kernel/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, false);
  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 fq_codel_sched_data *q = qdisc_priv(sch);
 292         int i;
 293
 294         INIT_LIST_HEAD(&q->new_flows);
 295         INIT_LIST_HEAD(&q->old_flows);
 296         for (i = 0; i < q->flows_cnt; i++) {
 297                 struct fq_codel_flow *flow = q->flows + i;
 298
 299                 while (flow->head) {
 300                         struct sk_buff *skb = dequeue_head(flow);
 301
 302                         qdisc_qstats_backlog_dec(sch, skb);
 303                         kfree_skb(skb);
 304                 }
 305
 306                 INIT_LIST_HEAD(&flow->flowchain);
 307                 codel_vars_init(&flow->cvars);
 308         }
 309         memset(q->backlogs, 0, q->flows_cnt * sizeof(u32));
 310         sch->q.qlen = 0;
 311 }
 312
 313 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
 314         [TCA_FQ_CODEL_TARGET]   = { .type = NLA_U32 },
 315         [TCA_FQ_CODEL_LIMIT]    = { .type = NLA_U32 },
 316         [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
 317         [TCA_FQ_CODEL_ECN]      = { .type = NLA_U32 },
 318         [TCA_FQ_CODEL_FLOWS]    = { .type = NLA_U32 },
 319         [TCA_FQ_CODEL_QUANTUM]  = { .type = NLA_U32 },
 320         [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 },
 321 };
 322
 323 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
 324 {
 325         struct fq_codel_sched_data *q = qdisc_priv(sch);
 326         struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
 327         int err;
 328
 329         if (!opt)
 330                 return -EINVAL;
 331
 332         err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
 333         if (err < 0)
 334                 return err;
 335         if (tb[TCA_FQ_CODEL_FLOWS]) {
 336                 if (q->flows)
 337                         return -EINVAL;
 338                 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
 339                 if (!q->flows_cnt ||
 340                     q->flows_cnt > 65536)
 341                         return -EINVAL;
 342         }
 343         sch_tree_lock(sch);
 344
 345         if (tb[TCA_FQ_CODEL_TARGET]) {
 346                 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
 347
 348                 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
 349         }
 350
 351         if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) {
 352                 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]);
 353
 354                 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT;
 355         }
 356
 357         if (tb[TCA_FQ_CODEL_INTERVAL]) {
 358                 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
 359
 360                 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
 361         }
 362
 363         if (tb[TCA_FQ_CODEL_LIMIT])
 364                 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
 365
 366         if (tb[TCA_FQ_CODEL_ECN])
 367                 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
 368
 369         if (tb[TCA_FQ_CODEL_QUANTUM])
 370                 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
 371
 372         while (sch->q.qlen > sch->limit) {
 373                 struct sk_buff *skb = fq_codel_dequeue(sch);
 374
 375                 kfree_skb(skb);
 376                 q->cstats.drop_count++;
 377         }
 378         qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 379         q->cstats.drop_count = 0;
 380
 381         sch_tree_unlock(sch);
 382         return 0;
 383 }
 384
 385 static void *fq_codel_zalloc(size_t sz)
 386 {
 387         void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
 388
 389         if (!ptr)
 390                 ptr = vzalloc(sz);
 391         return ptr;
 392 }
 393
 394 static void fq_codel_free(void *addr)
 395 {
 396         kvfree(addr);
 397 }
 398
 399 static void fq_codel_destroy(struct Qdisc *sch)
 400 {
 401         struct fq_codel_sched_data *q = qdisc_priv(sch);
 402
 403         tcf_destroy_chain(&q->filter_list);
 404         fq_codel_free(q->backlogs);
 405         fq_codel_free(q->flows);
 406 }
 407
 408 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
 409 {
 410         struct fq_codel_sched_data *q = qdisc_priv(sch);
 411         int i;
 412
 413         sch->limit = 10*1024;
 414         q->flows_cnt = 1024;
 415         q->quantum = psched_mtu(qdisc_dev(sch));
 416         q->perturbation = prandom_u32();
 417         INIT_LIST_HEAD(&q->new_flows);
 418         INIT_LIST_HEAD(&q->old_flows);
 419         codel_params_init(&q->cparams, sch);
 420         codel_stats_init(&q->cstats);
 421         q->cparams.ecn = true;
 422
 423         if (opt) {
 424                 int err = fq_codel_change(sch, opt);
 425                 if (err)
 426                         return err;
 427         }
 428
 429         if (!q->flows) {
 430                 q->flows = fq_codel_zalloc(q->flows_cnt *
 431                                            sizeof(struct fq_codel_flow));
 432                 if (!q->flows)
 433                         return -ENOMEM;
 434                 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
 435                 if (!q->backlogs) {
 436                         fq_codel_free(q->flows);
 437                         return -ENOMEM;
 438                 }
 439                 for (i = 0; i < q->flows_cnt; i++) {
 440                         struct fq_codel_flow *flow = q->flows + i;
 441
 442                         INIT_LIST_HEAD(&flow->flowchain);
 443                         codel_vars_init(&flow->cvars);
 444                 }
 445         }
 446         if (sch->limit >= 1)
 447                 sch->flags |= TCQ_F_CAN_BYPASS;
 448         else
 449                 sch->flags &= ~TCQ_F_CAN_BYPASS;
 450         return 0;
 451 }
 452
 453 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
 454 {
 455         struct fq_codel_sched_data *q = qdisc_priv(sch);
 456         struct nlattr *opts;
 457
 458         opts = nla_nest_start(skb, TCA_OPTIONS);
 459         if (opts == NULL)
 460                 goto nla_put_failure;
 461
 462         if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
 463                         codel_time_to_us(q->cparams.target)) ||
 464             nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
 465                         sch->limit) ||
 466             nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
 467                         codel_time_to_us(q->cparams.interval)) ||
 468             nla_put_u32(skb, TCA_FQ_CODEL_ECN,
 469                         q->cparams.ecn) ||
 470             nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
 471                         q->quantum) ||
 472             nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
 473                         q->flows_cnt))
 474                 goto nla_put_failure;
 475
 476         if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD &&
 477             nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD,
 478                         codel_time_to_us(q->cparams.ce_threshold)))
 479                 goto nla_put_failure;
 480
 481         return nla_nest_end(skb, opts);
 482
 483 nla_put_failure:
 484         return -1;
 485 }
 486
 487 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
 488 {
 489         struct fq_codel_sched_data *q = qdisc_priv(sch);
 490         struct tc_fq_codel_xstats st = {
 491                 .type                           = TCA_FQ_CODEL_XSTATS_QDISC,
 492         };
 493         struct list_head *pos;
 494
 495         st.qdisc_stats.maxpacket = q->cstats.maxpacket;
 496         st.qdisc_stats.drop_overlimit = q->drop_overlimit;
 497         st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
 498         st.qdisc_stats.new_flow_count = q->new_flow_count;
 499         st.qdisc_stats.ce_mark = q->cstats.ce_mark;
 500
 501         list_for_each(pos, &q->new_flows)
 502                 st.qdisc_stats.new_flows_len++;
 503
 504         list_for_each(pos, &q->old_flows)
 505                 st.qdisc_stats.old_flows_len++;
 506
 507         return gnet_stats_copy_app(d, &st, sizeof(st));
 508 }
 509
 510 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
 511 {
 512         return NULL;
 513 }
 514
 515 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
 516 {
 517         return 0;
 518 }
 519
 520 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
 521                               u32 classid)
 522 {
 523         /* we cannot bypass queue discipline anymore */
 524         sch->flags &= ~TCQ_F_CAN_BYPASS;
 525         return 0;
 526 }
 527
 528 static void fq_codel_put(struct Qdisc *q, unsigned long cl)
 529 {
 530 }
 531
 532 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch,
 533                                                   unsigned long cl)
 534 {
 535         struct fq_codel_sched_data *q = qdisc_priv(sch);
 536
 537         if (cl)
 538                 return NULL;
 539         return &q->filter_list;
 540 }
 541
 542 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
 543                           struct sk_buff *skb, struct tcmsg *tcm)
 544 {
 545         tcm->tcm_handle |= TC_H_MIN(cl);
 546         return 0;
 547 }
 548
 549 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 550                                      struct gnet_dump *d)
 551 {
 552         struct fq_codel_sched_data *q = qdisc_priv(sch);
 553         u32 idx = cl - 1;
 554         struct gnet_stats_queue qs = { 0 };
 555         struct tc_fq_codel_xstats xstats;
 556
 557         if (idx < q->flows_cnt) {
 558                 const struct fq_codel_flow *flow = &q->flows[idx];
 559                 const struct sk_buff *skb = flow->head;
 560
 561                 memset(&xstats, 0, sizeof(xstats));
 562                 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
 563                 xstats.class_stats.deficit = flow->deficit;
 564                 xstats.class_stats.ldelay =
 565                         codel_time_to_us(flow->cvars.ldelay);
 566                 xstats.class_stats.count = flow->cvars.count;
 567                 xstats.class_stats.lastcount = flow->cvars.lastcount;
 568                 xstats.class_stats.dropping = flow->cvars.dropping;
 569                 if (flow->cvars.dropping) {
 570                         codel_tdiff_t delta = flow->cvars.drop_next -
 571                                               codel_get_time();
 572
 573                         xstats.class_stats.drop_next = (delta >= 0) ?
 574                                 codel_time_to_us(delta) :
 575                                 -codel_time_to_us(-delta);
 576                 }
 577                 while (skb) {
 578                         qs.qlen++;
 579                         skb = skb->next;
 580                 }
 581                 qs.backlog = q->backlogs[idx];
 582                 qs.drops = flow->dropped;
 583         }
 584         if (gnet_stats_copy_queue(d, NULL, &qs, 0) < 0)
 585                 return -1;
 586         if (idx < q->flows_cnt)
 587                 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
 588         return 0;
 589 }
 590
 591 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
 592 {
 593         struct fq_codel_sched_data *q = qdisc_priv(sch);
 594         unsigned int i;
 595
 596         if (arg->stop)
 597                 return;
 598
 599         for (i = 0; i < q->flows_cnt; i++) {
 600                 if (list_empty(&q->flows[i].flowchain) ||
 601                     arg->count < arg->skip) {
 602                         arg->count++;
 603                         continue;
 604                 }
 605                 if (arg->fn(sch, i + 1, arg) < 0) {
 606                         arg->stop = 1;
 607                         break;
 608                 }
 609                 arg->count++;
 610         }
 611 }
 612
 613 static const struct Qdisc_class_ops fq_codel_class_ops = {
 614         .leaf           =       fq_codel_leaf,
 615         .get            =       fq_codel_get,
 616         .put            =       fq_codel_put,
 617         .tcf_chain      =       fq_codel_find_tcf,
 618         .bind_tcf       =       fq_codel_bind,
 619         .unbind_tcf     =       fq_codel_put,
 620         .dump           =       fq_codel_dump_class,
 621         .dump_stats     =       fq_codel_dump_class_stats,
 622         .walk           =       fq_codel_walk,
 623 };
 624
 625 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
 626         .cl_ops         =       &fq_codel_class_ops,
 627         .id             =       "fq_codel",
 628         .priv_size      =       sizeof(struct fq_codel_sched_data),
 629         .enqueue        =       fq_codel_enqueue,
 630         .dequeue        =       fq_codel_dequeue,
 631         .peek           =       qdisc_peek_dequeued,
 632         .drop           =       fq_codel_qdisc_drop,
 633         .init           =       fq_codel_init,
 634         .reset          =       fq_codel_reset,
 635         .destroy        =       fq_codel_destroy,
 636         .change         =       fq_codel_change,
 637         .dump           =       fq_codel_dump,
 638         .dump_stats =   fq_codel_dump_stats,
 639         .owner          =       THIS_MODULE,
 640 };
 641
 642 static int __init fq_codel_module_init(void)
 643 {
 644         return register_qdisc(&fq_codel_qdisc_ops);
 645 }
 646
 647 static void __exit fq_codel_module_exit(void)
 648 {
 649         unregister_qdisc(&fq_codel_qdisc_ops);
 650 }
 651
 652 module_init(fq_codel_module_init)
 653 module_exit(fq_codel_module_exit)
 654 MODULE_AUTHOR("Eric Dumazet");
 655 MODULE_LICENSE("GPL");