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dt-bindings: phy-rockchip-typec: deprecate some register properties.
[linux/fpc-iii.git] / kernel / rcu / rcutorture.c
blob308e6fdbced8450512cde14e0a45e70833440de4
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 #include <linux/sched/debug.h>
55
56 #include "rcu.h"
57
58 MODULE_LICENSE("GPL");
59 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
60
61
62 torture_param(int, cbflood_inter_holdoff, HZ,
63 "Holdoff between floods (jiffies)");
64 torture_param(int, cbflood_intra_holdoff, 1,
65 "Holdoff between bursts (jiffies)");
66 torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable");
67 torture_param(int, cbflood_n_per_burst, 20000,
68 "# callbacks per burst in flood");
69 torture_param(int, fqs_duration, 0,
70 "Duration of fqs bursts (us), 0 to disable");
71 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
72 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
73 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
74 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
75 torture_param(bool, gp_normal, false,
76 "Use normal (non-expedited) GP wait primitives");
77 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
78 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
79 torture_param(int, n_barrier_cbs, 0,
80 "# of callbacks/kthreads for barrier testing");
81 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
82 torture_param(int, nreaders, -1, "Number of RCU reader threads");
83 torture_param(int, object_debug, 0,
84 "Enable debug-object double call_rcu() testing");
85 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
86 torture_param(int, onoff_interval, 0,
87 "Time between CPU hotplugs (s), 0=disable");
88 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
89 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
90 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
91 torture_param(int, stall_cpu_holdoff, 10,
92 "Time to wait before starting stall (s).");
93 torture_param(int, stall_cpu_irqsoff, 0, "Disable interrupts while stalling.");
94 torture_param(int, stat_interval, 60,
95 "Number of seconds between stats printk()s");
96 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
97 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
98 torture_param(int, test_boost_duration, 4,
99 "Duration of each boost test, seconds.");
100 torture_param(int, test_boost_interval, 7,
101 "Interval between boost tests, seconds.");
102 torture_param(bool, test_no_idle_hz, true,
103 "Test support for tickless idle CPUs");
104 torture_param(bool, verbose, true,
105 "Enable verbose debugging printk()s");
106
107 static char *torture_type = "rcu";
108 module_param(torture_type, charp, 0444);
109 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
110
111 static int nrealreaders;
112 static int ncbflooders;
113 static struct task_struct *writer_task;
114 static struct task_struct **fakewriter_tasks;
115 static struct task_struct **reader_tasks;
116 static struct task_struct *stats_task;
117 static struct task_struct **cbflood_task;
118 static struct task_struct *fqs_task;
119 static struct task_struct *boost_tasks[NR_CPUS];
120 static struct task_struct *stall_task;
121 static struct task_struct **barrier_cbs_tasks;
122 static struct task_struct *barrier_task;
123
124 #define RCU_TORTURE_PIPE_LEN 10
125
126 struct rcu_torture {
127 struct rcu_head rtort_rcu;
128 int rtort_pipe_count;
129 struct list_head rtort_free;
130 int rtort_mbtest;
131 };
132
133 static LIST_HEAD(rcu_torture_freelist);
134 static struct rcu_torture __rcu *rcu_torture_current;
135 static unsigned long rcu_torture_current_version;
136 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
137 static DEFINE_SPINLOCK(rcu_torture_lock);
138 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
139 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
140 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
141 static atomic_t n_rcu_torture_alloc;
142 static atomic_t n_rcu_torture_alloc_fail;
143 static atomic_t n_rcu_torture_free;
144 static atomic_t n_rcu_torture_mberror;
145 static atomic_t n_rcu_torture_error;
146 static long n_rcu_torture_barrier_error;
147 static long n_rcu_torture_boost_ktrerror;
148 static long n_rcu_torture_boost_rterror;
149 static long n_rcu_torture_boost_failure;
150 static long n_rcu_torture_boosts;
151 static long n_rcu_torture_timers;
152 static long n_barrier_attempts;
153 static long n_barrier_successes;
154 static atomic_long_t n_cbfloods;
155 static struct list_head rcu_torture_removed;
156
157 static int rcu_torture_writer_state;
158 #define RTWS_FIXED_DELAY 0
159 #define RTWS_DELAY 1
160 #define RTWS_REPLACE 2
161 #define RTWS_DEF_FREE 3
162 #define RTWS_EXP_SYNC 4
163 #define RTWS_COND_GET 5
164 #define RTWS_COND_SYNC 6
165 #define RTWS_SYNC 7
166 #define RTWS_STUTTER 8
167 #define RTWS_STOPPING 9
168 static const char * const rcu_torture_writer_state_names[] = {
169 "RTWS_FIXED_DELAY",
170 "RTWS_DELAY",
171 "RTWS_REPLACE",
172 "RTWS_DEF_FREE",
173 "RTWS_EXP_SYNC",
174 "RTWS_COND_GET",
175 "RTWS_COND_SYNC",
176 "RTWS_SYNC",
177 "RTWS_STUTTER",
178 "RTWS_STOPPING",
179 };
180
181 static const char *rcu_torture_writer_state_getname(void)
182 {
183 unsigned int i = READ_ONCE(rcu_torture_writer_state);
184
185 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
186 return "???";
187 return rcu_torture_writer_state_names[i];
188 }
189
190 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
191 #define rcu_can_boost() 1
192 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
193 #define rcu_can_boost() 0
194 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
195
196 #ifdef CONFIG_RCU_TRACE
197 static u64 notrace rcu_trace_clock_local(void)
198 {
199 u64 ts = trace_clock_local();
200
201 (void)do_div(ts, NSEC_PER_USEC);
202 return ts;
203 }
204 #else /* #ifdef CONFIG_RCU_TRACE */
205 static u64 notrace rcu_trace_clock_local(void)
206 {
207 return 0ULL;
208 }
209 #endif /* #else #ifdef CONFIG_RCU_TRACE */
210
211 static unsigned long boost_starttime; /* jiffies of next boost test start. */
212 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
213 /* and boost task create/destroy. */
214 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
215 static bool barrier_phase; /* Test phase. */
216 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
217 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
218 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
219
220 /*
221 * Allocate an element from the rcu_tortures pool.
222 */
223 static struct rcu_torture *
224 rcu_torture_alloc(void)
225 {
226 struct list_head *p;
227
228 spin_lock_bh(&rcu_torture_lock);
229 if (list_empty(&rcu_torture_freelist)) {
230 atomic_inc(&n_rcu_torture_alloc_fail);
231 spin_unlock_bh(&rcu_torture_lock);
232 return NULL;
233 }
234 atomic_inc(&n_rcu_torture_alloc);
235 p = rcu_torture_freelist.next;
236 list_del_init(p);
237 spin_unlock_bh(&rcu_torture_lock);
238 return container_of(p, struct rcu_torture, rtort_free);
239 }
240
241 /*
242 * Free an element to the rcu_tortures pool.
243 */
244 static void
245 rcu_torture_free(struct rcu_torture *p)
246 {
247 atomic_inc(&n_rcu_torture_free);
248 spin_lock_bh(&rcu_torture_lock);
249 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
250 spin_unlock_bh(&rcu_torture_lock);
251 }
252
253 /*
254 * Operations vector for selecting different types of tests.
255 */
256
257 struct rcu_torture_ops {
258 int ttype;
259 void (*init)(void);
260 void (*cleanup)(void);
261 int (*readlock)(void);
262 void (*read_delay)(struct torture_random_state *rrsp);
263 void (*readunlock)(int idx);
264 unsigned long (*started)(void);
265 unsigned long (*completed)(void);
266 void (*deferred_free)(struct rcu_torture *p);
267 void (*sync)(void);
268 void (*exp_sync)(void);
269 unsigned long (*get_state)(void);
270 void (*cond_sync)(unsigned long oldstate);
271 call_rcu_func_t call;
272 void (*cb_barrier)(void);
273 void (*fqs)(void);
274 void (*stats)(void);
275 int irq_capable;
276 int can_boost;
277 const char *name;
278 };
279
280 static struct rcu_torture_ops *cur_ops;
281
282 /*
283 * Definitions for rcu torture testing.
284 */
285
286 static int rcu_torture_read_lock(void) __acquires(RCU)
287 {
288 rcu_read_lock();
289 return 0;
290 }
291
292 static void rcu_read_delay(struct torture_random_state *rrsp)
293 {
294 unsigned long started;
295 unsigned long completed;
296 const unsigned long shortdelay_us = 200;
297 const unsigned long longdelay_ms = 50;
298 unsigned long long ts;
299
300 /* We want a short delay sometimes to make a reader delay the grace
301 * period, and we want a long delay occasionally to trigger
302 * force_quiescent_state. */
303
304 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
305 started = cur_ops->completed();
306 ts = rcu_trace_clock_local();
307 mdelay(longdelay_ms);
308 completed = cur_ops->completed();
309 do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
310 started, completed);
311 }
312 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
313 udelay(shortdelay_us);
314 if (!preempt_count() &&
315 !(torture_random(rrsp) % (nrealreaders * 500)))
316 torture_preempt_schedule(); /* QS only if preemptible. */
317 }
318
319 static void rcu_torture_read_unlock(int idx) __releases(RCU)
320 {
321 rcu_read_unlock();
322 }
323
324 /*
325 * Update callback in the pipe. This should be invoked after a grace period.
326 */
327 static bool
328 rcu_torture_pipe_update_one(struct rcu_torture *rp)
329 {
330 int i;
331
332 i = rp->rtort_pipe_count;
333 if (i > RCU_TORTURE_PIPE_LEN)
334 i = RCU_TORTURE_PIPE_LEN;
335 atomic_inc(&rcu_torture_wcount[i]);
336 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
337 rp->rtort_mbtest = 0;
338 return true;
339 }
340 return false;
341 }
342
343 /*
344 * Update all callbacks in the pipe. Suitable for synchronous grace-period
345 * primitives.
346 */
347 static void
348 rcu_torture_pipe_update(struct rcu_torture *old_rp)
349 {
350 struct rcu_torture *rp;
351 struct rcu_torture *rp1;
352
353 if (old_rp)
354 list_add(&old_rp->rtort_free, &rcu_torture_removed);
355 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
356 if (rcu_torture_pipe_update_one(rp)) {
357 list_del(&rp->rtort_free);
358 rcu_torture_free(rp);
359 }
360 }
361 }
362
363 static void
364 rcu_torture_cb(struct rcu_head *p)
365 {
366 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
367
368 if (torture_must_stop_irq()) {
369 /* Test is ending, just drop callbacks on the floor. */
370 /* The next initialization will pick up the pieces. */
371 return;
372 }
373 if (rcu_torture_pipe_update_one(rp))
374 rcu_torture_free(rp);
375 else
376 cur_ops->deferred_free(rp);
377 }
378
379 static unsigned long rcu_no_completed(void)
380 {
381 return 0;
382 }
383
384 static void rcu_torture_deferred_free(struct rcu_torture *p)
385 {
386 call_rcu(&p->rtort_rcu, rcu_torture_cb);
387 }
388
389 static void rcu_sync_torture_init(void)
390 {
391 INIT_LIST_HEAD(&rcu_torture_removed);
392 }
393
394 static struct rcu_torture_ops rcu_ops = {
395 .ttype = RCU_FLAVOR,
396 .init = rcu_sync_torture_init,
397 .readlock = rcu_torture_read_lock,
398 .read_delay = rcu_read_delay,
399 .readunlock = rcu_torture_read_unlock,
400 .started = rcu_batches_started,
401 .completed = rcu_batches_completed,
402 .deferred_free = rcu_torture_deferred_free,
403 .sync = synchronize_rcu,
404 .exp_sync = synchronize_rcu_expedited,
405 .get_state = get_state_synchronize_rcu,
406 .cond_sync = cond_synchronize_rcu,
407 .call = call_rcu,
408 .cb_barrier = rcu_barrier,
409 .fqs = rcu_force_quiescent_state,
410 .stats = NULL,
411 .irq_capable = 1,
412 .can_boost = rcu_can_boost(),
413 .name = "rcu"
414 };
415
416 /*
417 * Definitions for rcu_bh torture testing.
418 */
419
420 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
421 {
422 rcu_read_lock_bh();
423 return 0;
424 }
425
426 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
427 {
428 rcu_read_unlock_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
436 static struct rcu_torture_ops rcu_bh_ops = {
437 .ttype = RCU_BH_FLAVOR,
438 .init = rcu_sync_torture_init,
439 .readlock = rcu_bh_torture_read_lock,
440 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
441 .readunlock = rcu_bh_torture_read_unlock,
442 .started = rcu_batches_started_bh,
443 .completed = rcu_batches_completed_bh,
444 .deferred_free = rcu_bh_torture_deferred_free,
445 .sync = synchronize_rcu_bh,
446 .exp_sync = synchronize_rcu_bh_expedited,
447 .call = call_rcu_bh,
448 .cb_barrier = rcu_barrier_bh,
449 .fqs = rcu_bh_force_quiescent_state,
450 .stats = NULL,
451 .irq_capable = 1,
452 .name = "rcu_bh"
453 };
454
455 /*
456 * Don't even think about trying any of these in real life!!!
457 * The names includes "busted", and they really means it!
458 * The only purpose of these functions is to provide a buggy RCU
459 * implementation to make sure that rcutorture correctly emits
460 * buggy-RCU error messages.
461 */
462 static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
463 {
464 /* This is a deliberate bug for testing purposes only! */
465 rcu_torture_cb(&p->rtort_rcu);
466 }
467
468 static void synchronize_rcu_busted(void)
469 {
470 /* This is a deliberate bug for testing purposes only! */
471 }
472
473 static void
474 call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
475 {
476 /* This is a deliberate bug for testing purposes only! */
477 func(head);
478 }
479
480 static struct rcu_torture_ops rcu_busted_ops = {
481 .ttype = INVALID_RCU_FLAVOR,
482 .init = rcu_sync_torture_init,
483 .readlock = rcu_torture_read_lock,
484 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
485 .readunlock = rcu_torture_read_unlock,
486 .started = rcu_no_completed,
487 .completed = rcu_no_completed,
488 .deferred_free = rcu_busted_torture_deferred_free,
489 .sync = synchronize_rcu_busted,
490 .exp_sync = synchronize_rcu_busted,
491 .call = call_rcu_busted,
492 .cb_barrier = NULL,
493 .fqs = NULL,
494 .stats = NULL,
495 .irq_capable = 1,
496 .name = "busted"
497 };
498
499 /*
500 * Definitions for srcu torture testing.
501 */
502
503 DEFINE_STATIC_SRCU(srcu_ctl);
504 static struct srcu_struct srcu_ctld;
505 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
506
507 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
508 {
509 return srcu_read_lock(srcu_ctlp);
510 }
511
512 static void srcu_read_delay(struct torture_random_state *rrsp)
513 {
514 long delay;
515 const long uspertick = 1000000 / HZ;
516 const long longdelay = 10;
517
518 /* We want there to be long-running readers, but not all the time. */
519
520 delay = torture_random(rrsp) %
521 (nrealreaders * 2 * longdelay * uspertick);
522 if (!delay && in_task())
523 schedule_timeout_interruptible(longdelay);
524 else
525 rcu_read_delay(rrsp);
526 }
527
528 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
529 {
530 srcu_read_unlock(srcu_ctlp, idx);
531 }
532
533 static unsigned long srcu_torture_completed(void)
534 {
535 return srcu_batches_completed(srcu_ctlp);
536 }
537
538 static void srcu_torture_deferred_free(struct rcu_torture *rp)
539 {
540 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
541 }
542
543 static void srcu_torture_synchronize(void)
544 {
545 synchronize_srcu(srcu_ctlp);
546 }
547
548 static void srcu_torture_call(struct rcu_head *head,
549 rcu_callback_t func)
550 {
551 call_srcu(srcu_ctlp, head, func);
552 }
553
554 static void srcu_torture_barrier(void)
555 {
556 srcu_barrier(srcu_ctlp);
557 }
558
559 static void srcu_torture_stats(void)
560 {
561 srcu_torture_stats_print(srcu_ctlp, torture_type, TORTURE_FLAG);
562 }
563
564 static void srcu_torture_synchronize_expedited(void)
565 {
566 synchronize_srcu_expedited(srcu_ctlp);
567 }
568
569 static struct rcu_torture_ops srcu_ops = {
570 .ttype = SRCU_FLAVOR,
571 .init = rcu_sync_torture_init,
572 .readlock = srcu_torture_read_lock,
573 .read_delay = srcu_read_delay,
574 .readunlock = srcu_torture_read_unlock,
575 .started = NULL,
576 .completed = srcu_torture_completed,
577 .deferred_free = srcu_torture_deferred_free,
578 .sync = srcu_torture_synchronize,
579 .exp_sync = srcu_torture_synchronize_expedited,
580 .call = srcu_torture_call,
581 .cb_barrier = srcu_torture_barrier,
582 .stats = srcu_torture_stats,
583 .irq_capable = 1,
584 .name = "srcu"
585 };
586
587 static void srcu_torture_init(void)
588 {
589 rcu_sync_torture_init();
590 WARN_ON(init_srcu_struct(&srcu_ctld));
591 srcu_ctlp = &srcu_ctld;
592 }
593
594 static void srcu_torture_cleanup(void)
595 {
596 cleanup_srcu_struct(&srcu_ctld);
597 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
598 }
599
600 /* As above, but dynamically allocated. */
601 static struct rcu_torture_ops srcud_ops = {
602 .ttype = SRCU_FLAVOR,
603 .init = srcu_torture_init,
604 .cleanup = srcu_torture_cleanup,
605 .readlock = srcu_torture_read_lock,
606 .read_delay = srcu_read_delay,
607 .readunlock = srcu_torture_read_unlock,
608 .started = NULL,
609 .completed = srcu_torture_completed,
610 .deferred_free = srcu_torture_deferred_free,
611 .sync = srcu_torture_synchronize,
612 .exp_sync = srcu_torture_synchronize_expedited,
613 .call = srcu_torture_call,
614 .cb_barrier = srcu_torture_barrier,
615 .stats = srcu_torture_stats,
616 .irq_capable = 1,
617 .name = "srcud"
618 };
619
620 /*
621 * Definitions for sched torture testing.
622 */
623
624 static int sched_torture_read_lock(void)
625 {
626 preempt_disable();
627 return 0;
628 }
629
630 static void sched_torture_read_unlock(int idx)
631 {
632 preempt_enable();
633 }
634
635 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
636 {
637 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
638 }
639
640 static struct rcu_torture_ops sched_ops = {
641 .ttype = RCU_SCHED_FLAVOR,
642 .init = rcu_sync_torture_init,
643 .readlock = sched_torture_read_lock,
644 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
645 .readunlock = sched_torture_read_unlock,
646 .started = rcu_batches_started_sched,
647 .completed = rcu_batches_completed_sched,
648 .deferred_free = rcu_sched_torture_deferred_free,
649 .sync = synchronize_sched,
650 .exp_sync = synchronize_sched_expedited,
651 .get_state = get_state_synchronize_sched,
652 .cond_sync = cond_synchronize_sched,
653 .call = call_rcu_sched,
654 .cb_barrier = rcu_barrier_sched,
655 .fqs = rcu_sched_force_quiescent_state,
656 .stats = NULL,
657 .irq_capable = 1,
658 .name = "sched"
659 };
660
661 /*
662 * Definitions for RCU-tasks torture testing.
663 */
664
665 static int tasks_torture_read_lock(void)
666 {
667 return 0;
668 }
669
670 static void tasks_torture_read_unlock(int idx)
671 {
672 }
673
674 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
675 {
676 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
677 }
678
679 static struct rcu_torture_ops tasks_ops = {
680 .ttype = RCU_TASKS_FLAVOR,
681 .init = rcu_sync_torture_init,
682 .readlock = tasks_torture_read_lock,
683 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
684 .readunlock = tasks_torture_read_unlock,
685 .started = rcu_no_completed,
686 .completed = rcu_no_completed,
687 .deferred_free = rcu_tasks_torture_deferred_free,
688 .sync = synchronize_rcu_tasks,
689 .exp_sync = synchronize_rcu_tasks,
690 .call = call_rcu_tasks,
691 .cb_barrier = rcu_barrier_tasks,
692 .fqs = NULL,
693 .stats = NULL,
694 .irq_capable = 1,
695 .name = "tasks"
696 };
697
698 static bool __maybe_unused torturing_tasks(void)
699 {
700 return cur_ops == &tasks_ops;
701 }
702
703 /*
704 * RCU torture priority-boost testing. Runs one real-time thread per
705 * CPU for moderate bursts, repeatedly registering RCU callbacks and
706 * spinning waiting for them to be invoked. If a given callback takes
707 * too long to be invoked, we assume that priority inversion has occurred.
708 */
709
710 struct rcu_boost_inflight {
711 struct rcu_head rcu;
712 int inflight;
713 };
714
715 static void rcu_torture_boost_cb(struct rcu_head *head)
716 {
717 struct rcu_boost_inflight *rbip =
718 container_of(head, struct rcu_boost_inflight, rcu);
719
720 /* Ensure RCU-core accesses precede clearing ->inflight */
721 smp_store_release(&rbip->inflight, 0);
722 }
723
724 static int rcu_torture_boost(void *arg)
725 {
726 unsigned long call_rcu_time;
727 unsigned long endtime;
728 unsigned long oldstarttime;
729 struct rcu_boost_inflight rbi = { .inflight = 0 };
730 struct sched_param sp;
731
732 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
733
734 /* Set real-time priority. */
735 sp.sched_priority = 1;
736 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
737 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
738 n_rcu_torture_boost_rterror++;
739 }
740
741 init_rcu_head_on_stack(&rbi.rcu);
742 /* Each pass through the following loop does one boost-test cycle. */
743 do {
744 /* Wait for the next test interval. */
745 oldstarttime = boost_starttime;
746 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
747 schedule_timeout_interruptible(oldstarttime - jiffies);
748 stutter_wait("rcu_torture_boost");
749 if (torture_must_stop())
750 goto checkwait;
751 }
752
753 /* Do one boost-test interval. */
754 endtime = oldstarttime + test_boost_duration * HZ;
755 call_rcu_time = jiffies;
756 while (ULONG_CMP_LT(jiffies, endtime)) {
757 /* If we don't have a callback in flight, post one. */
758 if (!smp_load_acquire(&rbi.inflight)) {
759 /* RCU core before ->inflight = 1. */
760 smp_store_release(&rbi.inflight, 1);
761 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
762 if (jiffies - call_rcu_time >
763 test_boost_duration * HZ - HZ / 2) {
764 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
765 n_rcu_torture_boost_failure++;
766 }
767 call_rcu_time = jiffies;
768 }
769 stutter_wait("rcu_torture_boost");
770 if (torture_must_stop())
771 goto checkwait;
772 }
773
774 /*
775 * Set the start time of the next test interval.
776 * Yes, this is vulnerable to long delays, but such
777 * delays simply cause a false negative for the next
778 * interval. Besides, we are running at RT priority,
779 * so delays should be relatively rare.
780 */
781 while (oldstarttime == boost_starttime &&
782 !kthread_should_stop()) {
783 if (mutex_trylock(&boost_mutex)) {
784 boost_starttime = jiffies +
785 test_boost_interval * HZ;
786 n_rcu_torture_boosts++;
787 mutex_unlock(&boost_mutex);
788 break;
789 }
790 schedule_timeout_uninterruptible(1);
791 }
792
793 /* Go do the stutter. */
794 checkwait: stutter_wait("rcu_torture_boost");
795 } while (!torture_must_stop());
796
797 /* Clean up and exit. */
798 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
799 torture_shutdown_absorb("rcu_torture_boost");
800 schedule_timeout_uninterruptible(1);
801 }
802 destroy_rcu_head_on_stack(&rbi.rcu);
803 torture_kthread_stopping("rcu_torture_boost");
804 return 0;
805 }
806
807 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
808 {
809 }
810
811 /*
812 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
813 * to call_rcu() or analogous, increasing the probability of occurrence
814 * of callback-overflow corner cases.
815 */
816 static int
817 rcu_torture_cbflood(void *arg)
818 {
819 int err = 1;
820 int i;
821 int j;
822 struct rcu_head *rhp;
823
824 if (cbflood_n_per_burst > 0 &&
825 cbflood_inter_holdoff > 0 &&
826 cbflood_intra_holdoff > 0 &&
827 cur_ops->call &&
828 cur_ops->cb_barrier) {
829 rhp = vmalloc(sizeof(*rhp) *
830 cbflood_n_burst * cbflood_n_per_burst);
831 err = !rhp;
832 }
833 if (err) {
834 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
835 goto wait_for_stop;
836 }
837 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
838 do {
839 schedule_timeout_interruptible(cbflood_inter_holdoff);
840 atomic_long_inc(&n_cbfloods);
841 WARN_ON(signal_pending(current));
842 for (i = 0; i < cbflood_n_burst; i++) {
843 for (j = 0; j < cbflood_n_per_burst; j++) {
844 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
845 rcu_torture_cbflood_cb);
846 }
847 schedule_timeout_interruptible(cbflood_intra_holdoff);
848 WARN_ON(signal_pending(current));
849 }
850 cur_ops->cb_barrier();
851 stutter_wait("rcu_torture_cbflood");
852 } while (!torture_must_stop());
853 vfree(rhp);
854 wait_for_stop:
855 torture_kthread_stopping("rcu_torture_cbflood");
856 return 0;
857 }
858
859 /*
860 * RCU torture force-quiescent-state kthread. Repeatedly induces
861 * bursts of calls to force_quiescent_state(), increasing the probability
862 * of occurrence of some important types of race conditions.
863 */
864 static int
865 rcu_torture_fqs(void *arg)
866 {
867 unsigned long fqs_resume_time;
868 int fqs_burst_remaining;
869
870 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
871 do {
872 fqs_resume_time = jiffies + fqs_stutter * HZ;
873 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
874 !kthread_should_stop()) {
875 schedule_timeout_interruptible(1);
876 }
877 fqs_burst_remaining = fqs_duration;
878 while (fqs_burst_remaining > 0 &&
879 !kthread_should_stop()) {
880 cur_ops->fqs();
881 udelay(fqs_holdoff);
882 fqs_burst_remaining -= fqs_holdoff;
883 }
884 stutter_wait("rcu_torture_fqs");
885 } while (!torture_must_stop());
886 torture_kthread_stopping("rcu_torture_fqs");
887 return 0;
888 }
889
890 /*
891 * RCU torture writer kthread. Repeatedly substitutes a new structure
892 * for that pointed to by rcu_torture_current, freeing the old structure
893 * after a series of grace periods (the "pipeline").
894 */
895 static int
896 rcu_torture_writer(void *arg)
897 {
898 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
899 int expediting = 0;
900 unsigned long gp_snap;
901 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
902 bool gp_sync1 = gp_sync;
903 int i;
904 struct rcu_torture *rp;
905 struct rcu_torture *old_rp;
906 static DEFINE_TORTURE_RANDOM(rand);
907 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
908 RTWS_COND_GET, RTWS_SYNC };
909 int nsynctypes = 0;
910
911 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
912 if (!can_expedite) {
913 pr_alert("%s" TORTURE_FLAG
914 " GP expediting controlled from boot/sysfs for %s,\n",
915 torture_type, cur_ops->name);
916 pr_alert("%s" TORTURE_FLAG
917 " Disabled dynamic grace-period expediting.\n",
918 torture_type);
919 }
920
921 /* Initialize synctype[] array. If none set, take default. */
922 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
923 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
924 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
925 synctype[nsynctypes++] = RTWS_COND_GET;
926 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
927 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
928 if (gp_exp1 && cur_ops->exp_sync)
929 synctype[nsynctypes++] = RTWS_EXP_SYNC;
930 else if (gp_exp && !cur_ops->exp_sync)
931 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
932 if (gp_normal1 && cur_ops->deferred_free)
933 synctype[nsynctypes++] = RTWS_DEF_FREE;
934 else if (gp_normal && !cur_ops->deferred_free)
935 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
936 if (gp_sync1 && cur_ops->sync)
937 synctype[nsynctypes++] = RTWS_SYNC;
938 else if (gp_sync && !cur_ops->sync)
939 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
940 if (WARN_ONCE(nsynctypes == 0,
941 "rcu_torture_writer: No update-side primitives.\n")) {
942 /*
943 * No updates primitives, so don't try updating.
944 * The resulting test won't be testing much, hence the
945 * above WARN_ONCE().
946 */
947 rcu_torture_writer_state = RTWS_STOPPING;
948 torture_kthread_stopping("rcu_torture_writer");
949 }
950
951 do {
952 rcu_torture_writer_state = RTWS_FIXED_DELAY;
953 schedule_timeout_uninterruptible(1);
954 rp = rcu_torture_alloc();
955 if (rp == NULL)
956 continue;
957 rp->rtort_pipe_count = 0;
958 rcu_torture_writer_state = RTWS_DELAY;
959 udelay(torture_random(&rand) & 0x3ff);
960 rcu_torture_writer_state = RTWS_REPLACE;
961 old_rp = rcu_dereference_check(rcu_torture_current,
962 current == writer_task);
963 rp->rtort_mbtest = 1;
964 rcu_assign_pointer(rcu_torture_current, rp);
965 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
966 if (old_rp) {
967 i = old_rp->rtort_pipe_count;
968 if (i > RCU_TORTURE_PIPE_LEN)
969 i = RCU_TORTURE_PIPE_LEN;
970 atomic_inc(&rcu_torture_wcount[i]);
971 old_rp->rtort_pipe_count++;
972 switch (synctype[torture_random(&rand) % nsynctypes]) {
973 case RTWS_DEF_FREE:
974 rcu_torture_writer_state = RTWS_DEF_FREE;
975 cur_ops->deferred_free(old_rp);
976 break;
977 case RTWS_EXP_SYNC:
978 rcu_torture_writer_state = RTWS_EXP_SYNC;
979 cur_ops->exp_sync();
980 rcu_torture_pipe_update(old_rp);
981 break;
982 case RTWS_COND_GET:
983 rcu_torture_writer_state = RTWS_COND_GET;
984 gp_snap = cur_ops->get_state();
985 i = torture_random(&rand) % 16;
986 if (i != 0)
987 schedule_timeout_interruptible(i);
988 udelay(torture_random(&rand) % 1000);
989 rcu_torture_writer_state = RTWS_COND_SYNC;
990 cur_ops->cond_sync(gp_snap);
991 rcu_torture_pipe_update(old_rp);
992 break;
993 case RTWS_SYNC:
994 rcu_torture_writer_state = RTWS_SYNC;
995 cur_ops->sync();
996 rcu_torture_pipe_update(old_rp);
997 break;
998 default:
999 WARN_ON_ONCE(1);
1000 break;
1001 }
1002 }
1003 rcutorture_record_progress(++rcu_torture_current_version);
1004 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1005 if (can_expedite &&
1006 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1007 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1008 if (expediting >= 0)
1009 rcu_expedite_gp();
1010 else
1011 rcu_unexpedite_gp();
1012 if (++expediting > 3)
1013 expediting = -expediting;
1014 }
1015 rcu_torture_writer_state = RTWS_STUTTER;
1016 stutter_wait("rcu_torture_writer");
1017 } while (!torture_must_stop());
1018 /* Reset expediting back to unexpedited. */
1019 if (expediting > 0)
1020 expediting = -expediting;
1021 while (can_expedite && expediting++ < 0)
1022 rcu_unexpedite_gp();
1023 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1024 rcu_torture_writer_state = RTWS_STOPPING;
1025 torture_kthread_stopping("rcu_torture_writer");
1026 return 0;
1027 }
1028
1029 /*
1030 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1031 * delay between calls.
1032 */
1033 static int
1034 rcu_torture_fakewriter(void *arg)
1035 {
1036 DEFINE_TORTURE_RANDOM(rand);
1037
1038 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1039 set_user_nice(current, MAX_NICE);
1040
1041 do {
1042 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1043 udelay(torture_random(&rand) & 0x3ff);
1044 if (cur_ops->cb_barrier != NULL &&
1045 torture_random(&rand) % (nfakewriters * 8) == 0) {
1046 cur_ops->cb_barrier();
1047 } else if (gp_normal == gp_exp) {
1048 if (torture_random(&rand) & 0x80)
1049 cur_ops->sync();
1050 else
1051 cur_ops->exp_sync();
1052 } else if (gp_normal) {
1053 cur_ops->sync();
1054 } else {
1055 cur_ops->exp_sync();
1056 }
1057 stutter_wait("rcu_torture_fakewriter");
1058 } while (!torture_must_stop());
1059
1060 torture_kthread_stopping("rcu_torture_fakewriter");
1061 return 0;
1062 }
1063
1064 static void rcu_torture_timer_cb(struct rcu_head *rhp)
1065 {
1066 kfree(rhp);
1067 }
1068
1069 /*
1070 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1071 * incrementing the corresponding element of the pipeline array. The
1072 * counter in the element should never be greater than 1, otherwise, the
1073 * RCU implementation is broken.
1074 */
1075 static void rcu_torture_timer(struct timer_list *unused)
1076 {
1077 int idx;
1078 unsigned long started;
1079 unsigned long completed;
1080 static DEFINE_TORTURE_RANDOM(rand);
1081 static DEFINE_SPINLOCK(rand_lock);
1082 struct rcu_torture *p;
1083 int pipe_count;
1084 unsigned long long ts;
1085
1086 idx = cur_ops->readlock();
1087 if (cur_ops->started)
1088 started = cur_ops->started();
1089 else
1090 started = cur_ops->completed();
1091 ts = rcu_trace_clock_local();
1092 p = rcu_dereference_check(rcu_torture_current,
1093 rcu_read_lock_bh_held() ||
1094 rcu_read_lock_sched_held() ||
1095 srcu_read_lock_held(srcu_ctlp) ||
1096 torturing_tasks());
1097 if (p == NULL) {
1098 /* Leave because rcu_torture_writer is not yet underway */
1099 cur_ops->readunlock(idx);
1100 return;
1101 }
1102 if (p->rtort_mbtest == 0)
1103 atomic_inc(&n_rcu_torture_mberror);
1104 spin_lock(&rand_lock);
1105 cur_ops->read_delay(&rand);
1106 n_rcu_torture_timers++;
1107 spin_unlock(&rand_lock);
1108 preempt_disable();
1109 pipe_count = p->rtort_pipe_count;
1110 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1111 /* Should not happen, but... */
1112 pipe_count = RCU_TORTURE_PIPE_LEN;
1113 }
1114 completed = cur_ops->completed();
1115 if (pipe_count > 1) {
1116 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1117 started, completed);
1118 rcu_ftrace_dump(DUMP_ALL);
1119 }
1120 __this_cpu_inc(rcu_torture_count[pipe_count]);
1121 completed = completed - started;
1122 if (cur_ops->started)
1123 completed++;
1124 if (completed > RCU_TORTURE_PIPE_LEN) {
1125 /* Should not happen, but... */
1126 completed = RCU_TORTURE_PIPE_LEN;
1127 }
1128 __this_cpu_inc(rcu_torture_batch[completed]);
1129 preempt_enable();
1130 cur_ops->readunlock(idx);
1131
1132 /* Test call_rcu() invocation from interrupt handler. */
1133 if (cur_ops->call) {
1134 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
1135
1136 if (rhp)
1137 cur_ops->call(rhp, rcu_torture_timer_cb);
1138 }
1139 }
1140
1141 /*
1142 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1143 * incrementing the corresponding element of the pipeline array. The
1144 * counter in the element should never be greater than 1, otherwise, the
1145 * RCU implementation is broken.
1146 */
1147 static int
1148 rcu_torture_reader(void *arg)
1149 {
1150 unsigned long started;
1151 unsigned long completed;
1152 int idx;
1153 DEFINE_TORTURE_RANDOM(rand);
1154 struct rcu_torture *p;
1155 int pipe_count;
1156 struct timer_list t;
1157 unsigned long long ts;
1158
1159 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1160 set_user_nice(current, MAX_NICE);
1161 if (irqreader && cur_ops->irq_capable)
1162 timer_setup_on_stack(&t, rcu_torture_timer, 0);
1163
1164 do {
1165 if (irqreader && cur_ops->irq_capable) {
1166 if (!timer_pending(&t))
1167 mod_timer(&t, jiffies + 1);
1168 }
1169 idx = cur_ops->readlock();
1170 if (cur_ops->started)
1171 started = cur_ops->started();
1172 else
1173 started = cur_ops->completed();
1174 ts = rcu_trace_clock_local();
1175 p = rcu_dereference_check(rcu_torture_current,
1176 rcu_read_lock_bh_held() ||
1177 rcu_read_lock_sched_held() ||
1178 srcu_read_lock_held(srcu_ctlp) ||
1179 torturing_tasks());
1180 if (p == NULL) {
1181 /* Wait for rcu_torture_writer to get underway */
1182 cur_ops->readunlock(idx);
1183 schedule_timeout_interruptible(HZ);
1184 continue;
1185 }
1186 if (p->rtort_mbtest == 0)
1187 atomic_inc(&n_rcu_torture_mberror);
1188 cur_ops->read_delay(&rand);
1189 preempt_disable();
1190 pipe_count = p->rtort_pipe_count;
1191 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1192 /* Should not happen, but... */
1193 pipe_count = RCU_TORTURE_PIPE_LEN;
1194 }
1195 completed = cur_ops->completed();
1196 if (pipe_count > 1) {
1197 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1198 ts, started, completed);
1199 rcu_ftrace_dump(DUMP_ALL);
1200 }
1201 __this_cpu_inc(rcu_torture_count[pipe_count]);
1202 completed = completed - started;
1203 if (cur_ops->started)
1204 completed++;
1205 if (completed > RCU_TORTURE_PIPE_LEN) {
1206 /* Should not happen, but... */
1207 completed = RCU_TORTURE_PIPE_LEN;
1208 }
1209 __this_cpu_inc(rcu_torture_batch[completed]);
1210 preempt_enable();
1211 cur_ops->readunlock(idx);
1212 stutter_wait("rcu_torture_reader");
1213 } while (!torture_must_stop());
1214 if (irqreader && cur_ops->irq_capable) {
1215 del_timer_sync(&t);
1216 destroy_timer_on_stack(&t);
1217 }
1218 torture_kthread_stopping("rcu_torture_reader");
1219 return 0;
1220 }
1221
1222 /*
1223 * Print torture statistics. Caller must ensure that there is only
1224 * one call to this function at a given time!!! This is normally
1225 * accomplished by relying on the module system to only have one copy
1226 * of the module loaded, and then by giving the rcu_torture_stats
1227 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1228 * thread is not running).
1229 */
1230 static void
1231 rcu_torture_stats_print(void)
1232 {
1233 int cpu;
1234 int i;
1235 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1236 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1237 static unsigned long rtcv_snap = ULONG_MAX;
1238 static bool splatted;
1239 struct task_struct *wtp;
1240
1241 for_each_possible_cpu(cpu) {
1242 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1243 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1244 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1245 }
1246 }
1247 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1248 if (pipesummary[i] != 0)
1249 break;
1250 }
1251
1252 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1253 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1254 rcu_torture_current,
1255 rcu_torture_current_version,
1256 list_empty(&rcu_torture_freelist),
1257 atomic_read(&n_rcu_torture_alloc),
1258 atomic_read(&n_rcu_torture_alloc_fail),
1259 atomic_read(&n_rcu_torture_free));
1260 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1261 atomic_read(&n_rcu_torture_mberror),
1262 n_rcu_torture_barrier_error,
1263 n_rcu_torture_boost_ktrerror,
1264 n_rcu_torture_boost_rterror);
1265 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1266 n_rcu_torture_boost_failure,
1267 n_rcu_torture_boosts,
1268 n_rcu_torture_timers);
1269 torture_onoff_stats();
1270 pr_cont("barrier: %ld/%ld:%ld ",
1271 n_barrier_successes,
1272 n_barrier_attempts,
1273 n_rcu_torture_barrier_error);
1274 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1275
1276 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1277 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1278 n_rcu_torture_barrier_error != 0 ||
1279 n_rcu_torture_boost_ktrerror != 0 ||
1280 n_rcu_torture_boost_rterror != 0 ||
1281 n_rcu_torture_boost_failure != 0 ||
1282 i > 1) {
1283 pr_cont("%s", "!!! ");
1284 atomic_inc(&n_rcu_torture_error);
1285 WARN_ON_ONCE(1);
1286 }
1287 pr_cont("Reader Pipe: ");
1288 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1289 pr_cont(" %ld", pipesummary[i]);
1290 pr_cont("\n");
1291
1292 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1293 pr_cont("Reader Batch: ");
1294 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1295 pr_cont(" %ld", batchsummary[i]);
1296 pr_cont("\n");
1297
1298 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1299 pr_cont("Free-Block Circulation: ");
1300 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1301 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1302 }
1303 pr_cont("\n");
1304
1305 if (cur_ops->stats)
1306 cur_ops->stats();
1307 if (rtcv_snap == rcu_torture_current_version &&
1308 rcu_torture_current != NULL) {
1309 int __maybe_unused flags = 0;
1310 unsigned long __maybe_unused gpnum = 0;
1311 unsigned long __maybe_unused completed = 0;
1312
1313 rcutorture_get_gp_data(cur_ops->ttype,
1314 &flags, &gpnum, &completed);
1315 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
1316 &flags, &gpnum, &completed);
1317 wtp = READ_ONCE(writer_task);
1318 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx cpu %d\n",
1319 rcu_torture_writer_state_getname(),
1320 rcu_torture_writer_state,
1321 gpnum, completed, flags,
1322 wtp == NULL ? ~0UL : wtp->state,
1323 wtp == NULL ? -1 : (int)task_cpu(wtp));
1324 if (!splatted && wtp) {
1325 sched_show_task(wtp);
1326 splatted = true;
1327 }
1328 show_rcu_gp_kthreads();
1329 rcu_ftrace_dump(DUMP_ALL);
1330 }
1331 rtcv_snap = rcu_torture_current_version;
1332 }
1333
1334 /*
1335 * Periodically prints torture statistics, if periodic statistics printing
1336 * was specified via the stat_interval module parameter.
1337 */
1338 static int
1339 rcu_torture_stats(void *arg)
1340 {
1341 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1342 do {
1343 schedule_timeout_interruptible(stat_interval * HZ);
1344 rcu_torture_stats_print();
1345 torture_shutdown_absorb("rcu_torture_stats");
1346 } while (!torture_must_stop());
1347 torture_kthread_stopping("rcu_torture_stats");
1348 return 0;
1349 }
1350
1351 static inline void
1352 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1353 {
1354 pr_alert("%s" TORTURE_FLAG
1355 "--- %s: nreaders=%d nfakewriters=%d "
1356 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1357 "shuffle_interval=%d stutter=%d irqreader=%d "
1358 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1359 "test_boost=%d/%d test_boost_interval=%d "
1360 "test_boost_duration=%d shutdown_secs=%d "
1361 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
1362 "n_barrier_cbs=%d "
1363 "onoff_interval=%d onoff_holdoff=%d\n",
1364 torture_type, tag, nrealreaders, nfakewriters,
1365 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1366 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1367 test_boost, cur_ops->can_boost,
1368 test_boost_interval, test_boost_duration, shutdown_secs,
1369 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
1370 n_barrier_cbs,
1371 onoff_interval, onoff_holdoff);
1372 }
1373
1374 static int rcutorture_booster_cleanup(unsigned int cpu)
1375 {
1376 struct task_struct *t;
1377
1378 if (boost_tasks[cpu] == NULL)
1379 return 0;
1380 mutex_lock(&boost_mutex);
1381 t = boost_tasks[cpu];
1382 boost_tasks[cpu] = NULL;
1383 mutex_unlock(&boost_mutex);
1384
1385 /* This must be outside of the mutex, otherwise deadlock! */
1386 torture_stop_kthread(rcu_torture_boost, t);
1387 return 0;
1388 }
1389
1390 static int rcutorture_booster_init(unsigned int cpu)
1391 {
1392 int retval;
1393
1394 if (boost_tasks[cpu] != NULL)
1395 return 0; /* Already created, nothing more to do. */
1396
1397 /* Don't allow time recalculation while creating a new task. */
1398 mutex_lock(&boost_mutex);
1399 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1400 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1401 cpu_to_node(cpu),
1402 "rcu_torture_boost");
1403 if (IS_ERR(boost_tasks[cpu])) {
1404 retval = PTR_ERR(boost_tasks[cpu]);
1405 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1406 n_rcu_torture_boost_ktrerror++;
1407 boost_tasks[cpu] = NULL;
1408 mutex_unlock(&boost_mutex);
1409 return retval;
1410 }
1411 kthread_bind(boost_tasks[cpu], cpu);
1412 wake_up_process(boost_tasks[cpu]);
1413 mutex_unlock(&boost_mutex);
1414 return 0;
1415 }
1416
1417 /*
1418 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1419 * induces a CPU stall for the time specified by stall_cpu.
1420 */
1421 static int rcu_torture_stall(void *args)
1422 {
1423 unsigned long stop_at;
1424
1425 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1426 if (stall_cpu_holdoff > 0) {
1427 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1428 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1429 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1430 }
1431 if (!kthread_should_stop()) {
1432 stop_at = get_seconds() + stall_cpu;
1433 /* RCU CPU stall is expected behavior in following code. */
1434 rcu_read_lock();
1435 if (stall_cpu_irqsoff)
1436 local_irq_disable();
1437 else
1438 preempt_disable();
1439 pr_alert("rcu_torture_stall start on CPU %d.\n",
1440 smp_processor_id());
1441 while (ULONG_CMP_LT(get_seconds(), stop_at))
1442 continue; /* Induce RCU CPU stall warning. */
1443 if (stall_cpu_irqsoff)
1444 local_irq_enable();
1445 else
1446 preempt_enable();
1447 rcu_read_unlock();
1448 pr_alert("rcu_torture_stall end.\n");
1449 }
1450 torture_shutdown_absorb("rcu_torture_stall");
1451 while (!kthread_should_stop())
1452 schedule_timeout_interruptible(10 * HZ);
1453 return 0;
1454 }
1455
1456 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1457 static int __init rcu_torture_stall_init(void)
1458 {
1459 if (stall_cpu <= 0)
1460 return 0;
1461 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1462 }
1463
1464 /* Callback function for RCU barrier testing. */
1465 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1466 {
1467 atomic_inc(&barrier_cbs_invoked);
1468 }
1469
1470 /* kthread function to register callbacks used to test RCU barriers. */
1471 static int rcu_torture_barrier_cbs(void *arg)
1472 {
1473 long myid = (long)arg;
1474 bool lastphase = 0;
1475 bool newphase;
1476 struct rcu_head rcu;
1477
1478 init_rcu_head_on_stack(&rcu);
1479 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1480 set_user_nice(current, MAX_NICE);
1481 do {
1482 wait_event(barrier_cbs_wq[myid],
1483 (newphase =
1484 smp_load_acquire(&barrier_phase)) != lastphase ||
1485 torture_must_stop());
1486 lastphase = newphase;
1487 if (torture_must_stop())
1488 break;
1489 /*
1490 * The above smp_load_acquire() ensures barrier_phase load
1491 * is ordered before the following ->call().
1492 */
1493 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1494 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1495 local_irq_enable();
1496 if (atomic_dec_and_test(&barrier_cbs_count))
1497 wake_up(&barrier_wq);
1498 } while (!torture_must_stop());
1499 if (cur_ops->cb_barrier != NULL)
1500 cur_ops->cb_barrier();
1501 destroy_rcu_head_on_stack(&rcu);
1502 torture_kthread_stopping("rcu_torture_barrier_cbs");
1503 return 0;
1504 }
1505
1506 /* kthread function to drive and coordinate RCU barrier testing. */
1507 static int rcu_torture_barrier(void *arg)
1508 {
1509 int i;
1510
1511 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1512 do {
1513 atomic_set(&barrier_cbs_invoked, 0);
1514 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1515 /* Ensure barrier_phase ordered after prior assignments. */
1516 smp_store_release(&barrier_phase, !barrier_phase);
1517 for (i = 0; i < n_barrier_cbs; i++)
1518 wake_up(&barrier_cbs_wq[i]);
1519 wait_event(barrier_wq,
1520 atomic_read(&barrier_cbs_count) == 0 ||
1521 torture_must_stop());
1522 if (torture_must_stop())
1523 break;
1524 n_barrier_attempts++;
1525 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1526 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1527 n_rcu_torture_barrier_error++;
1528 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1529 atomic_read(&barrier_cbs_invoked),
1530 n_barrier_cbs);
1531 WARN_ON_ONCE(1);
1532 }
1533 n_barrier_successes++;
1534 schedule_timeout_interruptible(HZ / 10);
1535 } while (!torture_must_stop());
1536 torture_kthread_stopping("rcu_torture_barrier");
1537 return 0;
1538 }
1539
1540 /* Initialize RCU barrier testing. */
1541 static int rcu_torture_barrier_init(void)
1542 {
1543 int i;
1544 int ret;
1545
1546 if (n_barrier_cbs <= 0)
1547 return 0;
1548 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1549 pr_alert("%s" TORTURE_FLAG
1550 " Call or barrier ops missing for %s,\n",
1551 torture_type, cur_ops->name);
1552 pr_alert("%s" TORTURE_FLAG
1553 " RCU barrier testing omitted from run.\n",
1554 torture_type);
1555 return 0;
1556 }
1557 atomic_set(&barrier_cbs_count, 0);
1558 atomic_set(&barrier_cbs_invoked, 0);
1559 barrier_cbs_tasks =
1560 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
1561 GFP_KERNEL);
1562 barrier_cbs_wq =
1563 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
1564 GFP_KERNEL);
1565 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1566 return -ENOMEM;
1567 for (i = 0; i < n_barrier_cbs; i++) {
1568 init_waitqueue_head(&barrier_cbs_wq[i]);
1569 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1570 (void *)(long)i,
1571 barrier_cbs_tasks[i]);
1572 if (ret)
1573 return ret;
1574 }
1575 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1576 }
1577
1578 /* Clean up after RCU barrier testing. */
1579 static void rcu_torture_barrier_cleanup(void)
1580 {
1581 int i;
1582
1583 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1584 if (barrier_cbs_tasks != NULL) {
1585 for (i = 0; i < n_barrier_cbs; i++)
1586 torture_stop_kthread(rcu_torture_barrier_cbs,
1587 barrier_cbs_tasks[i]);
1588 kfree(barrier_cbs_tasks);
1589 barrier_cbs_tasks = NULL;
1590 }
1591 if (barrier_cbs_wq != NULL) {
1592 kfree(barrier_cbs_wq);
1593 barrier_cbs_wq = NULL;
1594 }
1595 }
1596
1597 static enum cpuhp_state rcutor_hp;
1598
1599 static void
1600 rcu_torture_cleanup(void)
1601 {
1602 int i;
1603
1604 rcutorture_record_test_transition();
1605 if (torture_cleanup_begin()) {
1606 if (cur_ops->cb_barrier != NULL)
1607 cur_ops->cb_barrier();
1608 return;
1609 }
1610
1611 rcu_torture_barrier_cleanup();
1612 torture_stop_kthread(rcu_torture_stall, stall_task);
1613 torture_stop_kthread(rcu_torture_writer, writer_task);
1614
1615 if (reader_tasks) {
1616 for (i = 0; i < nrealreaders; i++)
1617 torture_stop_kthread(rcu_torture_reader,
1618 reader_tasks[i]);
1619 kfree(reader_tasks);
1620 }
1621 rcu_torture_current = NULL;
1622
1623 if (fakewriter_tasks) {
1624 for (i = 0; i < nfakewriters; i++) {
1625 torture_stop_kthread(rcu_torture_fakewriter,
1626 fakewriter_tasks[i]);
1627 }
1628 kfree(fakewriter_tasks);
1629 fakewriter_tasks = NULL;
1630 }
1631
1632 torture_stop_kthread(rcu_torture_stats, stats_task);
1633 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1634 for (i = 0; i < ncbflooders; i++)
1635 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1636 if ((test_boost == 1 && cur_ops->can_boost) ||
1637 test_boost == 2)
1638 cpuhp_remove_state(rcutor_hp);
1639
1640 /*
1641 * Wait for all RCU callbacks to fire, then do flavor-specific
1642 * cleanup operations.
1643 */
1644 if (cur_ops->cb_barrier != NULL)
1645 cur_ops->cb_barrier();
1646 if (cur_ops->cleanup != NULL)
1647 cur_ops->cleanup();
1648
1649 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1650
1651 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1652 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1653 else if (torture_onoff_failures())
1654 rcu_torture_print_module_parms(cur_ops,
1655 "End of test: RCU_HOTPLUG");
1656 else
1657 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1658 torture_cleanup_end();
1659 }
1660
1661 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1662 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1663 {
1664 }
1665
1666 static void rcu_torture_err_cb(struct rcu_head *rhp)
1667 {
1668 /*
1669 * This -might- happen due to race conditions, but is unlikely.
1670 * The scenario that leads to this happening is that the
1671 * first of the pair of duplicate callbacks is queued,
1672 * someone else starts a grace period that includes that
1673 * callback, then the second of the pair must wait for the
1674 * next grace period. Unlikely, but can happen. If it
1675 * does happen, the debug-objects subsystem won't have splatted.
1676 */
1677 pr_alert("rcutorture: duplicated callback was invoked.\n");
1678 }
1679 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1680
1681 /*
1682 * Verify that double-free causes debug-objects to complain, but only
1683 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1684 * cannot be carried out.
1685 */
1686 static void rcu_test_debug_objects(void)
1687 {
1688 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1689 struct rcu_head rh1;
1690 struct rcu_head rh2;
1691
1692 init_rcu_head_on_stack(&rh1);
1693 init_rcu_head_on_stack(&rh2);
1694 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1695
1696 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1697 preempt_disable(); /* Prevent preemption from interrupting test. */
1698 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1699 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1700 local_irq_disable(); /* Make it harder to start a new grace period. */
1701 call_rcu(&rh2, rcu_torture_leak_cb);
1702 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1703 local_irq_enable();
1704 rcu_read_unlock();
1705 preempt_enable();
1706
1707 /* Wait for them all to get done so we can safely return. */
1708 rcu_barrier();
1709 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1710 destroy_rcu_head_on_stack(&rh1);
1711 destroy_rcu_head_on_stack(&rh2);
1712 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1713 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1714 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1715 }
1716
1717 static int __init
1718 rcu_torture_init(void)
1719 {
1720 int i;
1721 int cpu;
1722 int firsterr = 0;
1723 static struct rcu_torture_ops *torture_ops[] = {
1724 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1725 &sched_ops, &tasks_ops,
1726 };
1727
1728 if (!torture_init_begin(torture_type, verbose))
1729 return -EBUSY;
1730
1731 /* Process args and tell the world that the torturer is on the job. */
1732 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1733 cur_ops = torture_ops[i];
1734 if (strcmp(torture_type, cur_ops->name) == 0)
1735 break;
1736 }
1737 if (i == ARRAY_SIZE(torture_ops)) {
1738 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1739 torture_type);
1740 pr_alert("rcu-torture types:");
1741 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1742 pr_alert(" %s", torture_ops[i]->name);
1743 pr_alert("\n");
1744 firsterr = -EINVAL;
1745 goto unwind;
1746 }
1747 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1748 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1749 fqs_duration = 0;
1750 }
1751 if (cur_ops->init)
1752 cur_ops->init();
1753
1754 if (nreaders >= 0) {
1755 nrealreaders = nreaders;
1756 } else {
1757 nrealreaders = num_online_cpus() - 2 - nreaders;
1758 if (nrealreaders <= 0)
1759 nrealreaders = 1;
1760 }
1761 rcu_torture_print_module_parms(cur_ops, "Start of test");
1762
1763 /* Set up the freelist. */
1764
1765 INIT_LIST_HEAD(&rcu_torture_freelist);
1766 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1767 rcu_tortures[i].rtort_mbtest = 0;
1768 list_add_tail(&rcu_tortures[i].rtort_free,
1769 &rcu_torture_freelist);
1770 }
1771
1772 /* Initialize the statistics so that each run gets its own numbers. */
1773
1774 rcu_torture_current = NULL;
1775 rcu_torture_current_version = 0;
1776 atomic_set(&n_rcu_torture_alloc, 0);
1777 atomic_set(&n_rcu_torture_alloc_fail, 0);
1778 atomic_set(&n_rcu_torture_free, 0);
1779 atomic_set(&n_rcu_torture_mberror, 0);
1780 atomic_set(&n_rcu_torture_error, 0);
1781 n_rcu_torture_barrier_error = 0;
1782 n_rcu_torture_boost_ktrerror = 0;
1783 n_rcu_torture_boost_rterror = 0;
1784 n_rcu_torture_boost_failure = 0;
1785 n_rcu_torture_boosts = 0;
1786 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1787 atomic_set(&rcu_torture_wcount[i], 0);
1788 for_each_possible_cpu(cpu) {
1789 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1790 per_cpu(rcu_torture_count, cpu)[i] = 0;
1791 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1792 }
1793 }
1794
1795 /* Start up the kthreads. */
1796
1797 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1798 writer_task);
1799 if (firsterr)
1800 goto unwind;
1801 if (nfakewriters > 0) {
1802 fakewriter_tasks = kzalloc(nfakewriters *
1803 sizeof(fakewriter_tasks[0]),
1804 GFP_KERNEL);
1805 if (fakewriter_tasks == NULL) {
1806 VERBOSE_TOROUT_ERRSTRING("out of memory");
1807 firsterr = -ENOMEM;
1808 goto unwind;
1809 }
1810 }
1811 for (i = 0; i < nfakewriters; i++) {
1812 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1813 NULL, fakewriter_tasks[i]);
1814 if (firsterr)
1815 goto unwind;
1816 }
1817 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
1818 GFP_KERNEL);
1819 if (reader_tasks == NULL) {
1820 VERBOSE_TOROUT_ERRSTRING("out of memory");
1821 firsterr = -ENOMEM;
1822 goto unwind;
1823 }
1824 for (i = 0; i < nrealreaders; i++) {
1825 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1826 reader_tasks[i]);
1827 if (firsterr)
1828 goto unwind;
1829 }
1830 if (stat_interval > 0) {
1831 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1832 stats_task);
1833 if (firsterr)
1834 goto unwind;
1835 }
1836 if (test_no_idle_hz && shuffle_interval > 0) {
1837 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1838 if (firsterr)
1839 goto unwind;
1840 }
1841 if (stutter < 0)
1842 stutter = 0;
1843 if (stutter) {
1844 firsterr = torture_stutter_init(stutter * HZ);
1845 if (firsterr)
1846 goto unwind;
1847 }
1848 if (fqs_duration < 0)
1849 fqs_duration = 0;
1850 if (fqs_duration) {
1851 /* Create the fqs thread */
1852 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1853 fqs_task);
1854 if (firsterr)
1855 goto unwind;
1856 }
1857 if (test_boost_interval < 1)
1858 test_boost_interval = 1;
1859 if (test_boost_duration < 2)
1860 test_boost_duration = 2;
1861 if ((test_boost == 1 && cur_ops->can_boost) ||
1862 test_boost == 2) {
1863
1864 boost_starttime = jiffies + test_boost_interval * HZ;
1865
1866 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
1867 rcutorture_booster_init,
1868 rcutorture_booster_cleanup);
1869 if (firsterr < 0)
1870 goto unwind;
1871 rcutor_hp = firsterr;
1872 }
1873 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1874 if (firsterr)
1875 goto unwind;
1876 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1877 if (firsterr)
1878 goto unwind;
1879 firsterr = rcu_torture_stall_init();
1880 if (firsterr)
1881 goto unwind;
1882 firsterr = rcu_torture_barrier_init();
1883 if (firsterr)
1884 goto unwind;
1885 if (object_debug)
1886 rcu_test_debug_objects();
1887 if (cbflood_n_burst > 0) {
1888 /* Create the cbflood threads */
1889 ncbflooders = (num_online_cpus() + 3) / 4;
1890 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1891 GFP_KERNEL);
1892 if (!cbflood_task) {
1893 VERBOSE_TOROUT_ERRSTRING("out of memory");
1894 firsterr = -ENOMEM;
1895 goto unwind;
1896 }
1897 for (i = 0; i < ncbflooders; i++) {
1898 firsterr = torture_create_kthread(rcu_torture_cbflood,
1899 NULL,
1900 cbflood_task[i]);
1901 if (firsterr)
1902 goto unwind;
1903 }
1904 }
1905 rcutorture_record_test_transition();
1906 torture_init_end();
1907 return 0;
1908
1909 unwind:
1910 torture_init_end();
1911 rcu_torture_cleanup();
1912 return firsterr;
1913 }
1914
1915 module_init(rcu_torture_init);
1916 module_exit(rcu_torture_cleanup);
Linux with added FPC-III support