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