net/sched/sch_gred.c

   1 /*
   2  * net/sched/sch_gred.c Generic Random Early Detection queue.
   3  *
   4  *
   5  *              This program is free software; you can redistribute it and/or
   6  *              modify it under the terms of the GNU General Public License
   7  *              as published by the Free Software Foundation; either version
   8  *              2 of the License, or (at your option) any later version.
   9  *
  10  * Authors:    J Hadi Salim (hadi@cyberus.ca) 1998-2002
  11  *
  12  *             991129: -  Bug fix with grio mode
  13  *                     - a better sing. AvgQ mode with Grio(WRED)
  14  *                     - A finer grained VQ dequeue based on sugestion
  15  *                       from Ren Liu
  16  *                     - More error checks
  17  *
  18  *
  19  *
  20  *  For all the glorious comments look at Alexey's sch_red.c
  21  */
  22
  23 #include <linux/config.h>
  24 #include <linux/module.h>
  25 #include <asm/uaccess.h>
  26 #include <asm/system.h>
  27 #include <linux/bitops.h>
  28 #include <linux/types.h>
  29 #include <linux/kernel.h>
  30 #include <linux/sched.h>
  31 #include <linux/string.h>
  32 #include <linux/mm.h>
  33 #include <linux/socket.h>
  34 #include <linux/sockios.h>
  35 #include <linux/in.h>
  36 #include <linux/errno.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/if_ether.h>
  39 #include <linux/inet.h>
  40 #include <linux/netdevice.h>
  41 #include <linux/etherdevice.h>
  42 #include <linux/notifier.h>
  43 #include <net/ip.h>
  44 #include <net/route.h>
  45 #include <linux/skbuff.h>
  46 #include <net/sock.h>
  47 #include <net/pkt_sched.h>
  48
  49 #if 1 /* control */
  50 #define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
  51 #else
  52 #define DPRINTK(format,args...)
  53 #endif
  54
  55 #if 0 /* data */
  56 #define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
  57 #else
  58 #define D2PRINTK(format,args...)
  59 #endif
  60
  61 #define GRED_DEF_PRIO (MAX_DPs / 2)
  62
  63 struct gred_sched_data;
  64 struct gred_sched;
  65
  66 struct gred_sched_data
  67 {
  68 /* Parameters */
  69         u32             limit;          /* HARD maximal queue length    */
  70         u32             qth_min;        /* Min average length threshold: A scaled */
  71         u32             qth_max;        /* Max average length threshold: A scaled */
  72         u32             DP;             /* the drop pramaters */
  73         char            Wlog;           /* log(W)               */
  74         char            Plog;           /* random number bits   */
  75         u32             Scell_max;
  76         u32             Rmask;
  77         u32             bytesin;        /* bytes seen on virtualQ so far*/
  78         u32             packetsin;      /* packets seen on virtualQ so far*/
  79         u32             backlog;        /* bytes on the virtualQ */
  80         u32             forced; /* packets dropped for exceeding limits */
  81         u32             early;  /* packets dropped as a warning */
  82         u32             other;  /* packets dropped by invoking drop() */
  83         u32             pdrop;  /* packets dropped because we exceeded physical queue limits */
  84         char            Scell_log;
  85         u8              Stab[256];
  86         u8              prio;        /* the prio of this vq */
  87
  88 /* Variables */
  89         unsigned long   qave;           /* Average queue length: A scaled */
  90         int             qcount;         /* Packets since last random number generation */
  91         u32             qR;             /* Cached random number */
  92
  93         psched_time_t   qidlestart;     /* Start of idle period */
  94 };
  95
  96 enum {
  97         GRED_WRED_MODE = 1,
  98         GRED_RIO_MODE,
  99 };
 100
 101 struct gred_sched
 102 {
 103         struct gred_sched_data *tab[MAX_DPs];
 104         unsigned long   flags;
 105         u32             DPs;
 106         u32             def;
 107         u8              initd;
 108 };
 109
 110 static inline int gred_wred_mode(struct gred_sched *table)
 111 {
 112         return test_bit(GRED_WRED_MODE, &table->flags);
 113 }
 114
 115 static inline void gred_enable_wred_mode(struct gred_sched *table)
 116 {
 117         __set_bit(GRED_WRED_MODE, &table->flags);
 118 }
 119
 120 static inline void gred_disable_wred_mode(struct gred_sched *table)
 121 {
 122         __clear_bit(GRED_WRED_MODE, &table->flags);
 123 }
 124
 125 static inline int gred_rio_mode(struct gred_sched *table)
 126 {
 127         return test_bit(GRED_RIO_MODE, &table->flags);
 128 }
 129
 130 static inline void gred_enable_rio_mode(struct gred_sched *table)
 131 {
 132         __set_bit(GRED_RIO_MODE, &table->flags);
 133 }
 134
 135 static inline void gred_disable_rio_mode(struct gred_sched *table)
 136 {
 137         __clear_bit(GRED_RIO_MODE, &table->flags);
 138 }
 139
 140 static inline int gred_wred_mode_check(struct Qdisc *sch)
 141 {
 142         struct gred_sched *table = qdisc_priv(sch);
 143         int i;
 144
 145         /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
 146         for (i = 0; i < table->DPs; i++) {
 147                 struct gred_sched_data *q = table->tab[i];
 148                 int n;
 149
 150                 if (q == NULL)
 151                         continue;
 152
 153                 for (n = 0; n < table->DPs; n++)
 154                         if (table->tab[n] && table->tab[n] != q &&
 155                             table->tab[n]->prio == q->prio)
 156                                 return 1;
 157         }
 158
 159         return 0;
 160 }
 161
 162 static int
 163 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 164 {
 165         psched_time_t now;
 166         struct gred_sched_data *q=NULL;
 167         struct gred_sched *t= qdisc_priv(sch);
 168         unsigned long   qave=0;
 169         int i=0;
 170
 171         if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
 172                 D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
 173                 goto do_enqueue;
 174         }
 175
 176
 177         if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
 178                 printk("GRED: setting to default (%d)\n ",t->def);
 179                 if (!(q=t->tab[t->def])) {
 180                         DPRINTK("GRED: setting to default FAILED! dropping!! "
 181                             "(%d)\n ", t->def);
 182                         goto drop;
 183                 }
 184                 /* fix tc_index? --could be controvesial but needed for
 185                    requeueing */
 186                 skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
 187         }
 188
 189         D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
 190             "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
 191             sch->qstats.backlog);
 192         /* sum up all the qaves of prios <= to ours to get the new qave*/
 193         if (!gred_wred_mode(t) && gred_rio_mode(t)) {
 194                 for (i=0;i<t->DPs;i++) {
 195                         if ((!t->tab[i]) || (i==q->DP))
 196                                 continue;
 197
 198                         if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
 199                                 qave +=t->tab[i]->qave;
 200                 }
 201
 202         }
 203
 204         q->packetsin++;
 205         q->bytesin+=skb->len;
 206
 207         if (gred_wred_mode(t)) {
 208                 qave=0;
 209                 q->qave=t->tab[t->def]->qave;
 210                 q->qidlestart=t->tab[t->def]->qidlestart;
 211         }
 212
 213         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
 214                 long us_idle;
 215                 PSCHED_GET_TIME(now);
 216                 us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
 217                 PSCHED_SET_PASTPERFECT(q->qidlestart);
 218
 219                 q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
 220         } else {
 221                 if (gred_wred_mode(t)) {
 222                         q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
 223                 } else {
 224                         q->qave += q->backlog - (q->qave >> q->Wlog);
 225                 }
 226
 227         }
 228
 229
 230         if (gred_wred_mode(t))
 231                 t->tab[t->def]->qave=q->qave;
 232
 233         if ((q->qave+qave) < q->qth_min) {
 234                 q->qcount = -1;
 235 enqueue:
 236                 if (q->backlog + skb->len <= q->limit) {
 237                         q->backlog += skb->len;
 238 do_enqueue:
 239                         __skb_queue_tail(&sch->q, skb);
 240                         sch->qstats.backlog += skb->len;
 241                         sch->bstats.bytes += skb->len;
 242                         sch->bstats.packets++;
 243                         return 0;
 244                 } else {
 245                         q->pdrop++;
 246                 }
 247
 248 drop:
 249                 kfree_skb(skb);
 250                 sch->qstats.drops++;
 251                 return NET_XMIT_DROP;
 252         }
 253         if ((q->qave+qave) >= q->qth_max) {
 254                 q->qcount = -1;
 255                 sch->qstats.overlimits++;
 256                 q->forced++;
 257                 goto drop;
 258         }
 259         if (++q->qcount) {
 260                 if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
 261                         goto enqueue;
 262                 q->qcount = 0;
 263                 q->qR = net_random()&q->Rmask;
 264                 sch->qstats.overlimits++;
 265                 q->early++;
 266                 goto drop;
 267         }
 268         q->qR = net_random()&q->Rmask;
 269         goto enqueue;
 270 }
 271
 272 static int
 273 gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
 274 {
 275         struct gred_sched_data *q;
 276         struct gred_sched *t= qdisc_priv(sch);
 277         q= t->tab[(skb->tc_index&0xf)];
 278 /* error checking here -- probably unnecessary */
 279         PSCHED_SET_PASTPERFECT(q->qidlestart);
 280
 281         __skb_queue_head(&sch->q, skb);
 282         sch->qstats.backlog += skb->len;
 283         sch->qstats.requeues++;
 284         q->backlog += skb->len;
 285         return 0;
 286 }
 287
 288 static struct sk_buff *
 289 gred_dequeue(struct Qdisc* sch)
 290 {
 291         struct sk_buff *skb;
 292         struct gred_sched_data *q;
 293         struct gred_sched *t= qdisc_priv(sch);
 294
 295         skb = __skb_dequeue(&sch->q);
 296         if (skb) {
 297                 sch->qstats.backlog -= skb->len;
 298                 q= t->tab[(skb->tc_index&0xf)];
 299                 if (q) {
 300                         q->backlog -= skb->len;
 301                         if (!q->backlog && !gred_wred_mode(t))
 302                                 PSCHED_GET_TIME(q->qidlestart);
 303                 } else {
 304                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
 305                 }
 306                 return skb;
 307         }
 308
 309         if (gred_wred_mode(t)) {
 310                         q= t->tab[t->def];
 311                         if (!q)
 312                                 D2PRINTK("no default VQ set: Results will be "
 313                                        "screwed up\n");
 314                         else
 315                                 PSCHED_GET_TIME(q->qidlestart);
 316         }
 317
 318         return NULL;
 319 }
 320
 321 static unsigned int gred_drop(struct Qdisc* sch)
 322 {
 323         struct sk_buff *skb;
 324
 325         struct gred_sched_data *q;
 326         struct gred_sched *t= qdisc_priv(sch);
 327
 328         skb = __skb_dequeue_tail(&sch->q);
 329         if (skb) {
 330                 unsigned int len = skb->len;
 331                 sch->qstats.backlog -= len;
 332                 sch->qstats.drops++;
 333                 q= t->tab[(skb->tc_index&0xf)];
 334                 if (q) {
 335                         q->backlog -= len;
 336                         q->other++;
 337                         if (!q->backlog && !gred_wred_mode(t))
 338                                 PSCHED_GET_TIME(q->qidlestart);
 339                 } else {
 340                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
 341                 }
 342
 343                 kfree_skb(skb);
 344                 return len;
 345         }
 346
 347         q=t->tab[t->def];
 348         if (!q) {
 349                 D2PRINTK("no default VQ set: Results might be screwed up\n");
 350                 return 0;
 351         }
 352
 353         PSCHED_GET_TIME(q->qidlestart);
 354         return 0;
 355
 356 }
 357
 358 static void gred_reset(struct Qdisc* sch)
 359 {
 360         int i;
 361         struct gred_sched_data *q;
 362         struct gred_sched *t= qdisc_priv(sch);
 363
 364         __skb_queue_purge(&sch->q);
 365
 366         sch->qstats.backlog = 0;
 367
 368         for (i=0;i<t->DPs;i++) {
 369                 q= t->tab[i];
 370                 if (!q)
 371                         continue;
 372                 PSCHED_SET_PASTPERFECT(q->qidlestart);
 373                 q->qave = 0;
 374                 q->qcount = -1;
 375                 q->backlog = 0;
 376                 q->other=0;
 377                 q->forced=0;
 378                 q->pdrop=0;
 379                 q->early=0;
 380         }
 381 }
 382
 383 static inline void gred_destroy_vq(struct gred_sched_data *q)
 384 {
 385         kfree(q);
 386 }
 387
 388 static inline int gred_change_table_def(struct Qdisc *sch, struct rtattr *dps)
 389 {
 390         struct gred_sched *table = qdisc_priv(sch);
 391         struct tc_gred_sopt *sopt;
 392         int i;
 393
 394         if (dps == NULL || RTA_PAYLOAD(dps) < sizeof(*sopt))
 395                 return -EINVAL;
 396
 397         sopt = RTA_DATA(dps);
 398
 399         if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
 400                 return -EINVAL;
 401
 402         sch_tree_lock(sch);
 403         table->DPs = sopt->DPs;
 404         table->def = sopt->def_DP;
 405
 406         /*
 407          * Every entry point to GRED is synchronized with the above code
 408          * and the DP is checked against DPs, i.e. shadowed VQs can no
 409          * longer be found so we can unlock right here.
 410          */
 411         sch_tree_unlock(sch);
 412
 413         if (sopt->grio) {
 414                 gred_enable_rio_mode(table);
 415                 gred_disable_wred_mode(table);
 416                 if (gred_wred_mode_check(sch))
 417                         gred_enable_wred_mode(table);
 418         } else {
 419                 gred_disable_rio_mode(table);
 420                 gred_disable_wred_mode(table);
 421         }
 422
 423         for (i = table->DPs; i < MAX_DPs; i++) {
 424                 if (table->tab[i]) {
 425                         printk(KERN_WARNING "GRED: Warning: Destroying "
 426                                "shadowed VQ 0x%x\n", i);
 427                         gred_destroy_vq(table->tab[i]);
 428                         table->tab[i] = NULL;
 429                 }
 430         }
 431
 432         table->initd = 0;
 433
 434         return 0;
 435 }
 436
 437 static inline int gred_change_vq(struct Qdisc *sch, int dp,
 438                                  struct tc_gred_qopt *ctl, int prio, u8 *stab)
 439 {
 440         struct gred_sched *table = qdisc_priv(sch);
 441         struct gred_sched_data *q;
 442
 443         if (table->tab[dp] == NULL) {
 444                 table->tab[dp] = kmalloc(sizeof(*q), GFP_KERNEL);
 445                 if (table->tab[dp] == NULL)
 446                         return -ENOMEM;
 447                 memset(table->tab[dp], 0, sizeof(*q));
 448         }
 449
 450         q = table->tab[dp];
 451         q->DP = dp;
 452         q->prio = prio;
 453
 454         q->Wlog = ctl->Wlog;
 455         q->Plog = ctl->Plog;
 456         q->limit = ctl->limit;
 457         q->Scell_log = ctl->Scell_log;
 458         q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
 459         q->Scell_max = (255<<q->Scell_log);
 460         q->qth_min = ctl->qth_min<<ctl->Wlog;
 461         q->qth_max = ctl->qth_max<<ctl->Wlog;
 462         q->qave=0;
 463         q->backlog=0;
 464         q->qcount = -1;
 465         q->other=0;
 466         q->forced=0;
 467         q->pdrop=0;
 468         q->early=0;
 469
 470         PSCHED_SET_PASTPERFECT(q->qidlestart);
 471         memcpy(q->Stab, stab, 256);
 472
 473         return 0;
 474 }
 475
 476 static int gred_change(struct Qdisc *sch, struct rtattr *opt)
 477 {
 478         struct gred_sched *table = qdisc_priv(sch);
 479         struct tc_gred_qopt *ctl;
 480         struct rtattr *tb[TCA_GRED_MAX];
 481         int err = -EINVAL, prio = GRED_DEF_PRIO;
 482         u8 *stab;
 483
 484         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
 485                 return -EINVAL;
 486
 487         if (tb[TCA_GRED_PARMS-1] == NULL && tb[TCA_GRED_STAB-1] == NULL)
 488                 return gred_change_table_def(sch, opt);
 489
 490         if (tb[TCA_GRED_PARMS-1] == NULL ||
 491             RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
 492             tb[TCA_GRED_STAB-1] == NULL ||
 493             RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
 494                 return -EINVAL;
 495
 496         ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
 497         stab = RTA_DATA(tb[TCA_GRED_STAB-1]);
 498
 499         if (ctl->DP >= table->DPs)
 500                 goto errout;
 501
 502         if (gred_rio_mode(table)) {
 503                 if (ctl->prio == 0) {
 504                         int def_prio = GRED_DEF_PRIO;
 505
 506                         if (table->tab[table->def])
 507                                 def_prio = table->tab[table->def]->prio;
 508
 509                         printk(KERN_DEBUG "GRED: DP %u does not have a prio "
 510                                "setting default to %d\n", ctl->DP, def_prio);
 511
 512                         prio = def_prio;
 513                 } else
 514                         prio = ctl->prio;
 515         }
 516
 517         sch_tree_lock(sch);
 518
 519         err = gred_change_vq(sch, ctl->DP, ctl, prio, stab);
 520         if (err < 0)
 521                 goto errout_locked;
 522
 523         if (table->tab[table->def] == NULL) {
 524                 if (gred_rio_mode(table))
 525                         prio = table->tab[ctl->DP]->prio;
 526
 527                 err = gred_change_vq(sch, table->def, ctl, prio, stab);
 528                 if (err < 0)
 529                         goto errout_locked;
 530         }
 531
 532         table->initd = 1;
 533
 534         if (gred_rio_mode(table)) {
 535                 gred_disable_wred_mode(table);
 536                 if (gred_wred_mode_check(sch))
 537                         gred_enable_wred_mode(table);
 538         }
 539
 540         err = 0;
 541
 542 errout_locked:
 543         sch_tree_unlock(sch);
 544 errout:
 545         return err;
 546 }
 547
 548 static int gred_init(struct Qdisc *sch, struct rtattr *opt)
 549 {
 550         struct rtattr *tb[TCA_GRED_MAX];
 551
 552         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
 553                 return -EINVAL;
 554
 555         if (tb[TCA_GRED_PARMS-1] || tb[TCA_GRED_STAB-1])
 556                 return -EINVAL;
 557
 558         return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
 559 }
 560
 561 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 562 {
 563         struct gred_sched *table = qdisc_priv(sch);
 564         struct rtattr *parms, *opts = NULL;
 565         int i;
 566         struct tc_gred_sopt sopt = {
 567                 .DPs    = table->DPs,
 568                 .def_DP = table->def,
 569                 .grio   = gred_rio_mode(table),
 570         };
 571
 572         opts = RTA_NEST(skb, TCA_OPTIONS);
 573         RTA_PUT(skb, TCA_GRED_DPS, sizeof(sopt), &sopt);
 574         parms = RTA_NEST(skb, TCA_GRED_PARMS);
 575
 576         for (i = 0; i < MAX_DPs; i++) {
 577                 struct gred_sched_data *q = table->tab[i];
 578                 struct tc_gred_qopt opt;
 579
 580                 memset(&opt, 0, sizeof(opt));
 581
 582                 if (!q) {
 583                         /* hack -- fix at some point with proper message
 584                            This is how we indicate to tc that there is no VQ
 585                            at this DP */
 586
 587                         opt.DP = MAX_DPs + i;
 588                         goto append_opt;
 589                 }
 590
 591                 opt.limit       = q->limit;
 592                 opt.DP          = q->DP;
 593                 opt.backlog     = q->backlog;
 594                 opt.prio        = q->prio;
 595                 opt.qth_min     = q->qth_min >> q->Wlog;
 596                 opt.qth_max     = q->qth_max >> q->Wlog;
 597                 opt.Wlog        = q->Wlog;
 598                 opt.Plog        = q->Plog;
 599                 opt.Scell_log   = q->Scell_log;
 600                 opt.other       = q->other;
 601                 opt.early       = q->early;
 602                 opt.forced      = q->forced;
 603                 opt.pdrop       = q->pdrop;
 604                 opt.packets     = q->packetsin;
 605                 opt.bytesin     = q->bytesin;
 606
 607                 if (q->qave) {
 608                         if (gred_wred_mode(table)) {
 609                                 q->qidlestart=table->tab[table->def]->qidlestart;
 610                                 q->qave=table->tab[table->def]->qave;
 611                         }
 612                         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
 613                                 long idle;
 614                                 unsigned long qave;
 615                                 psched_time_t now;
 616                                 PSCHED_GET_TIME(now);
 617                                 idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
 618                                 qave  = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
 619                                 opt.qave = qave >> q->Wlog;
 620
 621                         } else {
 622                                 opt.qave = q->qave >> q->Wlog;
 623                         }
 624                 }
 625
 626 append_opt:
 627                 RTA_APPEND(skb, sizeof(opt), &opt);
 628         }
 629
 630         RTA_NEST_END(skb, parms);
 631
 632         return RTA_NEST_END(skb, opts);
 633
 634 rtattr_failure:
 635         return RTA_NEST_CANCEL(skb, opts);
 636 }
 637
 638 static void gred_destroy(struct Qdisc *sch)
 639 {
 640         struct gred_sched *table = qdisc_priv(sch);
 641         int i;
 642
 643         for (i = 0;i < table->DPs; i++) {
 644                 if (table->tab[i])
 645                         gred_destroy_vq(table->tab[i]);
 646         }
 647 }
 648
 649 static struct Qdisc_ops gred_qdisc_ops = {
 650         .next           =       NULL,
 651         .cl_ops         =       NULL,
 652         .id             =       "gred",
 653         .priv_size      =       sizeof(struct gred_sched),
 654         .enqueue        =       gred_enqueue,
 655         .dequeue        =       gred_dequeue,
 656         .requeue        =       gred_requeue,
 657         .drop           =       gred_drop,
 658         .init           =       gred_init,
 659         .reset          =       gred_reset,
 660         .destroy        =       gred_destroy,
 661         .change         =       gred_change,
 662         .dump           =       gred_dump,
 663         .owner          =       THIS_MODULE,
 664 };
 665
 666 static int __init gred_module_init(void)
 667 {
 668         return register_qdisc(&gred_qdisc_ops);
 669 }
 670 static void __exit gred_module_exit(void)
 671 {
 672         unregister_qdisc(&gred_qdisc_ops);
 673 }
 674 module_init(gred_module_init)
 675 module_exit(gred_module_exit)
 676 MODULE_LICENSE("GPL");