?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
powerpc: Don't try to fix up misaligned load-with-reservation instructions
[linux/fpc-iii.git] / kernel / rcu / rcutorture.c
blobcccc417a813502f8bc0f6d0af930b25d3d1b4f52
1 /*
2 * Read-Copy Update module-based torture test facility
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
17 *
18 * Copyright (C) IBM Corporation, 2005, 2006
19 *
20 * Authors: Paul E. McKenney <paulmck@us.ibm.com>
21 * Josh Triplett <josh@joshtriplett.org>
22 *
23 * See also: Documentation/RCU/torture.txt
24 */
25 #include <linux/types.h>
26 #include <linux/kernel.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/kthread.h>
30 #include <linux/err.h>
31 #include <linux/spinlock.h>
32 #include <linux/smp.h>
33 #include <linux/rcupdate.h>
34 #include <linux/interrupt.h>
35 #include <linux/sched/signal.h>
36 #include <uapi/linux/sched/types.h>
37 #include <linux/atomic.h>
38 #include <linux/bitops.h>
39 #include <linux/completion.h>
40 #include <linux/moduleparam.h>
41 #include <linux/percpu.h>
42 #include <linux/notifier.h>
43 #include <linux/reboot.h>
44 #include <linux/freezer.h>
45 #include <linux/cpu.h>
46 #include <linux/delay.h>
47 #include <linux/stat.h>
48 #include <linux/srcu.h>
49 #include <linux/slab.h>
50 #include <linux/trace_clock.h>
51 #include <asm/byteorder.h>
52 #include <linux/torture.h>
53 #include <linux/vmalloc.h>
54
55 MODULE_LICENSE("GPL");
56 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
57
58
59 torture_param(int, cbflood_inter_holdoff, HZ,
60 "Holdoff between floods (jiffies)");
61 torture_param(int, cbflood_intra_holdoff, 1,
62 "Holdoff between bursts (jiffies)");
63 torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable");
64 torture_param(int, cbflood_n_per_burst, 20000,
65 "# callbacks per burst in flood");
66 torture_param(int, fqs_duration, 0,
67 "Duration of fqs bursts (us), 0 to disable");
68 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
69 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
70 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
71 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
72 torture_param(bool, gp_normal, false,
73 "Use normal (non-expedited) GP wait primitives");
74 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
75 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
76 torture_param(int, n_barrier_cbs, 0,
77 "# of callbacks/kthreads for barrier testing");
78 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
79 torture_param(int, nreaders, -1, "Number of RCU reader threads");
80 torture_param(int, object_debug, 0,
81 "Enable debug-object double call_rcu() testing");
82 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
83 torture_param(int, onoff_interval, 0,
84 "Time between CPU hotplugs (s), 0=disable");
85 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
86 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
87 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
88 torture_param(int, stall_cpu_holdoff, 10,
89 "Time to wait before starting stall (s).");
90 torture_param(int, stat_interval, 60,
91 "Number of seconds between stats printk()s");
92 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
93 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
94 torture_param(int, test_boost_duration, 4,
95 "Duration of each boost test, seconds.");
96 torture_param(int, test_boost_interval, 7,
97 "Interval between boost tests, seconds.");
98 torture_param(bool, test_no_idle_hz, true,
99 "Test support for tickless idle CPUs");
100 torture_param(bool, verbose, true,
101 "Enable verbose debugging printk()s");
102
103 static char *torture_type = "rcu";
104 module_param(torture_type, charp, 0444);
105 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
106
107 static int nrealreaders;
108 static int ncbflooders;
109 static struct task_struct *writer_task;
110 static struct task_struct **fakewriter_tasks;
111 static struct task_struct **reader_tasks;
112 static struct task_struct *stats_task;
113 static struct task_struct **cbflood_task;
114 static struct task_struct *fqs_task;
115 static struct task_struct *boost_tasks[NR_CPUS];
116 static struct task_struct *stall_task;
117 static struct task_struct **barrier_cbs_tasks;
118 static struct task_struct *barrier_task;
119
120 #define RCU_TORTURE_PIPE_LEN 10
121
122 struct rcu_torture {
123 struct rcu_head rtort_rcu;
124 int rtort_pipe_count;
125 struct list_head rtort_free;
126 int rtort_mbtest;
127 };
128
129 static LIST_HEAD(rcu_torture_freelist);
130 static struct rcu_torture __rcu *rcu_torture_current;
131 static unsigned long rcu_torture_current_version;
132 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
133 static DEFINE_SPINLOCK(rcu_torture_lock);
134 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count);
135 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
136 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
137 static atomic_t n_rcu_torture_alloc;
138 static atomic_t n_rcu_torture_alloc_fail;
139 static atomic_t n_rcu_torture_free;
140 static atomic_t n_rcu_torture_mberror;
141 static atomic_t n_rcu_torture_error;
142 static long n_rcu_torture_barrier_error;
143 static long n_rcu_torture_boost_ktrerror;
144 static long n_rcu_torture_boost_rterror;
145 static long n_rcu_torture_boost_failure;
146 static long n_rcu_torture_boosts;
147 static long n_rcu_torture_timers;
148 static long n_barrier_attempts;
149 static long n_barrier_successes;
150 static atomic_long_t n_cbfloods;
151 static struct list_head rcu_torture_removed;
152
153 static int rcu_torture_writer_state;
154 #define RTWS_FIXED_DELAY 0
155 #define RTWS_DELAY 1
156 #define RTWS_REPLACE 2
157 #define RTWS_DEF_FREE 3
158 #define RTWS_EXP_SYNC 4
159 #define RTWS_COND_GET 5
160 #define RTWS_COND_SYNC 6
161 #define RTWS_SYNC 7
162 #define RTWS_STUTTER 8
163 #define RTWS_STOPPING 9
164 static const char * const rcu_torture_writer_state_names[] = {
165 "RTWS_FIXED_DELAY",
166 "RTWS_DELAY",
167 "RTWS_REPLACE",
168 "RTWS_DEF_FREE",
169 "RTWS_EXP_SYNC",
170 "RTWS_COND_GET",
171 "RTWS_COND_SYNC",
172 "RTWS_SYNC",
173 "RTWS_STUTTER",
174 "RTWS_STOPPING",
175 };
176
177 static const char *rcu_torture_writer_state_getname(void)
178 {
179 unsigned int i = READ_ONCE(rcu_torture_writer_state);
180
181 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
182 return "???";
183 return rcu_torture_writer_state_names[i];
184 }
185
186 static int torture_runnable = IS_ENABLED(MODULE);
187 module_param(torture_runnable, int, 0444);
188 MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot");
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 unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC);
201 return ts;
202 }
203 #else /* #ifdef CONFIG_RCU_TRACE */
204 static u64 notrace rcu_trace_clock_local(void)
205 {
206 return 0ULL;
207 }
208 #endif /* #else #ifdef CONFIG_RCU_TRACE */
209
210 static unsigned long boost_starttime; /* jiffies of next boost test start. */
211 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
212 /* and boost task create/destroy. */
213 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
214 static bool barrier_phase; /* Test phase. */
215 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
216 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
217 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
218
219 /*
220 * Allocate an element from the rcu_tortures pool.
221 */
222 static struct rcu_torture *
223 rcu_torture_alloc(void)
224 {
225 struct list_head *p;
226
227 spin_lock_bh(&rcu_torture_lock);
228 if (list_empty(&rcu_torture_freelist)) {
229 atomic_inc(&n_rcu_torture_alloc_fail);
230 spin_unlock_bh(&rcu_torture_lock);
231 return NULL;
232 }
233 atomic_inc(&n_rcu_torture_alloc);
234 p = rcu_torture_freelist.next;
235 list_del_init(p);
236 spin_unlock_bh(&rcu_torture_lock);
237 return container_of(p, struct rcu_torture, rtort_free);
238 }
239
240 /*
241 * Free an element to the rcu_tortures pool.
242 */
243 static void
244 rcu_torture_free(struct rcu_torture *p)
245 {
246 atomic_inc(&n_rcu_torture_free);
247 spin_lock_bh(&rcu_torture_lock);
248 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
249 spin_unlock_bh(&rcu_torture_lock);
250 }
251
252 /*
253 * Operations vector for selecting different types of tests.
254 */
255
256 struct rcu_torture_ops {
257 int ttype;
258 void (*init)(void);
259 void (*cleanup)(void);
260 int (*readlock)(void);
261 void (*read_delay)(struct torture_random_state *rrsp);
262 void (*readunlock)(int idx);
263 unsigned long (*started)(void);
264 unsigned long (*completed)(void);
265 void (*deferred_free)(struct rcu_torture *p);
266 void (*sync)(void);
267 void (*exp_sync)(void);
268 unsigned long (*get_state)(void);
269 void (*cond_sync)(unsigned long oldstate);
270 call_rcu_func_t call;
271 void (*cb_barrier)(void);
272 void (*fqs)(void);
273 void (*stats)(void);
274 int irq_capable;
275 int can_boost;
276 const char *name;
277 };
278
279 static struct rcu_torture_ops *cur_ops;
280
281 /*
282 * Definitions for rcu torture testing.
283 */
284
285 static int rcu_torture_read_lock(void) __acquires(RCU)
286 {
287 rcu_read_lock();
288 return 0;
289 }
290
291 static void rcu_read_delay(struct torture_random_state *rrsp)
292 {
293 unsigned long started;
294 unsigned long completed;
295 const unsigned long shortdelay_us = 200;
296 const unsigned long longdelay_ms = 50;
297 unsigned long long ts;
298
299 /* We want a short delay sometimes to make a reader delay the grace
300 * period, and we want a long delay occasionally to trigger
301 * force_quiescent_state. */
302
303 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
304 started = cur_ops->completed();
305 ts = rcu_trace_clock_local();
306 mdelay(longdelay_ms);
307 completed = cur_ops->completed();
308 do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
309 started, completed);
310 }
311 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
312 udelay(shortdelay_us);
313 #ifdef CONFIG_PREEMPT
314 if (!preempt_count() &&
315 !(torture_random(rrsp) % (nrealreaders * 20000)))
316 preempt_schedule(); /* No QS if preempt_disable() in effect */
317 #endif
318 }
319
320 static void rcu_torture_read_unlock(int idx) __releases(RCU)
321 {
322 rcu_read_unlock();
323 }
324
325 /*
326 * Update callback in the pipe. This should be invoked after a grace period.
327 */
328 static bool
329 rcu_torture_pipe_update_one(struct rcu_torture *rp)
330 {
331 int i;
332
333 i = rp->rtort_pipe_count;
334 if (i > RCU_TORTURE_PIPE_LEN)
335 i = RCU_TORTURE_PIPE_LEN;
336 atomic_inc(&rcu_torture_wcount[i]);
337 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
338 rp->rtort_mbtest = 0;
339 return true;
340 }
341 return false;
342 }
343
344 /*
345 * Update all callbacks in the pipe. Suitable for synchronous grace-period
346 * primitives.
347 */
348 static void
349 rcu_torture_pipe_update(struct rcu_torture *old_rp)
350 {
351 struct rcu_torture *rp;
352 struct rcu_torture *rp1;
353
354 if (old_rp)
355 list_add(&old_rp->rtort_free, &rcu_torture_removed);
356 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
357 if (rcu_torture_pipe_update_one(rp)) {
358 list_del(&rp->rtort_free);
359 rcu_torture_free(rp);
360 }
361 }
362 }
363
364 static void
365 rcu_torture_cb(struct rcu_head *p)
366 {
367 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
368
369 if (torture_must_stop_irq()) {
370 /* Test is ending, just drop callbacks on the floor. */
371 /* The next initialization will pick up the pieces. */
372 return;
373 }
374 if (rcu_torture_pipe_update_one(rp))
375 rcu_torture_free(rp);
376 else
377 cur_ops->deferred_free(rp);
378 }
379
380 static unsigned long rcu_no_completed(void)
381 {
382 return 0;
383 }
384
385 static void rcu_torture_deferred_free(struct rcu_torture *p)
386 {
387 call_rcu(&p->rtort_rcu, rcu_torture_cb);
388 }
389
390 static void rcu_sync_torture_init(void)
391 {
392 INIT_LIST_HEAD(&rcu_torture_removed);
393 }
394
395 static struct rcu_torture_ops rcu_ops = {
396 .ttype = RCU_FLAVOR,
397 .init = rcu_sync_torture_init,
398 .readlock = rcu_torture_read_lock,
399 .read_delay = rcu_read_delay,
400 .readunlock = rcu_torture_read_unlock,
401 .started = rcu_batches_started,
402 .completed = rcu_batches_completed,
403 .deferred_free = rcu_torture_deferred_free,
404 .sync = synchronize_rcu,
405 .exp_sync = synchronize_rcu_expedited,
406 .get_state = get_state_synchronize_rcu,
407 .cond_sync = cond_synchronize_rcu,
408 .call = call_rcu,
409 .cb_barrier = rcu_barrier,
410 .fqs = rcu_force_quiescent_state,
411 .stats = NULL,
412 .irq_capable = 1,
413 .can_boost = rcu_can_boost(),
414 .name = "rcu"
415 };
416
417 /*
418 * Definitions for rcu_bh torture testing.
419 */
420
421 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
422 {
423 rcu_read_lock_bh();
424 return 0;
425 }
426
427 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
428 {
429 rcu_read_unlock_bh();
430 }
431
432 static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
433 {
434 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
435 }
436
437 static struct rcu_torture_ops rcu_bh_ops = {
438 .ttype = RCU_BH_FLAVOR,
439 .init = rcu_sync_torture_init,
440 .readlock = rcu_bh_torture_read_lock,
441 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
442 .readunlock = rcu_bh_torture_read_unlock,
443 .started = rcu_batches_started_bh,
444 .completed = rcu_batches_completed_bh,
445 .deferred_free = rcu_bh_torture_deferred_free,
446 .sync = synchronize_rcu_bh,
447 .exp_sync = synchronize_rcu_bh_expedited,
448 .call = call_rcu_bh,
449 .cb_barrier = rcu_barrier_bh,
450 .fqs = rcu_bh_force_quiescent_state,
451 .stats = NULL,
452 .irq_capable = 1,
453 .name = "rcu_bh"
454 };
455
456 /*
457 * Don't even think about trying any of these in real life!!!
458 * The names includes "busted", and they really means it!
459 * The only purpose of these functions is to provide a buggy RCU
460 * implementation to make sure that rcutorture correctly emits
461 * buggy-RCU error messages.
462 */
463 static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
464 {
465 /* This is a deliberate bug for testing purposes only! */
466 rcu_torture_cb(&p->rtort_rcu);
467 }
468
469 static void synchronize_rcu_busted(void)
470 {
471 /* This is a deliberate bug for testing purposes only! */
472 }
473
474 static void
475 call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
476 {
477 /* This is a deliberate bug for testing purposes only! */
478 func(head);
479 }
480
481 static struct rcu_torture_ops rcu_busted_ops = {
482 .ttype = INVALID_RCU_FLAVOR,
483 .init = rcu_sync_torture_init,
484 .readlock = rcu_torture_read_lock,
485 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
486 .readunlock = rcu_torture_read_unlock,
487 .started = rcu_no_completed,
488 .completed = rcu_no_completed,
489 .deferred_free = rcu_busted_torture_deferred_free,
490 .sync = synchronize_rcu_busted,
491 .exp_sync = synchronize_rcu_busted,
492 .call = call_rcu_busted,
493 .cb_barrier = NULL,
494 .fqs = NULL,
495 .stats = NULL,
496 .irq_capable = 1,
497 .name = "rcu_busted"
498 };
499
500 /*
501 * Definitions for srcu torture testing.
502 */
503
504 DEFINE_STATIC_SRCU(srcu_ctl);
505 static struct srcu_struct srcu_ctld;
506 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
507
508 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
509 {
510 return srcu_read_lock(srcu_ctlp);
511 }
512
513 static void srcu_read_delay(struct torture_random_state *rrsp)
514 {
515 long delay;
516 const long uspertick = 1000000 / HZ;
517 const long longdelay = 10;
518
519 /* We want there to be long-running readers, but not all the time. */
520
521 delay = torture_random(rrsp) %
522 (nrealreaders * 2 * longdelay * uspertick);
523 if (!delay)
524 schedule_timeout_interruptible(longdelay);
525 else
526 rcu_read_delay(rrsp);
527 }
528
529 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
530 {
531 srcu_read_unlock(srcu_ctlp, idx);
532 }
533
534 static unsigned long srcu_torture_completed(void)
535 {
536 return srcu_batches_completed(srcu_ctlp);
537 }
538
539 static void srcu_torture_deferred_free(struct rcu_torture *rp)
540 {
541 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
542 }
543
544 static void srcu_torture_synchronize(void)
545 {
546 synchronize_srcu(srcu_ctlp);
547 }
548
549 static void srcu_torture_call(struct rcu_head *head,
550 rcu_callback_t func)
551 {
552 call_srcu(srcu_ctlp, head, func);
553 }
554
555 static void srcu_torture_barrier(void)
556 {
557 srcu_barrier(srcu_ctlp);
558 }
559
560 static void srcu_torture_stats(void)
561 {
562 int cpu;
563 int idx = srcu_ctlp->completed & 0x1;
564
565 pr_alert("%s%s per-CPU(idx=%d):",
566 torture_type, TORTURE_FLAG, idx);
567 for_each_possible_cpu(cpu) {
568 unsigned long l0, l1;
569 unsigned long u0, u1;
570 long c0, c1;
571 struct srcu_array *counts = per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu);
572
573 u0 = counts->unlock_count[!idx];
574 u1 = counts->unlock_count[idx];
575
576 /*
577 * Make sure that a lock is always counted if the corresponding
578 * unlock is counted.
579 */
580 smp_rmb();
581
582 l0 = counts->lock_count[!idx];
583 l1 = counts->lock_count[idx];
584
585 c0 = l0 - u0;
586 c1 = l1 - u1;
587 pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
588 }
589 pr_cont("\n");
590 }
591
592 static void srcu_torture_synchronize_expedited(void)
593 {
594 synchronize_srcu_expedited(srcu_ctlp);
595 }
596
597 static struct rcu_torture_ops srcu_ops = {
598 .ttype = SRCU_FLAVOR,
599 .init = rcu_sync_torture_init,
600 .readlock = srcu_torture_read_lock,
601 .read_delay = srcu_read_delay,
602 .readunlock = srcu_torture_read_unlock,
603 .started = NULL,
604 .completed = srcu_torture_completed,
605 .deferred_free = srcu_torture_deferred_free,
606 .sync = srcu_torture_synchronize,
607 .exp_sync = srcu_torture_synchronize_expedited,
608 .call = srcu_torture_call,
609 .cb_barrier = srcu_torture_barrier,
610 .stats = srcu_torture_stats,
611 .name = "srcu"
612 };
613
614 static void srcu_torture_init(void)
615 {
616 rcu_sync_torture_init();
617 WARN_ON(init_srcu_struct(&srcu_ctld));
618 srcu_ctlp = &srcu_ctld;
619 }
620
621 static void srcu_torture_cleanup(void)
622 {
623 cleanup_srcu_struct(&srcu_ctld);
624 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
625 }
626
627 /* As above, but dynamically allocated. */
628 static struct rcu_torture_ops srcud_ops = {
629 .ttype = SRCU_FLAVOR,
630 .init = srcu_torture_init,
631 .cleanup = srcu_torture_cleanup,
632 .readlock = srcu_torture_read_lock,
633 .read_delay = srcu_read_delay,
634 .readunlock = srcu_torture_read_unlock,
635 .started = NULL,
636 .completed = srcu_torture_completed,
637 .deferred_free = srcu_torture_deferred_free,
638 .sync = srcu_torture_synchronize,
639 .exp_sync = srcu_torture_synchronize_expedited,
640 .call = srcu_torture_call,
641 .cb_barrier = srcu_torture_barrier,
642 .stats = srcu_torture_stats,
643 .name = "srcud"
644 };
645
646 /*
647 * Definitions for sched torture testing.
648 */
649
650 static int sched_torture_read_lock(void)
651 {
652 preempt_disable();
653 return 0;
654 }
655
656 static void sched_torture_read_unlock(int idx)
657 {
658 preempt_enable();
659 }
660
661 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
662 {
663 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
664 }
665
666 static struct rcu_torture_ops sched_ops = {
667 .ttype = RCU_SCHED_FLAVOR,
668 .init = rcu_sync_torture_init,
669 .readlock = sched_torture_read_lock,
670 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
671 .readunlock = sched_torture_read_unlock,
672 .started = rcu_batches_started_sched,
673 .completed = rcu_batches_completed_sched,
674 .deferred_free = rcu_sched_torture_deferred_free,
675 .sync = synchronize_sched,
676 .exp_sync = synchronize_sched_expedited,
677 .get_state = get_state_synchronize_sched,
678 .cond_sync = cond_synchronize_sched,
679 .call = call_rcu_sched,
680 .cb_barrier = rcu_barrier_sched,
681 .fqs = rcu_sched_force_quiescent_state,
682 .stats = NULL,
683 .irq_capable = 1,
684 .name = "sched"
685 };
686
687 #ifdef CONFIG_TASKS_RCU
688
689 /*
690 * Definitions for RCU-tasks torture testing.
691 */
692
693 static int tasks_torture_read_lock(void)
694 {
695 return 0;
696 }
697
698 static void tasks_torture_read_unlock(int idx)
699 {
700 }
701
702 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
703 {
704 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
705 }
706
707 static struct rcu_torture_ops tasks_ops = {
708 .ttype = RCU_TASKS_FLAVOR,
709 .init = rcu_sync_torture_init,
710 .readlock = tasks_torture_read_lock,
711 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
712 .readunlock = tasks_torture_read_unlock,
713 .started = rcu_no_completed,
714 .completed = rcu_no_completed,
715 .deferred_free = rcu_tasks_torture_deferred_free,
716 .sync = synchronize_rcu_tasks,
717 .exp_sync = synchronize_rcu_tasks,
718 .call = call_rcu_tasks,
719 .cb_barrier = rcu_barrier_tasks,
720 .fqs = NULL,
721 .stats = NULL,
722 .irq_capable = 1,
723 .name = "tasks"
724 };
725
726 #define RCUTORTURE_TASKS_OPS &tasks_ops,
727
728 static bool __maybe_unused torturing_tasks(void)
729 {
730 return cur_ops == &tasks_ops;
731 }
732
733 #else /* #ifdef CONFIG_TASKS_RCU */
734
735 #define RCUTORTURE_TASKS_OPS
736
737 static bool __maybe_unused torturing_tasks(void)
738 {
739 return false;
740 }
741
742 #endif /* #else #ifdef CONFIG_TASKS_RCU */
743
744 /*
745 * RCU torture priority-boost testing. Runs one real-time thread per
746 * CPU for moderate bursts, repeatedly registering RCU callbacks and
747 * spinning waiting for them to be invoked. If a given callback takes
748 * too long to be invoked, we assume that priority inversion has occurred.
749 */
750
751 struct rcu_boost_inflight {
752 struct rcu_head rcu;
753 int inflight;
754 };
755
756 static void rcu_torture_boost_cb(struct rcu_head *head)
757 {
758 struct rcu_boost_inflight *rbip =
759 container_of(head, struct rcu_boost_inflight, rcu);
760
761 /* Ensure RCU-core accesses precede clearing ->inflight */
762 smp_store_release(&rbip->inflight, 0);
763 }
764
765 static int rcu_torture_boost(void *arg)
766 {
767 unsigned long call_rcu_time;
768 unsigned long endtime;
769 unsigned long oldstarttime;
770 struct rcu_boost_inflight rbi = { .inflight = 0 };
771 struct sched_param sp;
772
773 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
774
775 /* Set real-time priority. */
776 sp.sched_priority = 1;
777 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
778 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
779 n_rcu_torture_boost_rterror++;
780 }
781
782 init_rcu_head_on_stack(&rbi.rcu);
783 /* Each pass through the following loop does one boost-test cycle. */
784 do {
785 /* Wait for the next test interval. */
786 oldstarttime = boost_starttime;
787 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
788 schedule_timeout_interruptible(oldstarttime - jiffies);
789 stutter_wait("rcu_torture_boost");
790 if (torture_must_stop())
791 goto checkwait;
792 }
793
794 /* Do one boost-test interval. */
795 endtime = oldstarttime + test_boost_duration * HZ;
796 call_rcu_time = jiffies;
797 while (ULONG_CMP_LT(jiffies, endtime)) {
798 /* If we don't have a callback in flight, post one. */
799 if (!smp_load_acquire(&rbi.inflight)) {
800 /* RCU core before ->inflight = 1. */
801 smp_store_release(&rbi.inflight, 1);
802 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
803 if (jiffies - call_rcu_time >
804 test_boost_duration * HZ - HZ / 2) {
805 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
806 n_rcu_torture_boost_failure++;
807 }
808 call_rcu_time = jiffies;
809 }
810 stutter_wait("rcu_torture_boost");
811 if (torture_must_stop())
812 goto checkwait;
813 }
814
815 /*
816 * Set the start time of the next test interval.
817 * Yes, this is vulnerable to long delays, but such
818 * delays simply cause a false negative for the next
819 * interval. Besides, we are running at RT priority,
820 * so delays should be relatively rare.
821 */
822 while (oldstarttime == boost_starttime &&
823 !kthread_should_stop()) {
824 if (mutex_trylock(&boost_mutex)) {
825 boost_starttime = jiffies +
826 test_boost_interval * HZ;
827 n_rcu_torture_boosts++;
828 mutex_unlock(&boost_mutex);
829 break;
830 }
831 schedule_timeout_uninterruptible(1);
832 }
833
834 /* Go do the stutter. */
835 checkwait: stutter_wait("rcu_torture_boost");
836 } while (!torture_must_stop());
837
838 /* Clean up and exit. */
839 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
840 torture_shutdown_absorb("rcu_torture_boost");
841 schedule_timeout_uninterruptible(1);
842 }
843 destroy_rcu_head_on_stack(&rbi.rcu);
844 torture_kthread_stopping("rcu_torture_boost");
845 return 0;
846 }
847
848 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
849 {
850 }
851
852 /*
853 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
854 * to call_rcu() or analogous, increasing the probability of occurrence
855 * of callback-overflow corner cases.
856 */
857 static int
858 rcu_torture_cbflood(void *arg)
859 {
860 int err = 1;
861 int i;
862 int j;
863 struct rcu_head *rhp;
864
865 if (cbflood_n_per_burst > 0 &&
866 cbflood_inter_holdoff > 0 &&
867 cbflood_intra_holdoff > 0 &&
868 cur_ops->call &&
869 cur_ops->cb_barrier) {
870 rhp = vmalloc(sizeof(*rhp) *
871 cbflood_n_burst * cbflood_n_per_burst);
872 err = !rhp;
873 }
874 if (err) {
875 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
876 goto wait_for_stop;
877 }
878 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
879 do {
880 schedule_timeout_interruptible(cbflood_inter_holdoff);
881 atomic_long_inc(&n_cbfloods);
882 WARN_ON(signal_pending(current));
883 for (i = 0; i < cbflood_n_burst; i++) {
884 for (j = 0; j < cbflood_n_per_burst; j++) {
885 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
886 rcu_torture_cbflood_cb);
887 }
888 schedule_timeout_interruptible(cbflood_intra_holdoff);
889 WARN_ON(signal_pending(current));
890 }
891 cur_ops->cb_barrier();
892 stutter_wait("rcu_torture_cbflood");
893 } while (!torture_must_stop());
894 vfree(rhp);
895 wait_for_stop:
896 torture_kthread_stopping("rcu_torture_cbflood");
897 return 0;
898 }
899
900 /*
901 * RCU torture force-quiescent-state kthread. Repeatedly induces
902 * bursts of calls to force_quiescent_state(), increasing the probability
903 * of occurrence of some important types of race conditions.
904 */
905 static int
906 rcu_torture_fqs(void *arg)
907 {
908 unsigned long fqs_resume_time;
909 int fqs_burst_remaining;
910
911 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
912 do {
913 fqs_resume_time = jiffies + fqs_stutter * HZ;
914 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
915 !kthread_should_stop()) {
916 schedule_timeout_interruptible(1);
917 }
918 fqs_burst_remaining = fqs_duration;
919 while (fqs_burst_remaining > 0 &&
920 !kthread_should_stop()) {
921 cur_ops->fqs();
922 udelay(fqs_holdoff);
923 fqs_burst_remaining -= fqs_holdoff;
924 }
925 stutter_wait("rcu_torture_fqs");
926 } while (!torture_must_stop());
927 torture_kthread_stopping("rcu_torture_fqs");
928 return 0;
929 }
930
931 /*
932 * RCU torture writer kthread. Repeatedly substitutes a new structure
933 * for that pointed to by rcu_torture_current, freeing the old structure
934 * after a series of grace periods (the "pipeline").
935 */
936 static int
937 rcu_torture_writer(void *arg)
938 {
939 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
940 int expediting = 0;
941 unsigned long gp_snap;
942 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
943 bool gp_sync1 = gp_sync;
944 int i;
945 struct rcu_torture *rp;
946 struct rcu_torture *old_rp;
947 static DEFINE_TORTURE_RANDOM(rand);
948 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
949 RTWS_COND_GET, RTWS_SYNC };
950 int nsynctypes = 0;
951
952 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
953 if (!can_expedite) {
954 pr_alert("%s" TORTURE_FLAG
955 " GP expediting controlled from boot/sysfs for %s,\n",
956 torture_type, cur_ops->name);
957 pr_alert("%s" TORTURE_FLAG
958 " Disabled dynamic grace-period expediting.\n",
959 torture_type);
960 }
961
962 /* Initialize synctype[] array. If none set, take default. */
963 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
964 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
965 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
966 synctype[nsynctypes++] = RTWS_COND_GET;
967 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
968 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
969 if (gp_exp1 && cur_ops->exp_sync)
970 synctype[nsynctypes++] = RTWS_EXP_SYNC;
971 else if (gp_exp && !cur_ops->exp_sync)
972 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
973 if (gp_normal1 && cur_ops->deferred_free)
974 synctype[nsynctypes++] = RTWS_DEF_FREE;
975 else if (gp_normal && !cur_ops->deferred_free)
976 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
977 if (gp_sync1 && cur_ops->sync)
978 synctype[nsynctypes++] = RTWS_SYNC;
979 else if (gp_sync && !cur_ops->sync)
980 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
981 if (WARN_ONCE(nsynctypes == 0,
982 "rcu_torture_writer: No update-side primitives.\n")) {
983 /*
984 * No updates primitives, so don't try updating.
985 * The resulting test won't be testing much, hence the
986 * above WARN_ONCE().
987 */
988 rcu_torture_writer_state = RTWS_STOPPING;
989 torture_kthread_stopping("rcu_torture_writer");
990 }
991
992 do {
993 rcu_torture_writer_state = RTWS_FIXED_DELAY;
994 schedule_timeout_uninterruptible(1);
995 rp = rcu_torture_alloc();
996 if (rp == NULL)
997 continue;
998 rp->rtort_pipe_count = 0;
999 rcu_torture_writer_state = RTWS_DELAY;
1000 udelay(torture_random(&rand) & 0x3ff);
1001 rcu_torture_writer_state = RTWS_REPLACE;
1002 old_rp = rcu_dereference_check(rcu_torture_current,
1003 current == writer_task);
1004 rp->rtort_mbtest = 1;
1005 rcu_assign_pointer(rcu_torture_current, rp);
1006 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
1007 if (old_rp) {
1008 i = old_rp->rtort_pipe_count;
1009 if (i > RCU_TORTURE_PIPE_LEN)
1010 i = RCU_TORTURE_PIPE_LEN;
1011 atomic_inc(&rcu_torture_wcount[i]);
1012 old_rp->rtort_pipe_count++;
1013 switch (synctype[torture_random(&rand) % nsynctypes]) {
1014 case RTWS_DEF_FREE:
1015 rcu_torture_writer_state = RTWS_DEF_FREE;
1016 cur_ops->deferred_free(old_rp);
1017 break;
1018 case RTWS_EXP_SYNC:
1019 rcu_torture_writer_state = RTWS_EXP_SYNC;
1020 cur_ops->exp_sync();
1021 rcu_torture_pipe_update(old_rp);
1022 break;
1023 case RTWS_COND_GET:
1024 rcu_torture_writer_state = RTWS_COND_GET;
1025 gp_snap = cur_ops->get_state();
1026 i = torture_random(&rand) % 16;
1027 if (i != 0)
1028 schedule_timeout_interruptible(i);
1029 udelay(torture_random(&rand) % 1000);
1030 rcu_torture_writer_state = RTWS_COND_SYNC;
1031 cur_ops->cond_sync(gp_snap);
1032 rcu_torture_pipe_update(old_rp);
1033 break;
1034 case RTWS_SYNC:
1035 rcu_torture_writer_state = RTWS_SYNC;
1036 cur_ops->sync();
1037 rcu_torture_pipe_update(old_rp);
1038 break;
1039 default:
1040 WARN_ON_ONCE(1);
1041 break;
1042 }
1043 }
1044 rcutorture_record_progress(++rcu_torture_current_version);
1045 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1046 if (can_expedite &&
1047 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1048 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1049 if (expediting >= 0)
1050 rcu_expedite_gp();
1051 else
1052 rcu_unexpedite_gp();
1053 if (++expediting > 3)
1054 expediting = -expediting;
1055 }
1056 rcu_torture_writer_state = RTWS_STUTTER;
1057 stutter_wait("rcu_torture_writer");
1058 } while (!torture_must_stop());
1059 /* Reset expediting back to unexpedited. */
1060 if (expediting > 0)
1061 expediting = -expediting;
1062 while (can_expedite && expediting++ < 0)
1063 rcu_unexpedite_gp();
1064 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1065 rcu_torture_writer_state = RTWS_STOPPING;
1066 torture_kthread_stopping("rcu_torture_writer");
1067 return 0;
1068 }
1069
1070 /*
1071 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1072 * delay between calls.
1073 */
1074 static int
1075 rcu_torture_fakewriter(void *arg)
1076 {
1077 DEFINE_TORTURE_RANDOM(rand);
1078
1079 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1080 set_user_nice(current, MAX_NICE);
1081
1082 do {
1083 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1084 udelay(torture_random(&rand) & 0x3ff);
1085 if (cur_ops->cb_barrier != NULL &&
1086 torture_random(&rand) % (nfakewriters * 8) == 0) {
1087 cur_ops->cb_barrier();
1088 } else if (gp_normal == gp_exp) {
1089 if (torture_random(&rand) & 0x80)
1090 cur_ops->sync();
1091 else
1092 cur_ops->exp_sync();
1093 } else if (gp_normal) {
1094 cur_ops->sync();
1095 } else {
1096 cur_ops->exp_sync();
1097 }
1098 stutter_wait("rcu_torture_fakewriter");
1099 } while (!torture_must_stop());
1100
1101 torture_kthread_stopping("rcu_torture_fakewriter");
1102 return 0;
1103 }
1104
1105 /*
1106 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1107 * incrementing the corresponding element of the pipeline array. The
1108 * counter in the element should never be greater than 1, otherwise, the
1109 * RCU implementation is broken.
1110 */
1111 static void rcu_torture_timer(unsigned long unused)
1112 {
1113 int idx;
1114 unsigned long started;
1115 unsigned long completed;
1116 static DEFINE_TORTURE_RANDOM(rand);
1117 static DEFINE_SPINLOCK(rand_lock);
1118 struct rcu_torture *p;
1119 int pipe_count;
1120 unsigned long long ts;
1121
1122 idx = cur_ops->readlock();
1123 if (cur_ops->started)
1124 started = cur_ops->started();
1125 else
1126 started = cur_ops->completed();
1127 ts = rcu_trace_clock_local();
1128 p = rcu_dereference_check(rcu_torture_current,
1129 rcu_read_lock_bh_held() ||
1130 rcu_read_lock_sched_held() ||
1131 srcu_read_lock_held(srcu_ctlp) ||
1132 torturing_tasks());
1133 if (p == NULL) {
1134 /* Leave because rcu_torture_writer is not yet underway */
1135 cur_ops->readunlock(idx);
1136 return;
1137 }
1138 if (p->rtort_mbtest == 0)
1139 atomic_inc(&n_rcu_torture_mberror);
1140 spin_lock(&rand_lock);
1141 cur_ops->read_delay(&rand);
1142 n_rcu_torture_timers++;
1143 spin_unlock(&rand_lock);
1144 preempt_disable();
1145 pipe_count = p->rtort_pipe_count;
1146 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1147 /* Should not happen, but... */
1148 pipe_count = RCU_TORTURE_PIPE_LEN;
1149 }
1150 completed = cur_ops->completed();
1151 if (pipe_count > 1) {
1152 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1153 started, completed);
1154 rcu_ftrace_dump(DUMP_ALL);
1155 }
1156 __this_cpu_inc(rcu_torture_count[pipe_count]);
1157 completed = completed - started;
1158 if (cur_ops->started)
1159 completed++;
1160 if (completed > RCU_TORTURE_PIPE_LEN) {
1161 /* Should not happen, but... */
1162 completed = RCU_TORTURE_PIPE_LEN;
1163 }
1164 __this_cpu_inc(rcu_torture_batch[completed]);
1165 preempt_enable();
1166 cur_ops->readunlock(idx);
1167 }
1168
1169 /*
1170 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1171 * incrementing the corresponding element of the pipeline array. The
1172 * counter in the element should never be greater than 1, otherwise, the
1173 * RCU implementation is broken.
1174 */
1175 static int
1176 rcu_torture_reader(void *arg)
1177 {
1178 unsigned long started;
1179 unsigned long completed;
1180 int idx;
1181 DEFINE_TORTURE_RANDOM(rand);
1182 struct rcu_torture *p;
1183 int pipe_count;
1184 struct timer_list t;
1185 unsigned long long ts;
1186
1187 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1188 set_user_nice(current, MAX_NICE);
1189 if (irqreader && cur_ops->irq_capable)
1190 setup_timer_on_stack(&t, rcu_torture_timer, 0);
1191
1192 do {
1193 if (irqreader && cur_ops->irq_capable) {
1194 if (!timer_pending(&t))
1195 mod_timer(&t, jiffies + 1);
1196 }
1197 idx = cur_ops->readlock();
1198 if (cur_ops->started)
1199 started = cur_ops->started();
1200 else
1201 started = cur_ops->completed();
1202 ts = rcu_trace_clock_local();
1203 p = rcu_dereference_check(rcu_torture_current,
1204 rcu_read_lock_bh_held() ||
1205 rcu_read_lock_sched_held() ||
1206 srcu_read_lock_held(srcu_ctlp) ||
1207 torturing_tasks());
1208 if (p == NULL) {
1209 /* Wait for rcu_torture_writer to get underway */
1210 cur_ops->readunlock(idx);
1211 schedule_timeout_interruptible(HZ);
1212 continue;
1213 }
1214 if (p->rtort_mbtest == 0)
1215 atomic_inc(&n_rcu_torture_mberror);
1216 cur_ops->read_delay(&rand);
1217 preempt_disable();
1218 pipe_count = p->rtort_pipe_count;
1219 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1220 /* Should not happen, but... */
1221 pipe_count = RCU_TORTURE_PIPE_LEN;
1222 }
1223 completed = cur_ops->completed();
1224 if (pipe_count > 1) {
1225 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1226 ts, started, completed);
1227 rcu_ftrace_dump(DUMP_ALL);
1228 }
1229 __this_cpu_inc(rcu_torture_count[pipe_count]);
1230 completed = completed - started;
1231 if (cur_ops->started)
1232 completed++;
1233 if (completed > RCU_TORTURE_PIPE_LEN) {
1234 /* Should not happen, but... */
1235 completed = RCU_TORTURE_PIPE_LEN;
1236 }
1237 __this_cpu_inc(rcu_torture_batch[completed]);
1238 preempt_enable();
1239 cur_ops->readunlock(idx);
1240 stutter_wait("rcu_torture_reader");
1241 } while (!torture_must_stop());
1242 if (irqreader && cur_ops->irq_capable) {
1243 del_timer_sync(&t);
1244 destroy_timer_on_stack(&t);
1245 }
1246 torture_kthread_stopping("rcu_torture_reader");
1247 return 0;
1248 }
1249
1250 /*
1251 * Print torture statistics. Caller must ensure that there is only
1252 * one call to this function at a given time!!! This is normally
1253 * accomplished by relying on the module system to only have one copy
1254 * of the module loaded, and then by giving the rcu_torture_stats
1255 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1256 * thread is not running).
1257 */
1258 static void
1259 rcu_torture_stats_print(void)
1260 {
1261 int cpu;
1262 int i;
1263 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1264 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1265 static unsigned long rtcv_snap = ULONG_MAX;
1266 struct task_struct *wtp;
1267
1268 for_each_possible_cpu(cpu) {
1269 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1270 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1271 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1272 }
1273 }
1274 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1275 if (pipesummary[i] != 0)
1276 break;
1277 }
1278
1279 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1280 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1281 rcu_torture_current,
1282 rcu_torture_current_version,
1283 list_empty(&rcu_torture_freelist),
1284 atomic_read(&n_rcu_torture_alloc),
1285 atomic_read(&n_rcu_torture_alloc_fail),
1286 atomic_read(&n_rcu_torture_free));
1287 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1288 atomic_read(&n_rcu_torture_mberror),
1289 n_rcu_torture_barrier_error,
1290 n_rcu_torture_boost_ktrerror,
1291 n_rcu_torture_boost_rterror);
1292 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1293 n_rcu_torture_boost_failure,
1294 n_rcu_torture_boosts,
1295 n_rcu_torture_timers);
1296 torture_onoff_stats();
1297 pr_cont("barrier: %ld/%ld:%ld ",
1298 n_barrier_successes,
1299 n_barrier_attempts,
1300 n_rcu_torture_barrier_error);
1301 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1302
1303 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1304 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1305 n_rcu_torture_barrier_error != 0 ||
1306 n_rcu_torture_boost_ktrerror != 0 ||
1307 n_rcu_torture_boost_rterror != 0 ||
1308 n_rcu_torture_boost_failure != 0 ||
1309 i > 1) {
1310 pr_cont("%s", "!!! ");
1311 atomic_inc(&n_rcu_torture_error);
1312 WARN_ON_ONCE(1);
1313 }
1314 pr_cont("Reader Pipe: ");
1315 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1316 pr_cont(" %ld", pipesummary[i]);
1317 pr_cont("\n");
1318
1319 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1320 pr_cont("Reader Batch: ");
1321 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1322 pr_cont(" %ld", batchsummary[i]);
1323 pr_cont("\n");
1324
1325 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1326 pr_cont("Free-Block Circulation: ");
1327 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1328 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1329 }
1330 pr_cont("\n");
1331
1332 if (cur_ops->stats)
1333 cur_ops->stats();
1334 if (rtcv_snap == rcu_torture_current_version &&
1335 rcu_torture_current != NULL) {
1336 int __maybe_unused flags;
1337 unsigned long __maybe_unused gpnum;
1338 unsigned long __maybe_unused completed;
1339
1340 rcutorture_get_gp_data(cur_ops->ttype,
1341 &flags, &gpnum, &completed);
1342 wtp = READ_ONCE(writer_task);
1343 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n",
1344 rcu_torture_writer_state_getname(),
1345 rcu_torture_writer_state,
1346 gpnum, completed, flags,
1347 wtp == NULL ? ~0UL : wtp->state);
1348 show_rcu_gp_kthreads();
1349 rcu_ftrace_dump(DUMP_ALL);
1350 }
1351 rtcv_snap = rcu_torture_current_version;
1352 }
1353
1354 /*
1355 * Periodically prints torture statistics, if periodic statistics printing
1356 * was specified via the stat_interval module parameter.
1357 */
1358 static int
1359 rcu_torture_stats(void *arg)
1360 {
1361 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1362 do {
1363 schedule_timeout_interruptible(stat_interval * HZ);
1364 rcu_torture_stats_print();
1365 torture_shutdown_absorb("rcu_torture_stats");
1366 } while (!torture_must_stop());
1367 torture_kthread_stopping("rcu_torture_stats");
1368 return 0;
1369 }
1370
1371 static inline void
1372 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1373 {
1374 pr_alert("%s" TORTURE_FLAG
1375 "--- %s: nreaders=%d nfakewriters=%d "
1376 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1377 "shuffle_interval=%d stutter=%d irqreader=%d "
1378 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1379 "test_boost=%d/%d test_boost_interval=%d "
1380 "test_boost_duration=%d shutdown_secs=%d "
1381 "stall_cpu=%d stall_cpu_holdoff=%d "
1382 "n_barrier_cbs=%d "
1383 "onoff_interval=%d onoff_holdoff=%d\n",
1384 torture_type, tag, nrealreaders, nfakewriters,
1385 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1386 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1387 test_boost, cur_ops->can_boost,
1388 test_boost_interval, test_boost_duration, shutdown_secs,
1389 stall_cpu, stall_cpu_holdoff,
1390 n_barrier_cbs,
1391 onoff_interval, onoff_holdoff);
1392 }
1393
1394 static int rcutorture_booster_cleanup(unsigned int cpu)
1395 {
1396 struct task_struct *t;
1397
1398 if (boost_tasks[cpu] == NULL)
1399 return 0;
1400 mutex_lock(&boost_mutex);
1401 t = boost_tasks[cpu];
1402 boost_tasks[cpu] = NULL;
1403 mutex_unlock(&boost_mutex);
1404
1405 /* This must be outside of the mutex, otherwise deadlock! */
1406 torture_stop_kthread(rcu_torture_boost, t);
1407 return 0;
1408 }
1409
1410 static int rcutorture_booster_init(unsigned int cpu)
1411 {
1412 int retval;
1413
1414 if (boost_tasks[cpu] != NULL)
1415 return 0; /* Already created, nothing more to do. */
1416
1417 /* Don't allow time recalculation while creating a new task. */
1418 mutex_lock(&boost_mutex);
1419 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1420 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1421 cpu_to_node(cpu),
1422 "rcu_torture_boost");
1423 if (IS_ERR(boost_tasks[cpu])) {
1424 retval = PTR_ERR(boost_tasks[cpu]);
1425 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1426 n_rcu_torture_boost_ktrerror++;
1427 boost_tasks[cpu] = NULL;
1428 mutex_unlock(&boost_mutex);
1429 return retval;
1430 }
1431 kthread_bind(boost_tasks[cpu], cpu);
1432 wake_up_process(boost_tasks[cpu]);
1433 mutex_unlock(&boost_mutex);
1434 return 0;
1435 }
1436
1437 /*
1438 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1439 * induces a CPU stall for the time specified by stall_cpu.
1440 */
1441 static int rcu_torture_stall(void *args)
1442 {
1443 unsigned long stop_at;
1444
1445 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1446 if (stall_cpu_holdoff > 0) {
1447 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1448 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1449 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1450 }
1451 if (!kthread_should_stop()) {
1452 stop_at = get_seconds() + stall_cpu;
1453 /* RCU CPU stall is expected behavior in following code. */
1454 pr_alert("rcu_torture_stall start.\n");
1455 rcu_read_lock();
1456 preempt_disable();
1457 while (ULONG_CMP_LT(get_seconds(), stop_at))
1458 continue; /* Induce RCU CPU stall warning. */
1459 preempt_enable();
1460 rcu_read_unlock();
1461 pr_alert("rcu_torture_stall end.\n");
1462 }
1463 torture_shutdown_absorb("rcu_torture_stall");
1464 while (!kthread_should_stop())
1465 schedule_timeout_interruptible(10 * HZ);
1466 return 0;
1467 }
1468
1469 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1470 static int __init rcu_torture_stall_init(void)
1471 {
1472 if (stall_cpu <= 0)
1473 return 0;
1474 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1475 }
1476
1477 /* Callback function for RCU barrier testing. */
1478 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1479 {
1480 atomic_inc(&barrier_cbs_invoked);
1481 }
1482
1483 /* kthread function to register callbacks used to test RCU barriers. */
1484 static int rcu_torture_barrier_cbs(void *arg)
1485 {
1486 long myid = (long)arg;
1487 bool lastphase = 0;
1488 bool newphase;
1489 struct rcu_head rcu;
1490
1491 init_rcu_head_on_stack(&rcu);
1492 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1493 set_user_nice(current, MAX_NICE);
1494 do {
1495 wait_event(barrier_cbs_wq[myid],
1496 (newphase =
1497 smp_load_acquire(&barrier_phase)) != lastphase ||
1498 torture_must_stop());
1499 lastphase = newphase;
1500 if (torture_must_stop())
1501 break;
1502 /*
1503 * The above smp_load_acquire() ensures barrier_phase load
1504 * is ordered before the following ->call().
1505 */
1506 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1507 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1508 local_irq_enable();
1509 if (atomic_dec_and_test(&barrier_cbs_count))
1510 wake_up(&barrier_wq);
1511 } while (!torture_must_stop());
1512 if (cur_ops->cb_barrier != NULL)
1513 cur_ops->cb_barrier();
1514 destroy_rcu_head_on_stack(&rcu);
1515 torture_kthread_stopping("rcu_torture_barrier_cbs");
1516 return 0;
1517 }
1518
1519 /* kthread function to drive and coordinate RCU barrier testing. */
1520 static int rcu_torture_barrier(void *arg)
1521 {
1522 int i;
1523
1524 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1525 do {
1526 atomic_set(&barrier_cbs_invoked, 0);
1527 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1528 /* Ensure barrier_phase ordered after prior assignments. */
1529 smp_store_release(&barrier_phase, !barrier_phase);
1530 for (i = 0; i < n_barrier_cbs; i++)
1531 wake_up(&barrier_cbs_wq[i]);
1532 wait_event(barrier_wq,
1533 atomic_read(&barrier_cbs_count) == 0 ||
1534 torture_must_stop());
1535 if (torture_must_stop())
1536 break;
1537 n_barrier_attempts++;
1538 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1539 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1540 n_rcu_torture_barrier_error++;
1541 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1542 atomic_read(&barrier_cbs_invoked),
1543 n_barrier_cbs);
1544 WARN_ON_ONCE(1);
1545 }
1546 n_barrier_successes++;
1547 schedule_timeout_interruptible(HZ / 10);
1548 } while (!torture_must_stop());
1549 torture_kthread_stopping("rcu_torture_barrier");
1550 return 0;
1551 }
1552
1553 /* Initialize RCU barrier testing. */
1554 static int rcu_torture_barrier_init(void)
1555 {
1556 int i;
1557 int ret;
1558
1559 if (n_barrier_cbs <= 0)
1560 return 0;
1561 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1562 pr_alert("%s" TORTURE_FLAG
1563 " Call or barrier ops missing for %s,\n",
1564 torture_type, cur_ops->name);
1565 pr_alert("%s" TORTURE_FLAG
1566 " RCU barrier testing omitted from run.\n",
1567 torture_type);
1568 return 0;
1569 }
1570 atomic_set(&barrier_cbs_count, 0);
1571 atomic_set(&barrier_cbs_invoked, 0);
1572 barrier_cbs_tasks =
1573 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
1574 GFP_KERNEL);
1575 barrier_cbs_wq =
1576 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
1577 GFP_KERNEL);
1578 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1579 return -ENOMEM;
1580 for (i = 0; i < n_barrier_cbs; i++) {
1581 init_waitqueue_head(&barrier_cbs_wq[i]);
1582 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1583 (void *)(long)i,
1584 barrier_cbs_tasks[i]);
1585 if (ret)
1586 return ret;
1587 }
1588 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1589 }
1590
1591 /* Clean up after RCU barrier testing. */
1592 static void rcu_torture_barrier_cleanup(void)
1593 {
1594 int i;
1595
1596 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1597 if (barrier_cbs_tasks != NULL) {
1598 for (i = 0; i < n_barrier_cbs; i++)
1599 torture_stop_kthread(rcu_torture_barrier_cbs,
1600 barrier_cbs_tasks[i]);
1601 kfree(barrier_cbs_tasks);
1602 barrier_cbs_tasks = NULL;
1603 }
1604 if (barrier_cbs_wq != NULL) {
1605 kfree(barrier_cbs_wq);
1606 barrier_cbs_wq = NULL;
1607 }
1608 }
1609
1610 static enum cpuhp_state rcutor_hp;
1611
1612 static void
1613 rcu_torture_cleanup(void)
1614 {
1615 int i;
1616
1617 rcutorture_record_test_transition();
1618 if (torture_cleanup_begin()) {
1619 if (cur_ops->cb_barrier != NULL)
1620 cur_ops->cb_barrier();
1621 return;
1622 }
1623
1624 rcu_torture_barrier_cleanup();
1625 torture_stop_kthread(rcu_torture_stall, stall_task);
1626 torture_stop_kthread(rcu_torture_writer, writer_task);
1627
1628 if (reader_tasks) {
1629 for (i = 0; i < nrealreaders; i++)
1630 torture_stop_kthread(rcu_torture_reader,
1631 reader_tasks[i]);
1632 kfree(reader_tasks);
1633 }
1634 rcu_torture_current = NULL;
1635
1636 if (fakewriter_tasks) {
1637 for (i = 0; i < nfakewriters; i++) {
1638 torture_stop_kthread(rcu_torture_fakewriter,
1639 fakewriter_tasks[i]);
1640 }
1641 kfree(fakewriter_tasks);
1642 fakewriter_tasks = NULL;
1643 }
1644
1645 torture_stop_kthread(rcu_torture_stats, stats_task);
1646 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1647 for (i = 0; i < ncbflooders; i++)
1648 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1649 if ((test_boost == 1 && cur_ops->can_boost) ||
1650 test_boost == 2)
1651 cpuhp_remove_state(rcutor_hp);
1652
1653 /*
1654 * Wait for all RCU callbacks to fire, then do flavor-specific
1655 * cleanup operations.
1656 */
1657 if (cur_ops->cb_barrier != NULL)
1658 cur_ops->cb_barrier();
1659 if (cur_ops->cleanup != NULL)
1660 cur_ops->cleanup();
1661
1662 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1663
1664 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1665 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1666 else if (torture_onoff_failures())
1667 rcu_torture_print_module_parms(cur_ops,
1668 "End of test: RCU_HOTPLUG");
1669 else
1670 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1671 torture_cleanup_end();
1672 }
1673
1674 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1675 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1676 {
1677 }
1678
1679 static void rcu_torture_err_cb(struct rcu_head *rhp)
1680 {
1681 /*
1682 * This -might- happen due to race conditions, but is unlikely.
1683 * The scenario that leads to this happening is that the
1684 * first of the pair of duplicate callbacks is queued,
1685 * someone else starts a grace period that includes that
1686 * callback, then the second of the pair must wait for the
1687 * next grace period. Unlikely, but can happen. If it
1688 * does happen, the debug-objects subsystem won't have splatted.
1689 */
1690 pr_alert("rcutorture: duplicated callback was invoked.\n");
1691 }
1692 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1693
1694 /*
1695 * Verify that double-free causes debug-objects to complain, but only
1696 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1697 * cannot be carried out.
1698 */
1699 static void rcu_test_debug_objects(void)
1700 {
1701 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1702 struct rcu_head rh1;
1703 struct rcu_head rh2;
1704
1705 init_rcu_head_on_stack(&rh1);
1706 init_rcu_head_on_stack(&rh2);
1707 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1708
1709 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1710 preempt_disable(); /* Prevent preemption from interrupting test. */
1711 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1712 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1713 local_irq_disable(); /* Make it harder to start a new grace period. */
1714 call_rcu(&rh2, rcu_torture_leak_cb);
1715 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1716 local_irq_enable();
1717 rcu_read_unlock();
1718 preempt_enable();
1719
1720 /* Wait for them all to get done so we can safely return. */
1721 rcu_barrier();
1722 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1723 destroy_rcu_head_on_stack(&rh1);
1724 destroy_rcu_head_on_stack(&rh2);
1725 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1726 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1727 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1728 }
1729
1730 static int __init
1731 rcu_torture_init(void)
1732 {
1733 int i;
1734 int cpu;
1735 int firsterr = 0;
1736 static struct rcu_torture_ops *torture_ops[] = {
1737 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1738 &sched_ops, RCUTORTURE_TASKS_OPS
1739 };
1740
1741 if (!torture_init_begin(torture_type, verbose, &torture_runnable))
1742 return -EBUSY;
1743
1744 /* Process args and tell the world that the torturer is on the job. */
1745 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1746 cur_ops = torture_ops[i];
1747 if (strcmp(torture_type, cur_ops->name) == 0)
1748 break;
1749 }
1750 if (i == ARRAY_SIZE(torture_ops)) {
1751 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1752 torture_type);
1753 pr_alert("rcu-torture types:");
1754 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1755 pr_alert(" %s", torture_ops[i]->name);
1756 pr_alert("\n");
1757 firsterr = -EINVAL;
1758 goto unwind;
1759 }
1760 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1761 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1762 fqs_duration = 0;
1763 }
1764 if (cur_ops->init)
1765 cur_ops->init();
1766
1767 if (nreaders >= 0) {
1768 nrealreaders = nreaders;
1769 } else {
1770 nrealreaders = num_online_cpus() - 2 - nreaders;
1771 if (nrealreaders <= 0)
1772 nrealreaders = 1;
1773 }
1774 rcu_torture_print_module_parms(cur_ops, "Start of test");
1775
1776 /* Set up the freelist. */
1777
1778 INIT_LIST_HEAD(&rcu_torture_freelist);
1779 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1780 rcu_tortures[i].rtort_mbtest = 0;
1781 list_add_tail(&rcu_tortures[i].rtort_free,
1782 &rcu_torture_freelist);
1783 }
1784
1785 /* Initialize the statistics so that each run gets its own numbers. */
1786
1787 rcu_torture_current = NULL;
1788 rcu_torture_current_version = 0;
1789 atomic_set(&n_rcu_torture_alloc, 0);
1790 atomic_set(&n_rcu_torture_alloc_fail, 0);
1791 atomic_set(&n_rcu_torture_free, 0);
1792 atomic_set(&n_rcu_torture_mberror, 0);
1793 atomic_set(&n_rcu_torture_error, 0);
1794 n_rcu_torture_barrier_error = 0;
1795 n_rcu_torture_boost_ktrerror = 0;
1796 n_rcu_torture_boost_rterror = 0;
1797 n_rcu_torture_boost_failure = 0;
1798 n_rcu_torture_boosts = 0;
1799 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1800 atomic_set(&rcu_torture_wcount[i], 0);
1801 for_each_possible_cpu(cpu) {
1802 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1803 per_cpu(rcu_torture_count, cpu)[i] = 0;
1804 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1805 }
1806 }
1807
1808 /* Start up the kthreads. */
1809
1810 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1811 writer_task);
1812 if (firsterr)
1813 goto unwind;
1814 if (nfakewriters > 0) {
1815 fakewriter_tasks = kzalloc(nfakewriters *
1816 sizeof(fakewriter_tasks[0]),
1817 GFP_KERNEL);
1818 if (fakewriter_tasks == NULL) {
1819 VERBOSE_TOROUT_ERRSTRING("out of memory");
1820 firsterr = -ENOMEM;
1821 goto unwind;
1822 }
1823 }
1824 for (i = 0; i < nfakewriters; i++) {
1825 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1826 NULL, fakewriter_tasks[i]);
1827 if (firsterr)
1828 goto unwind;
1829 }
1830 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
1831 GFP_KERNEL);
1832 if (reader_tasks == NULL) {
1833 VERBOSE_TOROUT_ERRSTRING("out of memory");
1834 firsterr = -ENOMEM;
1835 goto unwind;
1836 }
1837 for (i = 0; i < nrealreaders; i++) {
1838 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1839 reader_tasks[i]);
1840 if (firsterr)
1841 goto unwind;
1842 }
1843 if (stat_interval > 0) {
1844 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1845 stats_task);
1846 if (firsterr)
1847 goto unwind;
1848 }
1849 if (test_no_idle_hz && shuffle_interval > 0) {
1850 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1851 if (firsterr)
1852 goto unwind;
1853 }
1854 if (stutter < 0)
1855 stutter = 0;
1856 if (stutter) {
1857 firsterr = torture_stutter_init(stutter * HZ);
1858 if (firsterr)
1859 goto unwind;
1860 }
1861 if (fqs_duration < 0)
1862 fqs_duration = 0;
1863 if (fqs_duration) {
1864 /* Create the fqs thread */
1865 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1866 fqs_task);
1867 if (firsterr)
1868 goto unwind;
1869 }
1870 if (test_boost_interval < 1)
1871 test_boost_interval = 1;
1872 if (test_boost_duration < 2)
1873 test_boost_duration = 2;
1874 if ((test_boost == 1 && cur_ops->can_boost) ||
1875 test_boost == 2) {
1876
1877 boost_starttime = jiffies + test_boost_interval * HZ;
1878
1879 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
1880 rcutorture_booster_init,
1881 rcutorture_booster_cleanup);
1882 if (firsterr < 0)
1883 goto unwind;
1884 rcutor_hp = firsterr;
1885 }
1886 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1887 if (firsterr)
1888 goto unwind;
1889 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1890 if (firsterr)
1891 goto unwind;
1892 firsterr = rcu_torture_stall_init();
1893 if (firsterr)
1894 goto unwind;
1895 firsterr = rcu_torture_barrier_init();
1896 if (firsterr)
1897 goto unwind;
1898 if (object_debug)
1899 rcu_test_debug_objects();
1900 if (cbflood_n_burst > 0) {
1901 /* Create the cbflood threads */
1902 ncbflooders = (num_online_cpus() + 3) / 4;
1903 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1904 GFP_KERNEL);
1905 if (!cbflood_task) {
1906 VERBOSE_TOROUT_ERRSTRING("out of memory");
1907 firsterr = -ENOMEM;
1908 goto unwind;
1909 }
1910 for (i = 0; i < ncbflooders; i++) {
1911 firsterr = torture_create_kthread(rcu_torture_cbflood,
1912 NULL,
1913 cbflood_task[i]);
1914 if (firsterr)
1915 goto unwind;
1916 }
1917 }
1918 rcutorture_record_test_transition();
1919 torture_init_end();
1920 return 0;
1921
1922 unwind:
1923 torture_init_end();
1924 rcu_torture_cleanup();
1925 return firsterr;
1926 }
1927
1928 module_init(rcu_torture_init);
1929 module_exit(rcu_torture_cleanup);
Linux with added FPC-III support