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         sch->q.qlen--;
 159         qdisc_qstats_drop(sch);
 160         qdisc_qstats_backlog_dec(sch, skb);
 161         kfree_skb(skb);
 162         flow->dropped++;
 163         return idx;
 164 }
 165
 166 static unsigned int fq_codel_qdisc_drop(struct Qdisc *sch)
 167 {
 168         unsigned int prev_backlog;
 169
 170         prev_backlog = sch->qstats.backlog;
 171         fq_codel_drop(sch);
 172         return prev_backlog - sch->qstats.backlog;
 173 }
 174
 175 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 176 {
 177         struct fq_codel_sched_data *q = qdisc_priv(sch);
 178         unsigned int idx;
 179         struct fq_codel_flow *flow;
 180         int uninitialized_var(ret);
 181
 182         idx = fq_codel_classify(skb, sch, &ret);
 183         if (idx == 0) {
 184                 if (ret & __NET_XMIT_BYPASS)
 185                         qdisc_qstats_drop(sch);
 186                 kfree_skb(skb);
 187                 return ret;
 188         }
 189         idx--;
 190
 191         codel_set_enqueue_time(skb);
 192         flow = &q->flows[idx];
 193         flow_queue_add(flow, skb);
 194         q->backlogs[idx] += qdisc_pkt_len(skb);
 195         qdisc_qstats_backlog_inc(sch, skb);
 196
 197         if (list_empty(&flow->flowchain)) {
 198                 list_add_tail(&flow->flowchain, &q->new_flows);
 199                 q->new_flow_count++;
 200                 flow->deficit = q->quantum;
 201                 flow->dropped = 0;
 202         }
 203         if (++sch->q.qlen <= sch->limit)
 204                 return NET_XMIT_SUCCESS;
 205
 206         q->drop_overlimit++;
 207         /* Return Congestion Notification only if we dropped a packet
 208          * from this flow.
 209          */
 210         if (fq_codel_drop(sch) == idx)
 211                 return NET_XMIT_CN;
 212
 213         /* As we dropped a packet, better let upper stack know this */
 214         qdisc_tree_decrease_qlen(sch, 1);
 215         return NET_XMIT_SUCCESS;
 216 }
 217
 218 /* This is the specific function called from codel_dequeue()
 219  * to dequeue a packet from queue. Note: backlog is handled in
 220  * codel, we dont need to reduce it here.
 221  */
 222 static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
 223 {
 224         struct fq_codel_sched_data *q = qdisc_priv(sch);
 225         struct fq_codel_flow *flow;
 226         struct sk_buff *skb = NULL;
 227
 228         flow = container_of(vars, struct fq_codel_flow, cvars);
 229         if (flow->head) {
 230                 skb = dequeue_head(flow);
 231                 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
 232                 sch->q.qlen--;
 233         }
 234         return skb;
 235 }
 236
 237 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
 238 {
 239         struct fq_codel_sched_data *q = qdisc_priv(sch);
 240         struct sk_buff *skb;
 241         struct fq_codel_flow *flow;
 242         struct list_head *head;
 243         u32 prev_drop_count, prev_ecn_mark;
 244
 245 begin:
 246         head = &q->new_flows;
 247         if (list_empty(head)) {
 248                 head = &q->old_flows;
 249                 if (list_empty(head))
 250                         return NULL;
 251         }
 252         flow = list_first_entry(head, struct fq_codel_flow, flowchain);
 253
 254         if (flow->deficit <= 0) {
 255                 flow->deficit += q->quantum;
 256                 list_move_tail(&flow->flowchain, &q->old_flows);
 257                 goto begin;
 258         }
 259
 260         prev_drop_count = q->cstats.drop_count;
 261         prev_ecn_mark = q->cstats.ecn_mark;
 262
 263         skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
 264                             dequeue);
 265
 266         flow->dropped += q->cstats.drop_count - prev_drop_count;
 267         flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
 268
 269         if (!skb) {
 270                 /* force a pass through old_flows to prevent starvation */
 271                 if ((head == &q->new_flows) && !list_empty(&q->old_flows))
 272                         list_move_tail(&flow->flowchain, &q->old_flows);
 273                 else
 274                         list_del_init(&flow->flowchain);
 275                 goto begin;
 276         }
 277         qdisc_bstats_update(sch, skb);
 278         flow->deficit -= qdisc_pkt_len(skb);
 279         /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
 280          * or HTB crashes. Defer it for next round.
 281          */
 282         if (q->cstats.drop_count && sch->q.qlen) {
 283                 qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 284                 q->cstats.drop_count = 0;
 285         }
 286         return skb;
 287 }
 288
 289 static void fq_codel_reset(struct Qdisc *sch)
 290 {
 291         struct sk_buff *skb;
 292
 293         while ((skb = fq_codel_dequeue(sch)) != NULL)
 294                 kfree_skb(skb);
 295 }
 296
 297 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
 298         [TCA_FQ_CODEL_TARGET]   = { .type = NLA_U32 },
 299         [TCA_FQ_CODEL_LIMIT]    = { .type = NLA_U32 },
 300         [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
 301         [TCA_FQ_CODEL_ECN]      = { .type = NLA_U32 },
 302         [TCA_FQ_CODEL_FLOWS]    = { .type = NLA_U32 },
 303         [TCA_FQ_CODEL_QUANTUM]  = { .type = NLA_U32 },
 304         [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 },
 305 };
 306
 307 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
 308 {
 309         struct fq_codel_sched_data *q = qdisc_priv(sch);
 310         struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
 311         int err;
 312
 313         if (!opt)
 314                 return -EINVAL;
 315
 316         err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
 317         if (err < 0)
 318                 return err;
 319         if (tb[TCA_FQ_CODEL_FLOWS]) {
 320                 if (q->flows)
 321                         return -EINVAL;
 322                 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
 323                 if (!q->flows_cnt ||
 324                     q->flows_cnt > 65536)
 325                         return -EINVAL;
 326         }
 327         sch_tree_lock(sch);
 328
 329         if (tb[TCA_FQ_CODEL_TARGET]) {
 330                 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
 331
 332                 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
 333         }
 334
 335         if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) {
 336                 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]);
 337
 338                 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT;
 339         }
 340
 341         if (tb[TCA_FQ_CODEL_INTERVAL]) {
 342                 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
 343
 344                 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
 345         }
 346
 347         if (tb[TCA_FQ_CODEL_LIMIT])
 348                 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
 349
 350         if (tb[TCA_FQ_CODEL_ECN])
 351                 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
 352
 353         if (tb[TCA_FQ_CODEL_QUANTUM])
 354                 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
 355
 356         while (sch->q.qlen > sch->limit) {
 357                 struct sk_buff *skb = fq_codel_dequeue(sch);
 358
 359                 kfree_skb(skb);
 360                 q->cstats.drop_count++;
 361         }
 362         qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 363         q->cstats.drop_count = 0;
 364
 365         sch_tree_unlock(sch);
 366         return 0;
 367 }
 368
 369 static void *fq_codel_zalloc(size_t sz)
 370 {
 371         void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
 372
 373         if (!ptr)
 374                 ptr = vzalloc(sz);
 375         return ptr;
 376 }
 377
 378 static void fq_codel_free(void *addr)
 379 {
 380         kvfree(addr);
 381 }
 382
 383 static void fq_codel_destroy(struct Qdisc *sch)
 384 {
 385         struct fq_codel_sched_data *q = qdisc_priv(sch);
 386
 387         tcf_destroy_chain(&q->filter_list);
 388         fq_codel_free(q->backlogs);
 389         fq_codel_free(q->flows);
 390 }
 391
 392 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
 393 {
 394         struct fq_codel_sched_data *q = qdisc_priv(sch);
 395         int i;
 396
 397         sch->limit = 10*1024;
 398         q->flows_cnt = 1024;
 399         q->quantum = psched_mtu(qdisc_dev(sch));
 400         q->perturbation = prandom_u32();
 401         INIT_LIST_HEAD(&q->new_flows);
 402         INIT_LIST_HEAD(&q->old_flows);
 403         codel_params_init(&q->cparams, sch);
 404         codel_stats_init(&q->cstats);
 405         q->cparams.ecn = true;
 406
 407         if (opt) {
 408                 int err = fq_codel_change(sch, opt);
 409                 if (err)
 410                         return err;
 411         }
 412
 413         if (!q->flows) {
 414                 q->flows = fq_codel_zalloc(q->flows_cnt *
 415                                            sizeof(struct fq_codel_flow));
 416                 if (!q->flows)
 417                         return -ENOMEM;
 418                 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
 419                 if (!q->backlogs) {
 420                         fq_codel_free(q->flows);
 421                         return -ENOMEM;
 422                 }
 423                 for (i = 0; i < q->flows_cnt; i++) {
 424                         struct fq_codel_flow *flow = q->flows + i;
 425
 426                         INIT_LIST_HEAD(&flow->flowchain);
 427                         codel_vars_init(&flow->cvars);
 428                 }
 429         }
 430         if (sch->limit >= 1)
 431                 sch->flags |= TCQ_F_CAN_BYPASS;
 432         else
 433                 sch->flags &= ~TCQ_F_CAN_BYPASS;
 434         return 0;
 435 }
 436
 437 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
 438 {
 439         struct fq_codel_sched_data *q = qdisc_priv(sch);
 440         struct nlattr *opts;
 441
 442         opts = nla_nest_start(skb, TCA_OPTIONS);
 443         if (opts == NULL)
 444                 goto nla_put_failure;
 445
 446         if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
 447                         codel_time_to_us(q->cparams.target)) ||
 448             nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
 449                         sch->limit) ||
 450             nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
 451                         codel_time_to_us(q->cparams.interval)) ||
 452             nla_put_u32(skb, TCA_FQ_CODEL_ECN,
 453                         q->cparams.ecn) ||
 454             nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
 455                         q->quantum) ||
 456             nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
 457                         q->flows_cnt))
 458                 goto nla_put_failure;
 459
 460         if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD &&
 461             nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD,
 462                         codel_time_to_us(q->cparams.ce_threshold)))
 463                 goto nla_put_failure;
 464
 465         return nla_nest_end(skb, opts);
 466
 467 nla_put_failure:
 468         return -1;
 469 }
 470
 471 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 472 {
 473         struct fq_codel_sched_data *q = qdisc_priv(sch);
 474         struct tc_fq_codel_xstats st = {
 475                 .type                           = TCA_FQ_CODEL_XSTATS_QDISC,
 476         };
 477         struct list_head *pos;
 478
 479         st.qdisc_stats.maxpacket = q->cstats.maxpacket;
 480         st.qdisc_stats.drop_overlimit = q->drop_overlimit;
 481         st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
 482         st.qdisc_stats.new_flow_count = q->new_flow_count;
 483         st.qdisc_stats.ce_mark = q->cstats.ce_mark;
 484
 485         list_for_each(pos, &q->new_flows)
 486                 st.qdisc_stats.new_flows_len++;
 487
 488         list_for_each(pos, &q->old_flows)
 489                 st.qdisc_stats.old_flows_len++;
 490
 491         return gnet_stats_copy_app(d, &st, sizeof(st));
 492 }
 493
 494 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
 495 {
 496         return NULL;
 497 }
 498
 499 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
 500 {
 501         return 0;
 502 }
 503
 504 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
 505                               u32 classid)
 506 {
 507         /* we cannot bypass queue discipline anymore */
 508         sch->flags &= ~TCQ_F_CAN_BYPASS;
 509         return 0;
 510 }
 511
 512 static void fq_codel_put(struct Qdisc *q, unsigned long cl)
 513 {
 514 }
 515
 516 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch,
 517                                                   unsigned long cl)
 518 {
 519         struct fq_codel_sched_data *q = qdisc_priv(sch);
 520
 521         if (cl)
 522                 return NULL;
 523         return &q->filter_list;
 524 }
 525
 526 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
 527                           struct sk_buff *skb, struct tcmsg *tcm)
 528 {
 529         tcm->tcm_handle |= TC_H_MIN(cl);
 530         return 0;
 531 }
 532
 533 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 534                                      struct gnet_dump *d)
 535 {
 536         struct fq_codel_sched_data *q = qdisc_priv(sch);
 537         u32 idx = cl - 1;
 538         struct gnet_stats_queue qs = { 0 };
 539         struct tc_fq_codel_xstats xstats;
 540
 541         if (idx < q->flows_cnt) {
 542                 const struct fq_codel_flow *flow = &q->flows[idx];
 543                 const struct sk_buff *skb = flow->head;
 544
 545                 memset(&xstats, 0, sizeof(xstats));
 546                 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
 547                 xstats.class_stats.deficit = flow->deficit;
 548                 xstats.class_stats.ldelay =
 549                         codel_time_to_us(flow->cvars.ldelay);
 550                 xstats.class_stats.count = flow->cvars.count;
 551                 xstats.class_stats.lastcount = flow->cvars.lastcount;
 552                 xstats.class_stats.dropping = flow->cvars.dropping;
 553                 if (flow->cvars.dropping) {
 554                         codel_tdiff_t delta = flow->cvars.drop_next -
 555                                               codel_get_time();
 556
 557                         xstats.class_stats.drop_next = (delta >= 0) ?
 558                                 codel_time_to_us(delta) :
 559                                 -codel_time_to_us(-delta);
 560                 }
 561                 while (skb) {
 562                         qs.qlen++;
 563                         skb = skb->next;
 564                 }
 565                 qs.backlog = q->backlogs[idx];
 566                 qs.drops = flow->dropped;
 567         }
 568         if (gnet_stats_copy_queue(d, NULL, &qs, 0) < 0)
 569                 return -1;
 570         if (idx < q->flows_cnt)
 571                 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
 572         return 0;
 573 }
 574
 575 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 576 {
 577         struct fq_codel_sched_data *q = qdisc_priv(sch);
 578         unsigned int i;
 579
 580         if (arg->stop)
 581                 return;
 582
 583         for (i = 0; i < q->flows_cnt; i++) {
 584                 if (list_empty(&q->flows[i].flowchain) ||
 585                     arg->count < arg->skip) {
 586                         arg->count++;
 587                         continue;
 588                 }
 589                 if (arg->fn(sch, i + 1, arg) < 0) {
 590                         arg->stop = 1;
 591                         break;
 592                 }
 593                 arg->count++;
 594         }
 595 }
 596
 597 static const struct Qdisc_class_ops fq_codel_class_ops = {
 598         .leaf           =       fq_codel_leaf,
 599         .get            =       fq_codel_get,
 600         .put            =       fq_codel_put,
 601         .tcf_chain      =       fq_codel_find_tcf,
 602         .bind_tcf       =       fq_codel_bind,
 603         .unbind_tcf     =       fq_codel_put,
 604         .dump           =       fq_codel_dump_class,
 605         .dump_stats     =       fq_codel_dump_class_stats,
 606         .walk           =       fq_codel_walk,
 607 };
 608
 609 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
 610         .cl_ops         =       &fq_codel_class_ops,
 611         .id             =       "fq_codel",
 612         .priv_size      =       sizeof(struct fq_codel_sched_data),
 613         .enqueue        =       fq_codel_enqueue,
 614         .dequeue        =       fq_codel_dequeue,
 615         .peek           =       qdisc_peek_dequeued,
 616         .drop           =       fq_codel_qdisc_drop,
 617         .init           =       fq_codel_init,
 618         .reset          =       fq_codel_reset,
 619         .destroy        =       fq_codel_destroy,
 620         .change         =       fq_codel_change,
 621         .dump           =       fq_codel_dump,
 622         .dump_stats =   fq_codel_dump_stats,
 623         .owner          =       THIS_MODULE,
 624 };
 625
 626 static int __init fq_codel_module_init(void)
 627 {
 628         return register_qdisc(&fq_codel_qdisc_ops);
 629 }
 630
 631 static void __exit fq_codel_module_exit(void)
 632 {
 633         unregister_qdisc(&fq_codel_qdisc_ops);
 634 }
 635
 636 module_init(fq_codel_module_init)
 637 module_exit(fq_codel_module_exit)
 638 MODULE_AUTHOR("Eric Dumazet");
 639 MODULE_LICENSE("GPL");