| 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); |