kernel/locking/locktorture.c

   1 /*
   2  * Module-based torture test facility for locking
   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, 2014
  19  *
  20  * Author: Paul E. McKenney <paulmck@us.ibm.com>
  21  *      Based on kernel/rcu/torture.c.
  22  */
  23 #include <linux/types.h>
  24 #include <linux/kernel.h>
  25 #include <linux/init.h>
  26 #include <linux/module.h>
  27 #include <linux/kthread.h>
  28 #include <linux/err.h>
  29 #include <linux/spinlock.h>
  30 #include <linux/mutex.h>
  31 #include <linux/smp.h>
  32 #include <linux/interrupt.h>
  33 #include <linux/sched.h>
  34 #include <linux/atomic.h>
  35 #include <linux/bitops.h>
  36 #include <linux/completion.h>
  37 #include <linux/moduleparam.h>
  38 #include <linux/percpu.h>
  39 #include <linux/notifier.h>
  40 #include <linux/reboot.h>
  41 #include <linux/freezer.h>
  42 #include <linux/cpu.h>
  43 #include <linux/delay.h>
  44 #include <linux/stat.h>
  45 #include <linux/slab.h>
  46 #include <linux/trace_clock.h>
  47 #include <asm/byteorder.h>
  48 #include <linux/torture.h>
  49
  50 MODULE_LICENSE("GPL");
  51 MODULE_AUTHOR("Paul E. McKenney <paulmck@us.ibm.com>");
  52
  53 torture_param(int, nwriters_stress, -1,
  54              "Number of write-locking stress-test threads");
  55 torture_param(int, nreaders_stress, -1,
  56              "Number of read-locking stress-test threads");
  57 torture_param(int, onoff_holdoff, 0, "Time after boot before CPU hotplugs (s)");
  58 torture_param(int, onoff_interval, 0,
  59              "Time between CPU hotplugs (s), 0=disable");
  60 torture_param(int, shuffle_interval, 3,
  61              "Number of jiffies between shuffles, 0=disable");
  62 torture_param(int, shutdown_secs, 0, "Shutdown time (j), <= zero to disable.");
  63 torture_param(int, stat_interval, 60,
  64              "Number of seconds between stats printk()s");
  65 torture_param(int, stutter, 5, "Number of jiffies to run/halt test, 0=disable");
  66 torture_param(bool, verbose, true,
  67              "Enable verbose debugging printk()s");
  68
  69 static bool debug_lock = false;
  70 static char *torture_type = "spin_lock";
  71 module_param(torture_type, charp, 0444);
  72 MODULE_PARM_DESC(torture_type,
  73                  "Type of lock to torture (spin_lock, spin_lock_irq, mutex_lock, ...)");
  74
  75 static atomic_t n_lock_torture_errors;
  76
  77 static struct task_struct *stats_task;
  78 static struct task_struct **writer_tasks;
  79 static struct task_struct **reader_tasks;
  80
  81 static int nrealwriters_stress;
  82 static bool lock_is_write_held;
  83 static int nrealreaders_stress;
  84 static bool lock_is_read_held;
  85
  86 struct lock_stress_stats {
  87         long n_lock_fail;
  88         long n_lock_acquired;
  89 };
  90 static struct lock_stress_stats *lwsa; /* writer statistics */
  91 static struct lock_stress_stats *lrsa; /* reader statistics */
  92
  93 #if defined(MODULE)
  94 #define LOCKTORTURE_RUNNABLE_INIT 1
  95 #else
  96 #define LOCKTORTURE_RUNNABLE_INIT 0
  97 #endif
  98 int torture_runnable = LOCKTORTURE_RUNNABLE_INIT;
  99 module_param(torture_runnable, int, 0444);
 100 MODULE_PARM_DESC(torture_runnable, "Start locktorture at module init");
 101
 102 /* Forward reference. */
 103 static void lock_torture_cleanup(void);
 104
 105 /*
 106  * Operations vector for selecting different types of tests.
 107  */
 108 struct lock_torture_ops {
 109         void (*init)(void);
 110         int (*writelock)(void);
 111         void (*write_delay)(struct torture_random_state *trsp);
 112         void (*writeunlock)(void);
 113         int (*readlock)(void);
 114         void (*read_delay)(struct torture_random_state *trsp);
 115         void (*readunlock)(void);
 116         unsigned long flags;
 117         const char *name;
 118 };
 119
 120 static struct lock_torture_ops *cur_ops;
 121
 122 /*
 123  * Definitions for lock torture testing.
 124  */
 125
 126 static int torture_lock_busted_write_lock(void)
 127 {
 128         return 0;  /* BUGGY, do not use in real life!!! */
 129 }
 130
 131 static void torture_lock_busted_write_delay(struct torture_random_state *trsp)
 132 {
 133         const unsigned long longdelay_us = 100;
 134
 135         /* We want a long delay occasionally to force massive contention.  */
 136         if (!(torture_random(trsp) %
 137               (nrealwriters_stress * 2000 * longdelay_us)))
 138                 mdelay(longdelay_us);
 139 #ifdef CONFIG_PREEMPT
 140         if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
 141                 preempt_schedule();  /* Allow test to be preempted. */
 142 #endif
 143 }
 144
 145 static void torture_lock_busted_write_unlock(void)
 146 {
 147           /* BUGGY, do not use in real life!!! */
 148 }
 149
 150 static struct lock_torture_ops lock_busted_ops = {
 151         .writelock      = torture_lock_busted_write_lock,
 152         .write_delay    = torture_lock_busted_write_delay,
 153         .writeunlock    = torture_lock_busted_write_unlock,
 154         .readlock       = NULL,
 155         .read_delay     = NULL,
 156         .readunlock     = NULL,
 157         .name           = "lock_busted"
 158 };
 159
 160 static DEFINE_SPINLOCK(torture_spinlock);
 161
 162 static int torture_spin_lock_write_lock(void) __acquires(torture_spinlock)
 163 {
 164         spin_lock(&torture_spinlock);
 165         return 0;
 166 }
 167
 168 static void torture_spin_lock_write_delay(struct torture_random_state *trsp)
 169 {
 170         const unsigned long shortdelay_us = 2;
 171         const unsigned long longdelay_us = 100;
 172
 173         /* We want a short delay mostly to emulate likely code, and
 174          * we want a long delay occasionally to force massive contention.
 175          */
 176         if (!(torture_random(trsp) %
 177               (nrealwriters_stress * 2000 * longdelay_us)))
 178                 mdelay(longdelay_us);
 179         if (!(torture_random(trsp) %
 180               (nrealwriters_stress * 2 * shortdelay_us)))
 181                 udelay(shortdelay_us);
 182 #ifdef CONFIG_PREEMPT
 183         if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
 184                 preempt_schedule();  /* Allow test to be preempted. */
 185 #endif
 186 }
 187
 188 static void torture_spin_lock_write_unlock(void) __releases(torture_spinlock)
 189 {
 190         spin_unlock(&torture_spinlock);
 191 }
 192
 193 static struct lock_torture_ops spin_lock_ops = {
 194         .writelock      = torture_spin_lock_write_lock,
 195         .write_delay    = torture_spin_lock_write_delay,
 196         .writeunlock    = torture_spin_lock_write_unlock,
 197         .readlock       = NULL,
 198         .read_delay     = NULL,
 199         .readunlock     = NULL,
 200         .name           = "spin_lock"
 201 };
 202
 203 static int torture_spin_lock_write_lock_irq(void)
 204 __acquires(torture_spinlock_irq)
 205 {
 206         unsigned long flags;
 207
 208         spin_lock_irqsave(&torture_spinlock, flags);
 209         cur_ops->flags = flags;
 210         return 0;
 211 }
 212
 213 static void torture_lock_spin_write_unlock_irq(void)
 214 __releases(torture_spinlock)
 215 {
 216         spin_unlock_irqrestore(&torture_spinlock, cur_ops->flags);
 217 }
 218
 219 static struct lock_torture_ops spin_lock_irq_ops = {
 220         .writelock      = torture_spin_lock_write_lock_irq,
 221         .write_delay    = torture_spin_lock_write_delay,
 222         .writeunlock    = torture_lock_spin_write_unlock_irq,
 223         .readlock       = NULL,
 224         .read_delay     = NULL,
 225         .readunlock     = NULL,
 226         .name           = "spin_lock_irq"
 227 };
 228
 229 static DEFINE_MUTEX(torture_mutex);
 230
 231 static int torture_mutex_lock(void) __acquires(torture_mutex)
 232 {
 233         mutex_lock(&torture_mutex);
 234         return 0;
 235 }
 236
 237 static void torture_mutex_delay(struct torture_random_state *trsp)
 238 {
 239         const unsigned long longdelay_ms = 100;
 240
 241         /* We want a long delay occasionally to force massive contention.  */
 242         if (!(torture_random(trsp) %
 243               (nrealwriters_stress * 2000 * longdelay_ms)))
 244                 mdelay(longdelay_ms * 5);
 245         else
 246                 mdelay(longdelay_ms / 5);
 247 #ifdef CONFIG_PREEMPT
 248         if (!(torture_random(trsp) % (nrealwriters_stress * 20000)))
 249                 preempt_schedule();  /* Allow test to be preempted. */
 250 #endif
 251 }
 252
 253 static void torture_mutex_unlock(void) __releases(torture_mutex)
 254 {
 255         mutex_unlock(&torture_mutex);
 256 }
 257
 258 static struct lock_torture_ops mutex_lock_ops = {
 259         .writelock      = torture_mutex_lock,
 260         .write_delay    = torture_mutex_delay,
 261         .writeunlock    = torture_mutex_unlock,
 262         .readlock       = NULL,
 263         .read_delay     = NULL,
 264         .readunlock     = NULL,
 265         .name           = "mutex_lock"
 266 };
 267
 268 /*
 269  * Lock torture writer kthread.  Repeatedly acquires and releases
 270  * the lock, checking for duplicate acquisitions.
 271  */
 272 static int lock_torture_writer(void *arg)
 273 {
 274         struct lock_stress_stats *lwsp = arg;
 275         static DEFINE_TORTURE_RANDOM(rand);
 276
 277         VERBOSE_TOROUT_STRING("lock_torture_writer task started");
 278         set_user_nice(current, MAX_NICE);
 279
 280         do {
 281                 if ((torture_random(&rand) & 0xfffff) == 0)
 282                         schedule_timeout_uninterruptible(1);
 283                 cur_ops->writelock();
 284                 if (WARN_ON_ONCE(lock_is_write_held))
 285                         lwsp->n_lock_fail++;
 286                 lock_is_write_held = 1;
 287                 lwsp->n_lock_acquired++;
 288                 cur_ops->write_delay(&rand);
 289                 lock_is_write_held = 0;
 290                 cur_ops->writeunlock();
 291                 stutter_wait("lock_torture_writer");
 292         } while (!torture_must_stop());
 293         torture_kthread_stopping("lock_torture_writer");
 294         return 0;
 295 }
 296
 297 /*
 298  * Lock torture reader kthread.  Repeatedly acquires and releases
 299  * the reader lock.
 300  */
 301 static int lock_torture_reader(void *arg)
 302 {
 303         struct lock_stress_stats *lrsp = arg;
 304         static DEFINE_TORTURE_RANDOM(rand);
 305
 306         VERBOSE_TOROUT_STRING("lock_torture_reader task started");
 307         set_user_nice(current, MAX_NICE);
 308
 309         do {
 310                 if ((torture_random(&rand) & 0xfffff) == 0)
 311                         schedule_timeout_uninterruptible(1);
 312                 cur_ops->readlock();
 313                 lock_is_read_held = 1;
 314                 lrsp->n_lock_acquired++;
 315                 cur_ops->read_delay(&rand);
 316                 lock_is_read_held = 0;
 317                 cur_ops->readunlock();
 318                 stutter_wait("lock_torture_reader");
 319         } while (!torture_must_stop());
 320         torture_kthread_stopping("lock_torture_reader");
 321         return 0;
 322 }
 323
 324 /*
 325  * Create an lock-torture-statistics message in the specified buffer.
 326  */
 327 static void __torture_print_stats(char *page,
 328                                   struct lock_stress_stats *statp, bool write)
 329 {
 330         bool fail = 0;
 331         int i, n_stress;
 332         long max = 0;
 333         long min = statp[0].n_lock_acquired;
 334         long long sum = 0;
 335
 336         n_stress = write ? nrealwriters_stress : nrealreaders_stress;
 337         for (i = 0; i < n_stress; i++) {
 338                 if (statp[i].n_lock_fail)
 339                         fail = true;
 340                 sum += statp[i].n_lock_acquired;
 341                 if (max < statp[i].n_lock_fail)
 342                         max = statp[i].n_lock_fail;
 343                 if (min > statp[i].n_lock_fail)
 344                         min = statp[i].n_lock_fail;
 345         }
 346         page += sprintf(page,
 347                         "%s:  Total: %lld  Max/Min: %ld/%ld %s  Fail: %d %s\n",
 348                         write ? "Writes" : "Reads ",
 349                         sum, max, min, max / 2 > min ? "???" : "",
 350                         fail, fail ? "!!!" : "");
 351         if (fail)
 352                 atomic_inc(&n_lock_torture_errors);
 353 }
 354
 355 /*
 356  * Print torture statistics.  Caller must ensure that there is only one
 357  * call to this function at a given time!!!  This is normally accomplished
 358  * by relying on the module system to only have one copy of the module
 359  * loaded, and then by giving the lock_torture_stats kthread full control
 360  * (or the init/cleanup functions when lock_torture_stats thread is not
 361  * running).
 362  */
 363 static void lock_torture_stats_print(void)
 364 {
 365         int size = nrealwriters_stress * 200 + 8192;
 366         char *buf;
 367
 368         if (cur_ops->readlock)
 369                 size += nrealreaders_stress * 200 + 8192;
 370
 371         buf = kmalloc(size, GFP_KERNEL);
 372         if (!buf) {
 373                 pr_err("lock_torture_stats_print: Out of memory, need: %d",
 374                        size);
 375                 return;
 376         }
 377
 378         __torture_print_stats(buf, lwsa, true);
 379         pr_alert("%s", buf);
 380         kfree(buf);
 381
 382         if (cur_ops->readlock) {
 383                 buf = kmalloc(size, GFP_KERNEL);
 384                 if (!buf) {
 385                         pr_err("lock_torture_stats_print: Out of memory, need: %d",
 386                                size);
 387                         return;
 388                 }
 389
 390                 __torture_print_stats(buf, lrsa, false);
 391                 pr_alert("%s", buf);
 392                 kfree(buf);
 393         }
 394 }
 395
 396 /*
 397  * Periodically prints torture statistics, if periodic statistics printing
 398  * was specified via the stat_interval module parameter.
 399  *
 400  * No need to worry about fullstop here, since this one doesn't reference
 401  * volatile state or register callbacks.
 402  */
 403 static int lock_torture_stats(void *arg)
 404 {
 405         VERBOSE_TOROUT_STRING("lock_torture_stats task started");
 406         do {
 407                 schedule_timeout_interruptible(stat_interval * HZ);
 408                 lock_torture_stats_print();
 409                 torture_shutdown_absorb("lock_torture_stats");
 410         } while (!torture_must_stop());
 411         torture_kthread_stopping("lock_torture_stats");
 412         return 0;
 413 }
 414
 415 static inline void
 416 lock_torture_print_module_parms(struct lock_torture_ops *cur_ops,
 417                                 const char *tag)
 418 {
 419         pr_alert("%s" TORTURE_FLAG
 420                  "--- %s%s: nwriters_stress=%d nreaders_stress=%d stat_interval=%d verbose=%d shuffle_interval=%d stutter=%d shutdown_secs=%d onoff_interval=%d onoff_holdoff=%d\n",
 421                  torture_type, tag, debug_lock ? " [debug]": "",
 422                  nrealwriters_stress, nrealreaders_stress, stat_interval,
 423                  verbose, shuffle_interval, stutter, shutdown_secs,
 424                  onoff_interval, onoff_holdoff);
 425 }
 426
 427 static void lock_torture_cleanup(void)
 428 {
 429         int i;
 430
 431         if (torture_cleanup_begin())
 432                 return;
 433
 434         if (writer_tasks) {
 435                 for (i = 0; i < nrealwriters_stress; i++)
 436                         torture_stop_kthread(lock_torture_writer,
 437                                              writer_tasks[i]);
 438                 kfree(writer_tasks);
 439                 writer_tasks = NULL;
 440         }
 441
 442         if (reader_tasks) {
 443                 for (i = 0; i < nrealreaders_stress; i++)
 444                         torture_stop_kthread(lock_torture_reader,
 445                                              reader_tasks[i]);
 446                 kfree(reader_tasks);
 447                 reader_tasks = NULL;
 448         }
 449
 450         torture_stop_kthread(lock_torture_stats, stats_task);
 451         lock_torture_stats_print();  /* -After- the stats thread is stopped! */
 452
 453         if (atomic_read(&n_lock_torture_errors))
 454                 lock_torture_print_module_parms(cur_ops,
 455                                                 "End of test: FAILURE");
 456         else if (torture_onoff_failures())
 457                 lock_torture_print_module_parms(cur_ops,
 458                                                 "End of test: LOCK_HOTPLUG");
 459         else
 460                 lock_torture_print_module_parms(cur_ops,
 461                                                 "End of test: SUCCESS");
 462         torture_cleanup_end();
 463 }
 464
 465 static int __init lock_torture_init(void)
 466 {
 467         int i, j;
 468         int firsterr = 0;
 469         static struct lock_torture_ops *torture_ops[] = {
 470                 &lock_busted_ops, &spin_lock_ops, &spin_lock_irq_ops, &mutex_lock_ops,
 471         };
 472
 473         if (!torture_init_begin(torture_type, verbose, &torture_runnable))
 474                 return -EBUSY;
 475
 476         /* Process args and tell the world that the torturer is on the job. */
 477         for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
 478                 cur_ops = torture_ops[i];
 479                 if (strcmp(torture_type, cur_ops->name) == 0)
 480                         break;
 481         }
 482         if (i == ARRAY_SIZE(torture_ops)) {
 483                 pr_alert("lock-torture: invalid torture type: \"%s\"\n",
 484                          torture_type);
 485                 pr_alert("lock-torture types:");
 486                 for (i = 0; i < ARRAY_SIZE(torture_ops); i++)
 487                         pr_alert(" %s", torture_ops[i]->name);
 488                 pr_alert("\n");
 489                 torture_init_end();
 490                 return -EINVAL;
 491         }
 492         if (cur_ops->init)
 493                 cur_ops->init(); /* no "goto unwind" prior to this point!!! */
 494
 495         if (nwriters_stress >= 0)
 496                 nrealwriters_stress = nwriters_stress;
 497         else
 498                 nrealwriters_stress = 2 * num_online_cpus();
 499
 500 #ifdef CONFIG_DEBUG_MUTEXES
 501         if (strncmp(torture_type, "mutex", 5) == 0)
 502                 debug_lock = true;
 503 #endif
 504 #ifdef CONFIG_DEBUG_SPINLOCK
 505         if (strncmp(torture_type, "spin", 4) == 0)
 506                 debug_lock = true;
 507 #endif
 508
 509         /* Initialize the statistics so that each run gets its own numbers. */
 510
 511         lock_is_write_held = 0;
 512         lwsa = kmalloc(sizeof(*lwsa) * nrealwriters_stress, GFP_KERNEL);
 513         if (lwsa == NULL) {
 514                 VERBOSE_TOROUT_STRING("lwsa: Out of memory");
 515                 firsterr = -ENOMEM;
 516                 goto unwind;
 517         }
 518         for (i = 0; i < nrealwriters_stress; i++) {
 519                 lwsa[i].n_lock_fail = 0;
 520                 lwsa[i].n_lock_acquired = 0;
 521         }
 522
 523         if (cur_ops->readlock) {
 524                 if (nreaders_stress >= 0)
 525                         nrealreaders_stress = nreaders_stress;
 526                 else {
 527                         /*
 528                          * By default distribute evenly the number of
 529                          * readers and writers. We still run the same number
 530                          * of threads as the writer-only locks default.
 531                          */
 532                         if (nwriters_stress < 0) /* user doesn't care */
 533                                 nrealwriters_stress = num_online_cpus();
 534                         nrealreaders_stress = nrealwriters_stress;
 535                 }
 536
 537                 lock_is_read_held = 0;
 538                 lrsa = kmalloc(sizeof(*lrsa) * nrealreaders_stress, GFP_KERNEL);
 539                 if (lrsa == NULL) {
 540                         VERBOSE_TOROUT_STRING("lrsa: Out of memory");
 541                         firsterr = -ENOMEM;
 542                         kfree(lwsa);
 543                         goto unwind;
 544                 }
 545
 546                 for (i = 0; i < nrealreaders_stress; i++) {
 547                         lrsa[i].n_lock_fail = 0;
 548                         lrsa[i].n_lock_acquired = 0;
 549                 }
 550         }
 551         lock_torture_print_module_parms(cur_ops, "Start of test");
 552
 553         /* Prepare torture context. */
 554         if (onoff_interval > 0) {
 555                 firsterr = torture_onoff_init(onoff_holdoff * HZ,
 556                                               onoff_interval * HZ);
 557                 if (firsterr)
 558                         goto unwind;
 559         }
 560         if (shuffle_interval > 0) {
 561                 firsterr = torture_shuffle_init(shuffle_interval);
 562                 if (firsterr)
 563                         goto unwind;
 564         }
 565         if (shutdown_secs > 0) {
 566                 firsterr = torture_shutdown_init(shutdown_secs,
 567                                                  lock_torture_cleanup);
 568                 if (firsterr)
 569                         goto unwind;
 570         }
 571         if (stutter > 0) {
 572                 firsterr = torture_stutter_init(stutter);
 573                 if (firsterr)
 574                         goto unwind;
 575         }
 576
 577         writer_tasks = kzalloc(nrealwriters_stress * sizeof(writer_tasks[0]),
 578                                GFP_KERNEL);
 579         if (writer_tasks == NULL) {
 580                 VERBOSE_TOROUT_ERRSTRING("writer_tasks: Out of memory");
 581                 firsterr = -ENOMEM;
 582                 goto unwind;
 583         }
 584
 585         if (cur_ops->readlock) {
 586                 reader_tasks = kzalloc(nrealreaders_stress * sizeof(reader_tasks[0]),
 587                                        GFP_KERNEL);
 588                 if (reader_tasks == NULL) {
 589                         VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
 590                         firsterr = -ENOMEM;
 591                         goto unwind;
 592                 }
 593         }
 594
 595         /*
 596          * Create the kthreads and start torturing (oh, those poor little locks).
 597          *
 598          * TODO: Note that we interleave writers with readers, giving writers a
 599          * slight advantage, by creating its kthread first. This can be modified
 600          * for very specific needs, or even let the user choose the policy, if
 601          * ever wanted.
 602          */
 603         for (i = 0, j = 0; i < nrealwriters_stress ||
 604                     j < nrealreaders_stress; i++, j++) {
 605                 if (i >= nrealwriters_stress)
 606                         goto create_reader;
 607
 608                 /* Create writer. */
 609                 firsterr = torture_create_kthread(lock_torture_writer, &lwsa[i],
 610                                                   writer_tasks[i]);
 611                 if (firsterr)
 612                         goto unwind;
 613
 614         create_reader:
 615                 if (cur_ops->readlock == NULL || (j >= nrealreaders_stress))
 616                         continue;
 617                 /* Create reader. */
 618                 firsterr = torture_create_kthread(lock_torture_reader, &lrsa[j],
 619                                                   reader_tasks[j]);
 620                 if (firsterr)
 621                         goto unwind;
 622         }
 623         if (stat_interval > 0) {
 624                 firsterr = torture_create_kthread(lock_torture_stats, NULL,
 625                                                   stats_task);
 626                 if (firsterr)
 627                         goto unwind;
 628         }
 629         torture_init_end();
 630         return 0;
 631
 632 unwind:
 633         torture_init_end();
 634         lock_torture_cleanup();
 635         return firsterr;
 636 }
 637
 638 module_init(lock_torture_init);
 639 module_exit(lock_torture_cleanup);