n",
1546 torture_type);
1547 return 0;
1548 }
1549 atomic_set(&barrier_cbs_count, 0);
1550 atomic_set(&barrier_cbs_invoked, 0);
1551 barrier_cbs_tasks =
1552 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
1553 GFP_KERNEL);
1554 barrier_cbs_wq =
1555 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
1556 GFP_KERNEL);
1557 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1558 return -ENOMEM;
1559 for (i = 0; i < n_barrier_cbs; i++) {
1560 init_waitqueue_head(&barrier_cbs_wq[i]);
1561 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1562 (void *)(long)i,
1563 barrier_cbs_tasks[i]);
1564 if (ret)
1565 return ret;
1566 }
1567 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1568 }
1569
1570 /* Clean up after RCU barrier testing. */
1571 static void rcu_torture_barrier_cleanup(void)
1572 {
1573 int i;
1574
1575 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1576 if (barrier_cbs_tasks != NULL) {
1577 for (i = 0; i < n_barrier_cbs; i++)
1578 torture_stop_kthread(rcu_torture_barrier_cbs,
1579 barrier_cbs_tasks[i]);
1580 kfree(barrier_cbs_tasks);
1581 barrier_cbs_tasks = NULL;
1582 }
1583 if (barrier_cbs_wq != NULL) {
1584 kfree(barrier_cbs_wq);
1585 barrier_cbs_wq = NULL;
1586 }
1587 }
1588
1589 static enum cpuhp_state rcutor_hp;
1590
1591 static void
1592 rcu_torture_cleanup(void)
1593 {
1594 int i;
1595
1596 rcutorture_record_test_transition();
1597 if (torture_cleanup_begin()) {
1598 if (cur_ops->cb_barrier != NULL)
1599 cur_ops->cb_barrier();
1600 return;
1601 }
1602
1603 rcu_torture_barrier_cleanup();
1604 torture_stop_kthread(rcu_torture_stall, stall_task);
1605 torture_stop_kthread(rcu_torture_writer, writer_task);
1606
1607 if (reader_tasks) {
1608 for (i = 0; i < nrealreaders; i++)
1609 torture_stop_kthread(rcu_torture_reader,
1610 reader_tasks[i]);
1611 kfree(reader_tasks);
1612 }
1613 rcu_torture_current = NULL;
1614
1615 if (fakewriter_tasks) {
1616 for (i = 0; i < nfakewriters; i++) {
1617 torture_stop_kthread(rcu_torture_fakewriter,
1618 fakewriter_tasks[i]);
1619 }
1620 kfree(fakewriter_tasks);
1621 fakewriter_tasks = NULL;
1622 }
1623
1624 torture_stop_kthread(rcu_torture_stats, stats_task);
1625 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1626 for (i = 0; i < ncbflooders; i++)
1627 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1628 if ((test_boost == 1 && cur_ops->can_boost) ||
1629 test_boost == 2)
1630 cpuhp_remove_state(rcutor_hp);
1631
1632 /*
1633 * Wait for all RCU callbacks to fire, then do flavor-specific
1634 * cleanup operations.
1635 */
1636 if (cur_ops->cb_barrier != NULL)
1637 cur_ops->cb_barrier();
1638 if (cur_ops->cleanup != NULL)
1639 cur_ops->cleanup();
1640
1641 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1642
1643 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1644 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1645 else if (torture_onoff_failures())
1646 rcu_torture_print_module_parms(cur_ops,
1647 "End of test: RCU_HOTPLUG");
1648 else
1649 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1650 torture_cleanup_end();
1651 }
1652
1653 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1654 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1655 {
1656 }
1657
1658 static void rcu_torture_err_cb(struct rcu_head *rhp)
1659 {
1660 /*
1661 * This -might- happen due to race conditions, but is unlikely.
1662 * The scenario that leads to this happening is that the
1663 * first of the pair of duplicate callbacks is queued,
1664 * someone else starts a grace period that includes that
1665 * callback, then the second of the pair must wait for the
1666 * next grace period. Unlikely, but can happen. If it
1667 * does happen, the debug-objects subsystem won't have splatted.
1668 */
1669 pr_alert("rcutorture: duplicated callback was invoked.\n");
1670 }
1671 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1672
1673 /*
1674 * Verify that double-free causes debug-objects to complain, but only
1675 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1676 * cannot be carried out.
1677 */
1678 static void rcu_test_debug_objects(void)
1679 {
1680 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1681 struct rcu_head rh1;
1682 struct rcu_head rh2;
1683
1684 init_rcu_head_on_stack(&rh1);
1685 init_rcu_head_on_stack(&rh2);
1686 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1687
1688 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1689 preempt_disable(); /* Prevent preemption from interrupting test. */
1690 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1691 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1692 local_irq_disable(); /* Make it harder to start a new grace period. */
1693 call_rcu(&rh2, rcu_torture_leak_cb);
1694 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1695 local_irq_enable();
1696 rcu_read_unlock();
1697 preempt_enable();
1698
1699 /* Wait for them all to get done so we can safely return. */
1700 rcu_barrier();
1701 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1702 destroy_rcu_head_on_stack(&rh1);
1703 destroy_rcu_head_on_stack(&rh2);
1704 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1705 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1706 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1707 }
1708
1709 static int __init
1710 rcu_torture_init(void)
1711 {
1712 int i;
1713 int cpu;
1714 int firsterr = 0;
1715 static struct rcu_torture_ops *torture_ops[] = {
1716 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1717 &sched_ops, &tasks_ops,
1718 };
1719
1720 if (!torture_init_begin(torture_type, verbose, &torture_runnable))
1721 return -EBUSY;
1722
1723 /* Process args and tell the world that the torturer is on the job. */
1724 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1725 cur_ops = torture_ops[i];
1726 if (strcmp(torture_type, cur_ops->name) == 0)
1727 break;
1728 }
1729 if (i == ARRAY_SIZE(torture_ops)) {
1730 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1731 torture_type);
1732 pr_alert("rcu-torture types:");
1733 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1734 pr_alert(" %s", torture_ops[i]->name);
1735 pr_alert("\n");
1736 firsterr = -EINVAL;
1737 goto unwind;
1738 }
1739 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1740 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1741 fqs_duration = 0;
1742 }
1743 if (cur_ops->init)
1744 cur_ops->init();
1745
1746 if (nreaders >= 0) {
1747 nrealreaders = nreaders;
1748 } else {
1749 nrealreaders = num_online_cpus() - 2 - nreaders;
1750 if (nrealreaders <= 0)
1751 nrealreaders = 1;
1752 }
1753 rcu_torture_print_module_parms(cur_ops, "Start of test");
1754
1755 /* Set up the freelist. */
1756
1757 INIT_LIST_HEAD(&rcu_torture_freelist);
1758 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1759 rcu_tortures[i].rtort_mbtest = 0;
1760 list_add_tail(&rcu_tortures[i].rtort_free,
1761 &rcu_torture_freelist);
1762 }
1763
1764 /* Initialize the statistics so that each run gets its own numbers. */
1765
1766 rcu_torture_current = NULL;
1767 rcu_torture_current_version = 0;
1768 atomic_set(&n_rcu_torture_alloc, 0);
1769 atomic_set(&n_rcu_torture_alloc_fail, 0);
1770 atomic_set(&n_rcu_torture_free, 0);
1771 atomic_set(&n_rcu_torture_mberror, 0);
1772 atomic_set(&n_rcu_torture_error, 0);
1773 n_rcu_torture_barrier_error = 0;
1774 n_rcu_torture_boost_ktrerror = 0;
1775 n_rcu_torture_boost_rterror = 0;
1776 n_rcu_torture_boost_failure = 0;
1777 n_rcu_torture_boosts = 0;
1778 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1779 atomic_set(&rcu_torture_wcount[i], 0);
1780 for_each_possible_cpu(cpu) {
1781 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1782 per_cpu(rcu_torture_count, cpu)[i] = 0;
1783 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1784 }
1785 }
1786
1787 /* Start up the kthreads. */
1788
1789 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1790 writer_task);
1791 if (firsterr)
1792 goto unwind;
1793 if (nfakewriters > 0) {
1794 fakewriter_tasks = kzalloc(nfakewriters *
1795 sizeof(fakewriter_tasks[0]),
1796 GFP_KERNEL);
1797 if (fakewriter_tasks == NULL) {
1798 VERBOSE_TOROUT_ERRSTRING("out of memory");
1799 firsterr = -ENOMEM;
1800 goto unwind;
1801 }
1802 }
1803 for (i = 0; i < nfakewriters; i++) {
1804 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1805 NULL, fakewriter_tasks[i]);
1806 if (firsterr)
1807 goto unwind;
1808 }
1809 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
1810 GFP_KERNEL);
1811 if (reader_tasks == NULL) {
1812 VERBOSE_TOROUT_ERRSTRING("out of memory");
1813 firsterr = -ENOMEM;
1814 goto unwind;
1815 }
1816 for (i = 0; i < nrealreaders; i++) {
1817 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1818 reader_tasks[i]);
1819 if (firsterr)
1820 goto unwind;
1821 }
1822 if (stat_interval > 0) {
1823 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1824 stats_task);
1825 if (firsterr)
1826 goto unwind;
1827 }
1828 if (test_no_idle_hz && shuffle_interval > 0) {
1829 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1830 if (firsterr)
1831 goto unwind;
1832 }
1833 if (stutter < 0)
1834 stutter = 0;
1835 if (stutter) {
1836 firsterr = torture_stutter_init(stutter * HZ);
1837 if (firsterr)
1838 goto unwind;
1839 }
1840 if (fqs_duration < 0)
1841 fqs_duration = 0;
1842 if (fqs_duration) {
1843 /* Create the fqs thread */
1844 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1845 fqs_task);
1846 if (firsterr)
1847 goto unwind;
1848 }
1849 if (test_boost_interval < 1)
1850 test_boost_interval = 1;
1851 if (test_boost_duration < 2)
1852 test_boost_duration = 2;
1853 if ((test_boost == 1 && cur_ops->can_boost) ||
1854 test_boost == 2) {
1855
1856 boost_starttime = jiffies + test_boost_interval * HZ;
1857
1858 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
1859 rcutorture_booster_init,
1860 rcutorture_booster_cleanup);
1861 if (firsterr < 0)
1862 goto unwind;
1863 rcutor_hp = firsterr;
1864 }
1865 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1866 if (firsterr)
1867 goto unwind;
1868 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1869 if (firsterr)
1870 goto unwind;
1871 firsterr = rcu_torture_stall_init();
1872 if (firsterr)
1873 goto unwind;
1874 firsterr = rcu_torture_barrier_init();
1875 if (firsterr)
1876 goto unwind;
1877 if (object_debug)
1878 rcu_test_debug_objects();
1879 if (cbflood_n_burst > 0) {
1880 /* Create the cbflood threads */
1881 ncbflooders = (num_online_cpus() + 3) / 4;
1882 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1883 GFP_KERNEL);
1884 if (!cbflood_task) {
1885 VERBOSE_TOROUT_ERRSTRING("out of memory");
1886 firsterr = -ENOMEM;
1887 goto unwind;
1888 }
1889 for (i = 0; i < ncbflooders; i++) {
1890 firsterr = torture_create_kthread(rcu_torture_cbflood,
1891 NULL,
1892 cbflood_task[i]);
1893 if (firsterr)
1894 goto unwind;
1895 }
1896 }
1897 rcutorture_record_test_transition();
1898 torture_init_end();
1899 return 0;
1900
1901 unwind:
1902 torture_init_end();
1903 rcu_torture_cleanup();
1904 return firsterr;
1905 }
1906
1907 module_init(rcu_torture_init);
1908 module_exit(rcu_torture_cleanup);
CRIS linux kernel tree