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natsemi: add checks for dma mapping errors
[linux/fpc-iii.git] / kernel / rcu / rcutorture.c
blobd89328e260df6f4f953b649fea98587aacf12318
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.h>
36 #include <linux/atomic.h>
37 #include <linux/bitops.h>
38 #include <linux/completion.h>
39 #include <linux/moduleparam.h>
40 #include <linux/percpu.h>
41 #include <linux/notifier.h>
42 #include <linux/reboot.h>
43 #include <linux/freezer.h>
44 #include <linux/cpu.h>
45 #include <linux/delay.h>
46 #include <linux/stat.h>
47 #include <linux/srcu.h>
48 #include <linux/slab.h>
49 #include <linux/trace_clock.h>
50 #include <asm/byteorder.h>
51 #include <linux/torture.h>
52 #include <linux/vmalloc.h>
53
54 MODULE_LICENSE("GPL");
55 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>");
56
57
58 torture_param(int, cbflood_inter_holdoff, HZ,
59 "Holdoff between floods (jiffies)");
60 torture_param(int, cbflood_intra_holdoff, 1,
61 "Holdoff between bursts (jiffies)");
62 torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable");
63 torture_param(int, cbflood_n_per_burst, 20000,
64 "# callbacks per burst in flood");
65 torture_param(int, fqs_duration, 0,
66 "Duration of fqs bursts (us), 0 to disable");
67 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)");
68 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)");
69 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives");
70 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives");
71 torture_param(bool, gp_normal, false,
72 "Use normal (non-expedited) GP wait primitives");
73 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives");
74 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers");
75 torture_param(int, n_barrier_cbs, 0,
76 "# of callbacks/kthreads for barrier testing");
77 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads");
78 torture_param(int, nreaders, -1, "Number of RCU reader threads");
79 torture_param(int, object_debug, 0,
80 "Enable debug-object double call_rcu() testing");
81 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
82 torture_param(int, onoff_interval, 0,
83 "Time between CPU hotplugs (s), 0=disable");
84 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles");
85 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable.");
86 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable.");
87 torture_param(int, stall_cpu_holdoff, 10,
88 "Time to wait before starting stall (s).");
89 torture_param(int, stat_interval, 60,
90 "Number of seconds between stats printk()s");
91 torture_param(int, stutter, 5, "Number of seconds to run/halt test");
92 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
93 torture_param(int, test_boost_duration, 4,
94 "Duration of each boost test, seconds.");
95 torture_param(int, test_boost_interval, 7,
96 "Interval between boost tests, seconds.");
97 torture_param(bool, test_no_idle_hz, true,
98 "Test support for tickless idle CPUs");
99 torture_param(bool, verbose, true,
100 "Enable verbose debugging printk()s");
101
102 static char *torture_type = "rcu";
103 module_param(torture_type, charp, 0444);
104 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)");
105
106 static int nrealreaders;
107 static int ncbflooders;
108 static struct task_struct *writer_task;
109 static struct task_struct **fakewriter_tasks;
110 static struct task_struct **reader_tasks;
111 static struct task_struct *stats_task;
112 static struct task_struct **cbflood_task;
113 static struct task_struct *fqs_task;
114 static struct task_struct *boost_tasks[NR_CPUS];
115 static struct task_struct *stall_task;
116 static struct task_struct **barrier_cbs_tasks;
117 static struct task_struct *barrier_task;
118
119 #define RCU_TORTURE_PIPE_LEN 10
120
121 struct rcu_torture {
122 struct rcu_head rtort_rcu;
123 int rtort_pipe_count;
124 struct list_head rtort_free;
125 int rtort_mbtest;
126 };
127
128 static LIST_HEAD(rcu_torture_freelist);
129 static struct rcu_torture __rcu *rcu_torture_current;
130 static unsigned long rcu_torture_current_version;
131 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN];
132 static DEFINE_SPINLOCK(rcu_torture_lock);
133 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
134 rcu_torture_count) = { 0 };
135 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1],
136 rcu_torture_batch) = { 0 };
137 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
138 static atomic_t n_rcu_torture_alloc;
139 static atomic_t n_rcu_torture_alloc_fail;
140 static atomic_t n_rcu_torture_free;
141 static atomic_t n_rcu_torture_mberror;
142 static atomic_t n_rcu_torture_error;
143 static long n_rcu_torture_barrier_error;
144 static long n_rcu_torture_boost_ktrerror;
145 static long n_rcu_torture_boost_rterror;
146 static long n_rcu_torture_boost_failure;
147 static long n_rcu_torture_boosts;
148 static long n_rcu_torture_timers;
149 static long n_barrier_attempts;
150 static long n_barrier_successes;
151 static atomic_long_t n_cbfloods;
152 static struct list_head rcu_torture_removed;
153
154 static int rcu_torture_writer_state;
155 #define RTWS_FIXED_DELAY 0
156 #define RTWS_DELAY 1
157 #define RTWS_REPLACE 2
158 #define RTWS_DEF_FREE 3
159 #define RTWS_EXP_SYNC 4
160 #define RTWS_COND_GET 5
161 #define RTWS_COND_SYNC 6
162 #define RTWS_SYNC 7
163 #define RTWS_STUTTER 8
164 #define RTWS_STOPPING 9
165
166 #if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
167 #define RCUTORTURE_RUNNABLE_INIT 1
168 #else
169 #define RCUTORTURE_RUNNABLE_INIT 0
170 #endif
171 static int torture_runnable = RCUTORTURE_RUNNABLE_INIT;
172 module_param(torture_runnable, int, 0444);
173 MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot");
174
175 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
176 #define rcu_can_boost() 1
177 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
178 #define rcu_can_boost() 0
179 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
180
181 #ifdef CONFIG_RCU_TRACE
182 static u64 notrace rcu_trace_clock_local(void)
183 {
184 u64 ts = trace_clock_local();
185 unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC);
186 return ts;
187 }
188 #else /* #ifdef CONFIG_RCU_TRACE */
189 static u64 notrace rcu_trace_clock_local(void)
190 {
191 return 0ULL;
192 }
193 #endif /* #else #ifdef CONFIG_RCU_TRACE */
194
195 static unsigned long boost_starttime; /* jiffies of next boost test start. */
196 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
197 /* and boost task create/destroy. */
198 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
199 static bool barrier_phase; /* Test phase. */
200 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
201 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
202 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
203
204 /*
205 * Allocate an element from the rcu_tortures pool.
206 */
207 static struct rcu_torture *
208 rcu_torture_alloc(void)
209 {
210 struct list_head *p;
211
212 spin_lock_bh(&rcu_torture_lock);
213 if (list_empty(&rcu_torture_freelist)) {
214 atomic_inc(&n_rcu_torture_alloc_fail);
215 spin_unlock_bh(&rcu_torture_lock);
216 return NULL;
217 }
218 atomic_inc(&n_rcu_torture_alloc);
219 p = rcu_torture_freelist.next;
220 list_del_init(p);
221 spin_unlock_bh(&rcu_torture_lock);
222 return container_of(p, struct rcu_torture, rtort_free);
223 }
224
225 /*
226 * Free an element to the rcu_tortures pool.
227 */
228 static void
229 rcu_torture_free(struct rcu_torture *p)
230 {
231 atomic_inc(&n_rcu_torture_free);
232 spin_lock_bh(&rcu_torture_lock);
233 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
234 spin_unlock_bh(&rcu_torture_lock);
235 }
236
237 /*
238 * Operations vector for selecting different types of tests.
239 */
240
241 struct rcu_torture_ops {
242 int ttype;
243 void (*init)(void);
244 void (*cleanup)(void);
245 int (*readlock)(void);
246 void (*read_delay)(struct torture_random_state *rrsp);
247 void (*readunlock)(int idx);
248 unsigned long (*started)(void);
249 unsigned long (*completed)(void);
250 void (*deferred_free)(struct rcu_torture *p);
251 void (*sync)(void);
252 void (*exp_sync)(void);
253 unsigned long (*get_state)(void);
254 void (*cond_sync)(unsigned long oldstate);
255 call_rcu_func_t call;
256 void (*cb_barrier)(void);
257 void (*fqs)(void);
258 void (*stats)(void);
259 int irq_capable;
260 int can_boost;
261 const char *name;
262 };
263
264 static struct rcu_torture_ops *cur_ops;
265
266 /*
267 * Definitions for rcu torture testing.
268 */
269
270 static int rcu_torture_read_lock(void) __acquires(RCU)
271 {
272 rcu_read_lock();
273 return 0;
274 }
275
276 static void rcu_read_delay(struct torture_random_state *rrsp)
277 {
278 const unsigned long shortdelay_us = 200;
279 const unsigned long longdelay_ms = 50;
280
281 /* We want a short delay sometimes to make a reader delay the grace
282 * period, and we want a long delay occasionally to trigger
283 * force_quiescent_state. */
284
285 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms)))
286 mdelay(longdelay_ms);
287 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
288 udelay(shortdelay_us);
289 #ifdef CONFIG_PREEMPT
290 if (!preempt_count() &&
291 !(torture_random(rrsp) % (nrealreaders * 20000)))
292 preempt_schedule(); /* No QS if preempt_disable() in effect */
293 #endif
294 }
295
296 static void rcu_torture_read_unlock(int idx) __releases(RCU)
297 {
298 rcu_read_unlock();
299 }
300
301 /*
302 * Update callback in the pipe. This should be invoked after a grace period.
303 */
304 static bool
305 rcu_torture_pipe_update_one(struct rcu_torture *rp)
306 {
307 int i;
308
309 i = rp->rtort_pipe_count;
310 if (i > RCU_TORTURE_PIPE_LEN)
311 i = RCU_TORTURE_PIPE_LEN;
312 atomic_inc(&rcu_torture_wcount[i]);
313 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
314 rp->rtort_mbtest = 0;
315 return true;
316 }
317 return false;
318 }
319
320 /*
321 * Update all callbacks in the pipe. Suitable for synchronous grace-period
322 * primitives.
323 */
324 static void
325 rcu_torture_pipe_update(struct rcu_torture *old_rp)
326 {
327 struct rcu_torture *rp;
328 struct rcu_torture *rp1;
329
330 if (old_rp)
331 list_add(&old_rp->rtort_free, &rcu_torture_removed);
332 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
333 if (rcu_torture_pipe_update_one(rp)) {
334 list_del(&rp->rtort_free);
335 rcu_torture_free(rp);
336 }
337 }
338 }
339
340 static void
341 rcu_torture_cb(struct rcu_head *p)
342 {
343 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
344
345 if (torture_must_stop_irq()) {
346 /* Test is ending, just drop callbacks on the floor. */
347 /* The next initialization will pick up the pieces. */
348 return;
349 }
350 if (rcu_torture_pipe_update_one(rp))
351 rcu_torture_free(rp);
352 else
353 cur_ops->deferred_free(rp);
354 }
355
356 static unsigned long rcu_no_completed(void)
357 {
358 return 0;
359 }
360
361 static void rcu_torture_deferred_free(struct rcu_torture *p)
362 {
363 call_rcu(&p->rtort_rcu, rcu_torture_cb);
364 }
365
366 static void rcu_sync_torture_init(void)
367 {
368 INIT_LIST_HEAD(&rcu_torture_removed);
369 }
370
371 static struct rcu_torture_ops rcu_ops = {
372 .ttype = RCU_FLAVOR,
373 .init = rcu_sync_torture_init,
374 .readlock = rcu_torture_read_lock,
375 .read_delay = rcu_read_delay,
376 .readunlock = rcu_torture_read_unlock,
377 .started = rcu_batches_started,
378 .completed = rcu_batches_completed,
379 .deferred_free = rcu_torture_deferred_free,
380 .sync = synchronize_rcu,
381 .exp_sync = synchronize_rcu_expedited,
382 .get_state = get_state_synchronize_rcu,
383 .cond_sync = cond_synchronize_rcu,
384 .call = call_rcu,
385 .cb_barrier = rcu_barrier,
386 .fqs = rcu_force_quiescent_state,
387 .stats = NULL,
388 .irq_capable = 1,
389 .can_boost = rcu_can_boost(),
390 .name = "rcu"
391 };
392
393 /*
394 * Definitions for rcu_bh torture testing.
395 */
396
397 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
398 {
399 rcu_read_lock_bh();
400 return 0;
401 }
402
403 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
404 {
405 rcu_read_unlock_bh();
406 }
407
408 static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
409 {
410 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
411 }
412
413 static struct rcu_torture_ops rcu_bh_ops = {
414 .ttype = RCU_BH_FLAVOR,
415 .init = rcu_sync_torture_init,
416 .readlock = rcu_bh_torture_read_lock,
417 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
418 .readunlock = rcu_bh_torture_read_unlock,
419 .started = rcu_batches_started_bh,
420 .completed = rcu_batches_completed_bh,
421 .deferred_free = rcu_bh_torture_deferred_free,
422 .sync = synchronize_rcu_bh,
423 .exp_sync = synchronize_rcu_bh_expedited,
424 .call = call_rcu_bh,
425 .cb_barrier = rcu_barrier_bh,
426 .fqs = rcu_bh_force_quiescent_state,
427 .stats = NULL,
428 .irq_capable = 1,
429 .name = "rcu_bh"
430 };
431
432 /*
433 * Don't even think about trying any of these in real life!!!
434 * The names includes "busted", and they really means it!
435 * The only purpose of these functions is to provide a buggy RCU
436 * implementation to make sure that rcutorture correctly emits
437 * buggy-RCU error messages.
438 */
439 static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
440 {
441 /* This is a deliberate bug for testing purposes only! */
442 rcu_torture_cb(&p->rtort_rcu);
443 }
444
445 static void synchronize_rcu_busted(void)
446 {
447 /* This is a deliberate bug for testing purposes only! */
448 }
449
450 static void
451 call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
452 {
453 /* This is a deliberate bug for testing purposes only! */
454 func(head);
455 }
456
457 static struct rcu_torture_ops rcu_busted_ops = {
458 .ttype = INVALID_RCU_FLAVOR,
459 .init = rcu_sync_torture_init,
460 .readlock = rcu_torture_read_lock,
461 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
462 .readunlock = rcu_torture_read_unlock,
463 .started = rcu_no_completed,
464 .completed = rcu_no_completed,
465 .deferred_free = rcu_busted_torture_deferred_free,
466 .sync = synchronize_rcu_busted,
467 .exp_sync = synchronize_rcu_busted,
468 .call = call_rcu_busted,
469 .cb_barrier = NULL,
470 .fqs = NULL,
471 .stats = NULL,
472 .irq_capable = 1,
473 .name = "rcu_busted"
474 };
475
476 /*
477 * Definitions for srcu torture testing.
478 */
479
480 DEFINE_STATIC_SRCU(srcu_ctl);
481 static struct srcu_struct srcu_ctld;
482 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
483
484 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
485 {
486 return srcu_read_lock(srcu_ctlp);
487 }
488
489 static void srcu_read_delay(struct torture_random_state *rrsp)
490 {
491 long delay;
492 const long uspertick = 1000000 / HZ;
493 const long longdelay = 10;
494
495 /* We want there to be long-running readers, but not all the time. */
496
497 delay = torture_random(rrsp) %
498 (nrealreaders * 2 * longdelay * uspertick);
499 if (!delay)
500 schedule_timeout_interruptible(longdelay);
501 else
502 rcu_read_delay(rrsp);
503 }
504
505 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
506 {
507 srcu_read_unlock(srcu_ctlp, idx);
508 }
509
510 static unsigned long srcu_torture_completed(void)
511 {
512 return srcu_batches_completed(srcu_ctlp);
513 }
514
515 static void srcu_torture_deferred_free(struct rcu_torture *rp)
516 {
517 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
518 }
519
520 static void srcu_torture_synchronize(void)
521 {
522 synchronize_srcu(srcu_ctlp);
523 }
524
525 static void srcu_torture_call(struct rcu_head *head,
526 rcu_callback_t func)
527 {
528 call_srcu(srcu_ctlp, head, func);
529 }
530
531 static void srcu_torture_barrier(void)
532 {
533 srcu_barrier(srcu_ctlp);
534 }
535
536 static void srcu_torture_stats(void)
537 {
538 int cpu;
539 int idx = srcu_ctlp->completed & 0x1;
540
541 pr_alert("%s%s per-CPU(idx=%d):",
542 torture_type, TORTURE_FLAG, idx);
543 for_each_possible_cpu(cpu) {
544 long c0, c1;
545
546 c0 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[!idx];
547 c1 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[idx];
548 pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
549 }
550 pr_cont("\n");
551 }
552
553 static void srcu_torture_synchronize_expedited(void)
554 {
555 synchronize_srcu_expedited(srcu_ctlp);
556 }
557
558 static struct rcu_torture_ops srcu_ops = {
559 .ttype = SRCU_FLAVOR,
560 .init = rcu_sync_torture_init,
561 .readlock = srcu_torture_read_lock,
562 .read_delay = srcu_read_delay,
563 .readunlock = srcu_torture_read_unlock,
564 .started = NULL,
565 .completed = srcu_torture_completed,
566 .deferred_free = srcu_torture_deferred_free,
567 .sync = srcu_torture_synchronize,
568 .exp_sync = srcu_torture_synchronize_expedited,
569 .call = srcu_torture_call,
570 .cb_barrier = srcu_torture_barrier,
571 .stats = srcu_torture_stats,
572 .name = "srcu"
573 };
574
575 static void srcu_torture_init(void)
576 {
577 rcu_sync_torture_init();
578 WARN_ON(init_srcu_struct(&srcu_ctld));
579 srcu_ctlp = &srcu_ctld;
580 }
581
582 static void srcu_torture_cleanup(void)
583 {
584 cleanup_srcu_struct(&srcu_ctld);
585 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
586 }
587
588 /* As above, but dynamically allocated. */
589 static struct rcu_torture_ops srcud_ops = {
590 .ttype = SRCU_FLAVOR,
591 .init = srcu_torture_init,
592 .cleanup = srcu_torture_cleanup,
593 .readlock = srcu_torture_read_lock,
594 .read_delay = srcu_read_delay,
595 .readunlock = srcu_torture_read_unlock,
596 .started = NULL,
597 .completed = srcu_torture_completed,
598 .deferred_free = srcu_torture_deferred_free,
599 .sync = srcu_torture_synchronize,
600 .exp_sync = srcu_torture_synchronize_expedited,
601 .call = srcu_torture_call,
602 .cb_barrier = srcu_torture_barrier,
603 .stats = srcu_torture_stats,
604 .name = "srcud"
605 };
606
607 /*
608 * Definitions for sched torture testing.
609 */
610
611 static int sched_torture_read_lock(void)
612 {
613 preempt_disable();
614 return 0;
615 }
616
617 static void sched_torture_read_unlock(int idx)
618 {
619 preempt_enable();
620 }
621
622 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
623 {
624 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
625 }
626
627 static struct rcu_torture_ops sched_ops = {
628 .ttype = RCU_SCHED_FLAVOR,
629 .init = rcu_sync_torture_init,
630 .readlock = sched_torture_read_lock,
631 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
632 .readunlock = sched_torture_read_unlock,
633 .started = rcu_batches_started_sched,
634 .completed = rcu_batches_completed_sched,
635 .deferred_free = rcu_sched_torture_deferred_free,
636 .sync = synchronize_sched,
637 .exp_sync = synchronize_sched_expedited,
638 .get_state = get_state_synchronize_sched,
639 .cond_sync = cond_synchronize_sched,
640 .call = call_rcu_sched,
641 .cb_barrier = rcu_barrier_sched,
642 .fqs = rcu_sched_force_quiescent_state,
643 .stats = NULL,
644 .irq_capable = 1,
645 .name = "sched"
646 };
647
648 #ifdef CONFIG_TASKS_RCU
649
650 /*
651 * Definitions for RCU-tasks torture testing.
652 */
653
654 static int tasks_torture_read_lock(void)
655 {
656 return 0;
657 }
658
659 static void tasks_torture_read_unlock(int idx)
660 {
661 }
662
663 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
664 {
665 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
666 }
667
668 static struct rcu_torture_ops tasks_ops = {
669 .ttype = RCU_TASKS_FLAVOR,
670 .init = rcu_sync_torture_init,
671 .readlock = tasks_torture_read_lock,
672 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
673 .readunlock = tasks_torture_read_unlock,
674 .started = rcu_no_completed,
675 .completed = rcu_no_completed,
676 .deferred_free = rcu_tasks_torture_deferred_free,
677 .sync = synchronize_rcu_tasks,
678 .exp_sync = synchronize_rcu_tasks,
679 .call = call_rcu_tasks,
680 .cb_barrier = rcu_barrier_tasks,
681 .fqs = NULL,
682 .stats = NULL,
683 .irq_capable = 1,
684 .name = "tasks"
685 };
686
687 #define RCUTORTURE_TASKS_OPS &tasks_ops,
688
689 static bool __maybe_unused torturing_tasks(void)
690 {
691 return cur_ops == &tasks_ops;
692 }
693
694 #else /* #ifdef CONFIG_TASKS_RCU */
695
696 #define RCUTORTURE_TASKS_OPS
697
698 static bool __maybe_unused torturing_tasks(void)
699 {
700 return false;
701 }
702
703 #endif /* #else #ifdef CONFIG_TASKS_RCU */
704
705 /*
706 * RCU torture priority-boost testing. Runs one real-time thread per
707 * CPU for moderate bursts, repeatedly registering RCU callbacks and
708 * spinning waiting for them to be invoked. If a given callback takes
709 * too long to be invoked, we assume that priority inversion has occurred.
710 */
711
712 struct rcu_boost_inflight {
713 struct rcu_head rcu;
714 int inflight;
715 };
716
717 static void rcu_torture_boost_cb(struct rcu_head *head)
718 {
719 struct rcu_boost_inflight *rbip =
720 container_of(head, struct rcu_boost_inflight, rcu);
721
722 /* Ensure RCU-core accesses precede clearing ->inflight */
723 smp_store_release(&rbip->inflight, 0);
724 }
725
726 static int rcu_torture_boost(void *arg)
727 {
728 unsigned long call_rcu_time;
729 unsigned long endtime;
730 unsigned long oldstarttime;
731 struct rcu_boost_inflight rbi = { .inflight = 0 };
732 struct sched_param sp;
733
734 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
735
736 /* Set real-time priority. */
737 sp.sched_priority = 1;
738 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
739 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
740 n_rcu_torture_boost_rterror++;
741 }
742
743 init_rcu_head_on_stack(&rbi.rcu);
744 /* Each pass through the following loop does one boost-test cycle. */
745 do {
746 /* Wait for the next test interval. */
747 oldstarttime = boost_starttime;
748 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
749 schedule_timeout_interruptible(oldstarttime - jiffies);
750 stutter_wait("rcu_torture_boost");
751 if (torture_must_stop())
752 goto checkwait;
753 }
754
755 /* Do one boost-test interval. */
756 endtime = oldstarttime + test_boost_duration * HZ;
757 call_rcu_time = jiffies;
758 while (ULONG_CMP_LT(jiffies, endtime)) {
759 /* If we don't have a callback in flight, post one. */
760 if (!smp_load_acquire(&rbi.inflight)) {
761 /* RCU core before ->inflight = 1. */
762 smp_store_release(&rbi.inflight, 1);
763 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
764 if (jiffies - call_rcu_time >
765 test_boost_duration * HZ - HZ / 2) {
766 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
767 n_rcu_torture_boost_failure++;
768 }
769 call_rcu_time = jiffies;
770 }
771 stutter_wait("rcu_torture_boost");
772 if (torture_must_stop())
773 goto checkwait;
774 }
775
776 /*
777 * Set the start time of the next test interval.
778 * Yes, this is vulnerable to long delays, but such
779 * delays simply cause a false negative for the next
780 * interval. Besides, we are running at RT priority,
781 * so delays should be relatively rare.
782 */
783 while (oldstarttime == boost_starttime &&
784 !kthread_should_stop()) {
785 if (mutex_trylock(&boost_mutex)) {
786 boost_starttime = jiffies +
787 test_boost_interval * HZ;
788 n_rcu_torture_boosts++;
789 mutex_unlock(&boost_mutex);
790 break;
791 }
792 schedule_timeout_uninterruptible(1);
793 }
794
795 /* Go do the stutter. */
796 checkwait: stutter_wait("rcu_torture_boost");
797 } while (!torture_must_stop());
798
799 /* Clean up and exit. */
800 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
801 torture_shutdown_absorb("rcu_torture_boost");
802 schedule_timeout_uninterruptible(1);
803 }
804 destroy_rcu_head_on_stack(&rbi.rcu);
805 torture_kthread_stopping("rcu_torture_boost");
806 return 0;
807 }
808
809 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
810 {
811 }
812
813 /*
814 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
815 * to call_rcu() or analogous, increasing the probability of occurrence
816 * of callback-overflow corner cases.
817 */
818 static int
819 rcu_torture_cbflood(void *arg)
820 {
821 int err = 1;
822 int i;
823 int j;
824 struct rcu_head *rhp;
825
826 if (cbflood_n_per_burst > 0 &&
827 cbflood_inter_holdoff > 0 &&
828 cbflood_intra_holdoff > 0 &&
829 cur_ops->call &&
830 cur_ops->cb_barrier) {
831 rhp = vmalloc(sizeof(*rhp) *
832 cbflood_n_burst * cbflood_n_per_burst);
833 err = !rhp;
834 }
835 if (err) {
836 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
837 goto wait_for_stop;
838 }
839 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
840 do {
841 schedule_timeout_interruptible(cbflood_inter_holdoff);
842 atomic_long_inc(&n_cbfloods);
843 WARN_ON(signal_pending(current));
844 for (i = 0; i < cbflood_n_burst; i++) {
845 for (j = 0; j < cbflood_n_per_burst; j++) {
846 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
847 rcu_torture_cbflood_cb);
848 }
849 schedule_timeout_interruptible(cbflood_intra_holdoff);
850 WARN_ON(signal_pending(current));
851 }
852 cur_ops->cb_barrier();
853 stutter_wait("rcu_torture_cbflood");
854 } while (!torture_must_stop());
855 vfree(rhp);
856 wait_for_stop:
857 torture_kthread_stopping("rcu_torture_cbflood");
858 return 0;
859 }
860
861 /*
862 * RCU torture force-quiescent-state kthread. Repeatedly induces
863 * bursts of calls to force_quiescent_state(), increasing the probability
864 * of occurrence of some important types of race conditions.
865 */
866 static int
867 rcu_torture_fqs(void *arg)
868 {
869 unsigned long fqs_resume_time;
870 int fqs_burst_remaining;
871
872 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
873 do {
874 fqs_resume_time = jiffies + fqs_stutter * HZ;
875 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
876 !kthread_should_stop()) {
877 schedule_timeout_interruptible(1);
878 }
879 fqs_burst_remaining = fqs_duration;
880 while (fqs_burst_remaining > 0 &&
881 !kthread_should_stop()) {
882 cur_ops->fqs();
883 udelay(fqs_holdoff);
884 fqs_burst_remaining -= fqs_holdoff;
885 }
886 stutter_wait("rcu_torture_fqs");
887 } while (!torture_must_stop());
888 torture_kthread_stopping("rcu_torture_fqs");
889 return 0;
890 }
891
892 /*
893 * RCU torture writer kthread. Repeatedly substitutes a new structure
894 * for that pointed to by rcu_torture_current, freeing the old structure
895 * after a series of grace periods (the "pipeline").
896 */
897 static int
898 rcu_torture_writer(void *arg)
899 {
900 bool can_expedite = !rcu_gp_is_expedited();
901 int expediting = 0;
902 unsigned long gp_snap;
903 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
904 bool gp_sync1 = gp_sync;
905 int i;
906 struct rcu_torture *rp;
907 struct rcu_torture *old_rp;
908 static DEFINE_TORTURE_RANDOM(rand);
909 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
910 RTWS_COND_GET, RTWS_SYNC };
911 int nsynctypes = 0;
912
913 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
914 pr_alert("%s" TORTURE_FLAG
915 " Grace periods expedited from boot/sysfs for %s,\n",
916 torture_type, cur_ops->name);
917 pr_alert("%s" TORTURE_FLAG
918 " Testing of dynamic grace-period expediting diabled.\n",
919 torture_type);
920
921 /* Initialize synctype[] array. If none set, take default. */
922 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
923 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
924 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
925 synctype[nsynctypes++] = RTWS_COND_GET;
926 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
927 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
928 if (gp_exp1 && cur_ops->exp_sync)
929 synctype[nsynctypes++] = RTWS_EXP_SYNC;
930 else if (gp_exp && !cur_ops->exp_sync)
931 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
932 if (gp_normal1 && cur_ops->deferred_free)
933 synctype[nsynctypes++] = RTWS_DEF_FREE;
934 else if (gp_normal && !cur_ops->deferred_free)
935 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
936 if (gp_sync1 && cur_ops->sync)
937 synctype[nsynctypes++] = RTWS_SYNC;
938 else if (gp_sync && !cur_ops->sync)
939 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
940 if (WARN_ONCE(nsynctypes == 0,
941 "rcu_torture_writer: No update-side primitives.\n")) {
942 /*
943 * No updates primitives, so don't try updating.
944 * The resulting test won't be testing much, hence the
945 * above WARN_ONCE().
946 */
947 rcu_torture_writer_state = RTWS_STOPPING;
948 torture_kthread_stopping("rcu_torture_writer");
949 }
950
951 do {
952 rcu_torture_writer_state = RTWS_FIXED_DELAY;
953 schedule_timeout_uninterruptible(1);
954 rp = rcu_torture_alloc();
955 if (rp == NULL)
956 continue;
957 rp->rtort_pipe_count = 0;
958 rcu_torture_writer_state = RTWS_DELAY;
959 udelay(torture_random(&rand) & 0x3ff);
960 rcu_torture_writer_state = RTWS_REPLACE;
961 old_rp = rcu_dereference_check(rcu_torture_current,
962 current == writer_task);
963 rp->rtort_mbtest = 1;
964 rcu_assign_pointer(rcu_torture_current, rp);
965 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
966 if (old_rp) {
967 i = old_rp->rtort_pipe_count;
968 if (i > RCU_TORTURE_PIPE_LEN)
969 i = RCU_TORTURE_PIPE_LEN;
970 atomic_inc(&rcu_torture_wcount[i]);
971 old_rp->rtort_pipe_count++;
972 switch (synctype[torture_random(&rand) % nsynctypes]) {
973 case RTWS_DEF_FREE:
974 rcu_torture_writer_state = RTWS_DEF_FREE;
975 cur_ops->deferred_free(old_rp);
976 break;
977 case RTWS_EXP_SYNC:
978 rcu_torture_writer_state = RTWS_EXP_SYNC;
979 cur_ops->exp_sync();
980 rcu_torture_pipe_update(old_rp);
981 break;
982 case RTWS_COND_GET:
983 rcu_torture_writer_state = RTWS_COND_GET;
984 gp_snap = cur_ops->get_state();
985 i = torture_random(&rand) % 16;
986 if (i != 0)
987 schedule_timeout_interruptible(i);
988 udelay(torture_random(&rand) % 1000);
989 rcu_torture_writer_state = RTWS_COND_SYNC;
990 cur_ops->cond_sync(gp_snap);
991 rcu_torture_pipe_update(old_rp);
992 break;
993 case RTWS_SYNC:
994 rcu_torture_writer_state = RTWS_SYNC;
995 cur_ops->sync();
996 rcu_torture_pipe_update(old_rp);
997 break;
998 default:
999 WARN_ON_ONCE(1);
1000 break;
1001 }
1002 }
1003 rcutorture_record_progress(++rcu_torture_current_version);
1004 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1005 if (can_expedite &&
1006 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1007 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1008 if (expediting >= 0)
1009 rcu_expedite_gp();
1010 else
1011 rcu_unexpedite_gp();
1012 if (++expediting > 3)
1013 expediting = -expediting;
1014 }
1015 rcu_torture_writer_state = RTWS_STUTTER;
1016 stutter_wait("rcu_torture_writer");
1017 } while (!torture_must_stop());
1018 /* Reset expediting back to unexpedited. */
1019 if (expediting > 0)
1020 expediting = -expediting;
1021 while (can_expedite && expediting++ < 0)
1022 rcu_unexpedite_gp();
1023 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1024 rcu_torture_writer_state = RTWS_STOPPING;
1025 torture_kthread_stopping("rcu_torture_writer");
1026 return 0;
1027 }
1028
1029 /*
1030 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1031 * delay between calls.
1032 */
1033 static int
1034 rcu_torture_fakewriter(void *arg)
1035 {
1036 DEFINE_TORTURE_RANDOM(rand);
1037
1038 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1039 set_user_nice(current, MAX_NICE);
1040
1041 do {
1042 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1043 udelay(torture_random(&rand) & 0x3ff);
1044 if (cur_ops->cb_barrier != NULL &&
1045 torture_random(&rand) % (nfakewriters * 8) == 0) {
1046 cur_ops->cb_barrier();
1047 } else if (gp_normal == gp_exp) {
1048 if (torture_random(&rand) & 0x80)
1049 cur_ops->sync();
1050 else
1051 cur_ops->exp_sync();
1052 } else if (gp_normal) {
1053 cur_ops->sync();
1054 } else {
1055 cur_ops->exp_sync();
1056 }
1057 stutter_wait("rcu_torture_fakewriter");
1058 } while (!torture_must_stop());
1059
1060 torture_kthread_stopping("rcu_torture_fakewriter");
1061 return 0;
1062 }
1063
1064 static void rcutorture_trace_dump(void)
1065 {
1066 static atomic_t beenhere = ATOMIC_INIT(0);
1067
1068 if (atomic_read(&beenhere))
1069 return;
1070 if (atomic_xchg(&beenhere, 1) != 0)
1071 return;
1072 ftrace_dump(DUMP_ALL);
1073 }
1074
1075 /*
1076 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1077 * incrementing the corresponding element of the pipeline array. The
1078 * counter in the element should never be greater than 1, otherwise, the
1079 * RCU implementation is broken.
1080 */
1081 static void rcu_torture_timer(unsigned long unused)
1082 {
1083 int idx;
1084 unsigned long started;
1085 unsigned long completed;
1086 static DEFINE_TORTURE_RANDOM(rand);
1087 static DEFINE_SPINLOCK(rand_lock);
1088 struct rcu_torture *p;
1089 int pipe_count;
1090 unsigned long long ts;
1091
1092 idx = cur_ops->readlock();
1093 if (cur_ops->started)
1094 started = cur_ops->started();
1095 else
1096 started = cur_ops->completed();
1097 ts = rcu_trace_clock_local();
1098 p = rcu_dereference_check(rcu_torture_current,
1099 rcu_read_lock_bh_held() ||
1100 rcu_read_lock_sched_held() ||
1101 srcu_read_lock_held(srcu_ctlp) ||
1102 torturing_tasks());
1103 if (p == NULL) {
1104 /* Leave because rcu_torture_writer is not yet underway */
1105 cur_ops->readunlock(idx);
1106 return;
1107 }
1108 if (p->rtort_mbtest == 0)
1109 atomic_inc(&n_rcu_torture_mberror);
1110 spin_lock(&rand_lock);
1111 cur_ops->read_delay(&rand);
1112 n_rcu_torture_timers++;
1113 spin_unlock(&rand_lock);
1114 preempt_disable();
1115 pipe_count = p->rtort_pipe_count;
1116 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1117 /* Should not happen, but... */
1118 pipe_count = RCU_TORTURE_PIPE_LEN;
1119 }
1120 completed = cur_ops->completed();
1121 if (pipe_count > 1) {
1122 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1123 started, completed);
1124 rcutorture_trace_dump();
1125 }
1126 __this_cpu_inc(rcu_torture_count[pipe_count]);
1127 completed = completed - started;
1128 if (cur_ops->started)
1129 completed++;
1130 if (completed > RCU_TORTURE_PIPE_LEN) {
1131 /* Should not happen, but... */
1132 completed = RCU_TORTURE_PIPE_LEN;
1133 }
1134 __this_cpu_inc(rcu_torture_batch[completed]);
1135 preempt_enable();
1136 cur_ops->readunlock(idx);
1137 }
1138
1139 /*
1140 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1141 * incrementing the corresponding element of the pipeline array. The
1142 * counter in the element should never be greater than 1, otherwise, the
1143 * RCU implementation is broken.
1144 */
1145 static int
1146 rcu_torture_reader(void *arg)
1147 {
1148 unsigned long started;
1149 unsigned long completed;
1150 int idx;
1151 DEFINE_TORTURE_RANDOM(rand);
1152 struct rcu_torture *p;
1153 int pipe_count;
1154 struct timer_list t;
1155 unsigned long long ts;
1156
1157 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1158 set_user_nice(current, MAX_NICE);
1159 if (irqreader && cur_ops->irq_capable)
1160 setup_timer_on_stack(&t, rcu_torture_timer, 0);
1161
1162 do {
1163 if (irqreader && cur_ops->irq_capable) {
1164 if (!timer_pending(&t))
1165 mod_timer(&t, jiffies + 1);
1166 }
1167 idx = cur_ops->readlock();
1168 if (cur_ops->started)
1169 started = cur_ops->started();
1170 else
1171 started = cur_ops->completed();
1172 ts = rcu_trace_clock_local();
1173 p = rcu_dereference_check(rcu_torture_current,
1174 rcu_read_lock_bh_held() ||
1175 rcu_read_lock_sched_held() ||
1176 srcu_read_lock_held(srcu_ctlp) ||
1177 torturing_tasks());
1178 if (p == NULL) {
1179 /* Wait for rcu_torture_writer to get underway */
1180 cur_ops->readunlock(idx);
1181 schedule_timeout_interruptible(HZ);
1182 continue;
1183 }
1184 if (p->rtort_mbtest == 0)
1185 atomic_inc(&n_rcu_torture_mberror);
1186 cur_ops->read_delay(&rand);
1187 preempt_disable();
1188 pipe_count = p->rtort_pipe_count;
1189 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1190 /* Should not happen, but... */
1191 pipe_count = RCU_TORTURE_PIPE_LEN;
1192 }
1193 completed = cur_ops->completed();
1194 if (pipe_count > 1) {
1195 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1196 ts, started, completed);
1197 rcutorture_trace_dump();
1198 }
1199 __this_cpu_inc(rcu_torture_count[pipe_count]);
1200 completed = completed - started;
1201 if (cur_ops->started)
1202 completed++;
1203 if (completed > RCU_TORTURE_PIPE_LEN) {
1204 /* Should not happen, but... */
1205 completed = RCU_TORTURE_PIPE_LEN;
1206 }
1207 __this_cpu_inc(rcu_torture_batch[completed]);
1208 preempt_enable();
1209 cur_ops->readunlock(idx);
1210 stutter_wait("rcu_torture_reader");
1211 } while (!torture_must_stop());
1212 if (irqreader && cur_ops->irq_capable) {
1213 del_timer_sync(&t);
1214 destroy_timer_on_stack(&t);
1215 }
1216 torture_kthread_stopping("rcu_torture_reader");
1217 return 0;
1218 }
1219
1220 /*
1221 * Print torture statistics. Caller must ensure that there is only
1222 * one call to this function at a given time!!! This is normally
1223 * accomplished by relying on the module system to only have one copy
1224 * of the module loaded, and then by giving the rcu_torture_stats
1225 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1226 * thread is not running).
1227 */
1228 static void
1229 rcu_torture_stats_print(void)
1230 {
1231 int cpu;
1232 int i;
1233 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1234 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1235 static unsigned long rtcv_snap = ULONG_MAX;
1236
1237 for_each_possible_cpu(cpu) {
1238 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1239 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1240 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1241 }
1242 }
1243 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1244 if (pipesummary[i] != 0)
1245 break;
1246 }
1247
1248 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1249 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1250 rcu_torture_current,
1251 rcu_torture_current_version,
1252 list_empty(&rcu_torture_freelist),
1253 atomic_read(&n_rcu_torture_alloc),
1254 atomic_read(&n_rcu_torture_alloc_fail),
1255 atomic_read(&n_rcu_torture_free));
1256 pr_cont("rtmbe: %d rtbke: %ld rtbre: %ld ",
1257 atomic_read(&n_rcu_torture_mberror),
1258 n_rcu_torture_boost_ktrerror,
1259 n_rcu_torture_boost_rterror);
1260 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1261 n_rcu_torture_boost_failure,
1262 n_rcu_torture_boosts,
1263 n_rcu_torture_timers);
1264 torture_onoff_stats();
1265 pr_cont("barrier: %ld/%ld:%ld ",
1266 n_barrier_successes,
1267 n_barrier_attempts,
1268 n_rcu_torture_barrier_error);
1269 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1270
1271 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1272 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1273 n_rcu_torture_barrier_error != 0 ||
1274 n_rcu_torture_boost_ktrerror != 0 ||
1275 n_rcu_torture_boost_rterror != 0 ||
1276 n_rcu_torture_boost_failure != 0 ||
1277 i > 1) {
1278 pr_cont("%s", "!!! ");
1279 atomic_inc(&n_rcu_torture_error);
1280 WARN_ON_ONCE(1);
1281 }
1282 pr_cont("Reader Pipe: ");
1283 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1284 pr_cont(" %ld", pipesummary[i]);
1285 pr_cont("\n");
1286
1287 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1288 pr_cont("Reader Batch: ");
1289 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1290 pr_cont(" %ld", batchsummary[i]);
1291 pr_cont("\n");
1292
1293 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1294 pr_cont("Free-Block Circulation: ");
1295 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1296 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1297 }
1298 pr_cont("\n");
1299
1300 if (cur_ops->stats)
1301 cur_ops->stats();
1302 if (rtcv_snap == rcu_torture_current_version &&
1303 rcu_torture_current != NULL) {
1304 int __maybe_unused flags;
1305 unsigned long __maybe_unused gpnum;
1306 unsigned long __maybe_unused completed;
1307
1308 rcutorture_get_gp_data(cur_ops->ttype,
1309 &flags, &gpnum, &completed);
1310 pr_alert("??? Writer stall state %d g%lu c%lu f%#x\n",
1311 rcu_torture_writer_state,
1312 gpnum, completed, flags);
1313 show_rcu_gp_kthreads();
1314 rcutorture_trace_dump();
1315 }
1316 rtcv_snap = rcu_torture_current_version;
1317 }
1318
1319 /*
1320 * Periodically prints torture statistics, if periodic statistics printing
1321 * was specified via the stat_interval module parameter.
1322 */
1323 static int
1324 rcu_torture_stats(void *arg)
1325 {
1326 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1327 do {
1328 schedule_timeout_interruptible(stat_interval * HZ);
1329 rcu_torture_stats_print();
1330 torture_shutdown_absorb("rcu_torture_stats");
1331 } while (!torture_must_stop());
1332 torture_kthread_stopping("rcu_torture_stats");
1333 return 0;
1334 }
1335
1336 static inline void
1337 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1338 {
1339 pr_alert("%s" TORTURE_FLAG
1340 "--- %s: nreaders=%d nfakewriters=%d "
1341 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1342 "shuffle_interval=%d stutter=%d irqreader=%d "
1343 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1344 "test_boost=%d/%d test_boost_interval=%d "
1345 "test_boost_duration=%d shutdown_secs=%d "
1346 "stall_cpu=%d stall_cpu_holdoff=%d "
1347 "n_barrier_cbs=%d "
1348 "onoff_interval=%d onoff_holdoff=%d\n",
1349 torture_type, tag, nrealreaders, nfakewriters,
1350 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1351 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1352 test_boost, cur_ops->can_boost,
1353 test_boost_interval, test_boost_duration, shutdown_secs,
1354 stall_cpu, stall_cpu_holdoff,
1355 n_barrier_cbs,
1356 onoff_interval, onoff_holdoff);
1357 }
1358
1359 static void rcutorture_booster_cleanup(int cpu)
1360 {
1361 struct task_struct *t;
1362
1363 if (boost_tasks[cpu] == NULL)
1364 return;
1365 mutex_lock(&boost_mutex);
1366 t = boost_tasks[cpu];
1367 boost_tasks[cpu] = NULL;
1368 mutex_unlock(&boost_mutex);
1369
1370 /* This must be outside of the mutex, otherwise deadlock! */
1371 torture_stop_kthread(rcu_torture_boost, t);
1372 }
1373
1374 static int rcutorture_booster_init(int cpu)
1375 {
1376 int retval;
1377
1378 if (boost_tasks[cpu] != NULL)
1379 return 0; /* Already created, nothing more to do. */
1380
1381 /* Don't allow time recalculation while creating a new task. */
1382 mutex_lock(&boost_mutex);
1383 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1384 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1385 cpu_to_node(cpu),
1386 "rcu_torture_boost");
1387 if (IS_ERR(boost_tasks[cpu])) {
1388 retval = PTR_ERR(boost_tasks[cpu]);
1389 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1390 n_rcu_torture_boost_ktrerror++;
1391 boost_tasks[cpu] = NULL;
1392 mutex_unlock(&boost_mutex);
1393 return retval;
1394 }
1395 kthread_bind(boost_tasks[cpu], cpu);
1396 wake_up_process(boost_tasks[cpu]);
1397 mutex_unlock(&boost_mutex);
1398 return 0;
1399 }
1400
1401 /*
1402 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1403 * induces a CPU stall for the time specified by stall_cpu.
1404 */
1405 static int rcu_torture_stall(void *args)
1406 {
1407 unsigned long stop_at;
1408
1409 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1410 if (stall_cpu_holdoff > 0) {
1411 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1412 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1413 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1414 }
1415 if (!kthread_should_stop()) {
1416 stop_at = get_seconds() + stall_cpu;
1417 /* RCU CPU stall is expected behavior in following code. */
1418 pr_alert("rcu_torture_stall start.\n");
1419 rcu_read_lock();
1420 preempt_disable();
1421 while (ULONG_CMP_LT(get_seconds(), stop_at))
1422 continue; /* Induce RCU CPU stall warning. */
1423 preempt_enable();
1424 rcu_read_unlock();
1425 pr_alert("rcu_torture_stall end.\n");
1426 }
1427 torture_shutdown_absorb("rcu_torture_stall");
1428 while (!kthread_should_stop())
1429 schedule_timeout_interruptible(10 * HZ);
1430 return 0;
1431 }
1432
1433 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1434 static int __init rcu_torture_stall_init(void)
1435 {
1436 if (stall_cpu <= 0)
1437 return 0;
1438 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1439 }
1440
1441 /* Callback function for RCU barrier testing. */
1442 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1443 {
1444 atomic_inc(&barrier_cbs_invoked);
1445 }
1446
1447 /* kthread function to register callbacks used to test RCU barriers. */
1448 static int rcu_torture_barrier_cbs(void *arg)
1449 {
1450 long myid = (long)arg;
1451 bool lastphase = 0;
1452 bool newphase;
1453 struct rcu_head rcu;
1454
1455 init_rcu_head_on_stack(&rcu);
1456 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1457 set_user_nice(current, MAX_NICE);
1458 do {
1459 wait_event(barrier_cbs_wq[myid],
1460 (newphase =
1461 smp_load_acquire(&barrier_phase)) != lastphase ||
1462 torture_must_stop());
1463 lastphase = newphase;
1464 if (torture_must_stop())
1465 break;
1466 /*
1467 * The above smp_load_acquire() ensures barrier_phase load
1468 * is ordered before the folloiwng ->call().
1469 */
1470 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1471 if (atomic_dec_and_test(&barrier_cbs_count))
1472 wake_up(&barrier_wq);
1473 } while (!torture_must_stop());
1474 if (cur_ops->cb_barrier != NULL)
1475 cur_ops->cb_barrier();
1476 destroy_rcu_head_on_stack(&rcu);
1477 torture_kthread_stopping("rcu_torture_barrier_cbs");
1478 return 0;
1479 }
1480
1481 /* kthread function to drive and coordinate RCU barrier testing. */
1482 static int rcu_torture_barrier(void *arg)
1483 {
1484 int i;
1485
1486 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1487 do {
1488 atomic_set(&barrier_cbs_invoked, 0);
1489 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1490 /* Ensure barrier_phase ordered after prior assignments. */
1491 smp_store_release(&barrier_phase, !barrier_phase);
1492 for (i = 0; i < n_barrier_cbs; i++)
1493 wake_up(&barrier_cbs_wq[i]);
1494 wait_event(barrier_wq,
1495 atomic_read(&barrier_cbs_count) == 0 ||
1496 torture_must_stop());
1497 if (torture_must_stop())
1498 break;
1499 n_barrier_attempts++;
1500 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1501 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1502 n_rcu_torture_barrier_error++;
1503 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1504 atomic_read(&barrier_cbs_invoked),
1505 n_barrier_cbs);
1506 WARN_ON_ONCE(1);
1507 }
1508 n_barrier_successes++;
1509 schedule_timeout_interruptible(HZ / 10);
1510 } while (!torture_must_stop());
1511 torture_kthread_stopping("rcu_torture_barrier");
1512 return 0;
1513 }
1514
1515 /* Initialize RCU barrier testing. */
1516 static int rcu_torture_barrier_init(void)
1517 {
1518 int i;
1519 int ret;
1520
1521 if (n_barrier_cbs <= 0)
1522 return 0;
1523 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1524 pr_alert("%s" TORTURE_FLAG
1525 " Call or barrier ops missing for %s,\n",
1526 torture_type, cur_ops->name);
1527 pr_alert("%s" TORTURE_FLAG
1528 " RCU barrier testing omitted from run.\n",
1529 torture_type);
1530 return 0;
1531 }
1532 atomic_set(&barrier_cbs_count, 0);
1533 atomic_set(&barrier_cbs_invoked, 0);
1534 barrier_cbs_tasks =
1535 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
1536 GFP_KERNEL);
1537 barrier_cbs_wq =
1538 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
1539 GFP_KERNEL);
1540 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1541 return -ENOMEM;
1542 for (i = 0; i < n_barrier_cbs; i++) {
1543 init_waitqueue_head(&barrier_cbs_wq[i]);
1544 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1545 (void *)(long)i,
1546 barrier_cbs_tasks[i]);
1547 if (ret)
1548 return ret;
1549 }
1550 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1551 }
1552
1553 /* Clean up after RCU barrier testing. */
1554 static void rcu_torture_barrier_cleanup(void)
1555 {
1556 int i;
1557
1558 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1559 if (barrier_cbs_tasks != NULL) {
1560 for (i = 0; i < n_barrier_cbs; i++)
1561 torture_stop_kthread(rcu_torture_barrier_cbs,
1562 barrier_cbs_tasks[i]);
1563 kfree(barrier_cbs_tasks);
1564 barrier_cbs_tasks = NULL;
1565 }
1566 if (barrier_cbs_wq != NULL) {
1567 kfree(barrier_cbs_wq);
1568 barrier_cbs_wq = NULL;
1569 }
1570 }
1571
1572 static int rcutorture_cpu_notify(struct notifier_block *self,
1573 unsigned long action, void *hcpu)
1574 {
1575 long cpu = (long)hcpu;
1576
1577 switch (action) {
1578 case CPU_ONLINE:
1579 case CPU_DOWN_FAILED:
1580 (void)rcutorture_booster_init(cpu);
1581 break;
1582 case CPU_DOWN_PREPARE:
1583 rcutorture_booster_cleanup(cpu);
1584 break;
1585 default:
1586 break;
1587 }
1588 return NOTIFY_OK;
1589 }
1590
1591 static struct notifier_block rcutorture_cpu_nb = {
1592 .notifier_call = rcutorture_cpu_notify,
1593 };
1594
1595 static void
1596 rcu_torture_cleanup(void)
1597 {
1598 int i;
1599
1600 rcutorture_record_test_transition();
1601 if (torture_cleanup_begin()) {
1602 if (cur_ops->cb_barrier != NULL)
1603 cur_ops->cb_barrier();
1604 return;
1605 }
1606
1607 rcu_torture_barrier_cleanup();
1608 torture_stop_kthread(rcu_torture_stall, stall_task);
1609 torture_stop_kthread(rcu_torture_writer, writer_task);
1610
1611 if (reader_tasks) {
1612 for (i = 0; i < nrealreaders; i++)
1613 torture_stop_kthread(rcu_torture_reader,
1614 reader_tasks[i]);
1615 kfree(reader_tasks);
1616 }
1617 rcu_torture_current = NULL;
1618
1619 if (fakewriter_tasks) {
1620 for (i = 0; i < nfakewriters; i++) {
1621 torture_stop_kthread(rcu_torture_fakewriter,
1622 fakewriter_tasks[i]);
1623 }
1624 kfree(fakewriter_tasks);
1625 fakewriter_tasks = NULL;
1626 }
1627
1628 torture_stop_kthread(rcu_torture_stats, stats_task);
1629 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1630 for (i = 0; i < ncbflooders; i++)
1631 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1632 if ((test_boost == 1 && cur_ops->can_boost) ||
1633 test_boost == 2) {
1634 unregister_cpu_notifier(&rcutorture_cpu_nb);
1635 for_each_possible_cpu(i)
1636 rcutorture_booster_cleanup(i);
1637 }
1638
1639 /*
1640 * Wait for all RCU callbacks to fire, then do flavor-specific
1641 * cleanup operations.
1642 */
1643 if (cur_ops->cb_barrier != NULL)
1644 cur_ops->cb_barrier();
1645 if (cur_ops->cleanup != NULL)
1646 cur_ops->cleanup();
1647
1648 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1649
1650 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1651 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1652 else if (torture_onoff_failures())
1653 rcu_torture_print_module_parms(cur_ops,
1654 "End of test: RCU_HOTPLUG");
1655 else
1656 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1657 torture_cleanup_end();
1658 }
1659
1660 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1661 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1662 {
1663 }
1664
1665 static void rcu_torture_err_cb(struct rcu_head *rhp)
1666 {
1667 /*
1668 * This -might- happen due to race conditions, but is unlikely.
1669 * The scenario that leads to this happening is that the
1670 * first of the pair of duplicate callbacks is queued,
1671 * someone else starts a grace period that includes that
1672 * callback, then the second of the pair must wait for the
1673 * next grace period. Unlikely, but can happen. If it
1674 * does happen, the debug-objects subsystem won't have splatted.
1675 */
1676 pr_alert("rcutorture: duplicated callback was invoked.\n");
1677 }
1678 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1679
1680 /*
1681 * Verify that double-free causes debug-objects to complain, but only
1682 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1683 * cannot be carried out.
1684 */
1685 static void rcu_test_debug_objects(void)
1686 {
1687 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1688 struct rcu_head rh1;
1689 struct rcu_head rh2;
1690
1691 init_rcu_head_on_stack(&rh1);
1692 init_rcu_head_on_stack(&rh2);
1693 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1694
1695 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1696 preempt_disable(); /* Prevent preemption from interrupting test. */
1697 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1698 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1699 local_irq_disable(); /* Make it harder to start a new grace period. */
1700 call_rcu(&rh2, rcu_torture_leak_cb);
1701 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1702 local_irq_enable();
1703 rcu_read_unlock();
1704 preempt_enable();
1705
1706 /* Wait for them all to get done so we can safely return. */
1707 rcu_barrier();
1708 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1709 destroy_rcu_head_on_stack(&rh1);
1710 destroy_rcu_head_on_stack(&rh2);
1711 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1712 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1713 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1714 }
1715
1716 static int __init
1717 rcu_torture_init(void)
1718 {
1719 int i;
1720 int cpu;
1721 int firsterr = 0;
1722 static struct rcu_torture_ops *torture_ops[] = {
1723 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1724 &sched_ops, RCUTORTURE_TASKS_OPS
1725 };
1726
1727 if (!torture_init_begin(torture_type, verbose, &torture_runnable))
1728 return -EBUSY;
1729
1730 /* Process args and tell the world that the torturer is on the job. */
1731 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1732 cur_ops = torture_ops[i];
1733 if (strcmp(torture_type, cur_ops->name) == 0)
1734 break;
1735 }
1736 if (i == ARRAY_SIZE(torture_ops)) {
1737 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1738 torture_type);
1739 pr_alert("rcu-torture types:");
1740 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1741 pr_alert(" %s", torture_ops[i]->name);
1742 pr_alert("\n");
1743 firsterr = -EINVAL;
1744 goto unwind;
1745 }
1746 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1747 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1748 fqs_duration = 0;
1749 }
1750 if (cur_ops->init)
1751 cur_ops->init();
1752
1753 if (nreaders >= 0) {
1754 nrealreaders = nreaders;
1755 } else {
1756 nrealreaders = num_online_cpus() - 2 - nreaders;
1757 if (nrealreaders <= 0)
1758 nrealreaders = 1;
1759 }
1760 rcu_torture_print_module_parms(cur_ops, "Start of test");
1761
1762 /* Set up the freelist. */
1763
1764 INIT_LIST_HEAD(&rcu_torture_freelist);
1765 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1766 rcu_tortures[i].rtort_mbtest = 0;
1767 list_add_tail(&rcu_tortures[i].rtort_free,
1768 &rcu_torture_freelist);
1769 }
1770
1771 /* Initialize the statistics so that each run gets its own numbers. */
1772
1773 rcu_torture_current = NULL;
1774 rcu_torture_current_version = 0;
1775 atomic_set(&n_rcu_torture_alloc, 0);
1776 atomic_set(&n_rcu_torture_alloc_fail, 0);
1777 atomic_set(&n_rcu_torture_free, 0);
1778 atomic_set(&n_rcu_torture_mberror, 0);
1779 atomic_set(&n_rcu_torture_error, 0);
1780 n_rcu_torture_barrier_error = 0;
1781 n_rcu_torture_boost_ktrerror = 0;
1782 n_rcu_torture_boost_rterror = 0;
1783 n_rcu_torture_boost_failure = 0;
1784 n_rcu_torture_boosts = 0;
1785 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1786 atomic_set(&rcu_torture_wcount[i], 0);
1787 for_each_possible_cpu(cpu) {
1788 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1789 per_cpu(rcu_torture_count, cpu)[i] = 0;
1790 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1791 }
1792 }
1793
1794 /* Start up the kthreads. */
1795
1796 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1797 writer_task);
1798 if (firsterr)
1799 goto unwind;
1800 if (nfakewriters > 0) {
1801 fakewriter_tasks = kzalloc(nfakewriters *
1802 sizeof(fakewriter_tasks[0]),
1803 GFP_KERNEL);
1804 if (fakewriter_tasks == NULL) {
1805 VERBOSE_TOROUT_ERRSTRING("out of memory");
1806 firsterr = -ENOMEM;
1807 goto unwind;
1808 }
1809 }
1810 for (i = 0; i < nfakewriters; i++) {
1811 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1812 NULL, fakewriter_tasks[i]);
1813 if (firsterr)
1814 goto unwind;
1815 }
1816 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
1817 GFP_KERNEL);
1818 if (reader_tasks == NULL) {
1819 VERBOSE_TOROUT_ERRSTRING("out of memory");
1820 firsterr = -ENOMEM;
1821 goto unwind;
1822 }
1823 for (i = 0; i < nrealreaders; i++) {
1824 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1825 reader_tasks[i]);
1826 if (firsterr)
1827 goto unwind;
1828 }
1829 if (stat_interval > 0) {
1830 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1831 stats_task);
1832 if (firsterr)
1833 goto unwind;
1834 }
1835 if (test_no_idle_hz && shuffle_interval > 0) {
1836 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1837 if (firsterr)
1838 goto unwind;
1839 }
1840 if (stutter < 0)
1841 stutter = 0;
1842 if (stutter) {
1843 firsterr = torture_stutter_init(stutter * HZ);
1844 if (firsterr)
1845 goto unwind;
1846 }
1847 if (fqs_duration < 0)
1848 fqs_duration = 0;
1849 if (fqs_duration) {
1850 /* Create the fqs thread */
1851 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1852 fqs_task);
1853 if (firsterr)
1854 goto unwind;
1855 }
1856 if (test_boost_interval < 1)
1857 test_boost_interval = 1;
1858 if (test_boost_duration < 2)
1859 test_boost_duration = 2;
1860 if ((test_boost == 1 && cur_ops->can_boost) ||
1861 test_boost == 2) {
1862
1863 boost_starttime = jiffies + test_boost_interval * HZ;
1864 register_cpu_notifier(&rcutorture_cpu_nb);
1865 for_each_possible_cpu(i) {
1866 if (cpu_is_offline(i))
1867 continue; /* Heuristic: CPU can go offline. */
1868 firsterr = rcutorture_booster_init(i);
1869 if (firsterr)
1870 goto unwind;
1871 }
1872 }
1873 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1874 if (firsterr)
1875 goto unwind;
1876 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1877 if (firsterr)
1878 goto unwind;
1879 firsterr = rcu_torture_stall_init();
1880 if (firsterr)
1881 goto unwind;
1882 firsterr = rcu_torture_barrier_init();
1883 if (firsterr)
1884 goto unwind;
1885 if (object_debug)
1886 rcu_test_debug_objects();
1887 if (cbflood_n_burst > 0) {
1888 /* Create the cbflood threads */
1889 ncbflooders = (num_online_cpus() + 3) / 4;
1890 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1891 GFP_KERNEL);
1892 if (!cbflood_task) {
1893 VERBOSE_TOROUT_ERRSTRING("out of memory");
1894 firsterr = -ENOMEM;
1895 goto unwind;
1896 }
1897 for (i = 0; i < ncbflooders; i++) {
1898 firsterr = torture_create_kthread(rcu_torture_cbflood,
1899 NULL,
1900 cbflood_task[i]);
1901 if (firsterr)
1902 goto unwind;
1903 }
1904 }
1905 rcutorture_record_test_transition();
1906 torture_init_end();
1907 return 0;
1908
1909 unwind:
1910 torture_init_end();
1911 rcu_torture_cleanup();
1912 return firsterr;
1913 }
1914
1915 module_init(rcu_torture_init);
1916 module_exit(rcu_torture_cleanup);
Linux with added FPC-III support