net/sched/sch_fq_codel.c

   1 /*
   2  * Fair Queue CoDel discipline
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  *
   9  *  Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/types.h>
  14 #include <linux/kernel.h>
  15 #include <linux/jiffies.h>
  16 #include <linux/string.h>
  17 #include <linux/in.h>
  18 #include <linux/errno.h>
  19 #include <linux/init.h>
  20 #include <linux/skbuff.h>
  21 #include <linux/jhash.h>
  22 #include <linux/slab.h>
  23 #include <linux/vmalloc.h>
  24 #include <net/netlink.h>
  25 #include <net/pkt_sched.h>
  26 #include <net/codel.h>
  27
  28 /*      Fair Queue CoDel.
  29  *
  30  * Principles :
  31  * Packets are classified (internal classifier or external) on flows.
  32  * This is a Stochastic model (as we use a hash, several flows
  33  *                             might be hashed on same slot)
  34  * Each flow has a CoDel managed queue.
  35  * Flows are linked onto two (Round Robin) lists,
  36  * so that new flows have priority on old ones.
  37  *
  38  * For a given flow, packets are not reordered (CoDel uses a FIFO)
  39  * head drops only.
  40  * ECN capability is on by default.
  41  * Low memory footprint (64 bytes per flow)
  42  */
  43
  44 struct fq_codel_flow {
  45         struct sk_buff    *head;
  46         struct sk_buff    *tail;
  47         struct list_head  flowchain;
  48         int               deficit;
  49         u32               dropped; /* number of drops (or ECN marks) on this flow */
  50         struct codel_vars cvars;
  51 }; /* please try to keep this structure <= 64 bytes */
  52
  53 struct fq_codel_sched_data {
  54         struct tcf_proto __rcu *filter_list; /* optional external classifier */
  55         struct fq_codel_flow *flows;    /* Flows table [flows_cnt] */
  56         u32             *backlogs;      /* backlog table [flows_cnt] */
  57         u32             flows_cnt;      /* number of flows */
  58         u32             perturbation;   /* hash perturbation */
  59         u32             quantum;        /* psched_mtu(qdisc_dev(sch)); */
  60         struct codel_params cparams;
  61         struct codel_stats cstats;
  62         u32             drop_overlimit;
  63         u32             new_flow_count;
  64
  65         struct list_head new_flows;     /* list of new flows */
  66         struct list_head old_flows;     /* list of old flows */
  67 };
  68
  69 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q,
  70                                   struct sk_buff *skb)
  71 {
  72         u32 hash = skb_get_hash_perturb(skb, q->perturbation);
  73
  74         return reciprocal_scale(hash, q->flows_cnt);
  75 }
  76
  77 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
  78                                       int *qerr)
  79 {
  80         struct fq_codel_sched_data *q = qdisc_priv(sch);
  81         struct tcf_proto *filter;
  82         struct tcf_result res;
  83         int result;
  84
  85         if (TC_H_MAJ(skb->priority) == sch->handle &&
  86             TC_H_MIN(skb->priority) > 0 &&
  87             TC_H_MIN(skb->priority) <= q->flows_cnt)
  88                 return TC_H_MIN(skb->priority);
  89
  90         filter = rcu_dereference_bh(q->filter_list);
  91         if (!filter)
  92                 return fq_codel_hash(q, skb) + 1;
  93
  94         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
  95         result = tc_classify(skb, filter, &res);
  96         if (result >= 0) {
  97 #ifdef CONFIG_NET_CLS_ACT
  98                 switch (result) {
  99                 case TC_ACT_STOLEN:
 100                 case TC_ACT_QUEUED:
 101                         *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
 102                 case TC_ACT_SHOT:
 103                         return 0;
 104                 }
 105 #endif
 106                 if (TC_H_MIN(res.classid) <= q->flows_cnt)
 107                         return TC_H_MIN(res.classid);
 108         }
 109         return 0;
 110 }
 111
 112 /* helper functions : might be changed when/if skb use a standard list_head */
 113
 114 /* remove one skb from head of slot queue */
 115 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
 116 {
 117         struct sk_buff *skb = flow->head;
 118
 119         flow->head = skb->next;
 120         skb->next = NULL;
 121         return skb;
 122 }
 123
 124 /* add skb to flow queue (tail add) */
 125 static inline void flow_queue_add(struct fq_codel_flow *flow,
 126                                   struct sk_buff *skb)
 127 {
 128         if (flow->head == NULL)
 129                 flow->head = skb;
 130         else
 131                 flow->tail->next = skb;
 132         flow->tail = skb;
 133         skb->next = NULL;
 134 }
 135
 136 static unsigned int fq_codel_drop(struct Qdisc *sch)
 137 {
 138         struct fq_codel_sched_data *q = qdisc_priv(sch);
 139         struct sk_buff *skb;
 140         unsigned int maxbacklog = 0, idx = 0, i, len;
 141         struct fq_codel_flow *flow;
 142
 143         /* Queue is full! Find the fat flow and drop packet from it.
 144          * This might sound expensive, but with 1024 flows, we scan
 145          * 4KB of memory, and we dont need to handle a complex tree
 146          * in fast path (packet queue/enqueue) with many cache misses.
 147          */
 148         for (i = 0; i < q->flows_cnt; i++) {
 149                 if (q->backlogs[i] > maxbacklog) {
 150                         maxbacklog = q->backlogs[i];
 151                         idx = i;
 152                 }
 153         }
 154         flow = &q->flows[idx];
 155         skb = dequeue_head(flow);
 156         len = qdisc_pkt_len(skb);
 157         q->backlogs[idx] -= len;
 158         kfree_skb(skb);
 159         sch->q.qlen--;
 160         qdisc_qstats_drop(sch);
 161         qdisc_qstats_backlog_dec(sch, skb);
 162         flow->dropped++;
 163         return idx;
 164 }
 165
 166 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 167 {
 168         struct fq_codel_sched_data *q = qdisc_priv(sch);
 169         unsigned int idx;
 170         struct fq_codel_flow *flow;
 171         int uninitialized_var(ret);
 172
 173         idx = fq_codel_classify(skb, sch, &ret);
 174         if (idx == 0) {
 175                 if (ret & __NET_XMIT_BYPASS)
 176                         qdisc_qstats_drop(sch);
 177                 kfree_skb(skb);
 178                 return ret;
 179         }
 180         idx--;
 181
 182         codel_set_enqueue_time(skb);
 183         flow = &q->flows[idx];
 184         flow_queue_add(flow, skb);
 185         q->backlogs[idx] += qdisc_pkt_len(skb);
 186         qdisc_qstats_backlog_inc(sch, skb);
 187
 188         if (list_empty(&flow->flowchain)) {
 189                 list_add_tail(&flow->flowchain, &q->new_flows);
 190                 q->new_flow_count++;
 191                 flow->deficit = q->quantum;
 192                 flow->dropped = 0;
 193         }
 194         if (++sch->q.qlen <= sch->limit)
 195                 return NET_XMIT_SUCCESS;
 196
 197         q->drop_overlimit++;
 198         /* Return Congestion Notification only if we dropped a packet
 199          * from this flow.
 200          */
 201         if (fq_codel_drop(sch) == idx)
 202                 return NET_XMIT_CN;
 203
 204         /* As we dropped a packet, better let upper stack know this */
 205         qdisc_tree_decrease_qlen(sch, 1);
 206         return NET_XMIT_SUCCESS;
 207 }
 208
 209 /* This is the specific function called from codel_dequeue()
 210  * to dequeue a packet from queue. Note: backlog is handled in
 211  * codel, we dont need to reduce it here.
 212  */
 213 static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
 214 {
 215         struct fq_codel_sched_data *q = qdisc_priv(sch);
 216         struct fq_codel_flow *flow;
 217         struct sk_buff *skb = NULL;
 218
 219         flow = container_of(vars, struct fq_codel_flow, cvars);
 220         if (flow->head) {
 221                 skb = dequeue_head(flow);
 222                 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
 223                 sch->q.qlen--;
 224         }
 225         return skb;
 226 }
 227
 228 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
 229 {
 230         struct fq_codel_sched_data *q = qdisc_priv(sch);
 231         struct sk_buff *skb;
 232         struct fq_codel_flow *flow;
 233         struct list_head *head;
 234         u32 prev_drop_count, prev_ecn_mark;
 235
 236 begin:
 237         head = &q->new_flows;
 238         if (list_empty(head)) {
 239                 head = &q->old_flows;
 240                 if (list_empty(head))
 241                         return NULL;
 242         }
 243         flow = list_first_entry(head, struct fq_codel_flow, flowchain);
 244
 245         if (flow->deficit <= 0) {
 246                 flow->deficit += q->quantum;
 247                 list_move_tail(&flow->flowchain, &q->old_flows);
 248                 goto begin;
 249         }
 250
 251         prev_drop_count = q->cstats.drop_count;
 252         prev_ecn_mark = q->cstats.ecn_mark;
 253
 254         skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
 255                             dequeue);
 256
 257         flow->dropped += q->cstats.drop_count - prev_drop_count;
 258         flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
 259
 260         if (!skb) {
 261                 /* force a pass through old_flows to prevent starvation */
 262                 if ((head == &q->new_flows) && !list_empty(&q->old_flows))
 263                         list_move_tail(&flow->flowchain, &q->old_flows);
 264                 else
 265                         list_del_init(&flow->flowchain);
 266                 goto begin;
 267         }
 268         qdisc_bstats_update(sch, skb);
 269         flow->deficit -= qdisc_pkt_len(skb);
 270         /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
 271          * or HTB crashes. Defer it for next round.
 272          */
 273         if (q->cstats.drop_count && sch->q.qlen) {
 274                 qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 275                 q->cstats.drop_count = 0;
 276         }
 277         return skb;
 278 }
 279
 280 static void fq_codel_reset(struct Qdisc *sch)
 281 {
 282         struct sk_buff *skb;
 283
 284         while ((skb = fq_codel_dequeue(sch)) != NULL)
 285                 kfree_skb(skb);
 286 }
 287
 288 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
 289         [TCA_FQ_CODEL_TARGET]   = { .type = NLA_U32 },
 290         [TCA_FQ_CODEL_LIMIT]    = { .type = NLA_U32 },
 291         [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
 292         [TCA_FQ_CODEL_ECN]      = { .type = NLA_U32 },
 293         [TCA_FQ_CODEL_FLOWS]    = { .type = NLA_U32 },
 294         [TCA_FQ_CODEL_QUANTUM]  = { .type = NLA_U32 },
 295         [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 },
 296 };
 297
 298 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
 299 {
 300         struct fq_codel_sched_data *q = qdisc_priv(sch);
 301         struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
 302         int err;
 303
 304         if (!opt)
 305                 return -EINVAL;
 306
 307         err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
 308         if (err < 0)
 309                 return err;
 310         if (tb[TCA_FQ_CODEL_FLOWS]) {
 311                 if (q->flows)
 312                         return -EINVAL;
 313                 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
 314                 if (!q->flows_cnt ||
 315                     q->flows_cnt > 65536)
 316                         return -EINVAL;
 317         }
 318         sch_tree_lock(sch);
 319
 320         if (tb[TCA_FQ_CODEL_TARGET]) {
 321                 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
 322
 323                 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
 324         }
 325
 326         if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) {
 327                 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]);
 328
 329                 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT;
 330         }
 331
 332         if (tb[TCA_FQ_CODEL_INTERVAL]) {
 333                 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
 334
 335                 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
 336         }
 337
 338         if (tb[TCA_FQ_CODEL_LIMIT])
 339                 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
 340
 341         if (tb[TCA_FQ_CODEL_ECN])
 342                 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
 343
 344         if (tb[TCA_FQ_CODEL_QUANTUM])
 345                 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
 346
 347         while (sch->q.qlen > sch->limit) {
 348                 struct sk_buff *skb = fq_codel_dequeue(sch);
 349
 350                 kfree_skb(skb);
 351                 q->cstats.drop_count++;
 352         }
 353         qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 354         q->cstats.drop_count = 0;
 355
 356         sch_tree_unlock(sch);
 357         return 0;
 358 }
 359
 360 static void *fq_codel_zalloc(size_t sz)
 361 {
 362         void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
 363
 364         if (!ptr)
 365                 ptr = vzalloc(sz);
 366         return ptr;
 367 }
 368
 369 static void fq_codel_free(void *addr)
 370 {
 371         kvfree(addr);
 372 }
 373
 374 static void fq_codel_destroy(struct Qdisc *sch)
 375 {
 376         struct fq_codel_sched_data *q = qdisc_priv(sch);
 377
 378         tcf_destroy_chain(&q->filter_list);
 379         fq_codel_free(q->backlogs);
 380         fq_codel_free(q->flows);
 381 }
 382
 383 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
 384 {
 385         struct fq_codel_sched_data *q = qdisc_priv(sch);
 386         int i;
 387
 388         sch->limit = 10*1024;
 389         q->flows_cnt = 1024;
 390         q->quantum = psched_mtu(qdisc_dev(sch));
 391         q->perturbation = prandom_u32();
 392         INIT_LIST_HEAD(&q->new_flows);
 393         INIT_LIST_HEAD(&q->old_flows);
 394         codel_params_init(&q->cparams, sch);
 395         codel_stats_init(&q->cstats);
 396         q->cparams.ecn = true;
 397
 398         if (opt) {
 399                 int err = fq_codel_change(sch, opt);
 400                 if (err)
 401                         return err;
 402         }
 403
 404         if (!q->flows) {
 405                 q->flows = fq_codel_zalloc(q->flows_cnt *
 406                                            sizeof(struct fq_codel_flow));
 407                 if (!q->flows)
 408                         return -ENOMEM;
 409                 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
 410                 if (!q->backlogs) {
 411                         fq_codel_free(q->flows);
 412                         return -ENOMEM;
 413                 }
 414                 for (i = 0; i < q->flows_cnt; i++) {
 415                         struct fq_codel_flow *flow = q->flows + i;
 416
 417                         INIT_LIST_HEAD(&flow->flowchain);
 418                         codel_vars_init(&flow->cvars);
 419                 }
 420         }
 421         if (sch->limit >= 1)
 422                 sch->flags |= TCQ_F_CAN_BYPASS;
 423         else
 424                 sch->flags &= ~TCQ_F_CAN_BYPASS;
 425         return 0;
 426 }
 427
 428 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
 429 {
 430         struct fq_codel_sched_data *q = qdisc_priv(sch);
 431         struct nlattr *opts;
 432
 433         opts = nla_nest_start(skb, TCA_OPTIONS);
 434         if (opts == NULL)
 435                 goto nla_put_failure;
 436
 437         if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
 438                         codel_time_to_us(q->cparams.target)) ||
 439             nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
 440                         sch->limit) ||
 441             nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
 442                         codel_time_to_us(q->cparams.interval)) ||
 443             nla_put_u32(skb, TCA_FQ_CODEL_ECN,
 444                         q->cparams.ecn) ||
 445             nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
 446                         q->quantum) ||
 447             nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
 448                         q->flows_cnt))
 449                 goto nla_put_failure;
 450
 451         if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD &&
 452             nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD,
 453                         codel_time_to_us(q->cparams.ce_threshold)))
 454                 goto nla_put_failure;
 455
 456         return nla_nest_end(skb, opts);
 457
 458 nla_put_failure:
 459         return -1;
 460 }
 461
 462 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 463 {
 464         struct fq_codel_sched_data *q = qdisc_priv(sch);
 465         struct tc_fq_codel_xstats st = {
 466                 .type                           = TCA_FQ_CODEL_XSTATS_QDISC,
 467         };
 468         struct list_head *pos;
 469
 470         st.qdisc_stats.maxpacket = q->cstats.maxpacket;
 471         st.qdisc_stats.drop_overlimit = q->drop_overlimit;
 472         st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
 473         st.qdisc_stats.new_flow_count = q->new_flow_count;
 474         st.qdisc_stats.ce_mark = q->cstats.ce_mark;
 475
 476         list_for_each(pos, &q->new_flows)
 477                 st.qdisc_stats.new_flows_len++;
 478
 479         list_for_each(pos, &q->old_flows)
 480                 st.qdisc_stats.old_flows_len++;
 481
 482         return gnet_stats_copy_app(d, &st, sizeof(st));
 483 }
 484
 485 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
 486 {
 487         return NULL;
 488 }
 489
 490 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
 491 {
 492         return 0;
 493 }
 494
 495 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
 496                               u32 classid)
 497 {
 498         /* we cannot bypass queue discipline anymore */
 499         sch->flags &= ~TCQ_F_CAN_BYPASS;
 500         return 0;
 501 }
 502
 503 static void fq_codel_put(struct Qdisc *q, unsigned long cl)
 504 {
 505 }
 506
 507 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch,
 508                                                   unsigned long cl)
 509 {
 510         struct fq_codel_sched_data *q = qdisc_priv(sch);
 511
 512         if (cl)
 513                 return NULL;
 514         return &q->filter_list;
 515 }
 516
 517 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
 518                           struct sk_buff *skb, struct tcmsg *tcm)
 519 {
 520         tcm->tcm_handle |= TC_H_MIN(cl);
 521         return 0;
 522 }
 523
 524 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 525                                      struct gnet_dump *d)
 526 {
 527         struct fq_codel_sched_data *q = qdisc_priv(sch);
 528         u32 idx = cl - 1;
 529         struct gnet_stats_queue qs = { 0 };
 530         struct tc_fq_codel_xstats xstats;
 531
 532         if (idx < q->flows_cnt) {
 533                 const struct fq_codel_flow *flow = &q->flows[idx];
 534                 const struct sk_buff *skb = flow->head;
 535
 536                 memset(&xstats, 0, sizeof(xstats));
 537                 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
 538                 xstats.class_stats.deficit = flow->deficit;
 539                 xstats.class_stats.ldelay =
 540                         codel_time_to_us(flow->cvars.ldelay);
 541                 xstats.class_stats.count = flow->cvars.count;
 542                 xstats.class_stats.lastcount = flow->cvars.lastcount;
 543                 xstats.class_stats.dropping = flow->cvars.dropping;
 544                 if (flow->cvars.dropping) {
 545                         codel_tdiff_t delta = flow->cvars.drop_next -
 546                                               codel_get_time();
 547
 548                         xstats.class_stats.drop_next = (delta >= 0) ?
 549                                 codel_time_to_us(delta) :
 550                                 -codel_time_to_us(-delta);
 551                 }
 552                 while (skb) {
 553                         qs.qlen++;
 554                         skb = skb->next;
 555                 }
 556                 qs.backlog = q->backlogs[idx];
 557                 qs.drops = flow->dropped;
 558         }
 559         if (gnet_stats_copy_queue(d, NULL, &qs, 0) < 0)
 560                 return -1;
 561         if (idx < q->flows_cnt)
 562                 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
 563         return 0;
 564 }
 565
 566 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 567 {
 568         struct fq_codel_sched_data *q = qdisc_priv(sch);
 569         unsigned int i;
 570
 571         if (arg->stop)
 572                 return;
 573
 574         for (i = 0; i < q->flows_cnt; i++) {
 575                 if (list_empty(&q->flows[i].flowchain) ||
 576                     arg->count < arg->skip) {
 577                         arg->count++;
 578                         continue;
 579                 }
 580                 if (arg->fn(sch, i + 1, arg) < 0) {
 581                         arg->stop = 1;
 582                         break;
 583                 }
 584                 arg->count++;
 585         }
 586 }
 587
 588 static const struct Qdisc_class_ops fq_codel_class_ops = {
 589         .leaf           =       fq_codel_leaf,
 590         .get            =       fq_codel_get,
 591         .put            =       fq_codel_put,
 592         .tcf_chain      =       fq_codel_find_tcf,
 593         .bind_tcf       =       fq_codel_bind,
 594         .unbind_tcf     =       fq_codel_put,
 595         .dump           =       fq_codel_dump_class,
 596         .dump_stats     =       fq_codel_dump_class_stats,
 597         .walk           =       fq_codel_walk,
 598 };
 599
 600 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
 601         .cl_ops         =       &fq_codel_class_ops,
 602         .id             =       "fq_codel",
 603         .priv_size      =       sizeof(struct fq_codel_sched_data),
 604         .enqueue        =       fq_codel_enqueue,
 605         .dequeue        =       fq_codel_dequeue,
 606         .peek           =       qdisc_peek_dequeued,
 607         .drop           =       fq_codel_drop,
 608         .init           =       fq_codel_init,
 609         .reset          =       fq_codel_reset,
 610         .destroy        =       fq_codel_destroy,
 611         .change         =       fq_codel_change,
 612         .dump           =       fq_codel_dump,
 613         .dump_stats =   fq_codel_dump_stats,
 614         .owner          =       THIS_MODULE,
 615 };
 616
 617 static int __init fq_codel_module_init(void)
 618 {
 619         return register_qdisc(&fq_codel_qdisc_ops);
 620 }
 621
 622 static void __exit fq_codel_module_exit(void)
 623 {
 624         unregister_qdisc(&fq_codel_qdisc_ops);
 625 }
 626
 627 module_init(fq_codel_module_init)
 628 module_exit(fq_codel_module_exit)
 629 MODULE_AUTHOR("Eric Dumazet");
 630 MODULE_LICENSE("GPL");