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 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/flow_keys.h>
27 #include <net/codel.h>
28
29 /* Fair Queue CoDel.
30 *
31 * Principles :
32 * Packets are classified (internal classifier or external) on flows.
33 * This is a Stochastic model (as we use a hash, several flows
34 * might be hashed on same slot)
35 * Each flow has a CoDel managed queue.
36 * Flows are linked onto two (Round Robin) lists,
37 * so that new flows have priority on old ones.
38 *
39 * For a given flow, packets are not reordered (CoDel uses a FIFO)
40 * head drops only.
41 * ECN capability is on by default.
42 * Low memory footprint (64 bytes per flow)
43 */
44
45 struct fq_codel_flow {
46 struct sk_buff *head;
47 struct sk_buff *tail;
48 struct list_head flowchain;
49 int deficit;
50 u32 dropped; /* number of drops (or ECN marks) on this flow */
51 struct codel_vars cvars;
52 }; /* please try to keep this structure <= 64 bytes */
53
54 struct fq_codel_sched_data {
55 struct tcf_proto __rcu *filter_list; /* optional external classifier */
56 struct fq_codel_flow *flows; /* Flows table [flows_cnt] */
57 u32 *backlogs; /* backlog table [flows_cnt] */
58 u32 flows_cnt; /* number of flows */
59 u32 perturbation; /* hash perturbation */
60 u32 quantum; /* psched_mtu(qdisc_dev(sch)); */
61 struct codel_params cparams;
62 struct codel_stats cstats;
63 u32 drop_overlimit;
64 u32 new_flow_count;
65
66 struct list_head new_flows; /* list of new flows */
67 struct list_head old_flows; /* list of old flows */
68 };
69
fq_codel_hash(const struct fq_codel_sched_data * q,const struct sk_buff * skb)70 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q,
71 const struct sk_buff *skb)
72 {
73 struct flow_keys keys;
74 unsigned int hash;
75
76 skb_flow_dissect(skb, &keys);
77 hash = jhash_3words((__force u32)keys.dst,
78 (__force u32)keys.src ^ keys.ip_proto,
79 (__force u32)keys.ports, q->perturbation);
80
81 return reciprocal_scale(hash, q->flows_cnt);
82 }
83
fq_codel_classify(struct sk_buff * skb,struct Qdisc * sch,int * qerr)84 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch,
85 int *qerr)
86 {
87 struct fq_codel_sched_data *q = qdisc_priv(sch);
88 struct tcf_proto *filter;
89 struct tcf_result res;
90 int result;
91
92 if (TC_H_MAJ(skb->priority) == sch->handle &&
93 TC_H_MIN(skb->priority) > 0 &&
94 TC_H_MIN(skb->priority) <= q->flows_cnt)
95 return TC_H_MIN(skb->priority);
96
97 filter = rcu_dereference_bh(q->filter_list);
98 if (!filter)
99 return fq_codel_hash(q, skb) + 1;
100
101 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
102 result = tc_classify(skb, filter, &res);
103 if (result >= 0) {
104 #ifdef CONFIG_NET_CLS_ACT
105 switch (result) {
106 case TC_ACT_STOLEN:
107 case TC_ACT_QUEUED:
108 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
109 case TC_ACT_SHOT:
110 return 0;
111 }
112 #endif
113 if (TC_H_MIN(res.classid) <= q->flows_cnt)
114 return TC_H_MIN(res.classid);
115 }
116 return 0;
117 }
118
119 /* helper functions : might be changed when/if skb use a standard list_head */
120
121 /* remove one skb from head of slot queue */
dequeue_head(struct fq_codel_flow * flow)122 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow)
123 {
124 struct sk_buff *skb = flow->head;
125
126 flow->head = skb->next;
127 skb->next = NULL;
128 return skb;
129 }
130
131 /* add skb to flow queue (tail add) */
flow_queue_add(struct fq_codel_flow * flow,struct sk_buff * skb)132 static inline void flow_queue_add(struct fq_codel_flow *flow,
133 struct sk_buff *skb)
134 {
135 if (flow->head == NULL)
136 flow->head = skb;
137 else
138 flow->tail->next = skb;
139 flow->tail = skb;
140 skb->next = NULL;
141 }
142
fq_codel_drop(struct Qdisc * sch)143 static unsigned int fq_codel_drop(struct Qdisc *sch)
144 {
145 struct fq_codel_sched_data *q = qdisc_priv(sch);
146 struct sk_buff *skb;
147 unsigned int maxbacklog = 0, idx = 0, i, len;
148 struct fq_codel_flow *flow;
149
150 /* Queue is full! Find the fat flow and drop packet from it.
151 * This might sound expensive, but with 1024 flows, we scan
152 * 4KB of memory, and we dont need to handle a complex tree
153 * in fast path (packet queue/enqueue) with many cache misses.
154 */
155 for (i = 0; i < q->flows_cnt; i++) {
156 if (q->backlogs[i] > maxbacklog) {
157 maxbacklog = q->backlogs[i];
158 idx = i;
159 }
160 }
161 flow = &q->flows[idx];
162 skb = dequeue_head(flow);
163 len = qdisc_pkt_len(skb);
164 q->backlogs[idx] -= len;
165 kfree_skb(skb);
166 sch->q.qlen--;
167 qdisc_qstats_drop(sch);
168 qdisc_qstats_backlog_dec(sch, skb);
169 flow->dropped++;
170 return idx;
171 }
172
fq_codel_enqueue(struct sk_buff * skb,struct Qdisc * sch)173 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
174 {
175 struct fq_codel_sched_data *q = qdisc_priv(sch);
176 unsigned int idx, prev_backlog;
177 struct fq_codel_flow *flow;
178 int uninitialized_var(ret);
179
180 idx = fq_codel_classify(skb, sch, &ret);
181 if (idx == 0) {
182 if (ret & __NET_XMIT_BYPASS)
183 qdisc_qstats_drop(sch);
184 kfree_skb(skb);
185 return ret;
186 }
187 idx--;
188
189 codel_set_enqueue_time(skb);
190 flow = &q->flows[idx];
191 flow_queue_add(flow, skb);
192 q->backlogs[idx] += qdisc_pkt_len(skb);
193 qdisc_qstats_backlog_inc(sch, skb);
194
195 if (list_empty(&flow->flowchain)) {
196 list_add_tail(&flow->flowchain, &q->new_flows);
197 q->new_flow_count++;
198 flow->deficit = q->quantum;
199 flow->dropped = 0;
200 }
201 if (++sch->q.qlen <= sch->limit)
202 return NET_XMIT_SUCCESS;
203
204 prev_backlog = sch->qstats.backlog;
205 q->drop_overlimit++;
206 /* Return Congestion Notification only if we dropped a packet
207 * from this flow.
208 */
209 if (fq_codel_drop(sch) == idx)
210 return NET_XMIT_CN;
211
212 /* As we dropped a packet, better let upper stack know this */
213 qdisc_tree_reduce_backlog(sch, 1, prev_backlog - sch->qstats.backlog);
214 return NET_XMIT_SUCCESS;
215 }
216
217 /* This is the specific function called from codel_dequeue()
218 * to dequeue a packet from queue. Note: backlog is handled in
219 * codel, we dont need to reduce it here.
220 */
dequeue(struct codel_vars * vars,struct Qdisc * sch)221 static struct sk_buff *dequeue(struct codel_vars *vars, struct Qdisc *sch)
222 {
223 struct fq_codel_sched_data *q = qdisc_priv(sch);
224 struct fq_codel_flow *flow;
225 struct sk_buff *skb = NULL;
226
227 flow = container_of(vars, struct fq_codel_flow, cvars);
228 if (flow->head) {
229 skb = dequeue_head(flow);
230 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb);
231 sch->q.qlen--;
232 }
233 return skb;
234 }
235
fq_codel_dequeue(struct Qdisc * sch)236 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch)
237 {
238 struct fq_codel_sched_data *q = qdisc_priv(sch);
239 struct sk_buff *skb;
240 struct fq_codel_flow *flow;
241 struct list_head *head;
242 u32 prev_drop_count, prev_ecn_mark;
243 unsigned int prev_backlog;
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 prev_backlog = sch->qstats.backlog;
263
264 skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
265 dequeue);
266
267 flow->dropped += q->cstats.drop_count - prev_drop_count;
268 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark;
269
270 if (!skb) {
271 /* force a pass through old_flows to prevent starvation */
272 if ((head == &q->new_flows) && !list_empty(&q->old_flows))
273 list_move_tail(&flow->flowchain, &q->old_flows);
274 else
275 list_del_init(&flow->flowchain);
276 goto begin;
277 }
278 qdisc_bstats_update(sch, skb);
279 flow->deficit -= qdisc_pkt_len(skb);
280 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
281 * or HTB crashes. Defer it for next round.
282 */
283 if (q->cstats.drop_count && sch->q.qlen) {
284 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
285 q->cstats.drop_len);
286 q->cstats.drop_count = 0;
287 q->cstats.drop_len = 0;
288 }
289 return skb;
290 }
291
fq_codel_reset(struct Qdisc * sch)292 static void fq_codel_reset(struct Qdisc *sch)
293 {
294 struct sk_buff *skb;
295
296 while ((skb = fq_codel_dequeue(sch)) != NULL)
297 kfree_skb(skb);
298 }
299
300 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = {
301 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 },
302 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 },
303 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 },
304 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 },
305 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 },
306 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 },
307 };
308
fq_codel_change(struct Qdisc * sch,struct nlattr * opt)309 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt)
310 {
311 struct fq_codel_sched_data *q = qdisc_priv(sch);
312 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1];
313 int err;
314
315 if (!opt)
316 return -EINVAL;
317
318 err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy);
319 if (err < 0)
320 return err;
321 if (tb[TCA_FQ_CODEL_FLOWS]) {
322 if (q->flows)
323 return -EINVAL;
324 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]);
325 if (!q->flows_cnt ||
326 q->flows_cnt > 65536)
327 return -EINVAL;
328 }
329 sch_tree_lock(sch);
330
331 if (tb[TCA_FQ_CODEL_TARGET]) {
332 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]);
333
334 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT;
335 }
336
337 if (tb[TCA_FQ_CODEL_INTERVAL]) {
338 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]);
339
340 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT;
341 }
342
343 if (tb[TCA_FQ_CODEL_LIMIT])
344 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]);
345
346 if (tb[TCA_FQ_CODEL_ECN])
347 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]);
348
349 if (tb[TCA_FQ_CODEL_QUANTUM])
350 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM]));
351
352 while (sch->q.qlen > sch->limit) {
353 struct sk_buff *skb = fq_codel_dequeue(sch);
354
355 q->cstats.drop_len += qdisc_pkt_len(skb);
356 kfree_skb(skb);
357 q->cstats.drop_count++;
358 }
359 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len);
360 q->cstats.drop_count = 0;
361 q->cstats.drop_len = 0;
362
363 sch_tree_unlock(sch);
364 return 0;
365 }
366
fq_codel_zalloc(size_t sz)367 static void *fq_codel_zalloc(size_t sz)
368 {
369 void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN);
370
371 if (!ptr)
372 ptr = vzalloc(sz);
373 return ptr;
374 }
375
fq_codel_free(void * addr)376 static void fq_codel_free(void *addr)
377 {
378 kvfree(addr);
379 }
380
fq_codel_destroy(struct Qdisc * sch)381 static void fq_codel_destroy(struct Qdisc *sch)
382 {
383 struct fq_codel_sched_data *q = qdisc_priv(sch);
384
385 tcf_destroy_chain(&q->filter_list);
386 fq_codel_free(q->backlogs);
387 fq_codel_free(q->flows);
388 }
389
fq_codel_init(struct Qdisc * sch,struct nlattr * opt)390 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt)
391 {
392 struct fq_codel_sched_data *q = qdisc_priv(sch);
393 int i;
394
395 sch->limit = 10*1024;
396 q->flows_cnt = 1024;
397 q->quantum = psched_mtu(qdisc_dev(sch));
398 q->perturbation = prandom_u32();
399 INIT_LIST_HEAD(&q->new_flows);
400 INIT_LIST_HEAD(&q->old_flows);
401 codel_params_init(&q->cparams);
402 codel_stats_init(&q->cstats);
403 q->cparams.ecn = true;
404
405 if (opt) {
406 int err = fq_codel_change(sch, opt);
407 if (err)
408 return err;
409 }
410
411 if (!q->flows) {
412 q->flows = fq_codel_zalloc(q->flows_cnt *
413 sizeof(struct fq_codel_flow));
414 if (!q->flows)
415 return -ENOMEM;
416 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32));
417 if (!q->backlogs) {
418 fq_codel_free(q->flows);
419 return -ENOMEM;
420 }
421 for (i = 0; i < q->flows_cnt; i++) {
422 struct fq_codel_flow *flow = q->flows + i;
423
424 INIT_LIST_HEAD(&flow->flowchain);
425 codel_vars_init(&flow->cvars);
426 }
427 }
428 if (sch->limit >= 1)
429 sch->flags |= TCQ_F_CAN_BYPASS;
430 else
431 sch->flags &= ~TCQ_F_CAN_BYPASS;
432 return 0;
433 }
434
fq_codel_dump(struct Qdisc * sch,struct sk_buff * skb)435 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb)
436 {
437 struct fq_codel_sched_data *q = qdisc_priv(sch);
438 struct nlattr *opts;
439
440 opts = nla_nest_start(skb, TCA_OPTIONS);
441 if (opts == NULL)
442 goto nla_put_failure;
443
444 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET,
445 codel_time_to_us(q->cparams.target)) ||
446 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT,
447 sch->limit) ||
448 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL,
449 codel_time_to_us(q->cparams.interval)) ||
450 nla_put_u32(skb, TCA_FQ_CODEL_ECN,
451 q->cparams.ecn) ||
452 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM,
453 q->quantum) ||
454 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS,
455 q->flows_cnt))
456 goto nla_put_failure;
457
458 return nla_nest_end(skb, opts);
459
460 nla_put_failure:
461 return -1;
462 }
463
fq_codel_dump_stats(struct Qdisc * sch,struct gnet_dump * d)464 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
465 {
466 struct fq_codel_sched_data *q = qdisc_priv(sch);
467 struct tc_fq_codel_xstats st = {
468 .type = TCA_FQ_CODEL_XSTATS_QDISC,
469 };
470 struct list_head *pos;
471
472 st.qdisc_stats.maxpacket = q->cstats.maxpacket;
473 st.qdisc_stats.drop_overlimit = q->drop_overlimit;
474 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark;
475 st.qdisc_stats.new_flow_count = q->new_flow_count;
476
477 list_for_each(pos, &q->new_flows)
478 st.qdisc_stats.new_flows_len++;
479
480 list_for_each(pos, &q->old_flows)
481 st.qdisc_stats.old_flows_len++;
482
483 return gnet_stats_copy_app(d, &st, sizeof(st));
484 }
485
fq_codel_leaf(struct Qdisc * sch,unsigned long arg)486 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg)
487 {
488 return NULL;
489 }
490
fq_codel_get(struct Qdisc * sch,u32 classid)491 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid)
492 {
493 return 0;
494 }
495
fq_codel_bind(struct Qdisc * sch,unsigned long parent,u32 classid)496 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent,
497 u32 classid)
498 {
499 /* we cannot bypass queue discipline anymore */
500 sch->flags &= ~TCQ_F_CAN_BYPASS;
501 return 0;
502 }
503
fq_codel_put(struct Qdisc * q,unsigned long cl)504 static void fq_codel_put(struct Qdisc *q, unsigned long cl)
505 {
506 }
507
fq_codel_find_tcf(struct Qdisc * sch,unsigned long cl)508 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch,
509 unsigned long cl)
510 {
511 struct fq_codel_sched_data *q = qdisc_priv(sch);
512
513 if (cl)
514 return NULL;
515 return &q->filter_list;
516 }
517
fq_codel_dump_class(struct Qdisc * sch,unsigned long cl,struct sk_buff * skb,struct tcmsg * tcm)518 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl,
519 struct sk_buff *skb, struct tcmsg *tcm)
520 {
521 tcm->tcm_handle |= TC_H_MIN(cl);
522 return 0;
523 }
524
fq_codel_dump_class_stats(struct Qdisc * sch,unsigned long cl,struct gnet_dump * d)525 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl,
526 struct gnet_dump *d)
527 {
528 struct fq_codel_sched_data *q = qdisc_priv(sch);
529 u32 idx = cl - 1;
530 struct gnet_stats_queue qs = { 0 };
531 struct tc_fq_codel_xstats xstats;
532
533 if (idx < q->flows_cnt) {
534 const struct fq_codel_flow *flow = &q->flows[idx];
535 const struct sk_buff *skb = flow->head;
536
537 memset(&xstats, 0, sizeof(xstats));
538 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS;
539 xstats.class_stats.deficit = flow->deficit;
540 xstats.class_stats.ldelay =
541 codel_time_to_us(flow->cvars.ldelay);
542 xstats.class_stats.count = flow->cvars.count;
543 xstats.class_stats.lastcount = flow->cvars.lastcount;
544 xstats.class_stats.dropping = flow->cvars.dropping;
545 if (flow->cvars.dropping) {
546 codel_tdiff_t delta = flow->cvars.drop_next -
547 codel_get_time();
548
549 xstats.class_stats.drop_next = (delta >= 0) ?
550 codel_time_to_us(delta) :
551 -codel_time_to_us(-delta);
552 }
553 while (skb) {
554 qs.qlen++;
555 skb = skb->next;
556 }
557 qs.backlog = q->backlogs[idx];
558 qs.drops = flow->dropped;
559 }
560 if (gnet_stats_copy_queue(d, NULL, &qs, 0) < 0)
561 return -1;
562 if (idx < q->flows_cnt)
563 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
564 return 0;
565 }
566
fq_codel_walk(struct Qdisc * sch,struct qdisc_walker * arg)567 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg)
568 {
569 struct fq_codel_sched_data *q = qdisc_priv(sch);
570 unsigned int i;
571
572 if (arg->stop)
573 return;
574
575 for (i = 0; i < q->flows_cnt; i++) {
576 if (list_empty(&q->flows[i].flowchain) ||
577 arg->count < arg->skip) {
578 arg->count++;
579 continue;
580 }
581 if (arg->fn(sch, i + 1, arg) < 0) {
582 arg->stop = 1;
583 break;
584 }
585 arg->count++;
586 }
587 }
588
589 static const struct Qdisc_class_ops fq_codel_class_ops = {
590 .leaf = fq_codel_leaf,
591 .get = fq_codel_get,
592 .put = fq_codel_put,
593 .tcf_chain = fq_codel_find_tcf,
594 .bind_tcf = fq_codel_bind,
595 .unbind_tcf = fq_codel_put,
596 .dump = fq_codel_dump_class,
597 .dump_stats = fq_codel_dump_class_stats,
598 .walk = fq_codel_walk,
599 };
600
601 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = {
602 .cl_ops = &fq_codel_class_ops,
603 .id = "fq_codel",
604 .priv_size = sizeof(struct fq_codel_sched_data),
605 .enqueue = fq_codel_enqueue,
606 .dequeue = fq_codel_dequeue,
607 .peek = qdisc_peek_dequeued,
608 .drop = fq_codel_drop,
609 .init = fq_codel_init,
610 .reset = fq_codel_reset,
611 .destroy = fq_codel_destroy,
612 .change = fq_codel_change,
613 .dump = fq_codel_dump,
614 .dump_stats = fq_codel_dump_stats,
615 .owner = THIS_MODULE,
616 };
617
fq_codel_module_init(void)618 static int __init fq_codel_module_init(void)
619 {
620 return register_qdisc(&fq_codel_qdisc_ops);
621 }
622
fq_codel_module_exit(void)623 static void __exit fq_codel_module_exit(void)
624 {
625 unregister_qdisc(&fq_codel_qdisc_ops);
626 }
627
628 module_init(fq_codel_module_init)
629 module_exit(fq_codel_module_exit)
630 MODULE_AUTHOR("Eric Dumazet");
631 MODULE_LICENSE("GPL");
632