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powerpc/powernv: Report size of OPAL memcons log
[linux/fpc-iii.git] / kernel / rcu / rcutorture.c
blob87c51225ceeca991bf64505bac8eedf3e23e44cf
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], rcu_torture_count);
134 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch);
135 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1];
136 static atomic_t n_rcu_torture_alloc;
137 static atomic_t n_rcu_torture_alloc_fail;
138 static atomic_t n_rcu_torture_free;
139 static atomic_t n_rcu_torture_mberror;
140 static atomic_t n_rcu_torture_error;
141 static long n_rcu_torture_barrier_error;
142 static long n_rcu_torture_boost_ktrerror;
143 static long n_rcu_torture_boost_rterror;
144 static long n_rcu_torture_boost_failure;
145 static long n_rcu_torture_boosts;
146 static long n_rcu_torture_timers;
147 static long n_barrier_attempts;
148 static long n_barrier_successes;
149 static atomic_long_t n_cbfloods;
150 static struct list_head rcu_torture_removed;
151
152 static int rcu_torture_writer_state;
153 #define RTWS_FIXED_DELAY 0
154 #define RTWS_DELAY 1
155 #define RTWS_REPLACE 2
156 #define RTWS_DEF_FREE 3
157 #define RTWS_EXP_SYNC 4
158 #define RTWS_COND_GET 5
159 #define RTWS_COND_SYNC 6
160 #define RTWS_SYNC 7
161 #define RTWS_STUTTER 8
162 #define RTWS_STOPPING 9
163 static const char * const rcu_torture_writer_state_names[] = {
164 "RTWS_FIXED_DELAY",
165 "RTWS_DELAY",
166 "RTWS_REPLACE",
167 "RTWS_DEF_FREE",
168 "RTWS_EXP_SYNC",
169 "RTWS_COND_GET",
170 "RTWS_COND_SYNC",
171 "RTWS_SYNC",
172 "RTWS_STUTTER",
173 "RTWS_STOPPING",
174 };
175
176 static const char *rcu_torture_writer_state_getname(void)
177 {
178 unsigned int i = READ_ONCE(rcu_torture_writer_state);
179
180 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names))
181 return "???";
182 return rcu_torture_writer_state_names[i];
183 }
184
185 static int torture_runnable = IS_ENABLED(MODULE);
186 module_param(torture_runnable, int, 0444);
187 MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot");
188
189 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU)
190 #define rcu_can_boost() 1
191 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
192 #define rcu_can_boost() 0
193 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
194
195 #ifdef CONFIG_RCU_TRACE
196 static u64 notrace rcu_trace_clock_local(void)
197 {
198 u64 ts = trace_clock_local();
199 unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC);
200 return ts;
201 }
202 #else /* #ifdef CONFIG_RCU_TRACE */
203 static u64 notrace rcu_trace_clock_local(void)
204 {
205 return 0ULL;
206 }
207 #endif /* #else #ifdef CONFIG_RCU_TRACE */
208
209 static unsigned long boost_starttime; /* jiffies of next boost test start. */
210 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
211 /* and boost task create/destroy. */
212 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */
213 static bool barrier_phase; /* Test phase. */
214 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */
215 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */
216 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq);
217
218 /*
219 * Allocate an element from the rcu_tortures pool.
220 */
221 static struct rcu_torture *
222 rcu_torture_alloc(void)
223 {
224 struct list_head *p;
225
226 spin_lock_bh(&rcu_torture_lock);
227 if (list_empty(&rcu_torture_freelist)) {
228 atomic_inc(&n_rcu_torture_alloc_fail);
229 spin_unlock_bh(&rcu_torture_lock);
230 return NULL;
231 }
232 atomic_inc(&n_rcu_torture_alloc);
233 p = rcu_torture_freelist.next;
234 list_del_init(p);
235 spin_unlock_bh(&rcu_torture_lock);
236 return container_of(p, struct rcu_torture, rtort_free);
237 }
238
239 /*
240 * Free an element to the rcu_tortures pool.
241 */
242 static void
243 rcu_torture_free(struct rcu_torture *p)
244 {
245 atomic_inc(&n_rcu_torture_free);
246 spin_lock_bh(&rcu_torture_lock);
247 list_add_tail(&p->rtort_free, &rcu_torture_freelist);
248 spin_unlock_bh(&rcu_torture_lock);
249 }
250
251 /*
252 * Operations vector for selecting different types of tests.
253 */
254
255 struct rcu_torture_ops {
256 int ttype;
257 void (*init)(void);
258 void (*cleanup)(void);
259 int (*readlock)(void);
260 void (*read_delay)(struct torture_random_state *rrsp);
261 void (*readunlock)(int idx);
262 unsigned long (*started)(void);
263 unsigned long (*completed)(void);
264 void (*deferred_free)(struct rcu_torture *p);
265 void (*sync)(void);
266 void (*exp_sync)(void);
267 unsigned long (*get_state)(void);
268 void (*cond_sync)(unsigned long oldstate);
269 call_rcu_func_t call;
270 void (*cb_barrier)(void);
271 void (*fqs)(void);
272 void (*stats)(void);
273 int irq_capable;
274 int can_boost;
275 const char *name;
276 };
277
278 static struct rcu_torture_ops *cur_ops;
279
280 /*
281 * Definitions for rcu torture testing.
282 */
283
284 static int rcu_torture_read_lock(void) __acquires(RCU)
285 {
286 rcu_read_lock();
287 return 0;
288 }
289
290 static void rcu_read_delay(struct torture_random_state *rrsp)
291 {
292 unsigned long started;
293 unsigned long completed;
294 const unsigned long shortdelay_us = 200;
295 const unsigned long longdelay_ms = 50;
296 unsigned long long ts;
297
298 /* We want a short delay sometimes to make a reader delay the grace
299 * period, and we want a long delay occasionally to trigger
300 * force_quiescent_state. */
301
302 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) {
303 started = cur_ops->completed();
304 ts = rcu_trace_clock_local();
305 mdelay(longdelay_ms);
306 completed = cur_ops->completed();
307 do_trace_rcu_torture_read(cur_ops->name, NULL, ts,
308 started, completed);
309 }
310 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us)))
311 udelay(shortdelay_us);
312 #ifdef CONFIG_PREEMPT
313 if (!preempt_count() &&
314 !(torture_random(rrsp) % (nrealreaders * 20000)))
315 preempt_schedule(); /* No QS if preempt_disable() in effect */
316 #endif
317 }
318
319 static void rcu_torture_read_unlock(int idx) __releases(RCU)
320 {
321 rcu_read_unlock();
322 }
323
324 /*
325 * Update callback in the pipe. This should be invoked after a grace period.
326 */
327 static bool
328 rcu_torture_pipe_update_one(struct rcu_torture *rp)
329 {
330 int i;
331
332 i = rp->rtort_pipe_count;
333 if (i > RCU_TORTURE_PIPE_LEN)
334 i = RCU_TORTURE_PIPE_LEN;
335 atomic_inc(&rcu_torture_wcount[i]);
336 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) {
337 rp->rtort_mbtest = 0;
338 return true;
339 }
340 return false;
341 }
342
343 /*
344 * Update all callbacks in the pipe. Suitable for synchronous grace-period
345 * primitives.
346 */
347 static void
348 rcu_torture_pipe_update(struct rcu_torture *old_rp)
349 {
350 struct rcu_torture *rp;
351 struct rcu_torture *rp1;
352
353 if (old_rp)
354 list_add(&old_rp->rtort_free, &rcu_torture_removed);
355 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) {
356 if (rcu_torture_pipe_update_one(rp)) {
357 list_del(&rp->rtort_free);
358 rcu_torture_free(rp);
359 }
360 }
361 }
362
363 static void
364 rcu_torture_cb(struct rcu_head *p)
365 {
366 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu);
367
368 if (torture_must_stop_irq()) {
369 /* Test is ending, just drop callbacks on the floor. */
370 /* The next initialization will pick up the pieces. */
371 return;
372 }
373 if (rcu_torture_pipe_update_one(rp))
374 rcu_torture_free(rp);
375 else
376 cur_ops->deferred_free(rp);
377 }
378
379 static unsigned long rcu_no_completed(void)
380 {
381 return 0;
382 }
383
384 static void rcu_torture_deferred_free(struct rcu_torture *p)
385 {
386 call_rcu(&p->rtort_rcu, rcu_torture_cb);
387 }
388
389 static void rcu_sync_torture_init(void)
390 {
391 INIT_LIST_HEAD(&rcu_torture_removed);
392 }
393
394 static struct rcu_torture_ops rcu_ops = {
395 .ttype = RCU_FLAVOR,
396 .init = rcu_sync_torture_init,
397 .readlock = rcu_torture_read_lock,
398 .read_delay = rcu_read_delay,
399 .readunlock = rcu_torture_read_unlock,
400 .started = rcu_batches_started,
401 .completed = rcu_batches_completed,
402 .deferred_free = rcu_torture_deferred_free,
403 .sync = synchronize_rcu,
404 .exp_sync = synchronize_rcu_expedited,
405 .get_state = get_state_synchronize_rcu,
406 .cond_sync = cond_synchronize_rcu,
407 .call = call_rcu,
408 .cb_barrier = rcu_barrier,
409 .fqs = rcu_force_quiescent_state,
410 .stats = NULL,
411 .irq_capable = 1,
412 .can_boost = rcu_can_boost(),
413 .name = "rcu"
414 };
415
416 /*
417 * Definitions for rcu_bh torture testing.
418 */
419
420 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH)
421 {
422 rcu_read_lock_bh();
423 return 0;
424 }
425
426 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH)
427 {
428 rcu_read_unlock_bh();
429 }
430
431 static void rcu_bh_torture_deferred_free(struct rcu_torture *p)
432 {
433 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb);
434 }
435
436 static struct rcu_torture_ops rcu_bh_ops = {
437 .ttype = RCU_BH_FLAVOR,
438 .init = rcu_sync_torture_init,
439 .readlock = rcu_bh_torture_read_lock,
440 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
441 .readunlock = rcu_bh_torture_read_unlock,
442 .started = rcu_batches_started_bh,
443 .completed = rcu_batches_completed_bh,
444 .deferred_free = rcu_bh_torture_deferred_free,
445 .sync = synchronize_rcu_bh,
446 .exp_sync = synchronize_rcu_bh_expedited,
447 .call = call_rcu_bh,
448 .cb_barrier = rcu_barrier_bh,
449 .fqs = rcu_bh_force_quiescent_state,
450 .stats = NULL,
451 .irq_capable = 1,
452 .name = "rcu_bh"
453 };
454
455 /*
456 * Don't even think about trying any of these in real life!!!
457 * The names includes "busted", and they really means it!
458 * The only purpose of these functions is to provide a buggy RCU
459 * implementation to make sure that rcutorture correctly emits
460 * buggy-RCU error messages.
461 */
462 static void rcu_busted_torture_deferred_free(struct rcu_torture *p)
463 {
464 /* This is a deliberate bug for testing purposes only! */
465 rcu_torture_cb(&p->rtort_rcu);
466 }
467
468 static void synchronize_rcu_busted(void)
469 {
470 /* This is a deliberate bug for testing purposes only! */
471 }
472
473 static void
474 call_rcu_busted(struct rcu_head *head, rcu_callback_t func)
475 {
476 /* This is a deliberate bug for testing purposes only! */
477 func(head);
478 }
479
480 static struct rcu_torture_ops rcu_busted_ops = {
481 .ttype = INVALID_RCU_FLAVOR,
482 .init = rcu_sync_torture_init,
483 .readlock = rcu_torture_read_lock,
484 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
485 .readunlock = rcu_torture_read_unlock,
486 .started = rcu_no_completed,
487 .completed = rcu_no_completed,
488 .deferred_free = rcu_busted_torture_deferred_free,
489 .sync = synchronize_rcu_busted,
490 .exp_sync = synchronize_rcu_busted,
491 .call = call_rcu_busted,
492 .cb_barrier = NULL,
493 .fqs = NULL,
494 .stats = NULL,
495 .irq_capable = 1,
496 .name = "rcu_busted"
497 };
498
499 /*
500 * Definitions for srcu torture testing.
501 */
502
503 DEFINE_STATIC_SRCU(srcu_ctl);
504 static struct srcu_struct srcu_ctld;
505 static struct srcu_struct *srcu_ctlp = &srcu_ctl;
506
507 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp)
508 {
509 return srcu_read_lock(srcu_ctlp);
510 }
511
512 static void srcu_read_delay(struct torture_random_state *rrsp)
513 {
514 long delay;
515 const long uspertick = 1000000 / HZ;
516 const long longdelay = 10;
517
518 /* We want there to be long-running readers, but not all the time. */
519
520 delay = torture_random(rrsp) %
521 (nrealreaders * 2 * longdelay * uspertick);
522 if (!delay)
523 schedule_timeout_interruptible(longdelay);
524 else
525 rcu_read_delay(rrsp);
526 }
527
528 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp)
529 {
530 srcu_read_unlock(srcu_ctlp, idx);
531 }
532
533 static unsigned long srcu_torture_completed(void)
534 {
535 return srcu_batches_completed(srcu_ctlp);
536 }
537
538 static void srcu_torture_deferred_free(struct rcu_torture *rp)
539 {
540 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb);
541 }
542
543 static void srcu_torture_synchronize(void)
544 {
545 synchronize_srcu(srcu_ctlp);
546 }
547
548 static void srcu_torture_call(struct rcu_head *head,
549 rcu_callback_t func)
550 {
551 call_srcu(srcu_ctlp, head, func);
552 }
553
554 static void srcu_torture_barrier(void)
555 {
556 srcu_barrier(srcu_ctlp);
557 }
558
559 static void srcu_torture_stats(void)
560 {
561 int cpu;
562 int idx = srcu_ctlp->completed & 0x1;
563
564 pr_alert("%s%s per-CPU(idx=%d):",
565 torture_type, TORTURE_FLAG, idx);
566 for_each_possible_cpu(cpu) {
567 long c0, c1;
568
569 c0 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[!idx];
570 c1 = (long)per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu)->c[idx];
571 pr_cont(" %d(%ld,%ld)", cpu, c0, c1);
572 }
573 pr_cont("\n");
574 }
575
576 static void srcu_torture_synchronize_expedited(void)
577 {
578 synchronize_srcu_expedited(srcu_ctlp);
579 }
580
581 static struct rcu_torture_ops srcu_ops = {
582 .ttype = SRCU_FLAVOR,
583 .init = rcu_sync_torture_init,
584 .readlock = srcu_torture_read_lock,
585 .read_delay = srcu_read_delay,
586 .readunlock = srcu_torture_read_unlock,
587 .started = NULL,
588 .completed = srcu_torture_completed,
589 .deferred_free = srcu_torture_deferred_free,
590 .sync = srcu_torture_synchronize,
591 .exp_sync = srcu_torture_synchronize_expedited,
592 .call = srcu_torture_call,
593 .cb_barrier = srcu_torture_barrier,
594 .stats = srcu_torture_stats,
595 .name = "srcu"
596 };
597
598 static void srcu_torture_init(void)
599 {
600 rcu_sync_torture_init();
601 WARN_ON(init_srcu_struct(&srcu_ctld));
602 srcu_ctlp = &srcu_ctld;
603 }
604
605 static void srcu_torture_cleanup(void)
606 {
607 cleanup_srcu_struct(&srcu_ctld);
608 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */
609 }
610
611 /* As above, but dynamically allocated. */
612 static struct rcu_torture_ops srcud_ops = {
613 .ttype = SRCU_FLAVOR,
614 .init = srcu_torture_init,
615 .cleanup = srcu_torture_cleanup,
616 .readlock = srcu_torture_read_lock,
617 .read_delay = srcu_read_delay,
618 .readunlock = srcu_torture_read_unlock,
619 .started = NULL,
620 .completed = srcu_torture_completed,
621 .deferred_free = srcu_torture_deferred_free,
622 .sync = srcu_torture_synchronize,
623 .exp_sync = srcu_torture_synchronize_expedited,
624 .call = srcu_torture_call,
625 .cb_barrier = srcu_torture_barrier,
626 .stats = srcu_torture_stats,
627 .name = "srcud"
628 };
629
630 /*
631 * Definitions for sched torture testing.
632 */
633
634 static int sched_torture_read_lock(void)
635 {
636 preempt_disable();
637 return 0;
638 }
639
640 static void sched_torture_read_unlock(int idx)
641 {
642 preempt_enable();
643 }
644
645 static void rcu_sched_torture_deferred_free(struct rcu_torture *p)
646 {
647 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb);
648 }
649
650 static struct rcu_torture_ops sched_ops = {
651 .ttype = RCU_SCHED_FLAVOR,
652 .init = rcu_sync_torture_init,
653 .readlock = sched_torture_read_lock,
654 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
655 .readunlock = sched_torture_read_unlock,
656 .started = rcu_batches_started_sched,
657 .completed = rcu_batches_completed_sched,
658 .deferred_free = rcu_sched_torture_deferred_free,
659 .sync = synchronize_sched,
660 .exp_sync = synchronize_sched_expedited,
661 .get_state = get_state_synchronize_sched,
662 .cond_sync = cond_synchronize_sched,
663 .call = call_rcu_sched,
664 .cb_barrier = rcu_barrier_sched,
665 .fqs = rcu_sched_force_quiescent_state,
666 .stats = NULL,
667 .irq_capable = 1,
668 .name = "sched"
669 };
670
671 #ifdef CONFIG_TASKS_RCU
672
673 /*
674 * Definitions for RCU-tasks torture testing.
675 */
676
677 static int tasks_torture_read_lock(void)
678 {
679 return 0;
680 }
681
682 static void tasks_torture_read_unlock(int idx)
683 {
684 }
685
686 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p)
687 {
688 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb);
689 }
690
691 static struct rcu_torture_ops tasks_ops = {
692 .ttype = RCU_TASKS_FLAVOR,
693 .init = rcu_sync_torture_init,
694 .readlock = tasks_torture_read_lock,
695 .read_delay = rcu_read_delay, /* just reuse rcu's version. */
696 .readunlock = tasks_torture_read_unlock,
697 .started = rcu_no_completed,
698 .completed = rcu_no_completed,
699 .deferred_free = rcu_tasks_torture_deferred_free,
700 .sync = synchronize_rcu_tasks,
701 .exp_sync = synchronize_rcu_tasks,
702 .call = call_rcu_tasks,
703 .cb_barrier = rcu_barrier_tasks,
704 .fqs = NULL,
705 .stats = NULL,
706 .irq_capable = 1,
707 .name = "tasks"
708 };
709
710 #define RCUTORTURE_TASKS_OPS &tasks_ops,
711
712 static bool __maybe_unused torturing_tasks(void)
713 {
714 return cur_ops == &tasks_ops;
715 }
716
717 #else /* #ifdef CONFIG_TASKS_RCU */
718
719 #define RCUTORTURE_TASKS_OPS
720
721 static bool __maybe_unused torturing_tasks(void)
722 {
723 return false;
724 }
725
726 #endif /* #else #ifdef CONFIG_TASKS_RCU */
727
728 /*
729 * RCU torture priority-boost testing. Runs one real-time thread per
730 * CPU for moderate bursts, repeatedly registering RCU callbacks and
731 * spinning waiting for them to be invoked. If a given callback takes
732 * too long to be invoked, we assume that priority inversion has occurred.
733 */
734
735 struct rcu_boost_inflight {
736 struct rcu_head rcu;
737 int inflight;
738 };
739
740 static void rcu_torture_boost_cb(struct rcu_head *head)
741 {
742 struct rcu_boost_inflight *rbip =
743 container_of(head, struct rcu_boost_inflight, rcu);
744
745 /* Ensure RCU-core accesses precede clearing ->inflight */
746 smp_store_release(&rbip->inflight, 0);
747 }
748
749 static int rcu_torture_boost(void *arg)
750 {
751 unsigned long call_rcu_time;
752 unsigned long endtime;
753 unsigned long oldstarttime;
754 struct rcu_boost_inflight rbi = { .inflight = 0 };
755 struct sched_param sp;
756
757 VERBOSE_TOROUT_STRING("rcu_torture_boost started");
758
759 /* Set real-time priority. */
760 sp.sched_priority = 1;
761 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) {
762 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!");
763 n_rcu_torture_boost_rterror++;
764 }
765
766 init_rcu_head_on_stack(&rbi.rcu);
767 /* Each pass through the following loop does one boost-test cycle. */
768 do {
769 /* Wait for the next test interval. */
770 oldstarttime = boost_starttime;
771 while (ULONG_CMP_LT(jiffies, oldstarttime)) {
772 schedule_timeout_interruptible(oldstarttime - jiffies);
773 stutter_wait("rcu_torture_boost");
774 if (torture_must_stop())
775 goto checkwait;
776 }
777
778 /* Do one boost-test interval. */
779 endtime = oldstarttime + test_boost_duration * HZ;
780 call_rcu_time = jiffies;
781 while (ULONG_CMP_LT(jiffies, endtime)) {
782 /* If we don't have a callback in flight, post one. */
783 if (!smp_load_acquire(&rbi.inflight)) {
784 /* RCU core before ->inflight = 1. */
785 smp_store_release(&rbi.inflight, 1);
786 call_rcu(&rbi.rcu, rcu_torture_boost_cb);
787 if (jiffies - call_rcu_time >
788 test_boost_duration * HZ - HZ / 2) {
789 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed");
790 n_rcu_torture_boost_failure++;
791 }
792 call_rcu_time = jiffies;
793 }
794 stutter_wait("rcu_torture_boost");
795 if (torture_must_stop())
796 goto checkwait;
797 }
798
799 /*
800 * Set the start time of the next test interval.
801 * Yes, this is vulnerable to long delays, but such
802 * delays simply cause a false negative for the next
803 * interval. Besides, we are running at RT priority,
804 * so delays should be relatively rare.
805 */
806 while (oldstarttime == boost_starttime &&
807 !kthread_should_stop()) {
808 if (mutex_trylock(&boost_mutex)) {
809 boost_starttime = jiffies +
810 test_boost_interval * HZ;
811 n_rcu_torture_boosts++;
812 mutex_unlock(&boost_mutex);
813 break;
814 }
815 schedule_timeout_uninterruptible(1);
816 }
817
818 /* Go do the stutter. */
819 checkwait: stutter_wait("rcu_torture_boost");
820 } while (!torture_must_stop());
821
822 /* Clean up and exit. */
823 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) {
824 torture_shutdown_absorb("rcu_torture_boost");
825 schedule_timeout_uninterruptible(1);
826 }
827 destroy_rcu_head_on_stack(&rbi.rcu);
828 torture_kthread_stopping("rcu_torture_boost");
829 return 0;
830 }
831
832 static void rcu_torture_cbflood_cb(struct rcu_head *rhp)
833 {
834 }
835
836 /*
837 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls
838 * to call_rcu() or analogous, increasing the probability of occurrence
839 * of callback-overflow corner cases.
840 */
841 static int
842 rcu_torture_cbflood(void *arg)
843 {
844 int err = 1;
845 int i;
846 int j;
847 struct rcu_head *rhp;
848
849 if (cbflood_n_per_burst > 0 &&
850 cbflood_inter_holdoff > 0 &&
851 cbflood_intra_holdoff > 0 &&
852 cur_ops->call &&
853 cur_ops->cb_barrier) {
854 rhp = vmalloc(sizeof(*rhp) *
855 cbflood_n_burst * cbflood_n_per_burst);
856 err = !rhp;
857 }
858 if (err) {
859 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM");
860 goto wait_for_stop;
861 }
862 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started");
863 do {
864 schedule_timeout_interruptible(cbflood_inter_holdoff);
865 atomic_long_inc(&n_cbfloods);
866 WARN_ON(signal_pending(current));
867 for (i = 0; i < cbflood_n_burst; i++) {
868 for (j = 0; j < cbflood_n_per_burst; j++) {
869 cur_ops->call(&rhp[i * cbflood_n_per_burst + j],
870 rcu_torture_cbflood_cb);
871 }
872 schedule_timeout_interruptible(cbflood_intra_holdoff);
873 WARN_ON(signal_pending(current));
874 }
875 cur_ops->cb_barrier();
876 stutter_wait("rcu_torture_cbflood");
877 } while (!torture_must_stop());
878 vfree(rhp);
879 wait_for_stop:
880 torture_kthread_stopping("rcu_torture_cbflood");
881 return 0;
882 }
883
884 /*
885 * RCU torture force-quiescent-state kthread. Repeatedly induces
886 * bursts of calls to force_quiescent_state(), increasing the probability
887 * of occurrence of some important types of race conditions.
888 */
889 static int
890 rcu_torture_fqs(void *arg)
891 {
892 unsigned long fqs_resume_time;
893 int fqs_burst_remaining;
894
895 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started");
896 do {
897 fqs_resume_time = jiffies + fqs_stutter * HZ;
898 while (ULONG_CMP_LT(jiffies, fqs_resume_time) &&
899 !kthread_should_stop()) {
900 schedule_timeout_interruptible(1);
901 }
902 fqs_burst_remaining = fqs_duration;
903 while (fqs_burst_remaining > 0 &&
904 !kthread_should_stop()) {
905 cur_ops->fqs();
906 udelay(fqs_holdoff);
907 fqs_burst_remaining -= fqs_holdoff;
908 }
909 stutter_wait("rcu_torture_fqs");
910 } while (!torture_must_stop());
911 torture_kthread_stopping("rcu_torture_fqs");
912 return 0;
913 }
914
915 /*
916 * RCU torture writer kthread. Repeatedly substitutes a new structure
917 * for that pointed to by rcu_torture_current, freeing the old structure
918 * after a series of grace periods (the "pipeline").
919 */
920 static int
921 rcu_torture_writer(void *arg)
922 {
923 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal();
924 int expediting = 0;
925 unsigned long gp_snap;
926 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal;
927 bool gp_sync1 = gp_sync;
928 int i;
929 struct rcu_torture *rp;
930 struct rcu_torture *old_rp;
931 static DEFINE_TORTURE_RANDOM(rand);
932 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC,
933 RTWS_COND_GET, RTWS_SYNC };
934 int nsynctypes = 0;
935
936 VERBOSE_TOROUT_STRING("rcu_torture_writer task started");
937 if (!can_expedite) {
938 pr_alert("%s" TORTURE_FLAG
939 " GP expediting controlled from boot/sysfs for %s,\n",
940 torture_type, cur_ops->name);
941 pr_alert("%s" TORTURE_FLAG
942 " Disabled dynamic grace-period expediting.\n",
943 torture_type);
944 }
945
946 /* Initialize synctype[] array. If none set, take default. */
947 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1)
948 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true;
949 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync)
950 synctype[nsynctypes++] = RTWS_COND_GET;
951 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync))
952 pr_alert("rcu_torture_writer: gp_cond without primitives.\n");
953 if (gp_exp1 && cur_ops->exp_sync)
954 synctype[nsynctypes++] = RTWS_EXP_SYNC;
955 else if (gp_exp && !cur_ops->exp_sync)
956 pr_alert("rcu_torture_writer: gp_exp without primitives.\n");
957 if (gp_normal1 && cur_ops->deferred_free)
958 synctype[nsynctypes++] = RTWS_DEF_FREE;
959 else if (gp_normal && !cur_ops->deferred_free)
960 pr_alert("rcu_torture_writer: gp_normal without primitives.\n");
961 if (gp_sync1 && cur_ops->sync)
962 synctype[nsynctypes++] = RTWS_SYNC;
963 else if (gp_sync && !cur_ops->sync)
964 pr_alert("rcu_torture_writer: gp_sync without primitives.\n");
965 if (WARN_ONCE(nsynctypes == 0,
966 "rcu_torture_writer: No update-side primitives.\n")) {
967 /*
968 * No updates primitives, so don't try updating.
969 * The resulting test won't be testing much, hence the
970 * above WARN_ONCE().
971 */
972 rcu_torture_writer_state = RTWS_STOPPING;
973 torture_kthread_stopping("rcu_torture_writer");
974 }
975
976 do {
977 rcu_torture_writer_state = RTWS_FIXED_DELAY;
978 schedule_timeout_uninterruptible(1);
979 rp = rcu_torture_alloc();
980 if (rp == NULL)
981 continue;
982 rp->rtort_pipe_count = 0;
983 rcu_torture_writer_state = RTWS_DELAY;
984 udelay(torture_random(&rand) & 0x3ff);
985 rcu_torture_writer_state = RTWS_REPLACE;
986 old_rp = rcu_dereference_check(rcu_torture_current,
987 current == writer_task);
988 rp->rtort_mbtest = 1;
989 rcu_assign_pointer(rcu_torture_current, rp);
990 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */
991 if (old_rp) {
992 i = old_rp->rtort_pipe_count;
993 if (i > RCU_TORTURE_PIPE_LEN)
994 i = RCU_TORTURE_PIPE_LEN;
995 atomic_inc(&rcu_torture_wcount[i]);
996 old_rp->rtort_pipe_count++;
997 switch (synctype[torture_random(&rand) % nsynctypes]) {
998 case RTWS_DEF_FREE:
999 rcu_torture_writer_state = RTWS_DEF_FREE;
1000 cur_ops->deferred_free(old_rp);
1001 break;
1002 case RTWS_EXP_SYNC:
1003 rcu_torture_writer_state = RTWS_EXP_SYNC;
1004 cur_ops->exp_sync();
1005 rcu_torture_pipe_update(old_rp);
1006 break;
1007 case RTWS_COND_GET:
1008 rcu_torture_writer_state = RTWS_COND_GET;
1009 gp_snap = cur_ops->get_state();
1010 i = torture_random(&rand) % 16;
1011 if (i != 0)
1012 schedule_timeout_interruptible(i);
1013 udelay(torture_random(&rand) % 1000);
1014 rcu_torture_writer_state = RTWS_COND_SYNC;
1015 cur_ops->cond_sync(gp_snap);
1016 rcu_torture_pipe_update(old_rp);
1017 break;
1018 case RTWS_SYNC:
1019 rcu_torture_writer_state = RTWS_SYNC;
1020 cur_ops->sync();
1021 rcu_torture_pipe_update(old_rp);
1022 break;
1023 default:
1024 WARN_ON_ONCE(1);
1025 break;
1026 }
1027 }
1028 rcutorture_record_progress(++rcu_torture_current_version);
1029 /* Cycle through nesting levels of rcu_expedite_gp() calls. */
1030 if (can_expedite &&
1031 !(torture_random(&rand) & 0xff & (!!expediting - 1))) {
1032 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited());
1033 if (expediting >= 0)
1034 rcu_expedite_gp();
1035 else
1036 rcu_unexpedite_gp();
1037 if (++expediting > 3)
1038 expediting = -expediting;
1039 }
1040 rcu_torture_writer_state = RTWS_STUTTER;
1041 stutter_wait("rcu_torture_writer");
1042 } while (!torture_must_stop());
1043 /* Reset expediting back to unexpedited. */
1044 if (expediting > 0)
1045 expediting = -expediting;
1046 while (can_expedite && expediting++ < 0)
1047 rcu_unexpedite_gp();
1048 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited());
1049 rcu_torture_writer_state = RTWS_STOPPING;
1050 torture_kthread_stopping("rcu_torture_writer");
1051 return 0;
1052 }
1053
1054 /*
1055 * RCU torture fake writer kthread. Repeatedly calls sync, with a random
1056 * delay between calls.
1057 */
1058 static int
1059 rcu_torture_fakewriter(void *arg)
1060 {
1061 DEFINE_TORTURE_RANDOM(rand);
1062
1063 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started");
1064 set_user_nice(current, MAX_NICE);
1065
1066 do {
1067 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10);
1068 udelay(torture_random(&rand) & 0x3ff);
1069 if (cur_ops->cb_barrier != NULL &&
1070 torture_random(&rand) % (nfakewriters * 8) == 0) {
1071 cur_ops->cb_barrier();
1072 } else if (gp_normal == gp_exp) {
1073 if (torture_random(&rand) & 0x80)
1074 cur_ops->sync();
1075 else
1076 cur_ops->exp_sync();
1077 } else if (gp_normal) {
1078 cur_ops->sync();
1079 } else {
1080 cur_ops->exp_sync();
1081 }
1082 stutter_wait("rcu_torture_fakewriter");
1083 } while (!torture_must_stop());
1084
1085 torture_kthread_stopping("rcu_torture_fakewriter");
1086 return 0;
1087 }
1088
1089 /*
1090 * RCU torture reader from timer handler. Dereferences rcu_torture_current,
1091 * incrementing the corresponding element of the pipeline array. The
1092 * counter in the element should never be greater than 1, otherwise, the
1093 * RCU implementation is broken.
1094 */
1095 static void rcu_torture_timer(unsigned long unused)
1096 {
1097 int idx;
1098 unsigned long started;
1099 unsigned long completed;
1100 static DEFINE_TORTURE_RANDOM(rand);
1101 static DEFINE_SPINLOCK(rand_lock);
1102 struct rcu_torture *p;
1103 int pipe_count;
1104 unsigned long long ts;
1105
1106 idx = cur_ops->readlock();
1107 if (cur_ops->started)
1108 started = cur_ops->started();
1109 else
1110 started = cur_ops->completed();
1111 ts = rcu_trace_clock_local();
1112 p = rcu_dereference_check(rcu_torture_current,
1113 rcu_read_lock_bh_held() ||
1114 rcu_read_lock_sched_held() ||
1115 srcu_read_lock_held(srcu_ctlp) ||
1116 torturing_tasks());
1117 if (p == NULL) {
1118 /* Leave because rcu_torture_writer is not yet underway */
1119 cur_ops->readunlock(idx);
1120 return;
1121 }
1122 if (p->rtort_mbtest == 0)
1123 atomic_inc(&n_rcu_torture_mberror);
1124 spin_lock(&rand_lock);
1125 cur_ops->read_delay(&rand);
1126 n_rcu_torture_timers++;
1127 spin_unlock(&rand_lock);
1128 preempt_disable();
1129 pipe_count = p->rtort_pipe_count;
1130 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1131 /* Should not happen, but... */
1132 pipe_count = RCU_TORTURE_PIPE_LEN;
1133 }
1134 completed = cur_ops->completed();
1135 if (pipe_count > 1) {
1136 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts,
1137 started, completed);
1138 rcu_ftrace_dump(DUMP_ALL);
1139 }
1140 __this_cpu_inc(rcu_torture_count[pipe_count]);
1141 completed = completed - started;
1142 if (cur_ops->started)
1143 completed++;
1144 if (completed > RCU_TORTURE_PIPE_LEN) {
1145 /* Should not happen, but... */
1146 completed = RCU_TORTURE_PIPE_LEN;
1147 }
1148 __this_cpu_inc(rcu_torture_batch[completed]);
1149 preempt_enable();
1150 cur_ops->readunlock(idx);
1151 }
1152
1153 /*
1154 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current,
1155 * incrementing the corresponding element of the pipeline array. The
1156 * counter in the element should never be greater than 1, otherwise, the
1157 * RCU implementation is broken.
1158 */
1159 static int
1160 rcu_torture_reader(void *arg)
1161 {
1162 unsigned long started;
1163 unsigned long completed;
1164 int idx;
1165 DEFINE_TORTURE_RANDOM(rand);
1166 struct rcu_torture *p;
1167 int pipe_count;
1168 struct timer_list t;
1169 unsigned long long ts;
1170
1171 VERBOSE_TOROUT_STRING("rcu_torture_reader task started");
1172 set_user_nice(current, MAX_NICE);
1173 if (irqreader && cur_ops->irq_capable)
1174 setup_timer_on_stack(&t, rcu_torture_timer, 0);
1175
1176 do {
1177 if (irqreader && cur_ops->irq_capable) {
1178 if (!timer_pending(&t))
1179 mod_timer(&t, jiffies + 1);
1180 }
1181 idx = cur_ops->readlock();
1182 if (cur_ops->started)
1183 started = cur_ops->started();
1184 else
1185 started = cur_ops->completed();
1186 ts = rcu_trace_clock_local();
1187 p = rcu_dereference_check(rcu_torture_current,
1188 rcu_read_lock_bh_held() ||
1189 rcu_read_lock_sched_held() ||
1190 srcu_read_lock_held(srcu_ctlp) ||
1191 torturing_tasks());
1192 if (p == NULL) {
1193 /* Wait for rcu_torture_writer to get underway */
1194 cur_ops->readunlock(idx);
1195 schedule_timeout_interruptible(HZ);
1196 continue;
1197 }
1198 if (p->rtort_mbtest == 0)
1199 atomic_inc(&n_rcu_torture_mberror);
1200 cur_ops->read_delay(&rand);
1201 preempt_disable();
1202 pipe_count = p->rtort_pipe_count;
1203 if (pipe_count > RCU_TORTURE_PIPE_LEN) {
1204 /* Should not happen, but... */
1205 pipe_count = RCU_TORTURE_PIPE_LEN;
1206 }
1207 completed = cur_ops->completed();
1208 if (pipe_count > 1) {
1209 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu,
1210 ts, started, completed);
1211 rcu_ftrace_dump(DUMP_ALL);
1212 }
1213 __this_cpu_inc(rcu_torture_count[pipe_count]);
1214 completed = completed - started;
1215 if (cur_ops->started)
1216 completed++;
1217 if (completed > RCU_TORTURE_PIPE_LEN) {
1218 /* Should not happen, but... */
1219 completed = RCU_TORTURE_PIPE_LEN;
1220 }
1221 __this_cpu_inc(rcu_torture_batch[completed]);
1222 preempt_enable();
1223 cur_ops->readunlock(idx);
1224 stutter_wait("rcu_torture_reader");
1225 } while (!torture_must_stop());
1226 if (irqreader && cur_ops->irq_capable) {
1227 del_timer_sync(&t);
1228 destroy_timer_on_stack(&t);
1229 }
1230 torture_kthread_stopping("rcu_torture_reader");
1231 return 0;
1232 }
1233
1234 /*
1235 * Print torture statistics. Caller must ensure that there is only
1236 * one call to this function at a given time!!! This is normally
1237 * accomplished by relying on the module system to only have one copy
1238 * of the module loaded, and then by giving the rcu_torture_stats
1239 * kthread full control (or the init/cleanup functions when rcu_torture_stats
1240 * thread is not running).
1241 */
1242 static void
1243 rcu_torture_stats_print(void)
1244 {
1245 int cpu;
1246 int i;
1247 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1248 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 };
1249 static unsigned long rtcv_snap = ULONG_MAX;
1250 struct task_struct *wtp;
1251
1252 for_each_possible_cpu(cpu) {
1253 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1254 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i];
1255 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i];
1256 }
1257 }
1258 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) {
1259 if (pipesummary[i] != 0)
1260 break;
1261 }
1262
1263 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1264 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ",
1265 rcu_torture_current,
1266 rcu_torture_current_version,
1267 list_empty(&rcu_torture_freelist),
1268 atomic_read(&n_rcu_torture_alloc),
1269 atomic_read(&n_rcu_torture_alloc_fail),
1270 atomic_read(&n_rcu_torture_free));
1271 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ",
1272 atomic_read(&n_rcu_torture_mberror),
1273 n_rcu_torture_barrier_error,
1274 n_rcu_torture_boost_ktrerror,
1275 n_rcu_torture_boost_rterror);
1276 pr_cont("rtbf: %ld rtb: %ld nt: %ld ",
1277 n_rcu_torture_boost_failure,
1278 n_rcu_torture_boosts,
1279 n_rcu_torture_timers);
1280 torture_onoff_stats();
1281 pr_cont("barrier: %ld/%ld:%ld ",
1282 n_barrier_successes,
1283 n_barrier_attempts,
1284 n_rcu_torture_barrier_error);
1285 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods));
1286
1287 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1288 if (atomic_read(&n_rcu_torture_mberror) != 0 ||
1289 n_rcu_torture_barrier_error != 0 ||
1290 n_rcu_torture_boost_ktrerror != 0 ||
1291 n_rcu_torture_boost_rterror != 0 ||
1292 n_rcu_torture_boost_failure != 0 ||
1293 i > 1) {
1294 pr_cont("%s", "!!! ");
1295 atomic_inc(&n_rcu_torture_error);
1296 WARN_ON_ONCE(1);
1297 }
1298 pr_cont("Reader Pipe: ");
1299 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1300 pr_cont(" %ld", pipesummary[i]);
1301 pr_cont("\n");
1302
1303 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1304 pr_cont("Reader Batch: ");
1305 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1306 pr_cont(" %ld", batchsummary[i]);
1307 pr_cont("\n");
1308
1309 pr_alert("%s%s ", torture_type, TORTURE_FLAG);
1310 pr_cont("Free-Block Circulation: ");
1311 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1312 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i]));
1313 }
1314 pr_cont("\n");
1315
1316 if (cur_ops->stats)
1317 cur_ops->stats();
1318 if (rtcv_snap == rcu_torture_current_version &&
1319 rcu_torture_current != NULL) {
1320 int __maybe_unused flags;
1321 unsigned long __maybe_unused gpnum;
1322 unsigned long __maybe_unused completed;
1323
1324 rcutorture_get_gp_data(cur_ops->ttype,
1325 &flags, &gpnum, &completed);
1326 wtp = READ_ONCE(writer_task);
1327 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n",
1328 rcu_torture_writer_state_getname(),
1329 rcu_torture_writer_state,
1330 gpnum, completed, flags,
1331 wtp == NULL ? ~0UL : wtp->state);
1332 show_rcu_gp_kthreads();
1333 rcu_ftrace_dump(DUMP_ALL);
1334 }
1335 rtcv_snap = rcu_torture_current_version;
1336 }
1337
1338 /*
1339 * Periodically prints torture statistics, if periodic statistics printing
1340 * was specified via the stat_interval module parameter.
1341 */
1342 static int
1343 rcu_torture_stats(void *arg)
1344 {
1345 VERBOSE_TOROUT_STRING("rcu_torture_stats task started");
1346 do {
1347 schedule_timeout_interruptible(stat_interval * HZ);
1348 rcu_torture_stats_print();
1349 torture_shutdown_absorb("rcu_torture_stats");
1350 } while (!torture_must_stop());
1351 torture_kthread_stopping("rcu_torture_stats");
1352 return 0;
1353 }
1354
1355 static inline void
1356 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
1357 {
1358 pr_alert("%s" TORTURE_FLAG
1359 "--- %s: nreaders=%d nfakewriters=%d "
1360 "stat_interval=%d verbose=%d test_no_idle_hz=%d "
1361 "shuffle_interval=%d stutter=%d irqreader=%d "
1362 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
1363 "test_boost=%d/%d test_boost_interval=%d "
1364 "test_boost_duration=%d shutdown_secs=%d "
1365 "stall_cpu=%d stall_cpu_holdoff=%d "
1366 "n_barrier_cbs=%d "
1367 "onoff_interval=%d onoff_holdoff=%d\n",
1368 torture_type, tag, nrealreaders, nfakewriters,
1369 stat_interval, verbose, test_no_idle_hz, shuffle_interval,
1370 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
1371 test_boost, cur_ops->can_boost,
1372 test_boost_interval, test_boost_duration, shutdown_secs,
1373 stall_cpu, stall_cpu_holdoff,
1374 n_barrier_cbs,
1375 onoff_interval, onoff_holdoff);
1376 }
1377
1378 static int rcutorture_booster_cleanup(unsigned int cpu)
1379 {
1380 struct task_struct *t;
1381
1382 if (boost_tasks[cpu] == NULL)
1383 return 0;
1384 mutex_lock(&boost_mutex);
1385 t = boost_tasks[cpu];
1386 boost_tasks[cpu] = NULL;
1387 mutex_unlock(&boost_mutex);
1388
1389 /* This must be outside of the mutex, otherwise deadlock! */
1390 torture_stop_kthread(rcu_torture_boost, t);
1391 return 0;
1392 }
1393
1394 static int rcutorture_booster_init(unsigned int cpu)
1395 {
1396 int retval;
1397
1398 if (boost_tasks[cpu] != NULL)
1399 return 0; /* Already created, nothing more to do. */
1400
1401 /* Don't allow time recalculation while creating a new task. */
1402 mutex_lock(&boost_mutex);
1403 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task");
1404 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL,
1405 cpu_to_node(cpu),
1406 "rcu_torture_boost");
1407 if (IS_ERR(boost_tasks[cpu])) {
1408 retval = PTR_ERR(boost_tasks[cpu]);
1409 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed");
1410 n_rcu_torture_boost_ktrerror++;
1411 boost_tasks[cpu] = NULL;
1412 mutex_unlock(&boost_mutex);
1413 return retval;
1414 }
1415 kthread_bind(boost_tasks[cpu], cpu);
1416 wake_up_process(boost_tasks[cpu]);
1417 mutex_unlock(&boost_mutex);
1418 return 0;
1419 }
1420
1421 /*
1422 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then
1423 * induces a CPU stall for the time specified by stall_cpu.
1424 */
1425 static int rcu_torture_stall(void *args)
1426 {
1427 unsigned long stop_at;
1428
1429 VERBOSE_TOROUT_STRING("rcu_torture_stall task started");
1430 if (stall_cpu_holdoff > 0) {
1431 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff");
1432 schedule_timeout_interruptible(stall_cpu_holdoff * HZ);
1433 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff");
1434 }
1435 if (!kthread_should_stop()) {
1436 stop_at = get_seconds() + stall_cpu;
1437 /* RCU CPU stall is expected behavior in following code. */
1438 pr_alert("rcu_torture_stall start.\n");
1439 rcu_read_lock();
1440 preempt_disable();
1441 while (ULONG_CMP_LT(get_seconds(), stop_at))
1442 continue; /* Induce RCU CPU stall warning. */
1443 preempt_enable();
1444 rcu_read_unlock();
1445 pr_alert("rcu_torture_stall end.\n");
1446 }
1447 torture_shutdown_absorb("rcu_torture_stall");
1448 while (!kthread_should_stop())
1449 schedule_timeout_interruptible(10 * HZ);
1450 return 0;
1451 }
1452
1453 /* Spawn CPU-stall kthread, if stall_cpu specified. */
1454 static int __init rcu_torture_stall_init(void)
1455 {
1456 if (stall_cpu <= 0)
1457 return 0;
1458 return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
1459 }
1460
1461 /* Callback function for RCU barrier testing. */
1462 static void rcu_torture_barrier_cbf(struct rcu_head *rcu)
1463 {
1464 atomic_inc(&barrier_cbs_invoked);
1465 }
1466
1467 /* kthread function to register callbacks used to test RCU barriers. */
1468 static int rcu_torture_barrier_cbs(void *arg)
1469 {
1470 long myid = (long)arg;
1471 bool lastphase = 0;
1472 bool newphase;
1473 struct rcu_head rcu;
1474
1475 init_rcu_head_on_stack(&rcu);
1476 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started");
1477 set_user_nice(current, MAX_NICE);
1478 do {
1479 wait_event(barrier_cbs_wq[myid],
1480 (newphase =
1481 smp_load_acquire(&barrier_phase)) != lastphase ||
1482 torture_must_stop());
1483 lastphase = newphase;
1484 if (torture_must_stop())
1485 break;
1486 /*
1487 * The above smp_load_acquire() ensures barrier_phase load
1488 * is ordered before the following ->call().
1489 */
1490 local_irq_disable(); /* Just to test no-irq call_rcu(). */
1491 cur_ops->call(&rcu, rcu_torture_barrier_cbf);
1492 local_irq_enable();
1493 if (atomic_dec_and_test(&barrier_cbs_count))
1494 wake_up(&barrier_wq);
1495 } while (!torture_must_stop());
1496 if (cur_ops->cb_barrier != NULL)
1497 cur_ops->cb_barrier();
1498 destroy_rcu_head_on_stack(&rcu);
1499 torture_kthread_stopping("rcu_torture_barrier_cbs");
1500 return 0;
1501 }
1502
1503 /* kthread function to drive and coordinate RCU barrier testing. */
1504 static int rcu_torture_barrier(void *arg)
1505 {
1506 int i;
1507
1508 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting");
1509 do {
1510 atomic_set(&barrier_cbs_invoked, 0);
1511 atomic_set(&barrier_cbs_count, n_barrier_cbs);
1512 /* Ensure barrier_phase ordered after prior assignments. */
1513 smp_store_release(&barrier_phase, !barrier_phase);
1514 for (i = 0; i < n_barrier_cbs; i++)
1515 wake_up(&barrier_cbs_wq[i]);
1516 wait_event(barrier_wq,
1517 atomic_read(&barrier_cbs_count) == 0 ||
1518 torture_must_stop());
1519 if (torture_must_stop())
1520 break;
1521 n_barrier_attempts++;
1522 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */
1523 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) {
1524 n_rcu_torture_barrier_error++;
1525 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n",
1526 atomic_read(&barrier_cbs_invoked),
1527 n_barrier_cbs);
1528 WARN_ON_ONCE(1);
1529 }
1530 n_barrier_successes++;
1531 schedule_timeout_interruptible(HZ / 10);
1532 } while (!torture_must_stop());
1533 torture_kthread_stopping("rcu_torture_barrier");
1534 return 0;
1535 }
1536
1537 /* Initialize RCU barrier testing. */
1538 static int rcu_torture_barrier_init(void)
1539 {
1540 int i;
1541 int ret;
1542
1543 if (n_barrier_cbs <= 0)
1544 return 0;
1545 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) {
1546 pr_alert("%s" TORTURE_FLAG
1547 " Call or barrier ops missing for %s,\n",
1548 torture_type, cur_ops->name);
1549 pr_alert("%s" TORTURE_FLAG
1550 " RCU barrier testing omitted from run.\n",
1551 torture_type);
1552 return 0;
1553 }
1554 atomic_set(&barrier_cbs_count, 0);
1555 atomic_set(&barrier_cbs_invoked, 0);
1556 barrier_cbs_tasks =
1557 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]),
1558 GFP_KERNEL);
1559 barrier_cbs_wq =
1560 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]),
1561 GFP_KERNEL);
1562 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq)
1563 return -ENOMEM;
1564 for (i = 0; i < n_barrier_cbs; i++) {
1565 init_waitqueue_head(&barrier_cbs_wq[i]);
1566 ret = torture_create_kthread(rcu_torture_barrier_cbs,
1567 (void *)(long)i,
1568 barrier_cbs_tasks[i]);
1569 if (ret)
1570 return ret;
1571 }
1572 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
1573 }
1574
1575 /* Clean up after RCU barrier testing. */
1576 static void rcu_torture_barrier_cleanup(void)
1577 {
1578 int i;
1579
1580 torture_stop_kthread(rcu_torture_barrier, barrier_task);
1581 if (barrier_cbs_tasks != NULL) {
1582 for (i = 0; i < n_barrier_cbs; i++)
1583 torture_stop_kthread(rcu_torture_barrier_cbs,
1584 barrier_cbs_tasks[i]);
1585 kfree(barrier_cbs_tasks);
1586 barrier_cbs_tasks = NULL;
1587 }
1588 if (barrier_cbs_wq != NULL) {
1589 kfree(barrier_cbs_wq);
1590 barrier_cbs_wq = NULL;
1591 }
1592 }
1593
1594 static enum cpuhp_state rcutor_hp;
1595
1596 static void
1597 rcu_torture_cleanup(void)
1598 {
1599 int i;
1600
1601 rcutorture_record_test_transition();
1602 if (torture_cleanup_begin()) {
1603 if (cur_ops->cb_barrier != NULL)
1604 cur_ops->cb_barrier();
1605 return;
1606 }
1607
1608 rcu_torture_barrier_cleanup();
1609 torture_stop_kthread(rcu_torture_stall, stall_task);
1610 torture_stop_kthread(rcu_torture_writer, writer_task);
1611
1612 if (reader_tasks) {
1613 for (i = 0; i < nrealreaders; i++)
1614 torture_stop_kthread(rcu_torture_reader,
1615 reader_tasks[i]);
1616 kfree(reader_tasks);
1617 }
1618 rcu_torture_current = NULL;
1619
1620 if (fakewriter_tasks) {
1621 for (i = 0; i < nfakewriters; i++) {
1622 torture_stop_kthread(rcu_torture_fakewriter,
1623 fakewriter_tasks[i]);
1624 }
1625 kfree(fakewriter_tasks);
1626 fakewriter_tasks = NULL;
1627 }
1628
1629 torture_stop_kthread(rcu_torture_stats, stats_task);
1630 torture_stop_kthread(rcu_torture_fqs, fqs_task);
1631 for (i = 0; i < ncbflooders; i++)
1632 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]);
1633 if ((test_boost == 1 && cur_ops->can_boost) ||
1634 test_boost == 2)
1635 cpuhp_remove_state(rcutor_hp);
1636
1637 /*
1638 * Wait for all RCU callbacks to fire, then do flavor-specific
1639 * cleanup operations.
1640 */
1641 if (cur_ops->cb_barrier != NULL)
1642 cur_ops->cb_barrier();
1643 if (cur_ops->cleanup != NULL)
1644 cur_ops->cleanup();
1645
1646 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
1647
1648 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error)
1649 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE");
1650 else if (torture_onoff_failures())
1651 rcu_torture_print_module_parms(cur_ops,
1652 "End of test: RCU_HOTPLUG");
1653 else
1654 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS");
1655 torture_cleanup_end();
1656 }
1657
1658 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1659 static void rcu_torture_leak_cb(struct rcu_head *rhp)
1660 {
1661 }
1662
1663 static void rcu_torture_err_cb(struct rcu_head *rhp)
1664 {
1665 /*
1666 * This -might- happen due to race conditions, but is unlikely.
1667 * The scenario that leads to this happening is that the
1668 * first of the pair of duplicate callbacks is queued,
1669 * someone else starts a grace period that includes that
1670 * callback, then the second of the pair must wait for the
1671 * next grace period. Unlikely, but can happen. If it
1672 * does happen, the debug-objects subsystem won't have splatted.
1673 */
1674 pr_alert("rcutorture: duplicated callback was invoked.\n");
1675 }
1676 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1677
1678 /*
1679 * Verify that double-free causes debug-objects to complain, but only
1680 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test
1681 * cannot be carried out.
1682 */
1683 static void rcu_test_debug_objects(void)
1684 {
1685 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD
1686 struct rcu_head rh1;
1687 struct rcu_head rh2;
1688
1689 init_rcu_head_on_stack(&rh1);
1690 init_rcu_head_on_stack(&rh2);
1691 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n");
1692
1693 /* Try to queue the rh2 pair of callbacks for the same grace period. */
1694 preempt_disable(); /* Prevent preemption from interrupting test. */
1695 rcu_read_lock(); /* Make it impossible to finish a grace period. */
1696 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */
1697 local_irq_disable(); /* Make it harder to start a new grace period. */
1698 call_rcu(&rh2, rcu_torture_leak_cb);
1699 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */
1700 local_irq_enable();
1701 rcu_read_unlock();
1702 preempt_enable();
1703
1704 /* Wait for them all to get done so we can safely return. */
1705 rcu_barrier();
1706 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n");
1707 destroy_rcu_head_on_stack(&rh1);
1708 destroy_rcu_head_on_stack(&rh2);
1709 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1710 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n");
1711 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */
1712 }
1713
1714 static int __init
1715 rcu_torture_init(void)
1716 {
1717 int i;
1718 int cpu;
1719 int firsterr = 0;
1720 static struct rcu_torture_ops *torture_ops[] = {
1721 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops,
1722 &sched_ops, RCUTORTURE_TASKS_OPS
1723 };
1724
1725 if (!torture_init_begin(torture_type, verbose, &torture_runnable))
1726 return -EBUSY;
1727
1728 /* Process args and tell the world that the torturer is on the job. */
1729 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
1730 cur_ops = torture_ops[i];
1731 if (strcmp(torture_type, cur_ops->name) == 0)
1732 break;
1733 }
1734 if (i == ARRAY_SIZE(torture_ops)) {
1735 pr_alert("rcu-torture: invalid torture type: \"%s\"\n",
1736 torture_type);
1737 pr_alert("rcu-torture types:");
1738 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
1739 pr_alert(" %s", torture_ops[i]->name);
1740 pr_alert("\n");
1741 firsterr = -EINVAL;
1742 goto unwind;
1743 }
1744 if (cur_ops->fqs == NULL && fqs_duration != 0) {
1745 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n");
1746 fqs_duration = 0;
1747 }
1748 if (cur_ops->init)
1749 cur_ops->init();
1750
1751 if (nreaders >= 0) {
1752 nrealreaders = nreaders;
1753 } else {
1754 nrealreaders = num_online_cpus() - 2 - nreaders;
1755 if (nrealreaders <= 0)
1756 nrealreaders = 1;
1757 }
1758 rcu_torture_print_module_parms(cur_ops, "Start of test");
1759
1760 /* Set up the freelist. */
1761
1762 INIT_LIST_HEAD(&rcu_torture_freelist);
1763 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) {
1764 rcu_tortures[i].rtort_mbtest = 0;
1765 list_add_tail(&rcu_tortures[i].rtort_free,
1766 &rcu_torture_freelist);
1767 }
1768
1769 /* Initialize the statistics so that each run gets its own numbers. */
1770
1771 rcu_torture_current = NULL;
1772 rcu_torture_current_version = 0;
1773 atomic_set(&n_rcu_torture_alloc, 0);
1774 atomic_set(&n_rcu_torture_alloc_fail, 0);
1775 atomic_set(&n_rcu_torture_free, 0);
1776 atomic_set(&n_rcu_torture_mberror, 0);
1777 atomic_set(&n_rcu_torture_error, 0);
1778 n_rcu_torture_barrier_error = 0;
1779 n_rcu_torture_boost_ktrerror = 0;
1780 n_rcu_torture_boost_rterror = 0;
1781 n_rcu_torture_boost_failure = 0;
1782 n_rcu_torture_boosts = 0;
1783 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++)
1784 atomic_set(&rcu_torture_wcount[i], 0);
1785 for_each_possible_cpu(cpu) {
1786 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) {
1787 per_cpu(rcu_torture_count, cpu)[i] = 0;
1788 per_cpu(rcu_torture_batch, cpu)[i] = 0;
1789 }
1790 }
1791
1792 /* Start up the kthreads. */
1793
1794 firsterr = torture_create_kthread(rcu_torture_writer, NULL,
1795 writer_task);
1796 if (firsterr)
1797 goto unwind;
1798 if (nfakewriters > 0) {
1799 fakewriter_tasks = kzalloc(nfakewriters *
1800 sizeof(fakewriter_tasks[0]),
1801 GFP_KERNEL);
1802 if (fakewriter_tasks == NULL) {
1803 VERBOSE_TOROUT_ERRSTRING("out of memory");
1804 firsterr = -ENOMEM;
1805 goto unwind;
1806 }
1807 }
1808 for (i = 0; i < nfakewriters; i++) {
1809 firsterr = torture_create_kthread(rcu_torture_fakewriter,
1810 NULL, fakewriter_tasks[i]);
1811 if (firsterr)
1812 goto unwind;
1813 }
1814 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
1815 GFP_KERNEL);
1816 if (reader_tasks == NULL) {
1817 VERBOSE_TOROUT_ERRSTRING("out of memory");
1818 firsterr = -ENOMEM;
1819 goto unwind;
1820 }
1821 for (i = 0; i < nrealreaders; i++) {
1822 firsterr = torture_create_kthread(rcu_torture_reader, NULL,
1823 reader_tasks[i]);
1824 if (firsterr)
1825 goto unwind;
1826 }
1827 if (stat_interval > 0) {
1828 firsterr = torture_create_kthread(rcu_torture_stats, NULL,
1829 stats_task);
1830 if (firsterr)
1831 goto unwind;
1832 }
1833 if (test_no_idle_hz && shuffle_interval > 0) {
1834 firsterr = torture_shuffle_init(shuffle_interval * HZ);
1835 if (firsterr)
1836 goto unwind;
1837 }
1838 if (stutter < 0)
1839 stutter = 0;
1840 if (stutter) {
1841 firsterr = torture_stutter_init(stutter * HZ);
1842 if (firsterr)
1843 goto unwind;
1844 }
1845 if (fqs_duration < 0)
1846 fqs_duration = 0;
1847 if (fqs_duration) {
1848 /* Create the fqs thread */
1849 firsterr = torture_create_kthread(rcu_torture_fqs, NULL,
1850 fqs_task);
1851 if (firsterr)
1852 goto unwind;
1853 }
1854 if (test_boost_interval < 1)
1855 test_boost_interval = 1;
1856 if (test_boost_duration < 2)
1857 test_boost_duration = 2;
1858 if ((test_boost == 1 && cur_ops->can_boost) ||
1859 test_boost == 2) {
1860
1861 boost_starttime = jiffies + test_boost_interval * HZ;
1862
1863 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE",
1864 rcutorture_booster_init,
1865 rcutorture_booster_cleanup);
1866 if (firsterr < 0)
1867 goto unwind;
1868 rcutor_hp = firsterr;
1869 }
1870 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup);
1871 if (firsterr)
1872 goto unwind;
1873 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ);
1874 if (firsterr)
1875 goto unwind;
1876 firsterr = rcu_torture_stall_init();
1877 if (firsterr)
1878 goto unwind;
1879 firsterr = rcu_torture_barrier_init();
1880 if (firsterr)
1881 goto unwind;
1882 if (object_debug)
1883 rcu_test_debug_objects();
1884 if (cbflood_n_burst > 0) {
1885 /* Create the cbflood threads */
1886 ncbflooders = (num_online_cpus() + 3) / 4;
1887 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task),
1888 GFP_KERNEL);
1889 if (!cbflood_task) {
1890 VERBOSE_TOROUT_ERRSTRING("out of memory");
1891 firsterr = -ENOMEM;
1892 goto unwind;
1893 }
1894 for (i = 0; i < ncbflooders; i++) {
1895 firsterr = torture_create_kthread(rcu_torture_cbflood,
1896 NULL,
1897 cbflood_task[i]);
1898 if (firsterr)
1899 goto unwind;
1900 }
1901 }
1902 rcutorture_record_test_transition();
1903 torture_init_end();
1904 return 0;
1905
1906 unwind:
1907 torture_init_end();
1908 rcu_torture_cleanup();
1909 return firsterr;
1910 }
1911
1912 module_init(rcu_torture_init);
1913 module_exit(rcu_torture_cleanup);
Linux with added FPC-III support