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udl-kms: avoid prefetch
[linux/fpc-iii.git] / kernel / rcu / rcutorture.c
blob42fcb7f05fac27dc6785fab9955db4f3cc2a8efc
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 static DEFINE_TORTURE_RANDOM(rand);
597
598 if (torture_random(&rand) & 0x800)
599 cleanup_srcu_struct(&srcu_ctld);
600 else
601 cleanup_srcu_struct_quiesced(&srcu_ctld);
602 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
603 }
604
605 /* As above, but dynamically allocated. */
606 static struct rcu_torture_ops srcud_ops = {
607 .ttype = SRCU_FLAVOR,
608 .init = srcu_torture_init,
609 .cleanup = srcu_torture_cleanup,
610 .readlock = srcu_torture_read_lock,
611 .read_delay = srcu_read_delay,
612 .readunlock = srcu_torture_read_unlock,
613 .started = NULL,
614 .completed = srcu_torture_completed,
615 .deferred_free = srcu_torture_deferred_free,
616 .sync = srcu_torture_synchronize,
617 .exp_sync = srcu_torture_synchronize_expedited,
618 .call = srcu_torture_call,
619 .cb_barrier = srcu_torture_barrier,
620 .stats = srcu_torture_stats,
621 .irq_capable = 1,
622 .name = "srcud"
623 };
624
625 /*
626 * Definitions for sched torture testing.
627 */
628
629 static int sched_torture_read_lock(void)
630 {
631 preempt_disable();
632 return 0;
633 }
634
635 static void sched_torture_read_unlock(int idx)
636 {
637 preempt_enable();
638 }
639
640 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
641 {
642 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
643 }
644
645 static struct rcu_torture_ops sched_ops = {
646 .ttype = RCU_SCHED_FLAVOR,
647 .init = rcu_sync_torture_init,
648 .readlock = sched_torture_read_lock,
649 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
650 .readunlock = sched_torture_read_unlock,
651 .started = rcu_batches_started_sched,
652 .completed = rcu_batches_completed_sched,
653 .deferred_free = rcu_sched_torture_deferred_free,
654 .sync = synchronize_sched,
655 .exp_sync = synchronize_sched_expedited,
656 .get_state = get_state_synchronize_sched,
657 .cond_sync = cond_synchronize_sched,
658 .call = call_rcu_sched,
659 .cb_barrier = rcu_barrier_sched,
660 .fqs = rcu_sched_force_quiescent_state,
661 .stats = NULL,
662 .irq_capable = 1,
663 .name = "sched"
664 };
665
666 /*
667 * Definitions for RCU-tasks torture testing.
668 */
669
670 static int tasks_torture_read_lock(void)
671 {
672 return 0;
673 }
674
675 static void tasks_torture_read_unlock(int idx)
676 {
677 }
678
679 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
680 {
681 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
682 }
683
684 static struct rcu_torture_ops tasks_ops = {
685 .ttype = RCU_TASKS_FLAVOR,
686 .init = rcu_sync_torture_init,
687 .readlock = tasks_torture_read_lock,
688 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
689 .readunlock = tasks_torture_read_unlock,
690 .started = rcu_no_completed,
691 .completed = rcu_no_completed,
692 .deferred_free = rcu_tasks_torture_deferred_free,
693 .sync = synchronize_rcu_tasks,
694 .exp_sync = synchronize_rcu_tasks,
695 .call = call_rcu_tasks,
696 .cb_barrier = rcu_barrier_tasks,
697 .fqs = NULL,
698 .stats = NULL,
699 .irq_capable = 1,
700 .name = "tasks"
701 };
702
703 static bool __maybe_unused torturing_tasks(void)
704 {
705 return cur_ops == &tasks_ops;
706 }
707
708 /*
709 * RCU torture priority-boost testing. Runs one real-time thread per
710 * CPU for moderate bursts, repeatedly registering RCU callbacks and
711 * spinning waiting for them to be invoked. If a given callback takes
712 * too long to be invoked, we assume that priority inversion has occurred.
713 */
714
715 struct rcu_boost_inflight {
716 struct rcu_head rcu;
717 int inflight;
718 };
719
720 static void rcu_torture_boost_cb(struct rcu_head *head)
721 {
722 struct rcu_boost_inflight *rbip =
723 container_of(head, struct rcu_boost_inflight, rcu);
724
725 /* Ensure RCU-core accesses precede clearing ->inflight */
726 smp_store_release(&rbip->inflight, 0);
727 }
728
729 static int rcu_torture_boost(void *arg)
730 {
731 unsigned long call_rcu_time;
732 unsigned long endtime;
733 unsigned long oldstarttime;
734 struct rcu_boost_inflight rbi = { .inflight = 0 };
735 struct sched_param sp;
736
737 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
738
739 /* Set real-time priority. */
740 sp.sched_priority = 1;
741 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
742 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
743 n_rcu_torture_boost_rterror++;
744 }
745
746 init_rcu_head_on_stack(&rbi.rcu);
747 /* Each pass through the following loop does one boost-test cycle. */
748 do {
749 /* Wait for the next test interval. */
750 oldstarttime = boost_starttime;
751 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
752 schedule_timeout_interruptible(oldstarttime - jiffies);
753 stutter_wait("rcu_torture_boost");
754 if (torture_must_stop())
755 goto checkwait;
756 }
757
758 /* Do one boost-test interval. */
759 endtime = oldstarttime + test_boost_duration * HZ;
760 call_rcu_time = jiffies;
761 while (ULONG_CMP_LT(jiffies, endtime)) {
762 /* If we don't have a callback in flight, post one. */
763 if (!smp_load_acquire(&rbi.inflight)) {
764 /* RCU core before ->inflight = 1. */
765 smp_store_release(&rbi.inflight, 1);
766 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
767 if (jiffies - call_rcu_time >
768 test_boost_duration * HZ - HZ / 2) {
769 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
770 n_rcu_torture_boost_failure++;
771 }
772 call_rcu_time = jiffies;
773 }
774 stutter_wait("rcu_torture_boost");
775 if (torture_must_stop())
776 goto checkwait;
777 }
778
779 /*
780 * Set the start time of the next test interval.
781 * Yes, this is vulnerable to long delays, but such
782 * delays simply cause a false negative for the next
783 * interval. Besides, we are running at RT priority,
784 * so delays should be relatively rare.
785 */
786 while (oldstarttime == boost_starttime &&
787 !kthread_should_stop()) {
788 if (mutex_trylock(&boost_mutex)) {
789 boost_starttime = jiffies +
790 test_boost_interval * HZ;
791 n_rcu_torture_boosts++;
792 mutex_unlock(&boost_mutex);
793 break;
794 }
795 schedule_timeout_uninterruptible(1);
796 }
797
798 /* Go do the stutter. */
799 checkwait: stutter_wait("rcu_torture_boost");
800 } while (!torture_must_stop());
801
802 /* Clean up and exit. */
803 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
804 torture_shutdown_absorb("rcu_torture_boost");
805 schedule_timeout_uninterruptible(1);
806 }
807 destroy_rcu_head_on_stack(&rbi.rcu);
808 torture_kthread_stopping("rcu_torture_boost");
809 return 0;
810 }
811
812 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
813 {
814 }
815
816 /*
817 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
818 * to call_rcu() or analogous, increasing the probability of occurrence
819 * of callback-overflow corner cases.
820 */
821 static int
822 rcu_torture_cbflood(void *arg)
823 {
824 int err = 1;
825 int i;
826 int j;
827 struct rcu_head *rhp;
828
829 if (cbflood_n_per_burst > 0 &&
830 cbflood_inter_holdoff > 0 &&
831 cbflood_intra_holdoff > 0 &&
832 cur_ops->call &&
833 cur_ops->cb_barrier) {
834 rhp = vmalloc(array3_size(cbflood_n_burst,
835 cbflood_n_per_burst,
836 sizeof(*rhp)));
837 err = !rhp;
838 }
839 if (err) {
840 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
841 goto wait_for_stop;
842 }
843 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
844 do {
845 schedule_timeout_interruptible(cbflood_inter_holdoff);
846 atomic_long_inc(&n_cbfloods);
847 WARN_ON(signal_pending(current));
848 for (i = 0; i < cbflood_n_burst; i++) {
849 for (j = 0; j < cbflood_n_per_burst; j++) {
850 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
851 rcu_torture_cbflood_cb);
852 }
853 schedule_timeout_interruptible(cbflood_intra_holdoff);
854 WARN_ON(signal_pending(current));
855 }
856 cur_ops->cb_barrier();
857 stutter_wait("rcu_torture_cbflood");
858 } while (!torture_must_stop());
859 vfree(rhp);
860 wait_for_stop:
861 torture_kthread_stopping("rcu_torture_cbflood");
862 return 0;
863 }
864
865 /*
866 * RCU torture force-quiescent-state kthread. Repeatedly induces
867 * bursts of calls to force_quiescent_state(), increasing the probability
868 * of occurrence of some important types of race conditions.
869 */
870 static int
871 rcu_torture_fqs(void *arg)
872 {
873 unsigned long fqs_resume_time;
874 int fqs_burst_remaining;
875
876 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
877 do {
878 fqs_resume_time = jiffies + fqs_stutter * HZ;
879 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
880 !kthread_should_stop()) {
881 schedule_timeout_interruptible(1);
882 }
883 fqs_burst_remaining = fqs_duration;
884 while (fqs_burst_remaining > 0 &&
885 !kthread_should_stop()) {
886 cur_ops->fqs();
887 udelay(fqs_holdoff);
888 fqs_burst_remaining -= fqs_holdoff;
889 }
890 stutter_wait("rcu_torture_fqs");
891 } while (!torture_must_stop());
892 torture_kthread_stopping("rcu_torture_fqs");
893 return 0;
894 }
895
896 /*
897 * RCU torture writer kthread. Repeatedly substitutes a new structure
898 * for that pointed to by rcu_torture_current, freeing the old structure
899 * after a series of grace periods (the "pipeline").
900 */
901 static int
902 rcu_torture_writer(void *arg)
903 {
904 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
905 int expediting = 0;
906 unsigned long gp_snap;
907 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
908 bool gp_sync1 = gp_sync;
909 int i;
910 struct rcu_torture *rp;
911 struct rcu_torture *old_rp;
912 static DEFINE_TORTURE_RANDOM(rand);
913 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
914 RTWS_COND_GET, RTWS_SYNC };
915 int nsynctypes = 0;
916
917 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
918 if (!can_expedite)
919 pr_alert("%s" TORTURE_FLAG
920 " GP expediting controlled from boot/sysfs for %s.\n",
921 torture_type, cur_ops->name);
922
923 /* Initialize synctype[] array. If none set, take default. */
924 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
925 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
926 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) {
927 synctype[nsynctypes++] = RTWS_COND_GET;
928 pr_info("%s: Testing conditional GPs.\n", __func__);
929 } else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) {
930 pr_alert("%s: gp_cond without primitives.\n", __func__);
931 }
932 if (gp_exp1 && cur_ops->exp_sync) {
933 synctype[nsynctypes++] = RTWS_EXP_SYNC;
934 pr_info("%s: Testing expedited GPs.\n", __func__);
935 } else if (gp_exp && !cur_ops->exp_sync) {
936 pr_alert("%s: gp_exp without primitives.\n", __func__);
937 }
938 if (gp_normal1 && cur_ops->deferred_free) {
939 synctype[nsynctypes++] = RTWS_DEF_FREE;
940 pr_info("%s: Testing asynchronous GPs.\n", __func__);
941 } else if (gp_normal && !cur_ops->deferred_free) {
942 pr_alert("%s: gp_normal without primitives.\n", __func__);
943 }
944 if (gp_sync1 && cur_ops->sync) {
945 synctype[nsynctypes++] = RTWS_SYNC;
946 pr_info("%s: Testing normal GPs.\n", __func__);
947 } else if (gp_sync && !cur_ops->sync) {
948 pr_alert("%s: gp_sync without primitives.\n", __func__);
949 }
950 if (WARN_ONCE(nsynctypes == 0,
951 "rcu_torture_writer: No update-side primitives.\n")) {
952 /*
953 * No updates primitives, so don't try updating.
954 * The resulting test won't be testing much, hence the
955 * above WARN_ONCE().
956 */
957 rcu_torture_writer_state = RTWS_STOPPING;
958 torture_kthread_stopping("rcu_torture_writer");
959 }
960
961 do {
962 rcu_torture_writer_state = RTWS_FIXED_DELAY;
963 schedule_timeout_uninterruptible(1);
964 rp = rcu_torture_alloc();
965 if (rp == NULL)
966 continue;
967 rp->rtort_pipe_count = 0;
968 rcu_torture_writer_state = RTWS_DELAY;
969 udelay(torture_random(&rand) & 0x3ff);
970 rcu_torture_writer_state = RTWS_REPLACE;
971 old_rp = rcu_dereference_check(rcu_torture_current,
972 current == writer_task);
973 rp->rtort_mbtest = 1;
974 rcu_assign_pointer(rcu_torture_current, rp);
975 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
976 if (old_rp) {
977 i = old_rp->rtort_pipe_count;
978 if (i > RCU_TORTURE_PIPE_LEN)
979 i = RCU_TORTURE_PIPE_LEN;
980 atomic_inc(&rcu_torture_wcount[i]);
981 old_rp->rtort_pipe_count++;
982 switch (synctype[torture_random(&rand) % nsynctypes]) {
983 case RTWS_DEF_FREE:
984 rcu_torture_writer_state = RTWS_DEF_FREE;
985 cur_ops->deferred_free(old_rp);
986 break;
987 case RTWS_EXP_SYNC:
988 rcu_torture_writer_state = RTWS_EXP_SYNC;
989 cur_ops->exp_sync();
990 rcu_torture_pipe_update(old_rp);
991 break;
992 case RTWS_COND_GET:
993 rcu_torture_writer_state = RTWS_COND_GET;
994 gp_snap = cur_ops->get_state();
995 i = torture_random(&rand) % 16;
996 if (i != 0)
997 schedule_timeout_interruptible(i);
998 udelay(torture_random(&rand) % 1000);
999 rcu_torture_writer_state = RTWS_COND_SYNC;
1000 cur_ops->cond_sync(gp_snap);
1001 rcu_torture_pipe_update(old_rp);
1002 break;
1003 case RTWS_SYNC:
1004 rcu_torture_writer_state = RTWS_SYNC;
1005 cur_ops->sync();
1006 rcu_torture_pipe_update(old_rp);
1007 break;
1008 default:
1009 WARN_ON_ONCE(1);
1010 break;
1011 }
1012 }
1013 rcutorture_record_progress(++rcu_torture_current_version);
1014 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1015 if (can_expedite &&
1016 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1017 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1018 if (expediting >= 0)
1019 rcu_expedite_gp();
1020 else
1021 rcu_unexpedite_gp();
1022 if (++expediting > 3)
1023 expediting = -expediting;
1024 } else if (!can_expedite) { /* Disabled during boot, recheck. */
1025 can_expedite = !rcu_gp_is_expedited() &&
1026 !rcu_gp_is_normal();
1027 }
1028 rcu_torture_writer_state = RTWS_STUTTER;
1029 stutter_wait("rcu_torture_writer");
1030 } while (!torture_must_stop());
1031 /* Reset expediting back to unexpedited. */
1032 if (expediting > 0)
1033 expediting = -expediting;
1034 while (can_expedite && expediting++ < 0)
1035 rcu_unexpedite_gp();
1036 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1037 if (!can_expedite)
1038 pr_alert("%s" TORTURE_FLAG
1039 " Dynamic grace-period expediting was disabled.\n",
1040 torture_type);
1041 rcu_torture_writer_state = RTWS_STOPPING;
1042 torture_kthread_stopping("rcu_torture_writer");
1043 return 0;
1044 }
1045
1046 /*
1047 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1048 * delay between calls.
1049 */
1050 static int
1051 rcu_torture_fakewriter(void *arg)
1052 {
1053 DEFINE_TORTURE_RANDOM(rand);
1054
1055 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1056 set_user_nice(current, MAX_NICE);
1057
1058 do {
1059 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1060 udelay(torture_random(&rand) & 0x3ff);
1061 if (cur_ops->cb_barrier != NULL &&
1062 torture_random(&rand) % (nfakewriters * 8) == 0) {
1063 cur_ops->cb_barrier();
1064 } else if (gp_normal == gp_exp) {
1065 if (cur_ops->sync && torture_random(&rand) & 0x80)
1066 cur_ops->sync();
1067 else if (cur_ops->exp_sync)
1068 cur_ops->exp_sync();
1069 } else if (gp_normal && cur_ops->sync) {
1070 cur_ops->sync();
1071 } else if (cur_ops->exp_sync) {
1072 cur_ops->exp_sync();
1073 }
1074 stutter_wait("rcu_torture_fakewriter");
1075 } while (!torture_must_stop());
1076
1077 torture_kthread_stopping("rcu_torture_fakewriter");
1078 return 0;
1079 }
1080
1081 static void rcu_torture_timer_cb(struct rcu_head *rhp)
1082 {
1083 kfree(rhp);
1084 }
1085
1086 /*
1087 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1088 * incrementing the corresponding element of the pipeline array. The
1089 * counter in the element should never be greater than 1, otherwise, the
1090 * RCU implementation is broken.
1091 */
1092 static void rcu_torture_timer(struct timer_list *unused)
1093 {
1094 int idx;
1095 unsigned long started;
1096 unsigned long completed;
1097 static DEFINE_TORTURE_RANDOM(rand);
1098 static DEFINE_SPINLOCK(rand_lock);
1099 struct rcu_torture *p;
1100 int pipe_count;
1101 unsigned long long ts;
1102
1103 idx = cur_ops->readlock();
1104 if (cur_ops->started)
1105 started = cur_ops->started();
1106 else
1107 started = cur_ops->completed();
1108 ts = rcu_trace_clock_local();
1109 p = rcu_dereference_check(rcu_torture_current,
1110 rcu_read_lock_bh_held() ||
1111 rcu_read_lock_sched_held() ||
1112 srcu_read_lock_held(srcu_ctlp) ||
1113 torturing_tasks());
1114 if (p == NULL) {
1115 /* Leave because rcu_torture_writer is not yet underway */
1116 cur_ops->readunlock(idx);
1117 return;
1118 }
1119 if (p->rtort_mbtest == 0)
1120 atomic_inc(&n_rcu_torture_mberror);
1121 spin_lock(&rand_lock);
1122 cur_ops->read_delay(&rand);
1123 n_rcu_torture_timers++;
1124 spin_unlock(&rand_lock);
1125 preempt_disable();
1126 pipe_count = p->rtort_pipe_count;
1127 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1128 /* Should not happen, but... */
1129 pipe_count = RCU_TORTURE_PIPE_LEN;
1130 }
1131 completed = cur_ops->completed();
1132 if (pipe_count > 1) {
1133 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1134 started, completed);
1135 rcu_ftrace_dump(DUMP_ALL);
1136 }
1137 __this_cpu_inc(rcu_torture_count[pipe_count]);
1138 completed = completed - started;
1139 if (cur_ops->started)
1140 completed++;
1141 if (completed > RCU_TORTURE_PIPE_LEN) {
1142 /* Should not happen, but... */
1143 completed = RCU_TORTURE_PIPE_LEN;
1144 }
1145 __this_cpu_inc(rcu_torture_batch[completed]);
1146 preempt_enable();
1147 cur_ops->readunlock(idx);
1148
1149 /* Test call_rcu() invocation from interrupt handler. */
1150 if (cur_ops->call) {
1151 struct rcu_head *rhp = kmalloc(sizeof(*rhp), GFP_NOWAIT);
1152
1153 if (rhp)
1154 cur_ops->call(rhp, rcu_torture_timer_cb);
1155 }
1156 }
1157
1158 /*
1159 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1160 * incrementing the corresponding element of the pipeline array. The
1161 * counter in the element should never be greater than 1, otherwise, the
1162 * RCU implementation is broken.
1163 */
1164 static int
1165 rcu_torture_reader(void *arg)
1166 {
1167 unsigned long started;
1168 unsigned long completed;
1169 int idx;
1170 DEFINE_TORTURE_RANDOM(rand);
1171 struct rcu_torture *p;
1172 int pipe_count;
1173 struct timer_list t;
1174 unsigned long long ts;
1175
1176 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1177 set_user_nice(current, MAX_NICE);
1178 if (irqreader && cur_ops->irq_capable)
1179 timer_setup_on_stack(&t, rcu_torture_timer, 0);
1180
1181 do {
1182 if (irqreader && cur_ops->irq_capable) {
1183 if (!timer_pending(&t))
1184 mod_timer(&t, jiffies + 1);
1185 }
1186 idx = cur_ops->readlock();
1187 if (cur_ops->started)
1188 started = cur_ops->started();
1189 else
1190 started = cur_ops->completed();
1191 ts = rcu_trace_clock_local();
1192 p = rcu_dereference_check(rcu_torture_current,
1193 rcu_read_lock_bh_held() ||
1194 rcu_read_lock_sched_held() ||
1195 srcu_read_lock_held(srcu_ctlp) ||
1196 torturing_tasks());
1197 if (p == NULL) {
1198 /* Wait for rcu_torture_writer to get underway */
1199 cur_ops->readunlock(idx);
1200 schedule_timeout_interruptible(HZ);
1201 continue;
1202 }
1203 if (p->rtort_mbtest == 0)
1204 atomic_inc(&n_rcu_torture_mberror);
1205 cur_ops->read_delay(&rand);
1206 preempt_disable();
1207 pipe_count = p->rtort_pipe_count;
1208 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1209 /* Should not happen, but... */
1210 pipe_count = RCU_TORTURE_PIPE_LEN;
1211 }
1212 completed = cur_ops->completed();
1213 if (pipe_count > 1) {
1214 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1215 ts, started, completed);
1216 rcu_ftrace_dump(DUMP_ALL);
1217 }
1218 __this_cpu_inc(rcu_torture_count[pipe_count]);
1219 completed = completed - started;
1220 if (cur_ops->started)
1221 completed++;
1222 if (completed > RCU_TORTURE_PIPE_LEN) {
1223 /* Should not happen, but... */
1224 completed = RCU_TORTURE_PIPE_LEN;
1225 }
1226 __this_cpu_inc(rcu_torture_batch[completed]);
1227 preempt_enable();
1228 cur_ops->readunlock(idx);
1229 stutter_wait("rcu_torture_reader");
1230 } while (!torture_must_stop());
1231 if (irqreader && cur_ops->irq_capable) {
1232 del_timer_sync(&t);
1233 destroy_timer_on_stack(&t);
1234 }
1235 torture_kthread_stopping("rcu_torture_reader");
1236 return 0;
1237 }
1238
1239 /*
1240 * Print torture statistics. Caller must ensure that there is only
1241 * one call to this function at a given time!!! This is normally
1242 * accomplished by relying on the module system to only have one copy
1243 * of the module loaded, and then by giving the rcu_torture_stats
1244 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1245 * thread is not running).
1246 */
1247 static void
1248 rcu_torture_stats_print(void)
1249 {
1250 int cpu;
1251 int i;
1252 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1253 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1254 static unsigned long rtcv_snap = ULONG_MAX;
1255 static bool splatted;
1256 struct task_struct *wtp;
1257
1258 for_each_possible_cpu(cpu) {
1259 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1260 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1261 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1262 }
1263 }
1264 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1265 if (pipesummary[i] != 0)
1266 break;
1267 }
1268
1269 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1270 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1271 rcu_torture_current,
1272 rcu_torture_current_version,
1273 list_empty(&rcu_torture_freelist),
1274 atomic_read(&n_rcu_torture_alloc),
1275 atomic_read(&n_rcu_torture_alloc_fail),
1276 atomic_read(&n_rcu_torture_free));
1277 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1278 atomic_read(&n_rcu_torture_mberror),
1279 n_rcu_torture_barrier_error,
1280 n_rcu_torture_boost_ktrerror,
1281 n_rcu_torture_boost_rterror);
1282 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1283 n_rcu_torture_boost_failure,
1284 n_rcu_torture_boosts,
1285 n_rcu_torture_timers);
1286 torture_onoff_stats();
1287 pr_cont("barrier: %ld/%ld:%ld ",
1288 n_barrier_successes,
1289 n_barrier_attempts,
1290 n_rcu_torture_barrier_error);
1291 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1292
1293 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1294 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1295 n_rcu_torture_barrier_error != 0 ||
1296 n_rcu_torture_boost_ktrerror != 0 ||
1297 n_rcu_torture_boost_rterror != 0 ||
1298 n_rcu_torture_boost_failure != 0 ||
1299 i > 1) {
1300 pr_cont("%s", "!!! ");
1301 atomic_inc(&n_rcu_torture_error);
1302 WARN_ON_ONCE(1);
1303 }
1304 pr_cont("Reader Pipe: ");
1305 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1306 pr_cont(" %ld", pipesummary[i]);
1307 pr_cont("\n");
1308
1309 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1310 pr_cont("Reader Batch: ");
1311 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1312 pr_cont(" %ld", batchsummary[i]);
1313 pr_cont("\n");
1314
1315 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1316 pr_cont("Free-Block Circulation: ");
1317 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1318 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1319 }
1320 pr_cont("\n");
1321
1322 if (cur_ops->stats)
1323 cur_ops->stats();
1324 if (rtcv_snap == rcu_torture_current_version &&
1325 rcu_torture_current != NULL) {
1326 int __maybe_unused flags = 0;
1327 unsigned long __maybe_unused gpnum = 0;
1328 unsigned long __maybe_unused completed = 0;
1329
1330 rcutorture_get_gp_data(cur_ops->ttype,
1331 &flags, &gpnum, &completed);
1332 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
1333 &flags, &gpnum, &completed);
1334 wtp = READ_ONCE(writer_task);
1335 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx cpu %d\n",
1336 rcu_torture_writer_state_getname(),
1337 rcu_torture_writer_state,
1338 gpnum, completed, flags,
1339 wtp == NULL ? ~0UL : wtp->state,
1340 wtp == NULL ? -1 : (int)task_cpu(wtp));
1341 if (!splatted && wtp) {
1342 sched_show_task(wtp);
1343 splatted = true;
1344 }
1345 show_rcu_gp_kthreads();
1346 rcu_ftrace_dump(DUMP_ALL);
1347 }
1348 rtcv_snap = rcu_torture_current_version;
1349 }
1350
1351 /*
1352 * Periodically prints torture statistics, if periodic statistics printing
1353 * was specified via the stat_interval module parameter.
1354 */
1355 static int
1356 rcu_torture_stats(void *arg)
1357 {
1358 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1359 do {
1360 schedule_timeout_interruptible(stat_interval * HZ);
1361 rcu_torture_stats_print();
1362 torture_shutdown_absorb("rcu_torture_stats");
1363 } while (!torture_must_stop());
1364 torture_kthread_stopping("rcu_torture_stats");
1365 return 0;
1366 }
1367
1368 static inline void
1369 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1370 {
1371 pr_alert("%s" TORTURE_FLAG
1372 "--- %s: nreaders=%d nfakewriters=%d "
1373 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1374 "shuffle_interval=%d stutter=%d irqreader=%d "
1375 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1376 "test_boost=%d/%d test_boost_interval=%d "
1377 "test_boost_duration=%d shutdown_secs=%d "
1378 "stall_cpu=%d stall_cpu_holdoff=%d stall_cpu_irqsoff=%d "
1379 "n_barrier_cbs=%d "
1380 "onoff_interval=%d onoff_holdoff=%d\n",
1381 torture_type, tag, nrealreaders, nfakewriters,
1382 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1383 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1384 test_boost, cur_ops->can_boost,
1385 test_boost_interval, test_boost_duration, shutdown_secs,
1386 stall_cpu, stall_cpu_holdoff, stall_cpu_irqsoff,
1387 n_barrier_cbs,
1388 onoff_interval, onoff_holdoff);
1389 }
1390
1391 static int rcutorture_booster_cleanup(unsigned int cpu)
1392 {
1393 struct task_struct *t;
1394
1395 if (boost_tasks[cpu] == NULL)
1396 return 0;
1397 mutex_lock(&boost_mutex);
1398 t = boost_tasks[cpu];
1399 boost_tasks[cpu] = NULL;
1400 mutex_unlock(&boost_mutex);
1401
1402 /* This must be outside of the mutex, otherwise deadlock! */
1403 torture_stop_kthread(rcu_torture_boost, t);
1404 return 0;
1405 }
1406
1407 static int rcutorture_booster_init(unsigned int cpu)
1408 {
1409 int retval;
1410
1411 if (boost_tasks[cpu] != NULL)
1412 return 0; /* Already created, nothing more to do. */
1413
1414 /* Don't allow time recalculation while creating a new task. */
1415 mutex_lock(&boost_mutex);
1416 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1417 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1418 cpu_to_node(cpu),
1419 "rcu_torture_boost");
1420 if (IS_ERR(boost_tasks[cpu])) {
1421 retval = PTR_ERR(boost_tasks[cpu]);
1422 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1423 n_rcu_torture_boost_ktrerror++;
1424 boost_tasks[cpu] = NULL;
1425 mutex_unlock(&boost_mutex);
1426 return retval;
1427 }
1428 kthread_bind(boost_tasks[cpu], cpu);
1429 wake_up_process(boost_tasks[cpu]);
1430 mutex_unlock(&boost_mutex);
1431 return 0;
1432 }
1433
1434 /*
1435 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1436 * induces a CPU stall for the time specified by stall_cpu.
1437 */
1438 static int rcu_torture_stall(void *args)
1439 {
1440 unsigned long stop_at;
1441
1442 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1443 if (stall_cpu_holdoff > 0) {
1444 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1445 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1446 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1447 }
1448 if (!kthread_should_stop()) {
1449 stop_at = get_seconds() + stall_cpu;
1450 /* RCU CPU stall is expected behavior in following code. */
1451 rcu_read_lock();
1452 if (stall_cpu_irqsoff)
1453 local_irq_disable();
1454 else
1455 preempt_disable();
1456 pr_alert("rcu_torture_stall start on CPU %d.\n",
1457 smp_processor_id());
1458 while (ULONG_CMP_LT(get_seconds(), stop_at))
1459 continue; /* Induce RCU CPU stall warning. */
1460 if (stall_cpu_irqsoff)
1461 local_irq_enable();
1462 else
1463 preempt_enable();
1464 rcu_read_unlock();
1465 pr_alert("rcu_torture_stall end.\n");
1466 }
1467 torture_shutdown_absorb("rcu_torture_stall");
1468 while (!kthread_should_stop())
1469 schedule_timeout_interruptible(10 * HZ);
1470 return 0;
1471 }
1472
1473 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1474 static int __init rcu_torture_stall_init(void)
1475 {
1476 if (stall_cpu <= 0)
1477 return 0;
1478 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1479 }
1480
1481 /* Callback function for RCU barrier testing. */
1482 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1483 {
1484 atomic_inc(&barrier_cbs_invoked);
1485 }
1486
1487 /* kthread function to register callbacks used to test RCU barriers. */
1488 static int rcu_torture_barrier_cbs(void *arg)
1489 {
1490 long myid = (long)arg;
1491 bool lastphase = 0;
1492 bool newphase;
1493 struct rcu_head rcu;
1494
1495 init_rcu_head_on_stack(&rcu);
1496 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1497 set_user_nice(current, MAX_NICE);
1498 do {
1499 wait_event(barrier_cbs_wq[myid],
1500 (newphase =
1501 smp_load_acquire(&barrier_phase)) != lastphase ||
1502 torture_must_stop());
1503 lastphase = newphase;
1504 if (torture_must_stop())
1505 break;
1506 /*
1507 * The above smp_load_acquire() ensures barrier_phase load
1508 * is ordered before the following ->call().
1509 */
1510 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1511 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1512 local_irq_enable();
1513 if (atomic_dec_and_test(&barrier_cbs_count))
1514 wake_up(&barrier_wq);
1515 } while (!torture_must_stop());
1516 if (cur_ops->cb_barrier != NULL)
1517 cur_ops->cb_barrier();
1518 destroy_rcu_head_on_stack(&rcu);
1519 torture_kthread_stopping("rcu_torture_barrier_cbs");
1520 return 0;
1521 }
1522
1523 /* kthread function to drive and coordinate RCU barrier testing. */
1524 static int rcu_torture_barrier(void *arg)
1525 {
1526 int i;
1527
1528 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1529 do {
1530 atomic_set(&barrier_cbs_invoked, 0);
1531 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1532 /* Ensure barrier_phase ordered after prior assignments. */
1533 smp_store_release(&barrier_phase, !barrier_phase);
1534 for (i = 0; i < n_barrier_cbs; i++)
1535 wake_up(&barrier_cbs_wq[i]);
1536 wait_event(barrier_wq,
1537 atomic_read(&barrier_cbs_count) == 0 ||
1538 torture_must_stop());
1539 if (torture_must_stop())
1540 break;
1541 n_barrier_attempts++;
1542 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1543 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1544 n_rcu_torture_barrier_error++;
1545 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1546 atomic_read(&barrier_cbs_invoked),
1547 n_barrier_cbs);
1548 WARN_ON_ONCE(1);
1549 }
1550 n_barrier_successes++;
1551 schedule_timeout_interruptible(HZ / 10);
1552 } while (!torture_must_stop());
1553 torture_kthread_stopping("rcu_torture_barrier");
1554 return 0;
1555 }
1556
1557 /* Initialize RCU barrier testing. */
1558 static int rcu_torture_barrier_init(void)
1559 {
1560 int i;
1561 int ret;
1562
1563 if (n_barrier_cbs <= 0)
1564 return 0;
1565 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1566 pr_alert("%s" TORTURE_FLAG
1567 " Call or barrier ops missing for %s,\n",
1568 torture_type, cur_ops->name);
1569 pr_alert("%s" TORTURE_FLAG
1570 " RCU barrier testing omitted from run.\n",
1571 torture_type);
1572 return 0;
1573 }
1574 atomic_set(&barrier_cbs_count, 0);
1575 atomic_set(&barrier_cbs_invoked, 0);
1576 barrier_cbs_tasks =
1577 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_tasks[0]),
1578 GFP_KERNEL);
1579 barrier_cbs_wq =
1580 kcalloc(n_barrier_cbs, sizeof(barrier_cbs_wq[0]), GFP_KERNEL);
1581 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1582 return -ENOMEM;
1583 for (i = 0; i < n_barrier_cbs; i++) {
1584 init_waitqueue_head(&barrier_cbs_wq[i]);
1585 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1586 (void *)(long)i,
1587 barrier_cbs_tasks[i]);
1588 if (ret)
1589 return ret;
1590 }
1591 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1592 }
1593
1594 /* Clean up after RCU barrier testing. */
1595 static void rcu_torture_barrier_cleanup(void)
1596 {
1597 int i;
1598
1599 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1600 if (barrier_cbs_tasks != NULL) {
1601 for (i = 0; i < n_barrier_cbs; i++)
1602 torture_stop_kthread(rcu_torture_barrier_cbs,
1603 barrier_cbs_tasks[i]);
1604 kfree(barrier_cbs_tasks);
1605 barrier_cbs_tasks = NULL;
1606 }
1607 if (barrier_cbs_wq != NULL) {
1608 kfree(barrier_cbs_wq);
1609 barrier_cbs_wq = NULL;
1610 }
1611 }
1612
1613 static enum cpuhp_state rcutor_hp;
1614
1615 static void
1616 rcu_torture_cleanup(void)
1617 {
1618 int flags = 0;
1619 unsigned long gpnum = 0;
1620 unsigned long completed = 0;
1621 int i;
1622
1623 rcutorture_record_test_transition();
1624 if (torture_cleanup_begin()) {
1625 if (cur_ops->cb_barrier != NULL)
1626 cur_ops->cb_barrier();
1627 return;
1628 }
1629
1630 rcu_torture_barrier_cleanup();
1631 torture_stop_kthread(rcu_torture_stall, stall_task);
1632 torture_stop_kthread(rcu_torture_writer, writer_task);
1633
1634 if (reader_tasks) {
1635 for (i = 0; i < nrealreaders; i++)
1636 torture_stop_kthread(rcu_torture_reader,
1637 reader_tasks[i]);
1638 kfree(reader_tasks);
1639 }
1640 rcu_torture_current = NULL;
1641
1642 if (fakewriter_tasks) {
1643 for (i = 0; i < nfakewriters; i++) {
1644 torture_stop_kthread(rcu_torture_fakewriter,
1645 fakewriter_tasks[i]);
1646 }
1647 kfree(fakewriter_tasks);
1648 fakewriter_tasks = NULL;
1649 }
1650
1651 rcutorture_get_gp_data(cur_ops->ttype, &flags, &gpnum, &completed);
1652 srcutorture_get_gp_data(cur_ops->ttype, srcu_ctlp,
1653 &flags, &gpnum, &completed);
1654 pr_alert("%s: End-test grace-period state: g%lu c%lu f%#x\n",
1655 cur_ops->name, gpnum, completed, flags);
1656 torture_stop_kthread(rcu_torture_stats, stats_task);
1657 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1658 for (i = 0; i < ncbflooders; i++)
1659 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1660 if ((test_boost == 1 && cur_ops->can_boost) ||
1661 test_boost == 2)
1662 cpuhp_remove_state(rcutor_hp);
1663
1664 /*
1665 * Wait for all RCU callbacks to fire, then do flavor-specific
1666 * cleanup operations.
1667 */
1668 if (cur_ops->cb_barrier != NULL)
1669 cur_ops->cb_barrier();
1670 if (cur_ops->cleanup != NULL)
1671 cur_ops->cleanup();
1672
1673 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1674
1675 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1676 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1677 else if (torture_onoff_failures())
1678 rcu_torture_print_module_parms(cur_ops,
1679 "End of test: RCU_HOTPLUG");
1680 else
1681 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1682 torture_cleanup_end();
1683 }
1684
1685 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1686 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1687 {
1688 }
1689
1690 static void rcu_torture_err_cb(struct rcu_head *rhp)
1691 {
1692 /*
1693 * This -might- happen due to race conditions, but is unlikely.
1694 * The scenario that leads to this happening is that the
1695 * first of the pair of duplicate callbacks is queued,
1696 * someone else starts a grace period that includes that
1697 * callback, then the second of the pair must wait for the
1698 * next grace period. Unlikely, but can happen. If it
1699 * does happen, the debug-objects subsystem won't have splatted.
1700 */
1701 pr_alert("%s: duplicated callback was invoked.\n", KBUILD_MODNAME);
1702 }
1703 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1704
1705 /*
1706 * Verify that double-free causes debug-objects to complain, but only
1707 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1708 * cannot be carried out.
1709 */
1710 static void rcu_test_debug_objects(void)
1711 {
1712 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1713 struct rcu_head rh1;
1714 struct rcu_head rh2;
1715
1716 init_rcu_head_on_stack(&rh1);
1717 init_rcu_head_on_stack(&rh2);
1718 pr_alert("%s: WARN: Duplicate call_rcu() test starting.\n", KBUILD_MODNAME);
1719
1720 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1721 preempt_disable(); /* Prevent preemption from interrupting test. */
1722 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1723 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1724 local_irq_disable(); /* Make it harder to start a new grace period. */
1725 call_rcu(&rh2, rcu_torture_leak_cb);
1726 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1727 local_irq_enable();
1728 rcu_read_unlock();
1729 preempt_enable();
1730
1731 /* Wait for them all to get done so we can safely return. */
1732 rcu_barrier();
1733 pr_alert("%s: WARN: Duplicate call_rcu() test complete.\n", KBUILD_MODNAME);
1734 destroy_rcu_head_on_stack(&rh1);
1735 destroy_rcu_head_on_stack(&rh2);
1736 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1737 pr_alert("%s: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n", KBUILD_MODNAME);
1738 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1739 }
1740
1741 static int __init
1742 rcu_torture_init(void)
1743 {
1744 int i;
1745 int cpu;
1746 int firsterr = 0;
1747 static struct rcu_torture_ops *torture_ops[] = {
1748 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1749 &sched_ops, &tasks_ops,
1750 };
1751
1752 if (!torture_init_begin(torture_type, verbose))
1753 return -EBUSY;
1754
1755 /* Process args and tell the world that the torturer is on the job. */
1756 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1757 cur_ops = torture_ops[i];
1758 if (strcmp(torture_type, cur_ops->name) == 0)
1759 break;
1760 }
1761 if (i == ARRAY_SIZE(torture_ops)) {
1762 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1763 torture_type);
1764 pr_alert("rcu-torture types:");
1765 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1766 pr_alert(" %s", torture_ops[i]->name);
1767 pr_alert("\n");
1768 firsterr = -EINVAL;
1769 goto unwind;
1770 }
1771 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1772 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1773 fqs_duration = 0;
1774 }
1775 if (cur_ops->init)
1776 cur_ops->init();
1777
1778 if (nreaders >= 0) {
1779 nrealreaders = nreaders;
1780 } else {
1781 nrealreaders = num_online_cpus() - 2 - nreaders;
1782 if (nrealreaders <= 0)
1783 nrealreaders = 1;
1784 }
1785 rcu_torture_print_module_parms(cur_ops, "Start of test");
1786
1787 /* Set up the freelist. */
1788
1789 INIT_LIST_HEAD(&rcu_torture_freelist);
1790 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1791 rcu_tortures[i].rtort_mbtest = 0;
1792 list_add_tail(&rcu_tortures[i].rtort_free,
1793 &rcu_torture_freelist);
1794 }
1795
1796 /* Initialize the statistics so that each run gets its own numbers. */
1797
1798 rcu_torture_current = NULL;
1799 rcu_torture_current_version = 0;
1800 atomic_set(&n_rcu_torture_alloc, 0);
1801 atomic_set(&n_rcu_torture_alloc_fail, 0);
1802 atomic_set(&n_rcu_torture_free, 0);
1803 atomic_set(&n_rcu_torture_mberror, 0);
1804 atomic_set(&n_rcu_torture_error, 0);
1805 n_rcu_torture_barrier_error = 0;
1806 n_rcu_torture_boost_ktrerror = 0;
1807 n_rcu_torture_boost_rterror = 0;
1808 n_rcu_torture_boost_failure = 0;
1809 n_rcu_torture_boosts = 0;
1810 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1811 atomic_set(&rcu_torture_wcount[i], 0);
1812 for_each_possible_cpu(cpu) {
1813 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1814 per_cpu(rcu_torture_count, cpu)[i] = 0;
1815 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1816 }
1817 }
1818
1819 /* Start up the kthreads. */
1820
1821 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1822 writer_task);
1823 if (firsterr)
1824 goto unwind;
1825 if (nfakewriters > 0) {
1826 fakewriter_tasks = kcalloc(nfakewriters,
1827 sizeof(fakewriter_tasks[0]),
1828 GFP_KERNEL);
1829 if (fakewriter_tasks == NULL) {
1830 VERBOSE_TOROUT_ERRSTRING("out of memory");
1831 firsterr = -ENOMEM;
1832 goto unwind;
1833 }
1834 }
1835 for (i = 0; i < nfakewriters; i++) {
1836 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1837 NULL, fakewriter_tasks[i]);
1838 if (firsterr)
1839 goto unwind;
1840 }
1841 reader_tasks = kcalloc(nrealreaders, sizeof(reader_tasks[0]),
1842 GFP_KERNEL);
1843 if (reader_tasks == NULL) {
1844 VERBOSE_TOROUT_ERRSTRING("out of memory");
1845 firsterr = -ENOMEM;
1846 goto unwind;
1847 }
1848 for (i = 0; i < nrealreaders; i++) {
1849 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1850 reader_tasks[i]);
1851 if (firsterr)
1852 goto unwind;
1853 }
1854 if (stat_interval > 0) {
1855 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1856 stats_task);
1857 if (firsterr)
1858 goto unwind;
1859 }
1860 if (test_no_idle_hz && shuffle_interval > 0) {
1861 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1862 if (firsterr)
1863 goto unwind;
1864 }
1865 if (stutter < 0)
1866 stutter = 0;
1867 if (stutter) {
1868 firsterr = torture_stutter_init(stutter * HZ);
1869 if (firsterr)
1870 goto unwind;
1871 }
1872 if (fqs_duration < 0)
1873 fqs_duration = 0;
1874 if (fqs_duration) {
1875 /* Create the fqs thread */
1876 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1877 fqs_task);
1878 if (firsterr)
1879 goto unwind;
1880 }
1881 if (test_boost_interval < 1)
1882 test_boost_interval = 1;
1883 if (test_boost_duration < 2)
1884 test_boost_duration = 2;
1885 if ((test_boost == 1 && cur_ops->can_boost) ||
1886 test_boost == 2) {
1887
1888 boost_starttime = jiffies + test_boost_interval * HZ;
1889
1890 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
1891 rcutorture_booster_init,
1892 rcutorture_booster_cleanup);
1893 if (firsterr < 0)
1894 goto unwind;
1895 rcutor_hp = firsterr;
1896 }
1897 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1898 if (firsterr)
1899 goto unwind;
1900 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1901 if (firsterr)
1902 goto unwind;
1903 firsterr = rcu_torture_stall_init();
1904 if (firsterr)
1905 goto unwind;
1906 firsterr = rcu_torture_barrier_init();
1907 if (firsterr)
1908 goto unwind;
1909 if (object_debug)
1910 rcu_test_debug_objects();
1911 if (cbflood_n_burst > 0) {
1912 /* Create the cbflood threads */
1913 ncbflooders = (num_online_cpus() + 3) / 4;
1914 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1915 GFP_KERNEL);
1916 if (!cbflood_task) {
1917 VERBOSE_TOROUT_ERRSTRING("out of memory");
1918 firsterr = -ENOMEM;
1919 goto unwind;
1920 }
1921 for (i = 0; i < ncbflooders; i++) {
1922 firsterr = torture_create_kthread(rcu_torture_cbflood,
1923 NULL,
1924 cbflood_task[i]);
1925 if (firsterr)
1926 goto unwind;
1927 }
1928 }
1929 rcutorture_record_test_transition();
1930 torture_init_end();
1931 return 0;
1932
1933 unwind:
1934 torture_init_end();
1935 rcu_torture_cleanup();
1936 return firsterr;
1937 }
1938
1939 module_init(rcu_torture_init);
1940 module_exit(rcu_torture_cleanup);
Linux with added FPC-III support