kernel/pwqr.c

   1 /*
   2  * Copyright (C) 2012   Pierre Habouzit <pierre.habouzit@intersec.com>
   3  * Copyright (C) 2012   Intersec SAS
   4  *
   5  * This file implements the Linux Pthread Workqueue Regulator, and is part
   6  * of the linux kernel.
   7  *
   8  * The Linux Kernel is free software: you can redistribute it and/or modify it
   9  * under the terms of the GNU General Public License version 2 as published by
  10  * the Free Software Foundation.
  11  *
  12  * The Linux Kernel is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15  * License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License version 2
  18  * along with The Linux Kernel.  If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #include <linux/cdev.h>
  22 #include <linux/device.h>
  23 #include <linux/file.h>
  24 #include <linux/fs.h>
  25 #include <linux/hash.h>
  26 #include <linux/init.h>
  27 #include <linux/kref.h>
  28 #include <linux/module.h>
  29 #include <linux/sched.h>
  30 #include <linux/slab.h>
  31 #include <linux/spinlock.h>
  32 #include <linux/timer.h>
  33 #include <linux/uaccess.h>
  34 #include <linux/wait.h>
  35
  36 #ifndef CONFIG_PREEMPT_NOTIFIERS
  37 #  error PWQ module requires CONFIG_PREEMPT_NOTIFIERS
  38 #endif
  39
  40 #include "pwqr.h"
  41
  42 #define PWQR_UNPARK_DELAY       (HZ / 10)
  43 #define PWQR_HASH_BITS          5
  44 #define PWQR_HASH_SIZE          (1 << PWQR_HASH_BITS)
  45
  46 struct pwqr_task_bucket {
  47         spinlock_t              lock;
  48         struct hlist_head       tasks;
  49 };
  50
  51 struct pwqr_sb {
  52         struct kref             kref;
  53         struct rcu_head         rcu;
  54         struct timer_list       timer;
  55         wait_queue_head_t       wqh;
  56         pid_t                   tgid;
  57
  58         unsigned                concurrency;
  59         unsigned                registered;
  60
  61         unsigned                running;
  62         unsigned                waiting;
  63         unsigned                parked;
  64         unsigned                overcommit_wakes;
  65
  66         unsigned                dead;
  67 };
  68
  69 struct pwqr_task {
  70         struct preempt_notifier notifier;
  71         struct hlist_node       link;
  72         struct rcu_head         rcu;
  73         struct task_struct     *task;
  74         struct pwqr_sb         *sb;
  75 };
  76
  77 /*
  78  * Global variables
  79  */
  80 static struct class            *pwqr_class;
  81 static int                      pwqr_major;
  82 static struct pwqr_task_bucket  pwqr_tasks_hash[PWQR_HASH_SIZE];
  83 static struct preempt_ops       pwqr_preempt_running_ops;
  84 static struct preempt_ops       pwqr_preempt_blocked_ops;
  85 static struct preempt_ops       pwqr_preempt_noop_ops;
  86
  87 /*****************************************************************************
  88  * Scoreboards
  89  */
  90
  91 #define pwqr_sb_lock_irqsave(sb, flags) \
  92         spin_lock_irqsave(&(sb)->wqh.lock, flags)
  93 #define pwqr_sb_unlock_irqrestore(sb, flags) \
  94         spin_unlock_irqrestore(&(sb)->wqh.lock, flags)
  95
  96 static inline void __pwqr_sb_update_state(struct pwqr_sb *sb, int running_delta)
  97 {
  98         sb->running += running_delta;
  99         if (sb->running > sb->concurrency) {
 100                 /* TODO see ../Documentation/pwqr.adoc */
 101         } else if (sb->running == sb->concurrency) {
 102                 /* do nothing */
 103         } else if (sb->waiting == 0 && sb->parked) {
 104                 if (!timer_pending(&sb->timer)) {
 105                         mod_timer(&sb->timer, jiffies + PWQR_UNPARK_DELAY);
 106                 }
 107                 return;
 108         }
 109
 110         if (timer_pending(&sb->timer))
 111                 del_timer(&sb->timer);
 112 }
 113
 114 static void pwqr_sb_timer_cb(unsigned long arg)
 115 {
 116         struct pwqr_sb *sb = (struct pwqr_sb *)arg;
 117         unsigned long flags;
 118
 119         pwqr_sb_lock_irqsave(sb, flags);
 120         if (sb->waiting == 0 && sb->parked && sb->running < sb->concurrency) {
 121                 if (sb->overcommit_wakes == 0)
 122                         wake_up_locked(&sb->wqh);
 123         }
 124         pwqr_sb_unlock_irqrestore(sb, flags);
 125 }
 126
 127 static struct pwqr_sb *pwqr_sb_create(void)
 128 {
 129         struct pwqr_sb *sb;
 130
 131         sb = kzalloc(sizeof(struct pwqr_sb), GFP_KERNEL);
 132         if (sb == NULL)
 133                 return ERR_PTR(-ENOMEM);
 134
 135         kref_init(&sb->kref);
 136         init_waitqueue_head(&sb->wqh);
 137         sb->tgid        = current->tgid;
 138         sb->concurrency = num_online_cpus();
 139         init_timer(&sb->timer);
 140         sb->timer.function = pwqr_sb_timer_cb;
 141         sb->timer.data     = (unsigned long)sb;
 142
 143         __module_get(THIS_MODULE);
 144         return sb;
 145 }
 146 static inline void pwqr_sb_get(struct pwqr_sb *sb)
 147 {
 148         kref_get(&sb->kref);
 149 }
 150
 151 static void pwqr_sb_finalize(struct rcu_head *rcu)
 152 {
 153         struct pwqr_sb *sb = container_of(rcu, struct pwqr_sb, rcu);
 154
 155         module_put(THIS_MODULE);
 156         kfree(sb);
 157 }
 158
 159 static void pwqr_sb_release(struct kref *kref)
 160 {
 161         struct pwqr_sb *sb = container_of(kref, struct pwqr_sb, kref);
 162
 163         del_timer_sync(&sb->timer);
 164         call_rcu(&sb->rcu, pwqr_sb_finalize);
 165 }
 166 static inline void pwqr_sb_put(struct pwqr_sb *sb)
 167 {
 168         kref_put(&sb->kref, pwqr_sb_release);
 169 }
 170
 171 /*****************************************************************************
 172  * tasks
 173  */
 174 static inline struct pwqr_task_bucket *task_hbucket(struct task_struct *task)
 175 {
 176         return &pwqr_tasks_hash[hash_ptr(task, PWQR_HASH_BITS)];
 177 }
 178
 179 static struct pwqr_task *pwqr_task_find(struct task_struct *task)
 180 {
 181         struct pwqr_task_bucket *b = task_hbucket(task);
 182         struct hlist_node *node;
 183         struct pwqr_task *pwqt = NULL;
 184
 185         spin_lock(&b->lock);
 186         hlist_for_each_entry(pwqt, node, &b->tasks, link) {
 187                 if (pwqt->task == task)
 188                         break;
 189         }
 190         spin_unlock(&b->lock);
 191         return pwqt;
 192 }
 193
 194 static struct pwqr_task *pwqr_task_create(struct task_struct *task)
 195 {
 196         struct pwqr_task_bucket *b = task_hbucket(task);
 197         struct pwqr_task *pwqt;
 198
 199         pwqt = kmalloc(sizeof(*pwqt), GFP_KERNEL);
 200         if (pwqt == NULL)
 201                 return ERR_PTR(-ENOMEM);
 202
 203         preempt_notifier_init(&pwqt->notifier, &pwqr_preempt_running_ops);
 204         preempt_notifier_register(&pwqt->notifier);
 205         pwqt->task = task;
 206
 207         spin_lock(&b->lock);
 208         hlist_add_head(&pwqt->link, &b->tasks);
 209         spin_unlock(&b->lock);
 210
 211         return pwqt;
 212 }
 213
 214 __cold
 215 static void pwqr_task_detach(struct pwqr_task *pwqt, struct pwqr_sb *sb)
 216 {
 217         unsigned long flags;
 218
 219         pwqr_sb_lock_irqsave(sb, flags);
 220         sb->registered--;
 221         if (pwqt->notifier.ops == &pwqr_preempt_running_ops) {
 222                 __pwqr_sb_update_state(sb, -1);
 223         } else {
 224                 __pwqr_sb_update_state(sb, 0);
 225         }
 226         pwqr_sb_unlock_irqrestore(sb, flags);
 227         pwqr_sb_put(sb);
 228         pwqt->sb = NULL;
 229 }
 230
 231 __cold
 232 static void pwqr_task_attach(struct pwqr_task *pwqt, struct pwqr_sb *sb)
 233 {
 234         unsigned long flags;
 235
 236         pwqr_sb_lock_irqsave(sb, flags);
 237         pwqr_sb_get(pwqt->sb = sb);
 238         sb->registered++;
 239         __pwqr_sb_update_state(sb, 1);
 240         pwqr_sb_unlock_irqrestore(sb, flags);
 241 }
 242
 243 __cold
 244 static void pwqr_task_release(struct pwqr_task *pwqt, bool from_notifier)
 245 {
 246         struct pwqr_task_bucket *b = task_hbucket(pwqt->task);
 247
 248         spin_lock(&b->lock);
 249         hlist_del(&pwqt->link);
 250         spin_unlock(&b->lock);
 251         pwqt->notifier.ops = &pwqr_preempt_noop_ops;
 252
 253         if (from_notifier) {
 254                 /* When called from sched_{out,in}, it's not allowed to
 255                  * call preempt_notifier_unregister (or worse kfree())
 256                  *
 257                  * Though it's not a good idea to kfree() still registered
 258                  * callbacks if we're not dying, it'll panic on the next
 259                  * sched_{in,out} call.
 260                  */
 261                 BUG_ON(!(pwqt->task->state & TASK_DEAD));
 262                 kfree_rcu(pwqt, rcu);
 263         } else {
 264                 preempt_notifier_unregister(&pwqt->notifier);
 265                 kfree(pwqt);
 266         }
 267 }
 268
 269 static void pwqr_task_noop_sched_in(struct preempt_notifier *notifier, int cpu)
 270 {
 271 }
 272
 273 static void pwqr_task_noop_sched_out(struct preempt_notifier *notifier,
 274                                     struct task_struct *next)
 275 {
 276 }
 277
 278 static void pwqr_task_blocked_sched_in(struct preempt_notifier *notifier, int cpu)
 279 {
 280         struct pwqr_task *pwqt = container_of(notifier, struct pwqr_task, notifier);
 281         struct pwqr_sb   *sb   = pwqt->sb;
 282         unsigned long flags;
 283
 284         if (unlikely(sb->dead)) {
 285                 pwqr_task_detach(pwqt, sb);
 286                 pwqr_task_release(pwqt, true);
 287                 return;
 288         }
 289
 290         pwqt->notifier.ops = &pwqr_preempt_running_ops;
 291         pwqr_sb_lock_irqsave(sb, flags);
 292         __pwqr_sb_update_state(sb, 1);
 293         pwqr_sb_unlock_irqrestore(sb, flags);
 294 }
 295
 296 static void pwqr_task_sched_out(struct preempt_notifier *notifier,
 297                                struct task_struct *next)
 298 {
 299         struct pwqr_task    *pwqt = container_of(notifier, struct pwqr_task, notifier);
 300         struct pwqr_sb      *sb   = pwqt->sb;
 301         struct task_struct *p    = pwqt->task;
 302
 303         if (unlikely(p->state & TASK_DEAD) || unlikely(sb->dead)) {
 304                 pwqr_task_detach(pwqt, sb);
 305                 pwqr_task_release(pwqt, true);
 306                 return;
 307         }
 308         if (p->state == 0 || (p->state & (__TASK_STOPPED | __TASK_TRACED)))
 309                 return;
 310
 311         pwqt->notifier.ops = &pwqr_preempt_blocked_ops;
 312         /* see preempt.h: irq are disabled for sched_out */
 313         spin_lock(&sb->wqh.lock);
 314         __pwqr_sb_update_state(sb, -1);
 315         spin_unlock(&sb->wqh.lock);
 316 }
 317
 318 static struct preempt_ops __read_mostly pwqr_preempt_noop_ops = {
 319         .sched_in       = pwqr_task_noop_sched_in,
 320         .sched_out      = pwqr_task_noop_sched_out,
 321 };
 322
 323 static struct preempt_ops __read_mostly pwqr_preempt_running_ops = {
 324         .sched_in       = pwqr_task_noop_sched_in,
 325         .sched_out      = pwqr_task_sched_out,
 326 };
 327
 328 static struct preempt_ops __read_mostly pwqr_preempt_blocked_ops = {
 329         .sched_in       = pwqr_task_blocked_sched_in,
 330         .sched_out      = pwqr_task_sched_out,
 331 };
 332
 333 /*****************************************************************************
 334  * file descriptor
 335  */
 336 static int pwqr_open(struct inode *inode, struct file *filp)
 337 {
 338         struct pwqr_sb *sb;
 339
 340         sb = pwqr_sb_create();
 341         if (IS_ERR(sb))
 342                 return PTR_ERR(sb);
 343         filp->private_data = sb;
 344         return 0;
 345 }
 346
 347 static int pwqr_release(struct inode *inode, struct file *filp)
 348 {
 349         struct pwqr_sb *sb = filp->private_data;
 350         unsigned long flags;
 351
 352         pwqr_sb_lock_irqsave(sb, flags);
 353         sb->dead = true;
 354         pwqr_sb_unlock_irqrestore(sb, flags);
 355         wake_up_all(&sb->wqh);
 356         pwqr_sb_put(sb);
 357         return 0;
 358 }
 359
 360 static long
 361 do_pwqr_wait(struct pwqr_sb *sb, struct pwqr_task *pwqt,
 362             int is_wait, struct pwqr_ioc_wait __user *arg)
 363 {
 364         unsigned long flags;
 365         struct pwqr_ioc_wait wait;
 366         long rc = 0;
 367         u32 uval;
 368
 369         preempt_notifier_unregister(&pwqt->notifier);
 370
 371         if (is_wait) {
 372                 if (copy_from_user(&wait, arg, sizeof(wait))) {
 373                         rc = -EFAULT;
 374                         goto out;
 375                 }
 376                 if (unlikely((long)wait.pwqr_uaddr % sizeof(int) != 0)) {
 377                         rc = -EINVAL;
 378                         goto out;
 379                 }
 380         }
 381
 382         pwqr_sb_lock_irqsave(sb, flags);
 383         if (sb->running + sb->waiting <= sb->concurrency) {
 384                 if (is_wait) {
 385                         while (probe_kernel_address(wait.pwqr_uaddr, uval)) {
 386                                 pwqr_sb_unlock_irqrestore(sb, flags);
 387                                 rc = get_user(uval, (u32 *)wait.pwqr_uaddr);
 388                                 if (rc)
 389                                         goto out;
 390                                 pwqr_sb_lock_irqsave(sb, flags);
 391                         }
 392
 393                         if (uval != (u32)wait.pwqr_ticket) {
 394                                 rc = -EWOULDBLOCK;
 395                                 goto out_unlock;
 396                         }
 397                 } else {
 398                         goto out_unlock;
 399                 }
 400         }
 401
 402         /* @ see <wait_event_interruptible_exclusive_locked_irq> */
 403         if (likely(!sb->dead)) {
 404                 DEFINE_WAIT(__wait);
 405
 406                 __wait.flags |= WQ_FLAG_EXCLUSIVE;
 407
 408                 if (is_wait) {
 409                         sb->waiting++;
 410                         __add_wait_queue(&sb->wqh, &__wait);
 411                 } else {
 412                         sb->parked++;
 413                         __add_wait_queue_tail(&sb->wqh, &__wait);
 414                 }
 415                 __pwqr_sb_update_state(sb, -1);
 416                 set_current_state(TASK_INTERRUPTIBLE);
 417
 418                 do {
 419                         if (sb->overcommit_wakes)
 420                                 break;
 421                         if (signal_pending(current)) {
 422                                 rc = -ERESTARTSYS;
 423                                 break;
 424                         }
 425                         spin_unlock_irq(&sb->wqh.lock);
 426                         schedule();
 427                         spin_lock_irq(&sb->wqh.lock);
 428                         if (is_wait)
 429                                 break;
 430                         if (sb->running + sb->waiting < sb->concurrency)
 431                                 break;
 432                 } while (likely(!sb->dead));
 433
 434                 __remove_wait_queue(&sb->wqh, &__wait);
 435                 __set_current_state(TASK_RUNNING);
 436
 437                 if (is_wait) {
 438                         sb->waiting--;
 439                 } else {
 440                         sb->parked--;
 441                 }
 442                 __pwqr_sb_update_state(sb, 1);
 443                 if (sb->overcommit_wakes)
 444                         sb->overcommit_wakes--;
 445                 if (sb->waiting + sb->running > sb->concurrency)
 446                         rc = -EDQUOT;
 447         }
 448
 449 out_unlock:
 450         if (unlikely(sb->dead))
 451                 rc = -EBADFD;
 452         pwqr_sb_unlock_irqrestore(sb, flags);
 453 out:
 454         preempt_notifier_register(&pwqt->notifier);
 455         return rc;
 456 }
 457
 458 static long do_pwqr_unregister(struct pwqr_sb *sb, struct pwqr_task *pwqt)
 459 {
 460         if (!pwqt)
 461                 return -EINVAL;
 462         if (pwqt->sb != sb)
 463                 return -ENOENT;
 464         pwqr_task_detach(pwqt, sb);
 465         pwqr_task_release(pwqt, false);
 466         return 0;
 467 }
 468
 469 static long do_pwqr_set_conc(struct pwqr_sb *sb, int conc)
 470 {
 471         long old_conc = sb->concurrency;
 472         unsigned long flags;
 473
 474         pwqr_sb_lock_irqsave(sb, flags);
 475         if (conc <= 0)
 476                 conc = num_online_cpus();
 477         if (conc != old_conc) {
 478                 sb->concurrency = conc;
 479                 __pwqr_sb_update_state(sb, 0);
 480         }
 481         pwqr_sb_unlock_irqrestore(sb, flags);
 482
 483         return old_conc;
 484 }
 485
 486 static long do_pwqr_wake(struct pwqr_sb *sb, int oc, int count)
 487 {
 488         unsigned long flags;
 489         int nwake;
 490
 491         if (count < 0)
 492                 return -EINVAL;
 493
 494         pwqr_sb_lock_irqsave(sb, flags);
 495
 496         if (oc) {
 497                 nwake = sb->waiting + sb->parked - sb->overcommit_wakes;
 498                 if (count > nwake) {
 499                         count = nwake;
 500                 } else {
 501                         nwake = count;
 502                 }
 503                 sb->overcommit_wakes += count;
 504         } else if (sb->running + sb->overcommit_wakes < sb->concurrency) {
 505                 nwake = sb->concurrency - sb->overcommit_wakes - sb->running;
 506                 if (nwake > sb->waiting + sb->parked - sb->overcommit_wakes) {
 507                         nwake = sb->waiting + sb->parked -
 508                                 sb->overcommit_wakes;
 509                 }
 510                 if (count > nwake) {
 511                         count = nwake;
 512                 } else {
 513                         nwake = count;
 514                 }
 515         } else {
 516                 /*
 517                  * This codepath deserves an explanation: waking the thread
 518                  * "for real" would overcommit, though userspace KNOWS there
 519                  * is at least one waiting thread. Such threads are threads
 520                  * that are "quarantined".
 521                  *
 522                  * Quarantined threads are woken up one by one, to allow a
 523                  * slow ramp down, trying to minimize "waiting" <-> "parked"
 524                  * flip-flops, no matter how many wakes have been asked.
 525                  *
 526                  * Since releasing one quarantined thread will wake up a
 527                  * thread that will (almost) straight go to parked mode, lie
 528                  * to userland about the fact that we unblocked that thread,
 529                  * and return 0.
 530                  *
 531                  * Though if we're already waking all waiting threads for
 532                  * overcommitting jobs, well, we don't need that.
 533                  */
 534                 count = 0;
 535                 nwake = sb->waiting > sb->overcommit_wakes;
 536         }
 537         while (nwake-- > 0)
 538                 wake_up_locked(&sb->wqh);
 539         pwqr_sb_unlock_irqrestore(sb, flags);
 540
 541         return count;
 542 }
 543
 544 static long pwqr_ioctl(struct file *filp, unsigned command, unsigned long arg)
 545 {
 546         struct pwqr_sb      *sb   = filp->private_data;
 547         struct task_struct *task = current;
 548         struct pwqr_task    *pwqt;
 549         int rc = 0;
 550
 551         if (sb->tgid != current->tgid)
 552                 return -EBADFD;
 553
 554         switch (command) {
 555         case PWQR_GET_CONC:
 556                 return sb->concurrency;
 557         case PWQR_SET_CONC:
 558                 return do_pwqr_set_conc(sb, (int)arg);
 559
 560         case PWQR_WAKE:
 561         case PWQR_WAKE_OC:
 562                 return do_pwqr_wake(sb, command == PWQR_WAKE_OC, (int)arg);
 563
 564         case PWQR_WAIT:
 565         case PWQR_PARK:
 566         case PWQR_REGISTER:
 567         case PWQR_UNREGISTER:
 568                 break;
 569         default:
 570                 return -EINVAL;
 571         }
 572
 573         pwqt = pwqr_task_find(task);
 574         if (command == PWQR_UNREGISTER)
 575                 return do_pwqr_unregister(sb, pwqt);
 576
 577         if (pwqt == NULL) {
 578                 pwqt = pwqr_task_create(task);
 579                 if (IS_ERR(pwqt))
 580                         return PTR_ERR(pwqt);
 581                 pwqr_task_attach(pwqt, sb);
 582         } else if (unlikely(pwqt->sb != sb)) {
 583                 pwqr_task_detach(pwqt, pwqt->sb);
 584                 pwqr_task_attach(pwqt, sb);
 585         }
 586
 587         switch (command) {
 588         case PWQR_WAIT:
 589                 rc = do_pwqr_wait(sb, pwqt, true, (struct pwqr_ioc_wait __user *)arg);
 590                 break;
 591         case PWQR_PARK:
 592                 rc = do_pwqr_wait(sb, pwqt, false, NULL);
 593                 break;
 594         }
 595
 596         if (unlikely(sb->dead)) {
 597                 pwqr_task_detach(pwqt, pwqt->sb);
 598                 return -EBADFD;
 599         }
 600         return rc;
 601 }
 602
 603 static const struct file_operations pwqr_dev_fops = {
 604         .owner          = THIS_MODULE,
 605         .open           = pwqr_open,
 606         .release        = pwqr_release,
 607         .unlocked_ioctl = pwqr_ioctl,
 608 #ifdef CONFIG_COMPAT
 609         .compat_ioctl   = pwqr_ioctl,
 610 #endif
 611 };
 612
 613 /*****************************************************************************
 614  * module
 615  */
 616 static int __init pwqr_start(void)
 617 {
 618         int i;
 619
 620         for (i = 0; i < PWQR_HASH_SIZE; i++) {
 621                 spin_lock_init(&pwqr_tasks_hash[i].lock);
 622                 INIT_HLIST_HEAD(&pwqr_tasks_hash[i].tasks);
 623         }
 624
 625         /* Register as a character device */
 626         pwqr_major = register_chrdev(0, "pwqr", &pwqr_dev_fops);
 627         if (pwqr_major < 0) {
 628                 printk(KERN_ERR "pwqr: register_chrdev() failed\n");
 629                 return pwqr_major;
 630         }
 631
 632         /* Create a device node */
 633         pwqr_class = class_create(THIS_MODULE, PWQR_DEVICE_NAME);
 634         if (IS_ERR(pwqr_class)) {
 635                 printk(KERN_ERR "pwqr: Error creating raw class\n");
 636                 unregister_chrdev(pwqr_major, PWQR_DEVICE_NAME);
 637                 return PTR_ERR(pwqr_class);
 638         }
 639         device_create(pwqr_class, NULL, MKDEV(pwqr_major, 0), NULL, PWQR_DEVICE_NAME);
 640         printk(KERN_INFO "pwqr: PThreads Work Queues Regulator v1 loaded");
 641         return 0;
 642 }
 643
 644 static void __exit pwqr_end(void)
 645 {
 646         rcu_barrier();
 647         device_destroy(pwqr_class, MKDEV(pwqr_major, 0));
 648         class_destroy(pwqr_class);
 649         unregister_chrdev(pwqr_major, PWQR_DEVICE_NAME);
 650 }
 651
 652 module_init(pwqr_start);
 653 module_exit(pwqr_end);
 654
 655 MODULE_LICENSE("GPL");
 656 MODULE_AUTHOR("Pierre Habouzit <pierre.habouzit@intersec.com>");
 657 MODULE_DESCRIPTION("PThreads Work Queues Regulator");
 658
 659 // vim:noet:sw=8:cinoptions+=\:0,L-1,=1s: