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nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / net / sched / sch_sfb.c
blob0a833d0c1f6189eb16843a34d23d6fd157bfa03f
1 /*
2 * net/sched/sch_sfb.c Stochastic Fair Blue
3 *
4 * Copyright (c) 2008-2011 Juliusz Chroboczek <jch@pps.jussieu.fr>
5 * Copyright (c) 2011 Eric Dumazet <eric.dumazet@gmail.com>
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * version 2 as published by the Free Software Foundation.
10 *
11 * W. Feng, D. Kandlur, D. Saha, K. Shin. Blue:
12 * A New Class of Active Queue Management Algorithms.
13 * U. Michigan CSE-TR-387-99, April 1999.
14 *
15 * http://www.thefengs.com/wuchang/blue/CSE-TR-387-99.pdf
16 *
17 */
18
19 #include <linux/module.h>
20 #include <linux/types.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/skbuff.h>
24 #include <linux/random.h>
25 #include <linux/jhash.h>
26 #include <net/ip.h>
27 #include <net/pkt_sched.h>
28 #include <net/inet_ecn.h>
29
30 /*
31 * SFB uses two B[l][n] : L x N arrays of bins (L levels, N bins per level)
32 * This implementation uses L = 8 and N = 16
33 * This permits us to split one 32bit hash (provided per packet by rxhash or
34 * external classifier) into 8 subhashes of 4 bits.
35 */
36 #define SFB_BUCKET_SHIFT 4
37 #define SFB_NUMBUCKETS (1 << SFB_BUCKET_SHIFT) /* N bins per Level */
38 #define SFB_BUCKET_MASK (SFB_NUMBUCKETS - 1)
39 #define SFB_LEVELS (32 / SFB_BUCKET_SHIFT) /* L */
40
41 /* SFB algo uses a virtual queue, named "bin" */
42 struct sfb_bucket {
43 u16 qlen; /* length of virtual queue */
44 u16 p_mark; /* marking probability */
45 };
46
47 /* We use a double buffering right before hash change
48 * (Section 4.4 of SFB reference : moving hash functions)
49 */
50 struct sfb_bins {
51 u32 perturbation; /* jhash perturbation */
52 struct sfb_bucket bins[SFB_LEVELS][SFB_NUMBUCKETS];
53 };
54
55 struct sfb_sched_data {
56 struct Qdisc *qdisc;
57 struct tcf_proto *filter_list;
58 unsigned long rehash_interval;
59 unsigned long warmup_time; /* double buffering warmup time in jiffies */
60 u32 max;
61 u32 bin_size; /* maximum queue length per bin */
62 u32 increment; /* d1 */
63 u32 decrement; /* d2 */
64 u32 limit; /* HARD maximal queue length */
65 u32 penalty_rate;
66 u32 penalty_burst;
67 u32 tokens_avail;
68 unsigned long rehash_time;
69 unsigned long token_time;
70
71 u8 slot; /* current active bins (0 or 1) */
72 bool double_buffering;
73 struct sfb_bins bins[2];
74
75 struct {
76 u32 earlydrop;
77 u32 penaltydrop;
78 u32 bucketdrop;
79 u32 queuedrop;
80 u32 childdrop; /* drops in child qdisc */
81 u32 marked; /* ECN mark */
82 } stats;
83 };
84
85 /*
86 * Each queued skb might be hashed on one or two bins
87 * We store in skb_cb the two hash values.
88 * (A zero value means double buffering was not used)
89 */
90 struct sfb_skb_cb {
91 u32 hashes[2];
92 };
93
94 static inline struct sfb_skb_cb *sfb_skb_cb(const struct sk_buff *skb)
95 {
96 BUILD_BUG_ON(sizeof(skb->cb) <
97 sizeof(struct qdisc_skb_cb) + sizeof(struct sfb_skb_cb));
98 return (struct sfb_skb_cb *)qdisc_skb_cb(skb)->data;
99 }
100
101 /*
102 * If using 'internal' SFB flow classifier, hash comes from skb rxhash
103 * If using external classifier, hash comes from the classid.
104 */
105 static u32 sfb_hash(const struct sk_buff *skb, u32 slot)
106 {
107 return sfb_skb_cb(skb)->hashes[slot];
108 }
109
110 /* Probabilities are coded as Q0.16 fixed-point values,
111 * with 0xFFFF representing 65535/65536 (almost 1.0)
112 * Addition and subtraction are saturating in [0, 65535]
113 */
114 static u32 prob_plus(u32 p1, u32 p2)
115 {
116 u32 res = p1 + p2;
117
118 return min_t(u32, res, SFB_MAX_PROB);
119 }
120
121 static u32 prob_minus(u32 p1, u32 p2)
122 {
123 return p1 > p2 ? p1 - p2 : 0;
124 }
125
126 static void increment_one_qlen(u32 sfbhash, u32 slot, struct sfb_sched_data *q)
127 {
128 int i;
129 struct sfb_bucket *b = &q->bins[slot].bins[0][0];
130
131 for (i = 0; i < SFB_LEVELS; i++) {
132 u32 hash = sfbhash & SFB_BUCKET_MASK;
133
134 sfbhash >>= SFB_BUCKET_SHIFT;
135 if (b[hash].qlen < 0xFFFF)
136 b[hash].qlen++;
137 b += SFB_NUMBUCKETS; /* next level */
138 }
139 }
140
141 static void increment_qlen(const struct sk_buff *skb, struct sfb_sched_data *q)
142 {
143 u32 sfbhash;
144
145 sfbhash = sfb_hash(skb, 0);
146 if (sfbhash)
147 increment_one_qlen(sfbhash, 0, q);
148
149 sfbhash = sfb_hash(skb, 1);
150 if (sfbhash)
151 increment_one_qlen(sfbhash, 1, q);
152 }
153
154 static void decrement_one_qlen(u32 sfbhash, u32 slot,
155 struct sfb_sched_data *q)
156 {
157 int i;
158 struct sfb_bucket *b = &q->bins[slot].bins[0][0];
159
160 for (i = 0; i < SFB_LEVELS; i++) {
161 u32 hash = sfbhash & SFB_BUCKET_MASK;
162
163 sfbhash >>= SFB_BUCKET_SHIFT;
164 if (b[hash].qlen > 0)
165 b[hash].qlen--;
166 b += SFB_NUMBUCKETS; /* next level */
167 }
168 }
169
170 static void decrement_qlen(const struct sk_buff *skb, struct sfb_sched_data *q)
171 {
172 u32 sfbhash;
173
174 sfbhash = sfb_hash(skb, 0);
175 if (sfbhash)
176 decrement_one_qlen(sfbhash, 0, q);
177
178 sfbhash = sfb_hash(skb, 1);
179 if (sfbhash)
180 decrement_one_qlen(sfbhash, 1, q);
181 }
182
183 static void decrement_prob(struct sfb_bucket *b, struct sfb_sched_data *q)
184 {
185 b->p_mark = prob_minus(b->p_mark, q->decrement);
186 }
187
188 static void increment_prob(struct sfb_bucket *b, struct sfb_sched_data *q)
189 {
190 b->p_mark = prob_plus(b->p_mark, q->increment);
191 }
192
193 static void sfb_zero_all_buckets(struct sfb_sched_data *q)
194 {
195 memset(&q->bins, 0, sizeof(q->bins));
196 }
197
198 /*
199 * compute max qlen, max p_mark, and avg p_mark
200 */
201 static u32 sfb_compute_qlen(u32 *prob_r, u32 *avgpm_r, const struct sfb_sched_data *q)
202 {
203 int i;
204 u32 qlen = 0, prob = 0, totalpm = 0;
205 const struct sfb_bucket *b = &q->bins[q->slot].bins[0][0];
206
207 for (i = 0; i < SFB_LEVELS * SFB_NUMBUCKETS; i++) {
208 if (qlen < b->qlen)
209 qlen = b->qlen;
210 totalpm += b->p_mark;
211 if (prob < b->p_mark)
212 prob = b->p_mark;
213 b++;
214 }
215 *prob_r = prob;
216 *avgpm_r = totalpm / (SFB_LEVELS * SFB_NUMBUCKETS);
217 return qlen;
218 }
219
220
221 static void sfb_init_perturbation(u32 slot, struct sfb_sched_data *q)
222 {
223 q->bins[slot].perturbation = net_random();
224 }
225
226 static void sfb_swap_slot(struct sfb_sched_data *q)
227 {
228 sfb_init_perturbation(q->slot, q);
229 q->slot ^= 1;
230 q->double_buffering = false;
231 }
232
233 /* Non elastic flows are allowed to use part of the bandwidth, expressed
234 * in "penalty_rate" packets per second, with "penalty_burst" burst
235 */
236 static bool sfb_rate_limit(struct sk_buff *skb, struct sfb_sched_data *q)
237 {
238 if (q->penalty_rate == 0 || q->penalty_burst == 0)
239 return true;
240
241 if (q->tokens_avail < 1) {
242 unsigned long age = min(10UL * HZ, jiffies - q->token_time);
243
244 q->tokens_avail = (age * q->penalty_rate) / HZ;
245 if (q->tokens_avail > q->penalty_burst)
246 q->tokens_avail = q->penalty_burst;
247 q->token_time = jiffies;
248 if (q->tokens_avail < 1)
249 return true;
250 }
251
252 q->tokens_avail--;
253 return false;
254 }
255
256 static bool sfb_classify(struct sk_buff *skb, struct sfb_sched_data *q,
257 int *qerr, u32 *salt)
258 {
259 struct tcf_result res;
260 int result;
261
262 result = tc_classify(skb, q->filter_list, &res);
263 if (result >= 0) {
264 #ifdef CONFIG_NET_CLS_ACT
265 switch (result) {
266 case TC_ACT_STOLEN:
267 case TC_ACT_QUEUED:
268 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
269 case TC_ACT_SHOT:
270 return false;
271 }
272 #endif
273 *salt = TC_H_MIN(res.classid);
274 return true;
275 }
276 return false;
277 }
278
279 static int sfb_enqueue(struct sk_buff *skb, struct Qdisc *sch)
280 {
281
282 struct sfb_sched_data *q = qdisc_priv(sch);
283 struct Qdisc *child = q->qdisc;
284 int i;
285 u32 p_min = ~0;
286 u32 minqlen = ~0;
287 u32 r, slot, salt, sfbhash;
288 int ret = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
289
290 if (q->rehash_interval > 0) {
291 unsigned long limit = q->rehash_time + q->rehash_interval;
292
293 if (unlikely(time_after(jiffies, limit))) {
294 sfb_swap_slot(q);
295 q->rehash_time = jiffies;
296 } else if (unlikely(!q->double_buffering && q->warmup_time > 0 &&
297 time_after(jiffies, limit - q->warmup_time))) {
298 q->double_buffering = true;
299 }
300 }
301
302 if (q->filter_list) {
303 /* If using external classifiers, get result and record it. */
304 if (!sfb_classify(skb, q, &ret, &salt))
305 goto other_drop;
306 } else {
307 salt = skb_get_rxhash(skb);
308 }
309
310 slot = q->slot;
311
312 sfbhash = jhash_1word(salt, q->bins[slot].perturbation);
313 if (!sfbhash)
314 sfbhash = 1;
315 sfb_skb_cb(skb)->hashes[slot] = sfbhash;
316
317 for (i = 0; i < SFB_LEVELS; i++) {
318 u32 hash = sfbhash & SFB_BUCKET_MASK;
319 struct sfb_bucket *b = &q->bins[slot].bins[i][hash];
320
321 sfbhash >>= SFB_BUCKET_SHIFT;
322 if (b->qlen == 0)
323 decrement_prob(b, q);
324 else if (b->qlen >= q->bin_size)
325 increment_prob(b, q);
326 if (minqlen > b->qlen)
327 minqlen = b->qlen;
328 if (p_min > b->p_mark)
329 p_min = b->p_mark;
330 }
331
332 slot ^= 1;
333 sfb_skb_cb(skb)->hashes[slot] = 0;
334
335 if (unlikely(minqlen >= q->max || sch->q.qlen >= q->limit)) {
336 sch->qstats.overlimits++;
337 if (minqlen >= q->max)
338 q->stats.bucketdrop++;
339 else
340 q->stats.queuedrop++;
341 goto drop;
342 }
343
344 if (unlikely(p_min >= SFB_MAX_PROB)) {
345 /* Inelastic flow */
346 if (q->double_buffering) {
347 sfbhash = jhash_1word(salt, q->bins[slot].perturbation);
348 if (!sfbhash)
349 sfbhash = 1;
350 sfb_skb_cb(skb)->hashes[slot] = sfbhash;
351
352 for (i = 0; i < SFB_LEVELS; i++) {
353 u32 hash = sfbhash & SFB_BUCKET_MASK;
354 struct sfb_bucket *b = &q->bins[slot].bins[i][hash];
355
356 sfbhash >>= SFB_BUCKET_SHIFT;
357 if (b->qlen == 0)
358 decrement_prob(b, q);
359 else if (b->qlen >= q->bin_size)
360 increment_prob(b, q);
361 }
362 }
363 if (sfb_rate_limit(skb, q)) {
364 sch->qstats.overlimits++;
365 q->stats.penaltydrop++;
366 goto drop;
367 }
368 goto enqueue;
369 }
370
371 r = net_random() & SFB_MAX_PROB;
372
373 if (unlikely(r < p_min)) {
374 if (unlikely(p_min > SFB_MAX_PROB / 2)) {
375 /* If we're marking that many packets, then either
376 * this flow is unresponsive, or we're badly congested.
377 * In either case, we want to start dropping packets.
378 */
379 if (r < (p_min - SFB_MAX_PROB / 2) * 2) {
380 q->stats.earlydrop++;
381 goto drop;
382 }
383 }
384 if (INET_ECN_set_ce(skb)) {
385 q->stats.marked++;
386 } else {
387 q->stats.earlydrop++;
388 goto drop;
389 }
390 }
391
392 enqueue:
393 ret = qdisc_enqueue(skb, child);
394 if (likely(ret == NET_XMIT_SUCCESS)) {
395 sch->q.qlen++;
396 increment_qlen(skb, q);
397 } else if (net_xmit_drop_count(ret)) {
398 q->stats.childdrop++;
399 sch->qstats.drops++;
400 }
401 return ret;
402
403 drop:
404 qdisc_drop(skb, sch);
405 return NET_XMIT_CN;
406 other_drop:
407 if (ret & __NET_XMIT_BYPASS)
408 sch->qstats.drops++;
409 kfree_skb(skb);
410 return ret;
411 }
412
413 static struct sk_buff *sfb_dequeue(struct Qdisc *sch)
414 {
415 struct sfb_sched_data *q = qdisc_priv(sch);
416 struct Qdisc *child = q->qdisc;
417 struct sk_buff *skb;
418
419 skb = child->dequeue(q->qdisc);
420
421 if (skb) {
422 qdisc_bstats_update(sch, skb);
423 sch->q.qlen--;
424 decrement_qlen(skb, q);
425 }
426
427 return skb;
428 }
429
430 static struct sk_buff *sfb_peek(struct Qdisc *sch)
431 {
432 struct sfb_sched_data *q = qdisc_priv(sch);
433 struct Qdisc *child = q->qdisc;
434
435 return child->ops->peek(child);
436 }
437
438 /* No sfb_drop -- impossible since the child doesn't return the dropped skb. */
439
440 static void sfb_reset(struct Qdisc *sch)
441 {
442 struct sfb_sched_data *q = qdisc_priv(sch);
443
444 qdisc_reset(q->qdisc);
445 sch->q.qlen = 0;
446 q->slot = 0;
447 q->double_buffering = false;
448 sfb_zero_all_buckets(q);
449 sfb_init_perturbation(0, q);
450 }
451
452 static void sfb_destroy(struct Qdisc *sch)
453 {
454 struct sfb_sched_data *q = qdisc_priv(sch);
455
456 tcf_destroy_chain(&q->filter_list);
457 qdisc_destroy(q->qdisc);
458 }
459
460 static const struct nla_policy sfb_policy[TCA_SFB_MAX + 1] = {
461 [TCA_SFB_PARMS] = { .len = sizeof(struct tc_sfb_qopt) },
462 };
463
464 static const struct tc_sfb_qopt sfb_default_ops = {
465 .rehash_interval = 600 * MSEC_PER_SEC,
466 .warmup_time = 60 * MSEC_PER_SEC,
467 .limit = 0,
468 .max = 25,
469 .bin_size = 20,
470 .increment = (SFB_MAX_PROB + 500) / 1000, /* 0.1 % */
471 .decrement = (SFB_MAX_PROB + 3000) / 6000,
472 .penalty_rate = 10,
473 .penalty_burst = 20,
474 };
475
476 static int sfb_change(struct Qdisc *sch, struct nlattr *opt)
477 {
478 struct sfb_sched_data *q = qdisc_priv(sch);
479 struct Qdisc *child;
480 struct nlattr *tb[TCA_SFB_MAX + 1];
481 const struct tc_sfb_qopt *ctl = &sfb_default_ops;
482 u32 limit;
483 int err;
484
485 if (opt) {
486 err = nla_parse_nested(tb, TCA_SFB_MAX, opt, sfb_policy);
487 if (err < 0)
488 return -EINVAL;
489
490 if (tb[TCA_SFB_PARMS] == NULL)
491 return -EINVAL;
492
493 ctl = nla_data(tb[TCA_SFB_PARMS]);
494 }
495
496 limit = ctl->limit;
497 if (limit == 0)
498 limit = max_t(u32, qdisc_dev(sch)->tx_queue_len, 1);
499
500 child = fifo_create_dflt(sch, &pfifo_qdisc_ops, limit);
501 if (IS_ERR(child))
502 return PTR_ERR(child);
503
504 sch_tree_lock(sch);
505
506 qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
507 qdisc_destroy(q->qdisc);
508 q->qdisc = child;
509
510 q->rehash_interval = msecs_to_jiffies(ctl->rehash_interval);
511 q->warmup_time = msecs_to_jiffies(ctl->warmup_time);
512 q->rehash_time = jiffies;
513 q->limit = limit;
514 q->increment = ctl->increment;
515 q->decrement = ctl->decrement;
516 q->max = ctl->max;
517 q->bin_size = ctl->bin_size;
518 q->penalty_rate = ctl->penalty_rate;
519 q->penalty_burst = ctl->penalty_burst;
520 q->tokens_avail = ctl->penalty_burst;
521 q->token_time = jiffies;
522
523 q->slot = 0;
524 q->double_buffering = false;
525 sfb_zero_all_buckets(q);
526 sfb_init_perturbation(0, q);
527 sfb_init_perturbation(1, q);
528
529 sch_tree_unlock(sch);
530
531 return 0;
532 }
533
534 static int sfb_init(struct Qdisc *sch, struct nlattr *opt)
535 {
536 struct sfb_sched_data *q = qdisc_priv(sch);
537
538 q->qdisc = &noop_qdisc;
539 return sfb_change(sch, opt);
540 }
541
542 static int sfb_dump(struct Qdisc *sch, struct sk_buff *skb)
543 {
544 struct sfb_sched_data *q = qdisc_priv(sch);
545 struct nlattr *opts;
546 struct tc_sfb_qopt opt = {
547 .rehash_interval = jiffies_to_msecs(q->rehash_interval),
548 .warmup_time = jiffies_to_msecs(q->warmup_time),
549 .limit = q->limit,
550 .max = q->max,
551 .bin_size = q->bin_size,
552 .increment = q->increment,
553 .decrement = q->decrement,
554 .penalty_rate = q->penalty_rate,
555 .penalty_burst = q->penalty_burst,
556 };
557
558 sch->qstats.backlog = q->qdisc->qstats.backlog;
559 opts = nla_nest_start(skb, TCA_OPTIONS);
560 NLA_PUT(skb, TCA_SFB_PARMS, sizeof(opt), &opt);
561 return nla_nest_end(skb, opts);
562
563 nla_put_failure:
564 nla_nest_cancel(skb, opts);
565 return -EMSGSIZE;
566 }
567
568 static int sfb_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
569 {
570 struct sfb_sched_data *q = qdisc_priv(sch);
571 struct tc_sfb_xstats st = {
572 .earlydrop = q->stats.earlydrop,
573 .penaltydrop = q->stats.penaltydrop,
574 .bucketdrop = q->stats.bucketdrop,
575 .queuedrop = q->stats.queuedrop,
576 .childdrop = q->stats.childdrop,
577 .marked = q->stats.marked,
578 };
579
580 st.maxqlen = sfb_compute_qlen(&st.maxprob, &st.avgprob, q);
581
582 return gnet_stats_copy_app(d, &st, sizeof(st));
583 }
584
585 static int sfb_dump_class(struct Qdisc *sch, unsigned long cl,
586 struct sk_buff *skb, struct tcmsg *tcm)
587 {
588 return -ENOSYS;
589 }
590
591 static int sfb_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new,
592 struct Qdisc **old)
593 {
594 struct sfb_sched_data *q = qdisc_priv(sch);
595
596 if (new == NULL)
597 new = &noop_qdisc;
598
599 sch_tree_lock(sch);
600 *old = q->qdisc;
601 q->qdisc = new;
602 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen);
603 qdisc_reset(*old);
604 sch_tree_unlock(sch);
605 return 0;
606 }
607
608 static struct Qdisc *sfb_leaf(struct Qdisc *sch, unsigned long arg)
609 {
610 struct sfb_sched_data *q = qdisc_priv(sch);
611
612 return q->qdisc;
613 }
614
615 static unsigned long sfb_get(struct Qdisc *sch, u32 classid)
616 {
617 return 1;
618 }
619
620 static void sfb_put(struct Qdisc *sch, unsigned long arg)
621 {
622 }
623
624 static int sfb_change_class(struct Qdisc *sch, u32 classid, u32 parentid,
625 struct nlattr **tca, unsigned long *arg)
626 {
627 return -ENOSYS;
628 }
629
630 static int sfb_delete(struct Qdisc *sch, unsigned long cl)
631 {
632 return -ENOSYS;
633 }
634
635 static void sfb_walk(struct Qdisc *sch, struct qdisc_walker *walker)
636 {
637 if (!walker->stop) {
638 if (walker->count >= walker->skip)
639 if (walker->fn(sch, 1, walker) < 0) {
640 walker->stop = 1;
641 return;
642 }
643 walker->count++;
644 }
645 }
646
647 static struct tcf_proto **sfb_find_tcf(struct Qdisc *sch, unsigned long cl)
648 {
649 struct sfb_sched_data *q = qdisc_priv(sch);
650
651 if (cl)
652 return NULL;
653 return &q->filter_list;
654 }
655
656 static unsigned long sfb_bind(struct Qdisc *sch, unsigned long parent,
657 u32 classid)
658 {
659 return 0;
660 }
661
662
663 static const struct Qdisc_class_ops sfb_class_ops = {
664 .graft = sfb_graft,
665 .leaf = sfb_leaf,
666 .get = sfb_get,
667 .put = sfb_put,
668 .change = sfb_change_class,
669 .delete = sfb_delete,
670 .walk = sfb_walk,
671 .tcf_chain = sfb_find_tcf,
672 .bind_tcf = sfb_bind,
673 .unbind_tcf = sfb_put,
674 .dump = sfb_dump_class,
675 };
676
677 static struct Qdisc_ops sfb_qdisc_ops __read_mostly = {
678 .id = "sfb",
679 .priv_size = sizeof(struct sfb_sched_data),
680 .cl_ops = &sfb_class_ops,
681 .enqueue = sfb_enqueue,
682 .dequeue = sfb_dequeue,
683 .peek = sfb_peek,
684 .init = sfb_init,
685 .reset = sfb_reset,
686 .destroy = sfb_destroy,
687 .change = sfb_change,
688 .dump = sfb_dump,
689 .dump_stats = sfb_dump_stats,
690 .owner = THIS_MODULE,
691 };
692
693 static int __init sfb_module_init(void)
694 {
695 return register_qdisc(&sfb_qdisc_ops);
696 }
697
698 static void __exit sfb_module_exit(void)
699 {
700 unregister_qdisc(&sfb_qdisc_ops);
701 }
702
703 module_init(sfb_module_init)
704 module_exit(sfb_module_exit)
705
706 MODULE_DESCRIPTION("Stochastic Fair Blue queue discipline");
707 MODULE_AUTHOR("Juliusz Chroboczek");
708 MODULE_AUTHOR("Eric Dumazet");
709 MODULE_LICENSE("GPL");
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