1 /* 2 * Read-Copy Update module-based torture test facility 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, you can access it online at 16 * http://www.gnu.org/licenses/gpl-2.0.html. 17 * 18 * Copyright (C) IBM Corporation, 2005, 2006 19 * 20 * Authors: Paul E. McKenney <paulmck@us.ibm.com> 21 * Josh Triplett <josh@joshtriplett.org> 22 * 23 * See also: Documentation/RCU/torture.txt 24 */ 25 #include <linux/types.h> 26 #include <linux/kernel.h> 27 #include <linux/init.h> 28 #include <linux/module.h> 29 #include <linux/kthread.h> 30 #include <linux/err.h> 31 #include <linux/spinlock.h> 32 #include <linux/smp.h> 33 #include <linux/rcupdate.h> 34 #include <linux/interrupt.h> 35 #include <linux/sched/signal.h> 36 #include <uapi/linux/sched/types.h> 37 #include <linux/atomic.h> 38 #include <linux/bitops.h> 39 #include <linux/completion.h> 40 #include <linux/moduleparam.h> 41 #include <linux/percpu.h> 42 #include <linux/notifier.h> 43 #include <linux/reboot.h> 44 #include <linux/freezer.h> 45 #include <linux/cpu.h> 46 #include <linux/delay.h> 47 #include <linux/stat.h> 48 #include <linux/srcu.h> 49 #include <linux/slab.h> 50 #include <linux/trace_clock.h> 51 #include <asm/byteorder.h> 52 #include <linux/torture.h> 53 #include <linux/vmalloc.h> 54 55 MODULE_LICENSE("GPL"); 56 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com> and Josh Triplett <josh@joshtriplett.org>"); 57 58 59 torture_param(int, cbflood_inter_holdoff, HZ, 60 "Holdoff between floods (jiffies)"); 61 torture_param(int, cbflood_intra_holdoff, 1, 62 "Holdoff between bursts (jiffies)"); 63 torture_param(int, cbflood_n_burst, 3, "# bursts in flood, zero to disable"); 64 torture_param(int, cbflood_n_per_burst, 20000, 65 "# callbacks per burst in flood"); 66 torture_param(int, fqs_duration, 0, 67 "Duration of fqs bursts (us), 0 to disable"); 68 torture_param(int, fqs_holdoff, 0, "Holdoff time within fqs bursts (us)"); 69 torture_param(int, fqs_stutter, 3, "Wait time between fqs bursts (s)"); 70 torture_param(bool, gp_cond, false, "Use conditional/async GP wait primitives"); 71 torture_param(bool, gp_exp, false, "Use expedited GP wait primitives"); 72 torture_param(bool, gp_normal, false, 73 "Use normal (non-expedited) GP wait primitives"); 74 torture_param(bool, gp_sync, false, "Use synchronous GP wait primitives"); 75 torture_param(int, irqreader, 1, "Allow RCU readers from irq handlers"); 76 torture_param(int, n_barrier_cbs, 0, 77 "# of callbacks/kthreads for barrier testing"); 78 torture_param(int, nfakewriters, 4, "Number of RCU fake writer threads"); 79 torture_param(int, nreaders, -1, "Number of RCU reader threads"); 80 torture_param(int, object_debug, 0, 81 "Enable debug-object double call_rcu() testing"); 82 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)"); 83 torture_param(int, onoff_interval, 0, 84 "Time between CPU hotplugs (s), 0=disable"); 85 torture_param(int, shuffle_interval, 3, "Number of seconds between shuffles"); 86 torture_param(int, shutdown_secs, 0, "Shutdown time (s), <= zero to disable."); 87 torture_param(int, stall_cpu, 0, "Stall duration (s), zero to disable."); 88 torture_param(int, stall_cpu_holdoff, 10, 89 "Time to wait before starting stall (s)."); 90 torture_param(int, stat_interval, 60, 91 "Number of seconds between stats printk()s"); 92 torture_param(int, stutter, 5, "Number of seconds to run/halt test"); 93 torture_param(int, test_boost, 1, "Test RCU prio boost: 0=no, 1=maybe, 2=yes."); 94 torture_param(int, test_boost_duration, 4, 95 "Duration of each boost test, seconds."); 96 torture_param(int, test_boost_interval, 7, 97 "Interval between boost tests, seconds."); 98 torture_param(bool, test_no_idle_hz, true, 99 "Test support for tickless idle CPUs"); 100 torture_param(bool, verbose, true, 101 "Enable verbose debugging printk()s"); 102 103 static char *torture_type = "rcu"; 104 module_param(torture_type, charp, 0444); 105 MODULE_PARM_DESC(torture_type, "Type of RCU to torture (rcu, rcu_bh, ...)"); 106 107 static int nrealreaders; 108 static int ncbflooders; 109 static struct task_struct *writer_task; 110 static struct task_struct **fakewriter_tasks; 111 static struct task_struct **reader_tasks; 112 static struct task_struct *stats_task; 113 static struct task_struct **cbflood_task; 114 static struct task_struct *fqs_task; 115 static struct task_struct *boost_tasks[NR_CPUS]; 116 static struct task_struct *stall_task; 117 static struct task_struct **barrier_cbs_tasks; 118 static struct task_struct *barrier_task; 119 120 #define RCU_TORTURE_PIPE_LEN 10 121 122 struct rcu_torture { 123 struct rcu_head rtort_rcu; 124 int rtort_pipe_count; 125 struct list_head rtort_free; 126 int rtort_mbtest; 127 }; 128 129 static LIST_HEAD(rcu_torture_freelist); 130 static struct rcu_torture __rcu *rcu_torture_current; 131 static unsigned long rcu_torture_current_version; 132 static struct rcu_torture rcu_tortures[10 * RCU_TORTURE_PIPE_LEN]; 133 static DEFINE_SPINLOCK(rcu_torture_lock); 134 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_count); 135 static DEFINE_PER_CPU(long [RCU_TORTURE_PIPE_LEN + 1], rcu_torture_batch); 136 static atomic_t rcu_torture_wcount[RCU_TORTURE_PIPE_LEN + 1]; 137 static atomic_t n_rcu_torture_alloc; 138 static atomic_t n_rcu_torture_alloc_fail; 139 static atomic_t n_rcu_torture_free; 140 static atomic_t n_rcu_torture_mberror; 141 static atomic_t n_rcu_torture_error; 142 static long n_rcu_torture_barrier_error; 143 static long n_rcu_torture_boost_ktrerror; 144 static long n_rcu_torture_boost_rterror; 145 static long n_rcu_torture_boost_failure; 146 static long n_rcu_torture_boosts; 147 static long n_rcu_torture_timers; 148 static long n_barrier_attempts; 149 static long n_barrier_successes; 150 static atomic_long_t n_cbfloods; 151 static struct list_head rcu_torture_removed; 152 153 static int rcu_torture_writer_state; 154 #define RTWS_FIXED_DELAY 0 155 #define RTWS_DELAY 1 156 #define RTWS_REPLACE 2 157 #define RTWS_DEF_FREE 3 158 #define RTWS_EXP_SYNC 4 159 #define RTWS_COND_GET 5 160 #define RTWS_COND_SYNC 6 161 #define RTWS_SYNC 7 162 #define RTWS_STUTTER 8 163 #define RTWS_STOPPING 9 164 static const char * const rcu_torture_writer_state_names[] = { 165 "RTWS_FIXED_DELAY", 166 "RTWS_DELAY", 167 "RTWS_REPLACE", 168 "RTWS_DEF_FREE", 169 "RTWS_EXP_SYNC", 170 "RTWS_COND_GET", 171 "RTWS_COND_SYNC", 172 "RTWS_SYNC", 173 "RTWS_STUTTER", 174 "RTWS_STOPPING", 175 }; 176 177 static const char *rcu_torture_writer_state_getname(void) 178 { 179 unsigned int i = READ_ONCE(rcu_torture_writer_state); 180 181 if (i >= ARRAY_SIZE(rcu_torture_writer_state_names)) 182 return "???"; 183 return rcu_torture_writer_state_names[i]; 184 } 185 186 static int torture_runnable = IS_ENABLED(MODULE); 187 module_param(torture_runnable, int, 0444); 188 MODULE_PARM_DESC(torture_runnable, "Start rcutorture at boot"); 189 190 #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) 191 #define rcu_can_boost() 1 192 #else /* #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ 193 #define rcu_can_boost() 0 194 #endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */ 195 196 #ifdef CONFIG_RCU_TRACE 197 static u64 notrace rcu_trace_clock_local(void) 198 { 199 u64 ts = trace_clock_local(); 200 unsigned long __maybe_unused ts_rem = do_div(ts, NSEC_PER_USEC); 201 return ts; 202 } 203 #else /* #ifdef CONFIG_RCU_TRACE */ 204 static u64 notrace rcu_trace_clock_local(void) 205 { 206 return 0ULL; 207 } 208 #endif /* #else #ifdef CONFIG_RCU_TRACE */ 209 210 static unsigned long boost_starttime; /* jiffies of next boost test start. */ 211 static DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */ 212 /* and boost task create/destroy. */ 213 static atomic_t barrier_cbs_count; /* Barrier callbacks registered. */ 214 static bool barrier_phase; /* Test phase. */ 215 static atomic_t barrier_cbs_invoked; /* Barrier callbacks invoked. */ 216 static wait_queue_head_t *barrier_cbs_wq; /* Coordinate barrier testing. */ 217 static DECLARE_WAIT_QUEUE_HEAD(barrier_wq); 218 219 /* 220 * Allocate an element from the rcu_tortures pool. 221 */ 222 static struct rcu_torture * 223 rcu_torture_alloc(void) 224 { 225 struct list_head *p; 226 227 spin_lock_bh(&rcu_torture_lock); 228 if (list_empty(&rcu_torture_freelist)) { 229 atomic_inc(&n_rcu_torture_alloc_fail); 230 spin_unlock_bh(&rcu_torture_lock); 231 return NULL; 232 } 233 atomic_inc(&n_rcu_torture_alloc); 234 p = rcu_torture_freelist.next; 235 list_del_init(p); 236 spin_unlock_bh(&rcu_torture_lock); 237 return container_of(p, struct rcu_torture, rtort_free); 238 } 239 240 /* 241 * Free an element to the rcu_tortures pool. 242 */ 243 static void 244 rcu_torture_free(struct rcu_torture *p) 245 { 246 atomic_inc(&n_rcu_torture_free); 247 spin_lock_bh(&rcu_torture_lock); 248 list_add_tail(&p->rtort_free, &rcu_torture_freelist); 249 spin_unlock_bh(&rcu_torture_lock); 250 } 251 252 /* 253 * Operations vector for selecting different types of tests. 254 */ 255 256 struct rcu_torture_ops { 257 int ttype; 258 void (*init)(void); 259 void (*cleanup)(void); 260 int (*readlock)(void); 261 void (*read_delay)(struct torture_random_state *rrsp); 262 void (*readunlock)(int idx); 263 unsigned long (*started)(void); 264 unsigned long (*completed)(void); 265 void (*deferred_free)(struct rcu_torture *p); 266 void (*sync)(void); 267 void (*exp_sync)(void); 268 unsigned long (*get_state)(void); 269 void (*cond_sync)(unsigned long oldstate); 270 call_rcu_func_t call; 271 void (*cb_barrier)(void); 272 void (*fqs)(void); 273 void (*stats)(void); 274 int irq_capable; 275 int can_boost; 276 const char *name; 277 }; 278 279 static struct rcu_torture_ops *cur_ops; 280 281 /* 282 * Definitions for rcu torture testing. 283 */ 284 285 static int rcu_torture_read_lock(void) __acquires(RCU) 286 { 287 rcu_read_lock(); 288 return 0; 289 } 290 291 static void rcu_read_delay(struct torture_random_state *rrsp) 292 { 293 unsigned long started; 294 unsigned long completed; 295 const unsigned long shortdelay_us = 200; 296 const unsigned long longdelay_ms = 50; 297 unsigned long long ts; 298 299 /* We want a short delay sometimes to make a reader delay the grace 300 * period, and we want a long delay occasionally to trigger 301 * force_quiescent_state. */ 302 303 if (!(torture_random(rrsp) % (nrealreaders * 2000 * longdelay_ms))) { 304 started = cur_ops->completed(); 305 ts = rcu_trace_clock_local(); 306 mdelay(longdelay_ms); 307 completed = cur_ops->completed(); 308 do_trace_rcu_torture_read(cur_ops->name, NULL, ts, 309 started, completed); 310 } 311 if (!(torture_random(rrsp) % (nrealreaders * 2 * shortdelay_us))) 312 udelay(shortdelay_us); 313 #ifdef CONFIG_PREEMPT 314 if (!preempt_count() && 315 !(torture_random(rrsp) % (nrealreaders * 20000))) 316 preempt_schedule(); /* No QS if preempt_disable() in effect */ 317 #endif 318 } 319 320 static void rcu_torture_read_unlock(int idx) __releases(RCU) 321 { 322 rcu_read_unlock(); 323 } 324 325 /* 326 * Update callback in the pipe. This should be invoked after a grace period. 327 */ 328 static bool 329 rcu_torture_pipe_update_one(struct rcu_torture *rp) 330 { 331 int i; 332 333 i = rp->rtort_pipe_count; 334 if (i > RCU_TORTURE_PIPE_LEN) 335 i = RCU_TORTURE_PIPE_LEN; 336 atomic_inc(&rcu_torture_wcount[i]); 337 if (++rp->rtort_pipe_count >= RCU_TORTURE_PIPE_LEN) { 338 rp->rtort_mbtest = 0; 339 return true; 340 } 341 return false; 342 } 343 344 /* 345 * Update all callbacks in the pipe. Suitable for synchronous grace-period 346 * primitives. 347 */ 348 static void 349 rcu_torture_pipe_update(struct rcu_torture *old_rp) 350 { 351 struct rcu_torture *rp; 352 struct rcu_torture *rp1; 353 354 if (old_rp) 355 list_add(&old_rp->rtort_free, &rcu_torture_removed); 356 list_for_each_entry_safe(rp, rp1, &rcu_torture_removed, rtort_free) { 357 if (rcu_torture_pipe_update_one(rp)) { 358 list_del(&rp->rtort_free); 359 rcu_torture_free(rp); 360 } 361 } 362 } 363 364 static void 365 rcu_torture_cb(struct rcu_head *p) 366 { 367 struct rcu_torture *rp = container_of(p, struct rcu_torture, rtort_rcu); 368 369 if (torture_must_stop_irq()) { 370 /* Test is ending, just drop callbacks on the floor. */ 371 /* The next initialization will pick up the pieces. */ 372 return; 373 } 374 if (rcu_torture_pipe_update_one(rp)) 375 rcu_torture_free(rp); 376 else 377 cur_ops->deferred_free(rp); 378 } 379 380 static unsigned long rcu_no_completed(void) 381 { 382 return 0; 383 } 384 385 static void rcu_torture_deferred_free(struct rcu_torture *p) 386 { 387 call_rcu(&p->rtort_rcu, rcu_torture_cb); 388 } 389 390 static void rcu_sync_torture_init(void) 391 { 392 INIT_LIST_HEAD(&rcu_torture_removed); 393 } 394 395 static struct rcu_torture_ops rcu_ops = { 396 .ttype = RCU_FLAVOR, 397 .init = rcu_sync_torture_init, 398 .readlock = rcu_torture_read_lock, 399 .read_delay = rcu_read_delay, 400 .readunlock = rcu_torture_read_unlock, 401 .started = rcu_batches_started, 402 .completed = rcu_batches_completed, 403 .deferred_free = rcu_torture_deferred_free, 404 .sync = synchronize_rcu, 405 .exp_sync = synchronize_rcu_expedited, 406 .get_state = get_state_synchronize_rcu, 407 .cond_sync = cond_synchronize_rcu, 408 .call = call_rcu, 409 .cb_barrier = rcu_barrier, 410 .fqs = rcu_force_quiescent_state, 411 .stats = NULL, 412 .irq_capable = 1, 413 .can_boost = rcu_can_boost(), 414 .name = "rcu" 415 }; 416 417 /* 418 * Definitions for rcu_bh torture testing. 419 */ 420 421 static int rcu_bh_torture_read_lock(void) __acquires(RCU_BH) 422 { 423 rcu_read_lock_bh(); 424 return 0; 425 } 426 427 static void rcu_bh_torture_read_unlock(int idx) __releases(RCU_BH) 428 { 429 rcu_read_unlock_bh(); 430 } 431 432 static void rcu_bh_torture_deferred_free(struct rcu_torture *p) 433 { 434 call_rcu_bh(&p->rtort_rcu, rcu_torture_cb); 435 } 436 437 static struct rcu_torture_ops rcu_bh_ops = { 438 .ttype = RCU_BH_FLAVOR, 439 .init = rcu_sync_torture_init, 440 .readlock = rcu_bh_torture_read_lock, 441 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 442 .readunlock = rcu_bh_torture_read_unlock, 443 .started = rcu_batches_started_bh, 444 .completed = rcu_batches_completed_bh, 445 .deferred_free = rcu_bh_torture_deferred_free, 446 .sync = synchronize_rcu_bh, 447 .exp_sync = synchronize_rcu_bh_expedited, 448 .call = call_rcu_bh, 449 .cb_barrier = rcu_barrier_bh, 450 .fqs = rcu_bh_force_quiescent_state, 451 .stats = NULL, 452 .irq_capable = 1, 453 .name = "rcu_bh" 454 }; 455 456 /* 457 * Don't even think about trying any of these in real life!!! 458 * The names includes "busted", and they really means it! 459 * The only purpose of these functions is to provide a buggy RCU 460 * implementation to make sure that rcutorture correctly emits 461 * buggy-RCU error messages. 462 */ 463 static void rcu_busted_torture_deferred_free(struct rcu_torture *p) 464 { 465 /* This is a deliberate bug for testing purposes only! */ 466 rcu_torture_cb(&p->rtort_rcu); 467 } 468 469 static void synchronize_rcu_busted(void) 470 { 471 /* This is a deliberate bug for testing purposes only! */ 472 } 473 474 static void 475 call_rcu_busted(struct rcu_head *head, rcu_callback_t func) 476 { 477 /* This is a deliberate bug for testing purposes only! */ 478 func(head); 479 } 480 481 static struct rcu_torture_ops rcu_busted_ops = { 482 .ttype = INVALID_RCU_FLAVOR, 483 .init = rcu_sync_torture_init, 484 .readlock = rcu_torture_read_lock, 485 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 486 .readunlock = rcu_torture_read_unlock, 487 .started = rcu_no_completed, 488 .completed = rcu_no_completed, 489 .deferred_free = rcu_busted_torture_deferred_free, 490 .sync = synchronize_rcu_busted, 491 .exp_sync = synchronize_rcu_busted, 492 .call = call_rcu_busted, 493 .cb_barrier = NULL, 494 .fqs = NULL, 495 .stats = NULL, 496 .irq_capable = 1, 497 .name = "rcu_busted" 498 }; 499 500 /* 501 * Definitions for srcu torture testing. 502 */ 503 504 DEFINE_STATIC_SRCU(srcu_ctl); 505 static struct srcu_struct srcu_ctld; 506 static struct srcu_struct *srcu_ctlp = &srcu_ctl; 507 508 static int srcu_torture_read_lock(void) __acquires(srcu_ctlp) 509 { 510 return srcu_read_lock(srcu_ctlp); 511 } 512 513 static void srcu_read_delay(struct torture_random_state *rrsp) 514 { 515 long delay; 516 const long uspertick = 1000000 / HZ; 517 const long longdelay = 10; 518 519 /* We want there to be long-running readers, but not all the time. */ 520 521 delay = torture_random(rrsp) % 522 (nrealreaders * 2 * longdelay * uspertick); 523 if (!delay) 524 schedule_timeout_interruptible(longdelay); 525 else 526 rcu_read_delay(rrsp); 527 } 528 529 static void srcu_torture_read_unlock(int idx) __releases(srcu_ctlp) 530 { 531 srcu_read_unlock(srcu_ctlp, idx); 532 } 533 534 static unsigned long srcu_torture_completed(void) 535 { 536 return srcu_batches_completed(srcu_ctlp); 537 } 538 539 static void srcu_torture_deferred_free(struct rcu_torture *rp) 540 { 541 call_srcu(srcu_ctlp, &rp->rtort_rcu, rcu_torture_cb); 542 } 543 544 static void srcu_torture_synchronize(void) 545 { 546 synchronize_srcu(srcu_ctlp); 547 } 548 549 static void srcu_torture_call(struct rcu_head *head, 550 rcu_callback_t func) 551 { 552 call_srcu(srcu_ctlp, head, func); 553 } 554 555 static void srcu_torture_barrier(void) 556 { 557 srcu_barrier(srcu_ctlp); 558 } 559 560 static void srcu_torture_stats(void) 561 { 562 int cpu; 563 int idx = srcu_ctlp->completed & 0x1; 564 565 pr_alert("%s%s per-CPU(idx=%d):", 566 torture_type, TORTURE_FLAG, idx); 567 for_each_possible_cpu(cpu) { 568 unsigned long l0, l1; 569 unsigned long u0, u1; 570 long c0, c1; 571 struct srcu_array *counts = per_cpu_ptr(srcu_ctlp->per_cpu_ref, cpu); 572 573 u0 = counts->unlock_count[!idx]; 574 u1 = counts->unlock_count[idx]; 575 576 /* 577 * Make sure that a lock is always counted if the corresponding 578 * unlock is counted. 579 */ 580 smp_rmb(); 581 582 l0 = counts->lock_count[!idx]; 583 l1 = counts->lock_count[idx]; 584 585 c0 = l0 - u0; 586 c1 = l1 - u1; 587 pr_cont(" %d(%ld,%ld)", cpu, c0, c1); 588 } 589 pr_cont("\n"); 590 } 591 592 static void srcu_torture_synchronize_expedited(void) 593 { 594 synchronize_srcu_expedited(srcu_ctlp); 595 } 596 597 static struct rcu_torture_ops srcu_ops = { 598 .ttype = SRCU_FLAVOR, 599 .init = rcu_sync_torture_init, 600 .readlock = srcu_torture_read_lock, 601 .read_delay = srcu_read_delay, 602 .readunlock = srcu_torture_read_unlock, 603 .started = NULL, 604 .completed = srcu_torture_completed, 605 .deferred_free = srcu_torture_deferred_free, 606 .sync = srcu_torture_synchronize, 607 .exp_sync = srcu_torture_synchronize_expedited, 608 .call = srcu_torture_call, 609 .cb_barrier = srcu_torture_barrier, 610 .stats = srcu_torture_stats, 611 .name = "srcu" 612 }; 613 614 static void srcu_torture_init(void) 615 { 616 rcu_sync_torture_init(); 617 WARN_ON(init_srcu_struct(&srcu_ctld)); 618 srcu_ctlp = &srcu_ctld; 619 } 620 621 static void srcu_torture_cleanup(void) 622 { 623 cleanup_srcu_struct(&srcu_ctld); 624 srcu_ctlp = &srcu_ctl; /* In case of a later rcutorture run. */ 625 } 626 627 /* As above, but dynamically allocated. */ 628 static struct rcu_torture_ops srcud_ops = { 629 .ttype = SRCU_FLAVOR, 630 .init = srcu_torture_init, 631 .cleanup = srcu_torture_cleanup, 632 .readlock = srcu_torture_read_lock, 633 .read_delay = srcu_read_delay, 634 .readunlock = srcu_torture_read_unlock, 635 .started = NULL, 636 .completed = srcu_torture_completed, 637 .deferred_free = srcu_torture_deferred_free, 638 .sync = srcu_torture_synchronize, 639 .exp_sync = srcu_torture_synchronize_expedited, 640 .call = srcu_torture_call, 641 .cb_barrier = srcu_torture_barrier, 642 .stats = srcu_torture_stats, 643 .name = "srcud" 644 }; 645 646 /* 647 * Definitions for sched torture testing. 648 */ 649 650 static int sched_torture_read_lock(void) 651 { 652 preempt_disable(); 653 return 0; 654 } 655 656 static void sched_torture_read_unlock(int idx) 657 { 658 preempt_enable(); 659 } 660 661 static void rcu_sched_torture_deferred_free(struct rcu_torture *p) 662 { 663 call_rcu_sched(&p->rtort_rcu, rcu_torture_cb); 664 } 665 666 static struct rcu_torture_ops sched_ops = { 667 .ttype = RCU_SCHED_FLAVOR, 668 .init = rcu_sync_torture_init, 669 .readlock = sched_torture_read_lock, 670 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 671 .readunlock = sched_torture_read_unlock, 672 .started = rcu_batches_started_sched, 673 .completed = rcu_batches_completed_sched, 674 .deferred_free = rcu_sched_torture_deferred_free, 675 .sync = synchronize_sched, 676 .exp_sync = synchronize_sched_expedited, 677 .get_state = get_state_synchronize_sched, 678 .cond_sync = cond_synchronize_sched, 679 .call = call_rcu_sched, 680 .cb_barrier = rcu_barrier_sched, 681 .fqs = rcu_sched_force_quiescent_state, 682 .stats = NULL, 683 .irq_capable = 1, 684 .name = "sched" 685 }; 686 687 #ifdef CONFIG_TASKS_RCU 688 689 /* 690 * Definitions for RCU-tasks torture testing. 691 */ 692 693 static int tasks_torture_read_lock(void) 694 { 695 return 0; 696 } 697 698 static void tasks_torture_read_unlock(int idx) 699 { 700 } 701 702 static void rcu_tasks_torture_deferred_free(struct rcu_torture *p) 703 { 704 call_rcu_tasks(&p->rtort_rcu, rcu_torture_cb); 705 } 706 707 static struct rcu_torture_ops tasks_ops = { 708 .ttype = RCU_TASKS_FLAVOR, 709 .init = rcu_sync_torture_init, 710 .readlock = tasks_torture_read_lock, 711 .read_delay = rcu_read_delay, /* just reuse rcu's version. */ 712 .readunlock = tasks_torture_read_unlock, 713 .started = rcu_no_completed, 714 .completed = rcu_no_completed, 715 .deferred_free = rcu_tasks_torture_deferred_free, 716 .sync = synchronize_rcu_tasks, 717 .exp_sync = synchronize_rcu_tasks, 718 .call = call_rcu_tasks, 719 .cb_barrier = rcu_barrier_tasks, 720 .fqs = NULL, 721 .stats = NULL, 722 .irq_capable = 1, 723 .name = "tasks" 724 }; 725 726 #define RCUTORTURE_TASKS_OPS &tasks_ops, 727 728 static bool __maybe_unused torturing_tasks(void) 729 { 730 return cur_ops == &tasks_ops; 731 } 732 733 #else /* #ifdef CONFIG_TASKS_RCU */ 734 735 #define RCUTORTURE_TASKS_OPS 736 737 static bool __maybe_unused torturing_tasks(void) 738 { 739 return false; 740 } 741 742 #endif /* #else #ifdef CONFIG_TASKS_RCU */ 743 744 /* 745 * RCU torture priority-boost testing. Runs one real-time thread per 746 * CPU for moderate bursts, repeatedly registering RCU callbacks and 747 * spinning waiting for them to be invoked. If a given callback takes 748 * too long to be invoked, we assume that priority inversion has occurred. 749 */ 750 751 struct rcu_boost_inflight { 752 struct rcu_head rcu; 753 int inflight; 754 }; 755 756 static void rcu_torture_boost_cb(struct rcu_head *head) 757 { 758 struct rcu_boost_inflight *rbip = 759 container_of(head, struct rcu_boost_inflight, rcu); 760 761 /* Ensure RCU-core accesses precede clearing ->inflight */ 762 smp_store_release(&rbip->inflight, 0); 763 } 764 765 static int rcu_torture_boost(void *arg) 766 { 767 unsigned long call_rcu_time; 768 unsigned long endtime; 769 unsigned long oldstarttime; 770 struct rcu_boost_inflight rbi = { .inflight = 0 }; 771 struct sched_param sp; 772 773 VERBOSE_TOROUT_STRING("rcu_torture_boost started"); 774 775 /* Set real-time priority. */ 776 sp.sched_priority = 1; 777 if (sched_setscheduler(current, SCHED_FIFO, &sp) < 0) { 778 VERBOSE_TOROUT_STRING("rcu_torture_boost RT prio failed!"); 779 n_rcu_torture_boost_rterror++; 780 } 781 782 init_rcu_head_on_stack(&rbi.rcu); 783 /* Each pass through the following loop does one boost-test cycle. */ 784 do { 785 /* Wait for the next test interval. */ 786 oldstarttime = boost_starttime; 787 while (ULONG_CMP_LT(jiffies, oldstarttime)) { 788 schedule_timeout_interruptible(oldstarttime - jiffies); 789 stutter_wait("rcu_torture_boost"); 790 if (torture_must_stop()) 791 goto checkwait; 792 } 793 794 /* Do one boost-test interval. */ 795 endtime = oldstarttime + test_boost_duration * HZ; 796 call_rcu_time = jiffies; 797 while (ULONG_CMP_LT(jiffies, endtime)) { 798 /* If we don't have a callback in flight, post one. */ 799 if (!smp_load_acquire(&rbi.inflight)) { 800 /* RCU core before ->inflight = 1. */ 801 smp_store_release(&rbi.inflight, 1); 802 call_rcu(&rbi.rcu, rcu_torture_boost_cb); 803 if (jiffies - call_rcu_time > 804 test_boost_duration * HZ - HZ / 2) { 805 VERBOSE_TOROUT_STRING("rcu_torture_boost boosting failed"); 806 n_rcu_torture_boost_failure++; 807 } 808 call_rcu_time = jiffies; 809 } 810 stutter_wait("rcu_torture_boost"); 811 if (torture_must_stop()) 812 goto checkwait; 813 } 814 815 /* 816 * Set the start time of the next test interval. 817 * Yes, this is vulnerable to long delays, but such 818 * delays simply cause a false negative for the next 819 * interval. Besides, we are running at RT priority, 820 * so delays should be relatively rare. 821 */ 822 while (oldstarttime == boost_starttime && 823 !kthread_should_stop()) { 824 if (mutex_trylock(&boost_mutex)) { 825 boost_starttime = jiffies + 826 test_boost_interval * HZ; 827 n_rcu_torture_boosts++; 828 mutex_unlock(&boost_mutex); 829 break; 830 } 831 schedule_timeout_uninterruptible(1); 832 } 833 834 /* Go do the stutter. */ 835 checkwait: stutter_wait("rcu_torture_boost"); 836 } while (!torture_must_stop()); 837 838 /* Clean up and exit. */ 839 while (!kthread_should_stop() || smp_load_acquire(&rbi.inflight)) { 840 torture_shutdown_absorb("rcu_torture_boost"); 841 schedule_timeout_uninterruptible(1); 842 } 843 destroy_rcu_head_on_stack(&rbi.rcu); 844 torture_kthread_stopping("rcu_torture_boost"); 845 return 0; 846 } 847 848 static void rcu_torture_cbflood_cb(struct rcu_head *rhp) 849 { 850 } 851 852 /* 853 * RCU torture callback-flood kthread. Repeatedly induces bursts of calls 854 * to call_rcu() or analogous, increasing the probability of occurrence 855 * of callback-overflow corner cases. 856 */ 857 static int 858 rcu_torture_cbflood(void *arg) 859 { 860 int err = 1; 861 int i; 862 int j; 863 struct rcu_head *rhp; 864 865 if (cbflood_n_per_burst > 0 && 866 cbflood_inter_holdoff > 0 && 867 cbflood_intra_holdoff > 0 && 868 cur_ops->call && 869 cur_ops->cb_barrier) { 870 rhp = vmalloc(sizeof(*rhp) * 871 cbflood_n_burst * cbflood_n_per_burst); 872 err = !rhp; 873 } 874 if (err) { 875 VERBOSE_TOROUT_STRING("rcu_torture_cbflood disabled: Bad args or OOM"); 876 goto wait_for_stop; 877 } 878 VERBOSE_TOROUT_STRING("rcu_torture_cbflood task started"); 879 do { 880 schedule_timeout_interruptible(cbflood_inter_holdoff); 881 atomic_long_inc(&n_cbfloods); 882 WARN_ON(signal_pending(current)); 883 for (i = 0; i < cbflood_n_burst; i++) { 884 for (j = 0; j < cbflood_n_per_burst; j++) { 885 cur_ops->call(&rhp[i * cbflood_n_per_burst + j], 886 rcu_torture_cbflood_cb); 887 } 888 schedule_timeout_interruptible(cbflood_intra_holdoff); 889 WARN_ON(signal_pending(current)); 890 } 891 cur_ops->cb_barrier(); 892 stutter_wait("rcu_torture_cbflood"); 893 } while (!torture_must_stop()); 894 vfree(rhp); 895 wait_for_stop: 896 torture_kthread_stopping("rcu_torture_cbflood"); 897 return 0; 898 } 899 900 /* 901 * RCU torture force-quiescent-state kthread. Repeatedly induces 902 * bursts of calls to force_quiescent_state(), increasing the probability 903 * of occurrence of some important types of race conditions. 904 */ 905 static int 906 rcu_torture_fqs(void *arg) 907 { 908 unsigned long fqs_resume_time; 909 int fqs_burst_remaining; 910 911 VERBOSE_TOROUT_STRING("rcu_torture_fqs task started"); 912 do { 913 fqs_resume_time = jiffies + fqs_stutter * HZ; 914 while (ULONG_CMP_LT(jiffies, fqs_resume_time) && 915 !kthread_should_stop()) { 916 schedule_timeout_interruptible(1); 917 } 918 fqs_burst_remaining = fqs_duration; 919 while (fqs_burst_remaining > 0 && 920 !kthread_should_stop()) { 921 cur_ops->fqs(); 922 udelay(fqs_holdoff); 923 fqs_burst_remaining -= fqs_holdoff; 924 } 925 stutter_wait("rcu_torture_fqs"); 926 } while (!torture_must_stop()); 927 torture_kthread_stopping("rcu_torture_fqs"); 928 return 0; 929 } 930 931 /* 932 * RCU torture writer kthread. Repeatedly substitutes a new structure 933 * for that pointed to by rcu_torture_current, freeing the old structure 934 * after a series of grace periods (the "pipeline"). 935 */ 936 static int 937 rcu_torture_writer(void *arg) 938 { 939 bool can_expedite = !rcu_gp_is_expedited() && !rcu_gp_is_normal(); 940 int expediting = 0; 941 unsigned long gp_snap; 942 bool gp_cond1 = gp_cond, gp_exp1 = gp_exp, gp_normal1 = gp_normal; 943 bool gp_sync1 = gp_sync; 944 int i; 945 struct rcu_torture *rp; 946 struct rcu_torture *old_rp; 947 static DEFINE_TORTURE_RANDOM(rand); 948 int synctype[] = { RTWS_DEF_FREE, RTWS_EXP_SYNC, 949 RTWS_COND_GET, RTWS_SYNC }; 950 int nsynctypes = 0; 951 952 VERBOSE_TOROUT_STRING("rcu_torture_writer task started"); 953 if (!can_expedite) { 954 pr_alert("%s" TORTURE_FLAG 955 " GP expediting controlled from boot/sysfs for %s,\n", 956 torture_type, cur_ops->name); 957 pr_alert("%s" TORTURE_FLAG 958 " Disabled dynamic grace-period expediting.\n", 959 torture_type); 960 } 961 962 /* Initialize synctype[] array. If none set, take default. */ 963 if (!gp_cond1 && !gp_exp1 && !gp_normal1 && !gp_sync1) 964 gp_cond1 = gp_exp1 = gp_normal1 = gp_sync1 = true; 965 if (gp_cond1 && cur_ops->get_state && cur_ops->cond_sync) 966 synctype[nsynctypes++] = RTWS_COND_GET; 967 else if (gp_cond && (!cur_ops->get_state || !cur_ops->cond_sync)) 968 pr_alert("rcu_torture_writer: gp_cond without primitives.\n"); 969 if (gp_exp1 && cur_ops->exp_sync) 970 synctype[nsynctypes++] = RTWS_EXP_SYNC; 971 else if (gp_exp && !cur_ops->exp_sync) 972 pr_alert("rcu_torture_writer: gp_exp without primitives.\n"); 973 if (gp_normal1 && cur_ops->deferred_free) 974 synctype[nsynctypes++] = RTWS_DEF_FREE; 975 else if (gp_normal && !cur_ops->deferred_free) 976 pr_alert("rcu_torture_writer: gp_normal without primitives.\n"); 977 if (gp_sync1 && cur_ops->sync) 978 synctype[nsynctypes++] = RTWS_SYNC; 979 else if (gp_sync && !cur_ops->sync) 980 pr_alert("rcu_torture_writer: gp_sync without primitives.\n"); 981 if (WARN_ONCE(nsynctypes == 0, 982 "rcu_torture_writer: No update-side primitives.\n")) { 983 /* 984 * No updates primitives, so don't try updating. 985 * The resulting test won't be testing much, hence the 986 * above WARN_ONCE(). 987 */ 988 rcu_torture_writer_state = RTWS_STOPPING; 989 torture_kthread_stopping("rcu_torture_writer"); 990 } 991 992 do { 993 rcu_torture_writer_state = RTWS_FIXED_DELAY; 994 schedule_timeout_uninterruptible(1); 995 rp = rcu_torture_alloc(); 996 if (rp == NULL) 997 continue; 998 rp->rtort_pipe_count = 0; 999 rcu_torture_writer_state = RTWS_DELAY; 1000 udelay(torture_random(&rand) & 0x3ff); 1001 rcu_torture_writer_state = RTWS_REPLACE; 1002 old_rp = rcu_dereference_check(rcu_torture_current, 1003 current == writer_task); 1004 rp->rtort_mbtest = 1; 1005 rcu_assign_pointer(rcu_torture_current, rp); 1006 smp_wmb(); /* Mods to old_rp must follow rcu_assign_pointer() */ 1007 if (old_rp) { 1008 i = old_rp->rtort_pipe_count; 1009 if (i > RCU_TORTURE_PIPE_LEN) 1010 i = RCU_TORTURE_PIPE_LEN; 1011 atomic_inc(&rcu_torture_wcount[i]); 1012 old_rp->rtort_pipe_count++; 1013 switch (synctype[torture_random(&rand) % nsynctypes]) { 1014 case RTWS_DEF_FREE: 1015 rcu_torture_writer_state = RTWS_DEF_FREE; 1016 cur_ops->deferred_free(old_rp); 1017 break; 1018 case RTWS_EXP_SYNC: 1019 rcu_torture_writer_state = RTWS_EXP_SYNC; 1020 cur_ops->exp_sync(); 1021 rcu_torture_pipe_update(old_rp); 1022 break; 1023 case RTWS_COND_GET: 1024 rcu_torture_writer_state = RTWS_COND_GET; 1025 gp_snap = cur_ops->get_state(); 1026 i = torture_random(&rand) % 16; 1027 if (i != 0) 1028 schedule_timeout_interruptible(i); 1029 udelay(torture_random(&rand) % 1000); 1030 rcu_torture_writer_state = RTWS_COND_SYNC; 1031 cur_ops->cond_sync(gp_snap); 1032 rcu_torture_pipe_update(old_rp); 1033 break; 1034 case RTWS_SYNC: 1035 rcu_torture_writer_state = RTWS_SYNC; 1036 cur_ops->sync(); 1037 rcu_torture_pipe_update(old_rp); 1038 break; 1039 default: 1040 WARN_ON_ONCE(1); 1041 break; 1042 } 1043 } 1044 rcutorture_record_progress(++rcu_torture_current_version); 1045 /* Cycle through nesting levels of rcu_expedite_gp() calls. */ 1046 if (can_expedite && 1047 !(torture_random(&rand) & 0xff & (!!expediting - 1))) { 1048 WARN_ON_ONCE(expediting == 0 && rcu_gp_is_expedited()); 1049 if (expediting >= 0) 1050 rcu_expedite_gp(); 1051 else 1052 rcu_unexpedite_gp(); 1053 if (++expediting > 3) 1054 expediting = -expediting; 1055 } 1056 rcu_torture_writer_state = RTWS_STUTTER; 1057 stutter_wait("rcu_torture_writer"); 1058 } while (!torture_must_stop()); 1059 /* Reset expediting back to unexpedited. */ 1060 if (expediting > 0) 1061 expediting = -expediting; 1062 while (can_expedite && expediting++ < 0) 1063 rcu_unexpedite_gp(); 1064 WARN_ON_ONCE(can_expedite && rcu_gp_is_expedited()); 1065 rcu_torture_writer_state = RTWS_STOPPING; 1066 torture_kthread_stopping("rcu_torture_writer"); 1067 return 0; 1068 } 1069 1070 /* 1071 * RCU torture fake writer kthread. Repeatedly calls sync, with a random 1072 * delay between calls. 1073 */ 1074 static int 1075 rcu_torture_fakewriter(void *arg) 1076 { 1077 DEFINE_TORTURE_RANDOM(rand); 1078 1079 VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task started"); 1080 set_user_nice(current, MAX_NICE); 1081 1082 do { 1083 schedule_timeout_uninterruptible(1 + torture_random(&rand)%10); 1084 udelay(torture_random(&rand) & 0x3ff); 1085 if (cur_ops->cb_barrier != NULL && 1086 torture_random(&rand) % (nfakewriters * 8) == 0) { 1087 cur_ops->cb_barrier(); 1088 } else if (gp_normal == gp_exp) { 1089 if (torture_random(&rand) & 0x80) 1090 cur_ops->sync(); 1091 else 1092 cur_ops->exp_sync(); 1093 } else if (gp_normal) { 1094 cur_ops->sync(); 1095 } else { 1096 cur_ops->exp_sync(); 1097 } 1098 stutter_wait("rcu_torture_fakewriter"); 1099 } while (!torture_must_stop()); 1100 1101 torture_kthread_stopping("rcu_torture_fakewriter"); 1102 return 0; 1103 } 1104 1105 /* 1106 * RCU torture reader from timer handler. Dereferences rcu_torture_current, 1107 * incrementing the corresponding element of the pipeline array. The 1108 * counter in the element should never be greater than 1, otherwise, the 1109 * RCU implementation is broken. 1110 */ 1111 static void rcu_torture_timer(unsigned long unused) 1112 { 1113 int idx; 1114 unsigned long started; 1115 unsigned long completed; 1116 static DEFINE_TORTURE_RANDOM(rand); 1117 static DEFINE_SPINLOCK(rand_lock); 1118 struct rcu_torture *p; 1119 int pipe_count; 1120 unsigned long long ts; 1121 1122 idx = cur_ops->readlock(); 1123 if (cur_ops->started) 1124 started = cur_ops->started(); 1125 else 1126 started = cur_ops->completed(); 1127 ts = rcu_trace_clock_local(); 1128 p = rcu_dereference_check(rcu_torture_current, 1129 rcu_read_lock_bh_held() || 1130 rcu_read_lock_sched_held() || 1131 srcu_read_lock_held(srcu_ctlp) || 1132 torturing_tasks()); 1133 if (p == NULL) { 1134 /* Leave because rcu_torture_writer is not yet underway */ 1135 cur_ops->readunlock(idx); 1136 return; 1137 } 1138 if (p->rtort_mbtest == 0) 1139 atomic_inc(&n_rcu_torture_mberror); 1140 spin_lock(&rand_lock); 1141 cur_ops->read_delay(&rand); 1142 n_rcu_torture_timers++; 1143 spin_unlock(&rand_lock); 1144 preempt_disable(); 1145 pipe_count = p->rtort_pipe_count; 1146 if (pipe_count > RCU_TORTURE_PIPE_LEN) { 1147 /* Should not happen, but... */ 1148 pipe_count = RCU_TORTURE_PIPE_LEN; 1149 } 1150 completed = cur_ops->completed(); 1151 if (pipe_count > 1) { 1152 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, ts, 1153 started, completed); 1154 rcu_ftrace_dump(DUMP_ALL); 1155 } 1156 __this_cpu_inc(rcu_torture_count[pipe_count]); 1157 completed = completed - started; 1158 if (cur_ops->started) 1159 completed++; 1160 if (completed > RCU_TORTURE_PIPE_LEN) { 1161 /* Should not happen, but... */ 1162 completed = RCU_TORTURE_PIPE_LEN; 1163 } 1164 __this_cpu_inc(rcu_torture_batch[completed]); 1165 preempt_enable(); 1166 cur_ops->readunlock(idx); 1167 } 1168 1169 /* 1170 * RCU torture reader kthread. Repeatedly dereferences rcu_torture_current, 1171 * incrementing the corresponding element of the pipeline array. The 1172 * counter in the element should never be greater than 1, otherwise, the 1173 * RCU implementation is broken. 1174 */ 1175 static int 1176 rcu_torture_reader(void *arg) 1177 { 1178 unsigned long started; 1179 unsigned long completed; 1180 int idx; 1181 DEFINE_TORTURE_RANDOM(rand); 1182 struct rcu_torture *p; 1183 int pipe_count; 1184 struct timer_list t; 1185 unsigned long long ts; 1186 1187 VERBOSE_TOROUT_STRING("rcu_torture_reader task started"); 1188 set_user_nice(current, MAX_NICE); 1189 if (irqreader && cur_ops->irq_capable) 1190 setup_timer_on_stack(&t, rcu_torture_timer, 0); 1191 1192 do { 1193 if (irqreader && cur_ops->irq_capable) { 1194 if (!timer_pending(&t)) 1195 mod_timer(&t, jiffies + 1); 1196 } 1197 idx = cur_ops->readlock(); 1198 if (cur_ops->started) 1199 started = cur_ops->started(); 1200 else 1201 started = cur_ops->completed(); 1202 ts = rcu_trace_clock_local(); 1203 p = rcu_dereference_check(rcu_torture_current, 1204 rcu_read_lock_bh_held() || 1205 rcu_read_lock_sched_held() || 1206 srcu_read_lock_held(srcu_ctlp) || 1207 torturing_tasks()); 1208 if (p == NULL) { 1209 /* Wait for rcu_torture_writer to get underway */ 1210 cur_ops->readunlock(idx); 1211 schedule_timeout_interruptible(HZ); 1212 continue; 1213 } 1214 if (p->rtort_mbtest == 0) 1215 atomic_inc(&n_rcu_torture_mberror); 1216 cur_ops->read_delay(&rand); 1217 preempt_disable(); 1218 pipe_count = p->rtort_pipe_count; 1219 if (pipe_count > RCU_TORTURE_PIPE_LEN) { 1220 /* Should not happen, but... */ 1221 pipe_count = RCU_TORTURE_PIPE_LEN; 1222 } 1223 completed = cur_ops->completed(); 1224 if (pipe_count > 1) { 1225 do_trace_rcu_torture_read(cur_ops->name, &p->rtort_rcu, 1226 ts, started, completed); 1227 rcu_ftrace_dump(DUMP_ALL); 1228 } 1229 __this_cpu_inc(rcu_torture_count[pipe_count]); 1230 completed = completed - started; 1231 if (cur_ops->started) 1232 completed++; 1233 if (completed > RCU_TORTURE_PIPE_LEN) { 1234 /* Should not happen, but... */ 1235 completed = RCU_TORTURE_PIPE_LEN; 1236 } 1237 __this_cpu_inc(rcu_torture_batch[completed]); 1238 preempt_enable(); 1239 cur_ops->readunlock(idx); 1240 stutter_wait("rcu_torture_reader"); 1241 } while (!torture_must_stop()); 1242 if (irqreader && cur_ops->irq_capable) { 1243 del_timer_sync(&t); 1244 destroy_timer_on_stack(&t); 1245 } 1246 torture_kthread_stopping("rcu_torture_reader"); 1247 return 0; 1248 } 1249 1250 /* 1251 * Print torture statistics. Caller must ensure that there is only 1252 * one call to this function at a given time!!! This is normally 1253 * accomplished by relying on the module system to only have one copy 1254 * of the module loaded, and then by giving the rcu_torture_stats 1255 * kthread full control (or the init/cleanup functions when rcu_torture_stats 1256 * thread is not running). 1257 */ 1258 static void 1259 rcu_torture_stats_print(void) 1260 { 1261 int cpu; 1262 int i; 1263 long pipesummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 1264 long batchsummary[RCU_TORTURE_PIPE_LEN + 1] = { 0 }; 1265 static unsigned long rtcv_snap = ULONG_MAX; 1266 struct task_struct *wtp; 1267 1268 for_each_possible_cpu(cpu) { 1269 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 1270 pipesummary[i] += per_cpu(rcu_torture_count, cpu)[i]; 1271 batchsummary[i] += per_cpu(rcu_torture_batch, cpu)[i]; 1272 } 1273 } 1274 for (i = RCU_TORTURE_PIPE_LEN - 1; i >= 0; i--) { 1275 if (pipesummary[i] != 0) 1276 break; 1277 } 1278 1279 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 1280 pr_cont("rtc: %p ver: %lu tfle: %d rta: %d rtaf: %d rtf: %d ", 1281 rcu_torture_current, 1282 rcu_torture_current_version, 1283 list_empty(&rcu_torture_freelist), 1284 atomic_read(&n_rcu_torture_alloc), 1285 atomic_read(&n_rcu_torture_alloc_fail), 1286 atomic_read(&n_rcu_torture_free)); 1287 pr_cont("rtmbe: %d rtbe: %ld rtbke: %ld rtbre: %ld ", 1288 atomic_read(&n_rcu_torture_mberror), 1289 n_rcu_torture_barrier_error, 1290 n_rcu_torture_boost_ktrerror, 1291 n_rcu_torture_boost_rterror); 1292 pr_cont("rtbf: %ld rtb: %ld nt: %ld ", 1293 n_rcu_torture_boost_failure, 1294 n_rcu_torture_boosts, 1295 n_rcu_torture_timers); 1296 torture_onoff_stats(); 1297 pr_cont("barrier: %ld/%ld:%ld ", 1298 n_barrier_successes, 1299 n_barrier_attempts, 1300 n_rcu_torture_barrier_error); 1301 pr_cont("cbflood: %ld\n", atomic_long_read(&n_cbfloods)); 1302 1303 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 1304 if (atomic_read(&n_rcu_torture_mberror) != 0 || 1305 n_rcu_torture_barrier_error != 0 || 1306 n_rcu_torture_boost_ktrerror != 0 || 1307 n_rcu_torture_boost_rterror != 0 || 1308 n_rcu_torture_boost_failure != 0 || 1309 i > 1) { 1310 pr_cont("%s", "!!! "); 1311 atomic_inc(&n_rcu_torture_error); 1312 WARN_ON_ONCE(1); 1313 } 1314 pr_cont("Reader Pipe: "); 1315 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 1316 pr_cont(" %ld", pipesummary[i]); 1317 pr_cont("\n"); 1318 1319 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 1320 pr_cont("Reader Batch: "); 1321 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 1322 pr_cont(" %ld", batchsummary[i]); 1323 pr_cont("\n"); 1324 1325 pr_alert("%s%s ", torture_type, TORTURE_FLAG); 1326 pr_cont("Free-Block Circulation: "); 1327 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 1328 pr_cont(" %d", atomic_read(&rcu_torture_wcount[i])); 1329 } 1330 pr_cont("\n"); 1331 1332 if (cur_ops->stats) 1333 cur_ops->stats(); 1334 if (rtcv_snap == rcu_torture_current_version && 1335 rcu_torture_current != NULL) { 1336 int __maybe_unused flags; 1337 unsigned long __maybe_unused gpnum; 1338 unsigned long __maybe_unused completed; 1339 1340 rcutorture_get_gp_data(cur_ops->ttype, 1341 &flags, &gpnum, &completed); 1342 wtp = READ_ONCE(writer_task); 1343 pr_alert("??? Writer stall state %s(%d) g%lu c%lu f%#x ->state %#lx\n", 1344 rcu_torture_writer_state_getname(), 1345 rcu_torture_writer_state, 1346 gpnum, completed, flags, 1347 wtp == NULL ? ~0UL : wtp->state); 1348 show_rcu_gp_kthreads(); 1349 rcu_ftrace_dump(DUMP_ALL); 1350 } 1351 rtcv_snap = rcu_torture_current_version; 1352 } 1353 1354 /* 1355 * Periodically prints torture statistics, if periodic statistics printing 1356 * was specified via the stat_interval module parameter. 1357 */ 1358 static int 1359 rcu_torture_stats(void *arg) 1360 { 1361 VERBOSE_TOROUT_STRING("rcu_torture_stats task started"); 1362 do { 1363 schedule_timeout_interruptible(stat_interval * HZ); 1364 rcu_torture_stats_print(); 1365 torture_shutdown_absorb("rcu_torture_stats"); 1366 } while (!torture_must_stop()); 1367 torture_kthread_stopping("rcu_torture_stats"); 1368 return 0; 1369 } 1370 1371 static inline void 1372 rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag) 1373 { 1374 pr_alert("%s" TORTURE_FLAG 1375 "--- %s: nreaders=%d nfakewriters=%d " 1376 "stat_interval=%d verbose=%d test_no_idle_hz=%d " 1377 "shuffle_interval=%d stutter=%d irqreader=%d " 1378 "fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d " 1379 "test_boost=%d/%d test_boost_interval=%d " 1380 "test_boost_duration=%d shutdown_secs=%d " 1381 "stall_cpu=%d stall_cpu_holdoff=%d " 1382 "n_barrier_cbs=%d " 1383 "onoff_interval=%d onoff_holdoff=%d\n", 1384 torture_type, tag, nrealreaders, nfakewriters, 1385 stat_interval, verbose, test_no_idle_hz, shuffle_interval, 1386 stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter, 1387 test_boost, cur_ops->can_boost, 1388 test_boost_interval, test_boost_duration, shutdown_secs, 1389 stall_cpu, stall_cpu_holdoff, 1390 n_barrier_cbs, 1391 onoff_interval, onoff_holdoff); 1392 } 1393 1394 static int rcutorture_booster_cleanup(unsigned int cpu) 1395 { 1396 struct task_struct *t; 1397 1398 if (boost_tasks[cpu] == NULL) 1399 return 0; 1400 mutex_lock(&boost_mutex); 1401 t = boost_tasks[cpu]; 1402 boost_tasks[cpu] = NULL; 1403 mutex_unlock(&boost_mutex); 1404 1405 /* This must be outside of the mutex, otherwise deadlock! */ 1406 torture_stop_kthread(rcu_torture_boost, t); 1407 return 0; 1408 } 1409 1410 static int rcutorture_booster_init(unsigned int cpu) 1411 { 1412 int retval; 1413 1414 if (boost_tasks[cpu] != NULL) 1415 return 0; /* Already created, nothing more to do. */ 1416 1417 /* Don't allow time recalculation while creating a new task. */ 1418 mutex_lock(&boost_mutex); 1419 VERBOSE_TOROUT_STRING("Creating rcu_torture_boost task"); 1420 boost_tasks[cpu] = kthread_create_on_node(rcu_torture_boost, NULL, 1421 cpu_to_node(cpu), 1422 "rcu_torture_boost"); 1423 if (IS_ERR(boost_tasks[cpu])) { 1424 retval = PTR_ERR(boost_tasks[cpu]); 1425 VERBOSE_TOROUT_STRING("rcu_torture_boost task create failed"); 1426 n_rcu_torture_boost_ktrerror++; 1427 boost_tasks[cpu] = NULL; 1428 mutex_unlock(&boost_mutex); 1429 return retval; 1430 } 1431 kthread_bind(boost_tasks[cpu], cpu); 1432 wake_up_process(boost_tasks[cpu]); 1433 mutex_unlock(&boost_mutex); 1434 return 0; 1435 } 1436 1437 /* 1438 * CPU-stall kthread. It waits as specified by stall_cpu_holdoff, then 1439 * induces a CPU stall for the time specified by stall_cpu. 1440 */ 1441 static int rcu_torture_stall(void *args) 1442 { 1443 unsigned long stop_at; 1444 1445 VERBOSE_TOROUT_STRING("rcu_torture_stall task started"); 1446 if (stall_cpu_holdoff > 0) { 1447 VERBOSE_TOROUT_STRING("rcu_torture_stall begin holdoff"); 1448 schedule_timeout_interruptible(stall_cpu_holdoff * HZ); 1449 VERBOSE_TOROUT_STRING("rcu_torture_stall end holdoff"); 1450 } 1451 if (!kthread_should_stop()) { 1452 stop_at = get_seconds() + stall_cpu; 1453 /* RCU CPU stall is expected behavior in following code. */ 1454 pr_alert("rcu_torture_stall start.\n"); 1455 rcu_read_lock(); 1456 preempt_disable(); 1457 while (ULONG_CMP_LT(get_seconds(), stop_at)) 1458 continue; /* Induce RCU CPU stall warning. */ 1459 preempt_enable(); 1460 rcu_read_unlock(); 1461 pr_alert("rcu_torture_stall end.\n"); 1462 } 1463 torture_shutdown_absorb("rcu_torture_stall"); 1464 while (!kthread_should_stop()) 1465 schedule_timeout_interruptible(10 * HZ); 1466 return 0; 1467 } 1468 1469 /* Spawn CPU-stall kthread, if stall_cpu specified. */ 1470 static int __init rcu_torture_stall_init(void) 1471 { 1472 if (stall_cpu <= 0) 1473 return 0; 1474 return torture_create_kthread(rcu_torture_stall, NULL, stall_task); 1475 } 1476 1477 /* Callback function for RCU barrier testing. */ 1478 static void rcu_torture_barrier_cbf(struct rcu_head *rcu) 1479 { 1480 atomic_inc(&barrier_cbs_invoked); 1481 } 1482 1483 /* kthread function to register callbacks used to test RCU barriers. */ 1484 static int rcu_torture_barrier_cbs(void *arg) 1485 { 1486 long myid = (long)arg; 1487 bool lastphase = 0; 1488 bool newphase; 1489 struct rcu_head rcu; 1490 1491 init_rcu_head_on_stack(&rcu); 1492 VERBOSE_TOROUT_STRING("rcu_torture_barrier_cbs task started"); 1493 set_user_nice(current, MAX_NICE); 1494 do { 1495 wait_event(barrier_cbs_wq[myid], 1496 (newphase = 1497 smp_load_acquire(&barrier_phase)) != lastphase || 1498 torture_must_stop()); 1499 lastphase = newphase; 1500 if (torture_must_stop()) 1501 break; 1502 /* 1503 * The above smp_load_acquire() ensures barrier_phase load 1504 * is ordered before the following ->call(). 1505 */ 1506 local_irq_disable(); /* Just to test no-irq call_rcu(). */ 1507 cur_ops->call(&rcu, rcu_torture_barrier_cbf); 1508 local_irq_enable(); 1509 if (atomic_dec_and_test(&barrier_cbs_count)) 1510 wake_up(&barrier_wq); 1511 } while (!torture_must_stop()); 1512 if (cur_ops->cb_barrier != NULL) 1513 cur_ops->cb_barrier(); 1514 destroy_rcu_head_on_stack(&rcu); 1515 torture_kthread_stopping("rcu_torture_barrier_cbs"); 1516 return 0; 1517 } 1518 1519 /* kthread function to drive and coordinate RCU barrier testing. */ 1520 static int rcu_torture_barrier(void *arg) 1521 { 1522 int i; 1523 1524 VERBOSE_TOROUT_STRING("rcu_torture_barrier task starting"); 1525 do { 1526 atomic_set(&barrier_cbs_invoked, 0); 1527 atomic_set(&barrier_cbs_count, n_barrier_cbs); 1528 /* Ensure barrier_phase ordered after prior assignments. */ 1529 smp_store_release(&barrier_phase, !barrier_phase); 1530 for (i = 0; i < n_barrier_cbs; i++) 1531 wake_up(&barrier_cbs_wq[i]); 1532 wait_event(barrier_wq, 1533 atomic_read(&barrier_cbs_count) == 0 || 1534 torture_must_stop()); 1535 if (torture_must_stop()) 1536 break; 1537 n_barrier_attempts++; 1538 cur_ops->cb_barrier(); /* Implies smp_mb() for wait_event(). */ 1539 if (atomic_read(&barrier_cbs_invoked) != n_barrier_cbs) { 1540 n_rcu_torture_barrier_error++; 1541 pr_err("barrier_cbs_invoked = %d, n_barrier_cbs = %d\n", 1542 atomic_read(&barrier_cbs_invoked), 1543 n_barrier_cbs); 1544 WARN_ON_ONCE(1); 1545 } 1546 n_barrier_successes++; 1547 schedule_timeout_interruptible(HZ / 10); 1548 } while (!torture_must_stop()); 1549 torture_kthread_stopping("rcu_torture_barrier"); 1550 return 0; 1551 } 1552 1553 /* Initialize RCU barrier testing. */ 1554 static int rcu_torture_barrier_init(void) 1555 { 1556 int i; 1557 int ret; 1558 1559 if (n_barrier_cbs <= 0) 1560 return 0; 1561 if (cur_ops->call == NULL || cur_ops->cb_barrier == NULL) { 1562 pr_alert("%s" TORTURE_FLAG 1563 " Call or barrier ops missing for %s,\n", 1564 torture_type, cur_ops->name); 1565 pr_alert("%s" TORTURE_FLAG 1566 " RCU barrier testing omitted from run.\n", 1567 torture_type); 1568 return 0; 1569 } 1570 atomic_set(&barrier_cbs_count, 0); 1571 atomic_set(&barrier_cbs_invoked, 0); 1572 barrier_cbs_tasks = 1573 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_tasks[0]), 1574 GFP_KERNEL); 1575 barrier_cbs_wq = 1576 kzalloc(n_barrier_cbs * sizeof(barrier_cbs_wq[0]), 1577 GFP_KERNEL); 1578 if (barrier_cbs_tasks == NULL || !barrier_cbs_wq) 1579 return -ENOMEM; 1580 for (i = 0; i < n_barrier_cbs; i++) { 1581 init_waitqueue_head(&barrier_cbs_wq[i]); 1582 ret = torture_create_kthread(rcu_torture_barrier_cbs, 1583 (void *)(long)i, 1584 barrier_cbs_tasks[i]); 1585 if (ret) 1586 return ret; 1587 } 1588 return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task); 1589 } 1590 1591 /* Clean up after RCU barrier testing. */ 1592 static void rcu_torture_barrier_cleanup(void) 1593 { 1594 int i; 1595 1596 torture_stop_kthread(rcu_torture_barrier, barrier_task); 1597 if (barrier_cbs_tasks != NULL) { 1598 for (i = 0; i < n_barrier_cbs; i++) 1599 torture_stop_kthread(rcu_torture_barrier_cbs, 1600 barrier_cbs_tasks[i]); 1601 kfree(barrier_cbs_tasks); 1602 barrier_cbs_tasks = NULL; 1603 } 1604 if (barrier_cbs_wq != NULL) { 1605 kfree(barrier_cbs_wq); 1606 barrier_cbs_wq = NULL; 1607 } 1608 } 1609 1610 static enum cpuhp_state rcutor_hp; 1611 1612 static void 1613 rcu_torture_cleanup(void) 1614 { 1615 int i; 1616 1617 rcutorture_record_test_transition(); 1618 if (torture_cleanup_begin()) { 1619 if (cur_ops->cb_barrier != NULL) 1620 cur_ops->cb_barrier(); 1621 return; 1622 } 1623 1624 rcu_torture_barrier_cleanup(); 1625 torture_stop_kthread(rcu_torture_stall, stall_task); 1626 torture_stop_kthread(rcu_torture_writer, writer_task); 1627 1628 if (reader_tasks) { 1629 for (i = 0; i < nrealreaders; i++) 1630 torture_stop_kthread(rcu_torture_reader, 1631 reader_tasks[i]); 1632 kfree(reader_tasks); 1633 } 1634 rcu_torture_current = NULL; 1635 1636 if (fakewriter_tasks) { 1637 for (i = 0; i < nfakewriters; i++) { 1638 torture_stop_kthread(rcu_torture_fakewriter, 1639 fakewriter_tasks[i]); 1640 } 1641 kfree(fakewriter_tasks); 1642 fakewriter_tasks = NULL; 1643 } 1644 1645 torture_stop_kthread(rcu_torture_stats, stats_task); 1646 torture_stop_kthread(rcu_torture_fqs, fqs_task); 1647 for (i = 0; i < ncbflooders; i++) 1648 torture_stop_kthread(rcu_torture_cbflood, cbflood_task[i]); 1649 if ((test_boost == 1 && cur_ops->can_boost) || 1650 test_boost == 2) 1651 cpuhp_remove_state(rcutor_hp); 1652 1653 /* 1654 * Wait for all RCU callbacks to fire, then do flavor-specific 1655 * cleanup operations. 1656 */ 1657 if (cur_ops->cb_barrier != NULL) 1658 cur_ops->cb_barrier(); 1659 if (cur_ops->cleanup != NULL) 1660 cur_ops->cleanup(); 1661 1662 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ 1663 1664 if (atomic_read(&n_rcu_torture_error) || n_rcu_torture_barrier_error) 1665 rcu_torture_print_module_parms(cur_ops, "End of test: FAILURE"); 1666 else if (torture_onoff_failures()) 1667 rcu_torture_print_module_parms(cur_ops, 1668 "End of test: RCU_HOTPLUG"); 1669 else 1670 rcu_torture_print_module_parms(cur_ops, "End of test: SUCCESS"); 1671 torture_cleanup_end(); 1672 } 1673 1674 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD 1675 static void rcu_torture_leak_cb(struct rcu_head *rhp) 1676 { 1677 } 1678 1679 static void rcu_torture_err_cb(struct rcu_head *rhp) 1680 { 1681 /* 1682 * This -might- happen due to race conditions, but is unlikely. 1683 * The scenario that leads to this happening is that the 1684 * first of the pair of duplicate callbacks is queued, 1685 * someone else starts a grace period that includes that 1686 * callback, then the second of the pair must wait for the 1687 * next grace period. Unlikely, but can happen. If it 1688 * does happen, the debug-objects subsystem won't have splatted. 1689 */ 1690 pr_alert("rcutorture: duplicated callback was invoked.\n"); 1691 } 1692 #endif /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 1693 1694 /* 1695 * Verify that double-free causes debug-objects to complain, but only 1696 * if CONFIG_DEBUG_OBJECTS_RCU_HEAD=y. Otherwise, say that the test 1697 * cannot be carried out. 1698 */ 1699 static void rcu_test_debug_objects(void) 1700 { 1701 #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD 1702 struct rcu_head rh1; 1703 struct rcu_head rh2; 1704 1705 init_rcu_head_on_stack(&rh1); 1706 init_rcu_head_on_stack(&rh2); 1707 pr_alert("rcutorture: WARN: Duplicate call_rcu() test starting.\n"); 1708 1709 /* Try to queue the rh2 pair of callbacks for the same grace period. */ 1710 preempt_disable(); /* Prevent preemption from interrupting test. */ 1711 rcu_read_lock(); /* Make it impossible to finish a grace period. */ 1712 call_rcu(&rh1, rcu_torture_leak_cb); /* Start grace period. */ 1713 local_irq_disable(); /* Make it harder to start a new grace period. */ 1714 call_rcu(&rh2, rcu_torture_leak_cb); 1715 call_rcu(&rh2, rcu_torture_err_cb); /* Duplicate callback. */ 1716 local_irq_enable(); 1717 rcu_read_unlock(); 1718 preempt_enable(); 1719 1720 /* Wait for them all to get done so we can safely return. */ 1721 rcu_barrier(); 1722 pr_alert("rcutorture: WARN: Duplicate call_rcu() test complete.\n"); 1723 destroy_rcu_head_on_stack(&rh1); 1724 destroy_rcu_head_on_stack(&rh2); 1725 #else /* #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 1726 pr_alert("rcutorture: !CONFIG_DEBUG_OBJECTS_RCU_HEAD, not testing duplicate call_rcu()\n"); 1727 #endif /* #else #ifdef CONFIG_DEBUG_OBJECTS_RCU_HEAD */ 1728 } 1729 1730 static int __init 1731 rcu_torture_init(void) 1732 { 1733 int i; 1734 int cpu; 1735 int firsterr = 0; 1736 static struct rcu_torture_ops *torture_ops[] = { 1737 &rcu_ops, &rcu_bh_ops, &rcu_busted_ops, &srcu_ops, &srcud_ops, 1738 &sched_ops, RCUTORTURE_TASKS_OPS 1739 }; 1740 1741 if (!torture_init_begin(torture_type, verbose, &torture_runnable)) 1742 return -EBUSY; 1743 1744 /* Process args and tell the world that the torturer is on the job. */ 1745 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) { 1746 cur_ops = torture_ops[i]; 1747 if (strcmp(torture_type, cur_ops->name) == 0) 1748 break; 1749 } 1750 if (i == ARRAY_SIZE(torture_ops)) { 1751 pr_alert("rcu-torture: invalid torture type: \"%s\"\n", 1752 torture_type); 1753 pr_alert("rcu-torture types:"); 1754 for (i = 0; i < ARRAY_SIZE(torture_ops); i++) 1755 pr_alert(" %s", torture_ops[i]->name); 1756 pr_alert("\n"); 1757 firsterr = -EINVAL; 1758 goto unwind; 1759 } 1760 if (cur_ops->fqs == NULL && fqs_duration != 0) { 1761 pr_alert("rcu-torture: ->fqs NULL and non-zero fqs_duration, fqs disabled.\n"); 1762 fqs_duration = 0; 1763 } 1764 if (cur_ops->init) 1765 cur_ops->init(); 1766 1767 if (nreaders >= 0) { 1768 nrealreaders = nreaders; 1769 } else { 1770 nrealreaders = num_online_cpus() - 2 - nreaders; 1771 if (nrealreaders <= 0) 1772 nrealreaders = 1; 1773 } 1774 rcu_torture_print_module_parms(cur_ops, "Start of test"); 1775 1776 /* Set up the freelist. */ 1777 1778 INIT_LIST_HEAD(&rcu_torture_freelist); 1779 for (i = 0; i < ARRAY_SIZE(rcu_tortures); i++) { 1780 rcu_tortures[i].rtort_mbtest = 0; 1781 list_add_tail(&rcu_tortures[i].rtort_free, 1782 &rcu_torture_freelist); 1783 } 1784 1785 /* Initialize the statistics so that each run gets its own numbers. */ 1786 1787 rcu_torture_current = NULL; 1788 rcu_torture_current_version = 0; 1789 atomic_set(&n_rcu_torture_alloc, 0); 1790 atomic_set(&n_rcu_torture_alloc_fail, 0); 1791 atomic_set(&n_rcu_torture_free, 0); 1792 atomic_set(&n_rcu_torture_mberror, 0); 1793 atomic_set(&n_rcu_torture_error, 0); 1794 n_rcu_torture_barrier_error = 0; 1795 n_rcu_torture_boost_ktrerror = 0; 1796 n_rcu_torture_boost_rterror = 0; 1797 n_rcu_torture_boost_failure = 0; 1798 n_rcu_torture_boosts = 0; 1799 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) 1800 atomic_set(&rcu_torture_wcount[i], 0); 1801 for_each_possible_cpu(cpu) { 1802 for (i = 0; i < RCU_TORTURE_PIPE_LEN + 1; i++) { 1803 per_cpu(rcu_torture_count, cpu)[i] = 0; 1804 per_cpu(rcu_torture_batch, cpu)[i] = 0; 1805 } 1806 } 1807 1808 /* Start up the kthreads. */ 1809 1810 firsterr = torture_create_kthread(rcu_torture_writer, NULL, 1811 writer_task); 1812 if (firsterr) 1813 goto unwind; 1814 if (nfakewriters > 0) { 1815 fakewriter_tasks = kzalloc(nfakewriters * 1816 sizeof(fakewriter_tasks[0]), 1817 GFP_KERNEL); 1818 if (fakewriter_tasks == NULL) { 1819 VERBOSE_TOROUT_ERRSTRING("out of memory"); 1820 firsterr = -ENOMEM; 1821 goto unwind; 1822 } 1823 } 1824 for (i = 0; i < nfakewriters; i++) { 1825 firsterr = torture_create_kthread(rcu_torture_fakewriter, 1826 NULL, fakewriter_tasks[i]); 1827 if (firsterr) 1828 goto unwind; 1829 } 1830 reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]), 1831 GFP_KERNEL); 1832 if (reader_tasks == NULL) { 1833 VERBOSE_TOROUT_ERRSTRING("out of memory"); 1834 firsterr = -ENOMEM; 1835 goto unwind; 1836 } 1837 for (i = 0; i < nrealreaders; i++) { 1838 firsterr = torture_create_kthread(rcu_torture_reader, NULL, 1839 reader_tasks[i]); 1840 if (firsterr) 1841 goto unwind; 1842 } 1843 if (stat_interval > 0) { 1844 firsterr = torture_create_kthread(rcu_torture_stats, NULL, 1845 stats_task); 1846 if (firsterr) 1847 goto unwind; 1848 } 1849 if (test_no_idle_hz && shuffle_interval > 0) { 1850 firsterr = torture_shuffle_init(shuffle_interval * HZ); 1851 if (firsterr) 1852 goto unwind; 1853 } 1854 if (stutter < 0) 1855 stutter = 0; 1856 if (stutter) { 1857 firsterr = torture_stutter_init(stutter * HZ); 1858 if (firsterr) 1859 goto unwind; 1860 } 1861 if (fqs_duration < 0) 1862 fqs_duration = 0; 1863 if (fqs_duration) { 1864 /* Create the fqs thread */ 1865 firsterr = torture_create_kthread(rcu_torture_fqs, NULL, 1866 fqs_task); 1867 if (firsterr) 1868 goto unwind; 1869 } 1870 if (test_boost_interval < 1) 1871 test_boost_interval = 1; 1872 if (test_boost_duration < 2) 1873 test_boost_duration = 2; 1874 if ((test_boost == 1 && cur_ops->can_boost) || 1875 test_boost == 2) { 1876 1877 boost_starttime = jiffies + test_boost_interval * HZ; 1878 1879 firsterr = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "RCU_TORTURE", 1880 rcutorture_booster_init, 1881 rcutorture_booster_cleanup); 1882 if (firsterr < 0) 1883 goto unwind; 1884 rcutor_hp = firsterr; 1885 } 1886 firsterr = torture_shutdown_init(shutdown_secs, rcu_torture_cleanup); 1887 if (firsterr) 1888 goto unwind; 1889 firsterr = torture_onoff_init(onoff_holdoff * HZ, onoff_interval * HZ); 1890 if (firsterr) 1891 goto unwind; 1892 firsterr = rcu_torture_stall_init(); 1893 if (firsterr) 1894 goto unwind; 1895 firsterr = rcu_torture_barrier_init(); 1896 if (firsterr) 1897 goto unwind; 1898 if (object_debug) 1899 rcu_test_debug_objects(); 1900 if (cbflood_n_burst > 0) { 1901 /* Create the cbflood threads */ 1902 ncbflooders = (num_online_cpus() + 3) / 4; 1903 cbflood_task = kcalloc(ncbflooders, sizeof(*cbflood_task), 1904 GFP_KERNEL); 1905 if (!cbflood_task) { 1906 VERBOSE_TOROUT_ERRSTRING("out of memory"); 1907 firsterr = -ENOMEM; 1908 goto unwind; 1909 } 1910 for (i = 0; i < ncbflooders; i++) { 1911 firsterr = torture_create_kthread(rcu_torture_cbflood, 1912 NULL, 1913 cbflood_task[i]); 1914 if (firsterr) 1915 goto unwind; 1916 } 1917 } 1918 rcutorture_record_test_transition(); 1919 torture_init_end(); 1920 return 0; 1921 1922 unwind: 1923 torture_init_end(); 1924 rcu_torture_cleanup(); 1925 return firsterr; 1926 } 1927 1928 module_init(rcu_torture_init); 1929 module_exit(rcu_torture_cleanup); 1930