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 struct gred_sched_data;
  62 struct gred_sched;
  63
  64 struct gred_sched_data
  65 {
  66 /* Parameters */
  67         u32             limit;          /* HARD maximal queue length    */
  68         u32             qth_min;        /* Min average length threshold: A scaled */
  69         u32             qth_max;        /* Max average length threshold: A scaled */
  70         u32             DP;             /* the drop pramaters */
  71         char            Wlog;           /* log(W)               */
  72         char            Plog;           /* random number bits   */
  73         u32             Scell_max;
  74         u32             Rmask;
  75         u32             bytesin;        /* bytes seen on virtualQ so far*/
  76         u32             packetsin;      /* packets seen on virtualQ so far*/
  77         u32             backlog;        /* bytes on the virtualQ */
  78         u32             forced; /* packets dropped for exceeding limits */
  79         u32             early;  /* packets dropped as a warning */
  80         u32             other;  /* packets dropped by invoking drop() */
  81         u32             pdrop;  /* packets dropped because we exceeded physical queue limits */
  82         char            Scell_log;
  83         u8              Stab[256];
  84         u8              prio;        /* the prio of this vq */
  85
  86 /* Variables */
  87         unsigned long   qave;           /* Average queue length: A scaled */
  88         int             qcount;         /* Packets since last random number generation */
  89         u32             qR;             /* Cached random number */
  90
  91         psched_time_t   qidlestart;     /* Start of idle period */
  92 };
  93
  94 enum {
  95         GRED_WRED_MODE = 1,
  96         GRED_RIO_MODE,
  97 };
  98
  99 struct gred_sched
 100 {
 101         struct gred_sched_data *tab[MAX_DPs];
 102         unsigned long   flags;
 103         u32             DPs;
 104         u32             def;
 105         u8              initd;
 106 };
 107
 108 static inline int gred_wred_mode(struct gred_sched *table)
 109 {
 110         return test_bit(GRED_WRED_MODE, &table->flags);
 111 }
 112
 113 static inline void gred_enable_wred_mode(struct gred_sched *table)
 114 {
 115         __set_bit(GRED_WRED_MODE, &table->flags);
 116 }
 117
 118 static inline void gred_disable_wred_mode(struct gred_sched *table)
 119 {
 120         __clear_bit(GRED_WRED_MODE, &table->flags);
 121 }
 122
 123 static inline int gred_rio_mode(struct gred_sched *table)
 124 {
 125         return test_bit(GRED_RIO_MODE, &table->flags);
 126 }
 127
 128 static inline void gred_enable_rio_mode(struct gred_sched *table)
 129 {
 130         __set_bit(GRED_RIO_MODE, &table->flags);
 131 }
 132
 133 static inline void gred_disable_rio_mode(struct gred_sched *table)
 134 {
 135         __clear_bit(GRED_RIO_MODE, &table->flags);
 136 }
 137
 138 static inline int gred_wred_mode_check(struct Qdisc *sch)
 139 {
 140         struct gred_sched *table = qdisc_priv(sch);
 141         int i;
 142
 143         /* Really ugly O(n^2) but shouldn't be necessary too frequent. */
 144         for (i = 0; i < table->DPs; i++) {
 145                 struct gred_sched_data *q = table->tab[i];
 146                 int n;
 147
 148                 if (q == NULL)
 149                         continue;
 150
 151                 for (n = 0; n < table->DPs; n++)
 152                         if (table->tab[n] && table->tab[n] != q &&
 153                             table->tab[n]->prio == q->prio)
 154                                 return 1;
 155         }
 156
 157         return 0;
 158 }
 159
 160 static int
 161 gred_enqueue(struct sk_buff *skb, struct Qdisc* sch)
 162 {
 163         psched_time_t now;
 164         struct gred_sched_data *q=NULL;
 165         struct gred_sched *t= qdisc_priv(sch);
 166         unsigned long   qave=0;
 167         int i=0;
 168
 169         if (!t->initd && skb_queue_len(&sch->q) < (sch->dev->tx_queue_len ? : 1)) {
 170                 D2PRINTK("NO GRED Queues setup yet! Enqueued anyway\n");
 171                 goto do_enqueue;
 172         }
 173
 174
 175         if ( ((skb->tc_index&0xf) > (t->DPs -1)) || !(q=t->tab[skb->tc_index&0xf])) {
 176                 printk("GRED: setting to default (%d)\n ",t->def);
 177                 if (!(q=t->tab[t->def])) {
 178                         DPRINTK("GRED: setting to default FAILED! dropping!! "
 179                             "(%d)\n ", t->def);
 180                         goto drop;
 181                 }
 182                 /* fix tc_index? --could be controvesial but needed for
 183                    requeueing */
 184                 skb->tc_index=(skb->tc_index&0xfffffff0) | t->def;
 185         }
 186
 187         D2PRINTK("gred_enqueue virtualQ 0x%x classid %x backlog %d "
 188             "general backlog %d\n",skb->tc_index&0xf,sch->handle,q->backlog,
 189             sch->qstats.backlog);
 190         /* sum up all the qaves of prios <= to ours to get the new qave*/
 191         if (!gred_wred_mode(t) && gred_rio_mode(t)) {
 192                 for (i=0;i<t->DPs;i++) {
 193                         if ((!t->tab[i]) || (i==q->DP))
 194                                 continue;
 195
 196                         if ((t->tab[i]->prio < q->prio) && (PSCHED_IS_PASTPERFECT(t->tab[i]->qidlestart)))
 197                                 qave +=t->tab[i]->qave;
 198                 }
 199
 200         }
 201
 202         q->packetsin++;
 203         q->bytesin+=skb->len;
 204
 205         if (gred_wred_mode(t)) {
 206                 qave=0;
 207                 q->qave=t->tab[t->def]->qave;
 208                 q->qidlestart=t->tab[t->def]->qidlestart;
 209         }
 210
 211         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
 212                 long us_idle;
 213                 PSCHED_GET_TIME(now);
 214                 us_idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
 215                 PSCHED_SET_PASTPERFECT(q->qidlestart);
 216
 217                 q->qave >>= q->Stab[(us_idle>>q->Scell_log)&0xFF];
 218         } else {
 219                 if (gred_wred_mode(t)) {
 220                         q->qave += sch->qstats.backlog - (q->qave >> q->Wlog);
 221                 } else {
 222                         q->qave += q->backlog - (q->qave >> q->Wlog);
 223                 }
 224
 225         }
 226
 227
 228         if (gred_wred_mode(t))
 229                 t->tab[t->def]->qave=q->qave;
 230
 231         if ((q->qave+qave) < q->qth_min) {
 232                 q->qcount = -1;
 233 enqueue:
 234                 if (q->backlog + skb->len <= q->limit) {
 235                         q->backlog += skb->len;
 236 do_enqueue:
 237                         __skb_queue_tail(&sch->q, skb);
 238                         sch->qstats.backlog += skb->len;
 239                         sch->bstats.bytes += skb->len;
 240                         sch->bstats.packets++;
 241                         return 0;
 242                 } else {
 243                         q->pdrop++;
 244                 }
 245
 246 drop:
 247                 kfree_skb(skb);
 248                 sch->qstats.drops++;
 249                 return NET_XMIT_DROP;
 250         }
 251         if ((q->qave+qave) >= q->qth_max) {
 252                 q->qcount = -1;
 253                 sch->qstats.overlimits++;
 254                 q->forced++;
 255                 goto drop;
 256         }
 257         if (++q->qcount) {
 258                 if ((((qave+q->qave) - q->qth_min)>>q->Wlog)*q->qcount < q->qR)
 259                         goto enqueue;
 260                 q->qcount = 0;
 261                 q->qR = net_random()&q->Rmask;
 262                 sch->qstats.overlimits++;
 263                 q->early++;
 264                 goto drop;
 265         }
 266         q->qR = net_random()&q->Rmask;
 267         goto enqueue;
 268 }
 269
 270 static int
 271 gred_requeue(struct sk_buff *skb, struct Qdisc* sch)
 272 {
 273         struct gred_sched_data *q;
 274         struct gred_sched *t= qdisc_priv(sch);
 275         q= t->tab[(skb->tc_index&0xf)];
 276 /* error checking here -- probably unnecessary */
 277         PSCHED_SET_PASTPERFECT(q->qidlestart);
 278
 279         __skb_queue_head(&sch->q, skb);
 280         sch->qstats.backlog += skb->len;
 281         sch->qstats.requeues++;
 282         q->backlog += skb->len;
 283         return 0;
 284 }
 285
 286 static struct sk_buff *
 287 gred_dequeue(struct Qdisc* sch)
 288 {
 289         struct sk_buff *skb;
 290         struct gred_sched_data *q;
 291         struct gred_sched *t= qdisc_priv(sch);
 292
 293         skb = __skb_dequeue(&sch->q);
 294         if (skb) {
 295                 sch->qstats.backlog -= skb->len;
 296                 q= t->tab[(skb->tc_index&0xf)];
 297                 if (q) {
 298                         q->backlog -= skb->len;
 299                         if (!q->backlog && !gred_wred_mode(t))
 300                                 PSCHED_GET_TIME(q->qidlestart);
 301                 } else {
 302                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
 303                 }
 304                 return skb;
 305         }
 306
 307         if (gred_wred_mode(t)) {
 308                         q= t->tab[t->def];
 309                         if (!q)
 310                                 D2PRINTK("no default VQ set: Results will be "
 311                                        "screwed up\n");
 312                         else
 313                                 PSCHED_GET_TIME(q->qidlestart);
 314         }
 315
 316         return NULL;
 317 }
 318
 319 static unsigned int gred_drop(struct Qdisc* sch)
 320 {
 321         struct sk_buff *skb;
 322
 323         struct gred_sched_data *q;
 324         struct gred_sched *t= qdisc_priv(sch);
 325
 326         skb = __skb_dequeue_tail(&sch->q);
 327         if (skb) {
 328                 unsigned int len = skb->len;
 329                 sch->qstats.backlog -= len;
 330                 sch->qstats.drops++;
 331                 q= t->tab[(skb->tc_index&0xf)];
 332                 if (q) {
 333                         q->backlog -= len;
 334                         q->other++;
 335                         if (!q->backlog && !gred_wred_mode(t))
 336                                 PSCHED_GET_TIME(q->qidlestart);
 337                 } else {
 338                         D2PRINTK("gred_dequeue: skb has bad tcindex %x\n",skb->tc_index&0xf);
 339                 }
 340
 341                 kfree_skb(skb);
 342                 return len;
 343         }
 344
 345         q=t->tab[t->def];
 346         if (!q) {
 347                 D2PRINTK("no default VQ set: Results might be screwed up\n");
 348                 return 0;
 349         }
 350
 351         PSCHED_GET_TIME(q->qidlestart);
 352         return 0;
 353
 354 }
 355
 356 static void gred_reset(struct Qdisc* sch)
 357 {
 358         int i;
 359         struct gred_sched_data *q;
 360         struct gred_sched *t= qdisc_priv(sch);
 361
 362         __skb_queue_purge(&sch->q);
 363
 364         sch->qstats.backlog = 0;
 365
 366         for (i=0;i<t->DPs;i++) {
 367                 q= t->tab[i];
 368                 if (!q)
 369                         continue;
 370                 PSCHED_SET_PASTPERFECT(q->qidlestart);
 371                 q->qave = 0;
 372                 q->qcount = -1;
 373                 q->backlog = 0;
 374                 q->other=0;
 375                 q->forced=0;
 376                 q->pdrop=0;
 377                 q->early=0;
 378         }
 379 }
 380
 381 static inline void gred_destroy_vq(struct gred_sched_data *q)
 382 {
 383         kfree(q);
 384 }
 385
 386 static inline int gred_change_table_def(struct Qdisc *sch, struct rtattr *dps)
 387 {
 388         struct gred_sched *table = qdisc_priv(sch);
 389         struct tc_gred_sopt *sopt;
 390         int i;
 391
 392         if (dps == NULL || RTA_PAYLOAD(dps) < sizeof(*sopt))
 393                 return -EINVAL;
 394
 395         sopt = RTA_DATA(dps);
 396
 397         if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
 398                 return -EINVAL;
 399
 400         sch_tree_lock(sch);
 401         table->DPs = sopt->DPs;
 402         table->def = sopt->def_DP;
 403
 404         /*
 405          * Every entry point to GRED is synchronized with the above code
 406          * and the DP is checked against DPs, i.e. shadowed VQs can no
 407          * longer be found so we can unlock right here.
 408          */
 409         sch_tree_unlock(sch);
 410
 411         if (sopt->grio) {
 412                 gred_enable_rio_mode(table);
 413                 gred_disable_wred_mode(table);
 414                 if (gred_wred_mode_check(sch))
 415                         gred_enable_wred_mode(table);
 416         } else {
 417                 gred_disable_rio_mode(table);
 418                 gred_disable_wred_mode(table);
 419         }
 420
 421         for (i = table->DPs; i < MAX_DPs; i++) {
 422                 if (table->tab[i]) {
 423                         printk(KERN_WARNING "GRED: Warning: Destroying "
 424                                "shadowed VQ 0x%x\n", i);
 425                         gred_destroy_vq(table->tab[i]);
 426                         table->tab[i] = NULL;
 427                 }
 428         }
 429
 430         table->initd = 0;
 431
 432         return 0;
 433 }
 434
 435 static int gred_change(struct Qdisc *sch, struct rtattr *opt)
 436 {
 437         struct gred_sched *table = qdisc_priv(sch);
 438         struct gred_sched_data *q;
 439         struct tc_gred_qopt *ctl;
 440         struct rtattr *tb[TCA_GRED_STAB];
 441
 442         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
 443                 return -EINVAL;
 444
 445         if (tb[TCA_GRED_PARMS-1] == NULL && tb[TCA_GRED_STAB-1] == NULL)
 446                 return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
 447
 448         if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
 449                 RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
 450                 RTA_PAYLOAD(tb[TCA_GRED_STAB-1]) < 256)
 451                         return -EINVAL;
 452
 453         ctl = RTA_DATA(tb[TCA_GRED_PARMS-1]);
 454
 455         if (ctl->DP >= table->DPs)
 456                 return -EINVAL;
 457
 458         if (table->tab[ctl->DP] == NULL) {
 459                 table->tab[ctl->DP]=kmalloc(sizeof(struct gred_sched_data),
 460                                             GFP_KERNEL);
 461                 if (NULL == table->tab[ctl->DP])
 462                         return -ENOMEM;
 463                 memset(table->tab[ctl->DP], 0, (sizeof(struct gred_sched_data)));
 464         }
 465         q= table->tab[ctl->DP];
 466
 467         if (gred_rio_mode(table)) {
 468                 if (ctl->prio <=0) {
 469                         if (table->def && table->tab[table->def]) {
 470                                 DPRINTK("\nGRED: DP %u does not have a prio"
 471                                         "setting default to %d\n",ctl->DP,
 472                                         table->tab[table->def]->prio);
 473                                 q->prio=table->tab[table->def]->prio;
 474                         } else {
 475                                 DPRINTK("\nGRED: DP %u does not have a prio"
 476                                         " setting default to 8\n",ctl->DP);
 477                                 q->prio=8;
 478                         }
 479                 } else {
 480                         q->prio=ctl->prio;
 481                 }
 482         } else {
 483                 q->prio=8;
 484         }
 485
 486
 487         q->DP=ctl->DP;
 488         q->Wlog = ctl->Wlog;
 489         q->Plog = ctl->Plog;
 490         q->limit = ctl->limit;
 491         q->Scell_log = ctl->Scell_log;
 492         q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
 493         q->Scell_max = (255<<q->Scell_log);
 494         q->qth_min = ctl->qth_min<<ctl->Wlog;
 495         q->qth_max = ctl->qth_max<<ctl->Wlog;
 496         q->qave=0;
 497         q->backlog=0;
 498         q->qcount = -1;
 499         q->other=0;
 500         q->forced=0;
 501         q->pdrop=0;
 502         q->early=0;
 503
 504         PSCHED_SET_PASTPERFECT(q->qidlestart);
 505         memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
 506
 507         if (gred_rio_mode(table)) {
 508                 gred_disable_wred_mode(table);
 509                 if (gred_wred_mode_check(sch))
 510                         gred_enable_wred_mode(table);
 511         }
 512
 513         if (!table->initd) {
 514                 table->initd=1;
 515                 /*
 516                 the first entry also goes into the default until
 517                 over-written
 518                 */
 519
 520                 if (table->tab[table->def] == NULL) {
 521                         table->tab[table->def]=
 522                                 kmalloc(sizeof(struct gred_sched_data), GFP_KERNEL);
 523                         if (NULL == table->tab[table->def])
 524                                 return -ENOMEM;
 525
 526                         memset(table->tab[table->def], 0,
 527                                (sizeof(struct gred_sched_data)));
 528                 }
 529                 q= table->tab[table->def];
 530                 q->DP=table->def;
 531                 q->Wlog = ctl->Wlog;
 532                 q->Plog = ctl->Plog;
 533                 q->limit = ctl->limit;
 534                 q->Scell_log = ctl->Scell_log;
 535                 q->Rmask = ctl->Plog < 32 ? ((1<<ctl->Plog) - 1) : ~0UL;
 536                 q->Scell_max = (255<<q->Scell_log);
 537                 q->qth_min = ctl->qth_min<<ctl->Wlog;
 538                 q->qth_max = ctl->qth_max<<ctl->Wlog;
 539
 540                 if (gred_rio_mode(table))
 541                         q->prio=table->tab[ctl->DP]->prio;
 542                 else
 543                         q->prio=8;
 544
 545                 q->qcount = -1;
 546                 PSCHED_SET_PASTPERFECT(q->qidlestart);
 547                 memcpy(q->Stab, RTA_DATA(tb[TCA_GRED_STAB-1]), 256);
 548         }
 549         return 0;
 550
 551 }
 552
 553 static int gred_init(struct Qdisc *sch, struct rtattr *opt)
 554 {
 555         struct rtattr *tb[TCA_GRED_MAX];
 556
 557         if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
 558                 return -EINVAL;
 559
 560         if (tb[TCA_GRED_PARMS-1] || tb[TCA_GRED_STAB-1])
 561                 return -EINVAL;
 562
 563         return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
 564 }
 565
 566 static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
 567 {
 568         struct gred_sched *table = qdisc_priv(sch);
 569         struct rtattr *parms, *opts = NULL;
 570         int i;
 571         struct tc_gred_sopt sopt = {
 572                 .DPs    = table->DPs,
 573                 .def_DP = table->def,
 574                 .grio   = gred_rio_mode(table),
 575         };
 576
 577         opts = RTA_NEST(skb, TCA_OPTIONS);
 578         RTA_PUT(skb, TCA_GRED_DPS, sizeof(sopt), &sopt);
 579         parms = RTA_NEST(skb, TCA_GRED_PARMS);
 580
 581         for (i = 0; i < MAX_DPs; i++) {
 582                 struct gred_sched_data *q = table->tab[i];
 583                 struct tc_gred_qopt opt;
 584
 585                 memset(&opt, 0, sizeof(opt));
 586
 587                 if (!q) {
 588                         /* hack -- fix at some point with proper message
 589                            This is how we indicate to tc that there is no VQ
 590                            at this DP */
 591
 592                         opt.DP = MAX_DPs + i;
 593                         goto append_opt;
 594                 }
 595
 596                 opt.limit       = q->limit;
 597                 opt.DP          = q->DP;
 598                 opt.backlog     = q->backlog;
 599                 opt.prio        = q->prio;
 600                 opt.qth_min     = q->qth_min >> q->Wlog;
 601                 opt.qth_max     = q->qth_max >> q->Wlog;
 602                 opt.Wlog        = q->Wlog;
 603                 opt.Plog        = q->Plog;
 604                 opt.Scell_log   = q->Scell_log;
 605                 opt.other       = q->other;
 606                 opt.early       = q->early;
 607                 opt.forced      = q->forced;
 608                 opt.pdrop       = q->pdrop;
 609                 opt.packets     = q->packetsin;
 610                 opt.bytesin     = q->bytesin;
 611
 612                 if (q->qave) {
 613                         if (gred_wred_mode(table)) {
 614                                 q->qidlestart=table->tab[table->def]->qidlestart;
 615                                 q->qave=table->tab[table->def]->qave;
 616                         }
 617                         if (!PSCHED_IS_PASTPERFECT(q->qidlestart)) {
 618                                 long idle;
 619                                 unsigned long qave;
 620                                 psched_time_t now;
 621                                 PSCHED_GET_TIME(now);
 622                                 idle = PSCHED_TDIFF_SAFE(now, q->qidlestart, q->Scell_max);
 623                                 qave  = q->qave >> q->Stab[(idle>>q->Scell_log)&0xFF];
 624                                 opt.qave = qave >> q->Wlog;
 625
 626                         } else {
 627                                 opt.qave = q->qave >> q->Wlog;
 628                         }
 629                 }
 630
 631 append_opt:
 632                 RTA_APPEND(skb, sizeof(opt), &opt);
 633         }
 634
 635         RTA_NEST_END(skb, parms);
 636
 637         return RTA_NEST_END(skb, opts);
 638
 639 rtattr_failure:
 640         return RTA_NEST_CANCEL(skb, opts);
 641 }
 642
 643 static void gred_destroy(struct Qdisc *sch)
 644 {
 645         struct gred_sched *table = qdisc_priv(sch);
 646         int i;
 647
 648         for (i = 0;i < table->DPs; i++) {
 649                 if (table->tab[i])
 650                         gred_destroy_vq(table->tab[i]);
 651         }
 652 }
 653
 654 static struct Qdisc_ops gred_qdisc_ops = {
 655         .next           =       NULL,
 656         .cl_ops         =       NULL,
 657         .id             =       "gred",
 658         .priv_size      =       sizeof(struct gred_sched),
 659         .enqueue        =       gred_enqueue,
 660         .dequeue        =       gred_dequeue,
 661         .requeue        =       gred_requeue,
 662         .drop           =       gred_drop,
 663         .init           =       gred_init,
 664         .reset          =       gred_reset,
 665         .destroy        =       gred_destroy,
 666         .change         =       gred_change,
 667         .dump           =       gred_dump,
 668         .owner          =       THIS_MODULE,
 669 };
 670
 671 static int __init gred_module_init(void)
 672 {
 673         return register_qdisc(&gred_qdisc_ops);
 674 }
 675 static void __exit gred_module_exit(void)
 676 {
 677         unregister_qdisc(&gred_qdisc_ops);
 678 }
 679 module_init(gred_module_init)
 680 module_exit(gred_module_exit)
 681 MODULE_LICENSE("GPL");