2 * net/sched/sch_sfq.c Stochastic Fairness Queueing discipline.
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.
9 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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>
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>
30 /* Stochastic Fairness Queuing algorithm.
31 =======================================
34 Paul E. McKenney "Stochastic Fairness Queuing",
35 IEEE INFOCOMM'90 Proceedings, San Francisco, 1990.
37 Paul E. McKenney "Stochastic Fairness Queuing",
38 "Interworking: Research and Experience", v.2, 1991, p.113-131.
42 M. Shreedhar and George Varghese "Efficient Fair
43 Queuing using Deficit Round Robin", Proc. SIGCOMM 95.
46 This is not the thing that is usually called (W)FQ nowadays.
47 It does not use any timestamp mechanism, but instead
48 processes queues in round-robin order.
52 - It is very cheap. Both CPU and memory requirements are minimal.
56 - "Stochastic" -> It is not 100% fair.
57 When hash collisions occur, several flows are considered as one.
59 - "Round-robin" -> It introduces larger delays than virtual clock
60 based schemes, and should not be used for isolating interactive
61 traffic from non-interactive. It means, that this scheduler
62 should be used as leaf of CBQ or P3, which put interactive traffic
63 to higher priority band.
65 We still need true WFQ for top level CSZ, but using WFQ
66 for the best effort traffic is absolutely pointless:
67 SFQ is superior for this purpose.
70 This implementation limits :
71 - maximal queue length per flow to 127 packets.
74 - number of hash buckets to 65536.
76 It is easy to increase these values, but not in flight. */
78 #define SFQ_MAX_DEPTH 127 /* max number of packets per flow */
79 #define SFQ_DEFAULT_FLOWS 128
80 #define SFQ_MAX_FLOWS (0x10000 - SFQ_MAX_DEPTH - 1) /* max number of flows */
81 #define SFQ_EMPTY_SLOT 0xffff
82 #define SFQ_DEFAULT_HASH_DIVISOR 1024
84 /* We use 16 bits to store allot, and want to handle packets up to 64K
85 * Scale allot by 8 (1<<3) so that no overflow occurs.
87 #define SFQ_ALLOT_SHIFT 3
88 #define SFQ_ALLOT_SIZE(X) DIV_ROUND_UP(X, 1 << SFQ_ALLOT_SHIFT)
90 /* This type should contain at least SFQ_MAX_DEPTH + 1 + SFQ_MAX_FLOWS values */
91 typedef u16 sfq_index;
94 * We dont use pointers to save space.
95 * Small indexes [0 ... SFQ_MAX_FLOWS - 1] are 'pointers' to slots[] array
96 * while following values [SFQ_MAX_FLOWS ... SFQ_MAX_FLOWS + SFQ_MAX_DEPTH]
97 * are 'pointers' to dep[] array
105 struct sk_buff *skblist_next;
106 struct sk_buff *skblist_prev;
107 sfq_index qlen; /* number of skbs in skblist */
108 sfq_index next; /* next slot in sfq RR chain */
109 struct sfq_head dep; /* anchor in dep[] chains */
110 unsigned short hash; /* hash value (index in ht[]) */
111 short allot; /* credit for this slot */
113 unsigned int backlog;
114 struct red_vars vars;
117 struct sfq_sched_data {
118 /* frequently used fields */
119 int limit; /* limit of total number of packets in this qdisc */
120 unsigned int divisor; /* number of slots in hash table */
122 u8 maxdepth; /* limit of packets per flow */
125 u8 cur_depth; /* depth of longest slot */
127 unsigned short scaled_quantum; /* SFQ_ALLOT_SIZE(quantum) */
128 struct tcf_proto *filter_list;
129 sfq_index *ht; /* Hash table ('divisor' slots) */
130 struct sfq_slot *slots; /* Flows table ('maxflows' entries) */
132 struct red_parms *red_parms;
133 struct tc_sfqred_stats stats;
134 struct sfq_slot *tail; /* current slot in round */
136 struct sfq_head dep[SFQ_MAX_DEPTH + 1];
137 /* Linked lists of slots, indexed by depth
138 * dep[0] : list of unused flows
139 * dep[1] : list of flows with 1 packet
140 * dep[X] : list of flows with X packets
143 unsigned int maxflows; /* number of flows in flows array */
145 unsigned int quantum; /* Allotment per round: MUST BE >= MTU */
146 struct timer_list perturb_timer;
150 * sfq_head are either in a sfq_slot or in dep[] array
152 static inline struct sfq_head *sfq_dep_head(struct sfq_sched_data *q, sfq_index val)
154 if (val < SFQ_MAX_FLOWS)
155 return &q->slots[val].dep;
156 return &q->dep[val - SFQ_MAX_FLOWS];
160 * In order to be able to quickly rehash our queue when timer changes
161 * q->perturbation, we store flow_keys in skb->cb[]
164 struct flow_keys keys;
167 static inline struct sfq_skb_cb *sfq_skb_cb(const struct sk_buff *skb)
169 qdisc_cb_private_validate(skb, sizeof(struct sfq_skb_cb));
170 return (struct sfq_skb_cb *)qdisc_skb_cb(skb)->data;
173 static unsigned int sfq_hash(const struct sfq_sched_data *q,
174 const struct sk_buff *skb)
176 const struct flow_keys *keys = &sfq_skb_cb(skb)->keys;
179 hash = jhash_3words((__force u32)keys->dst,
180 (__force u32)keys->src ^ keys->ip_proto,
181 (__force u32)keys->ports, q->perturbation);
182 return hash & (q->divisor - 1);
185 static unsigned int sfq_classify(struct sk_buff *skb, struct Qdisc *sch,
188 struct sfq_sched_data *q = qdisc_priv(sch);
189 struct tcf_result res;
192 if (TC_H_MAJ(skb->priority) == sch->handle &&
193 TC_H_MIN(skb->priority) > 0 &&
194 TC_H_MIN(skb->priority) <= q->divisor)
195 return TC_H_MIN(skb->priority);
197 if (!q->filter_list) {
198 skb_flow_dissect(skb, &sfq_skb_cb(skb)->keys);
199 return sfq_hash(q, skb) + 1;
202 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS;
203 result = tc_classify(skb, q->filter_list, &res);
205 #ifdef CONFIG_NET_CLS_ACT
209 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN;
214 if (TC_H_MIN(res.classid) <= q->divisor)
215 return TC_H_MIN(res.classid);
221 * x : slot number [0 .. SFQ_MAX_FLOWS - 1]
223 static inline void sfq_link(struct sfq_sched_data *q, sfq_index x)
226 struct sfq_slot *slot = &q->slots[x];
227 int qlen = slot->qlen;
229 p = qlen + SFQ_MAX_FLOWS;
230 n = q->dep[qlen].next;
235 q->dep[qlen].next = x; /* sfq_dep_head(q, p)->next = x */
236 sfq_dep_head(q, n)->prev = x;
239 #define sfq_unlink(q, x, n, p) \
240 n = q->slots[x].dep.next; \
241 p = q->slots[x].dep.prev; \
242 sfq_dep_head(q, p)->next = n; \
243 sfq_dep_head(q, n)->prev = p
246 static inline void sfq_dec(struct sfq_sched_data *q, sfq_index x)
251 sfq_unlink(q, x, n, p);
253 d = q->slots[x].qlen--;
254 if (n == p && q->cur_depth == d)
259 static inline void sfq_inc(struct sfq_sched_data *q, sfq_index x)
264 sfq_unlink(q, x, n, p);
266 d = ++q->slots[x].qlen;
267 if (q->cur_depth < d)
272 /* helper functions : might be changed when/if skb use a standard list_head */
274 /* remove one skb from tail of slot queue */
275 static inline struct sk_buff *slot_dequeue_tail(struct sfq_slot *slot)
277 struct sk_buff *skb = slot->skblist_prev;
279 slot->skblist_prev = skb->prev;
280 skb->prev->next = (struct sk_buff *)slot;
281 skb->next = skb->prev = NULL;
285 /* remove one skb from head of slot queue */
286 static inline struct sk_buff *slot_dequeue_head(struct sfq_slot *slot)
288 struct sk_buff *skb = slot->skblist_next;
290 slot->skblist_next = skb->next;
291 skb->next->prev = (struct sk_buff *)slot;
292 skb->next = skb->prev = NULL;
296 static inline void slot_queue_init(struct sfq_slot *slot)
298 memset(slot, 0, sizeof(*slot));
299 slot->skblist_prev = slot->skblist_next = (struct sk_buff *)slot;
302 /* add skb to slot queue (tail add) */
303 static inline void slot_queue_add(struct sfq_slot *slot, struct sk_buff *skb)
305 skb->prev = slot->skblist_prev;
306 skb->next = (struct sk_buff *)slot;
307 slot->skblist_prev->next = skb;
308 slot->skblist_prev = skb;
311 #define slot_queue_walk(slot, skb) \
312 for (skb = slot->skblist_next; \
313 skb != (struct sk_buff *)slot; \
316 static unsigned int sfq_drop(struct Qdisc *sch)
318 struct sfq_sched_data *q = qdisc_priv(sch);
319 sfq_index x, d = q->cur_depth;
322 struct sfq_slot *slot;
324 /* Queue is full! Find the longest slot and drop tail packet from it */
329 skb = q->headdrop ? slot_dequeue_head(slot) : slot_dequeue_tail(slot);
330 len = qdisc_pkt_len(skb);
331 slot->backlog -= len;
336 sch->qstats.backlog -= len;
341 /* It is difficult to believe, but ALL THE SLOTS HAVE LENGTH 1. */
344 q->tail->next = slot->next;
345 q->ht[slot->hash] = SFQ_EMPTY_SLOT;
352 /* Is ECN parameter configured */
353 static int sfq_prob_mark(const struct sfq_sched_data *q)
355 return q->flags & TC_RED_ECN;
358 /* Should packets over max threshold just be marked */
359 static int sfq_hard_mark(const struct sfq_sched_data *q)
361 return (q->flags & (TC_RED_ECN | TC_RED_HARDDROP)) == TC_RED_ECN;
364 static int sfq_headdrop(const struct sfq_sched_data *q)
370 sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
372 struct sfq_sched_data *q = qdisc_priv(sch);
375 struct sfq_slot *slot;
376 int uninitialized_var(ret);
377 struct sk_buff *head;
380 hash = sfq_classify(skb, sch, &ret);
382 if (ret & __NET_XMIT_BYPASS)
391 if (x == SFQ_EMPTY_SLOT) {
392 x = q->dep[0].next; /* get a free slot */
393 if (x >= SFQ_MAX_FLOWS)
394 return qdisc_drop(skb, sch);
398 slot->backlog = 0; /* should already be 0 anyway... */
399 red_set_vars(&slot->vars);
403 slot->vars.qavg = red_calc_qavg_no_idle_time(q->red_parms,
406 switch (red_action(q->red_parms,
413 sch->qstats.overlimits++;
414 if (sfq_prob_mark(q)) {
415 /* We know we have at least one packet in queue */
416 if (sfq_headdrop(q) &&
417 INET_ECN_set_ce(slot->skblist_next)) {
418 q->stats.prob_mark_head++;
421 if (INET_ECN_set_ce(skb)) {
422 q->stats.prob_mark++;
426 q->stats.prob_drop++;
427 goto congestion_drop;
430 sch->qstats.overlimits++;
431 if (sfq_hard_mark(q)) {
432 /* We know we have at least one packet in queue */
433 if (sfq_headdrop(q) &&
434 INET_ECN_set_ce(slot->skblist_next)) {
435 q->stats.forced_mark_head++;
438 if (INET_ECN_set_ce(skb)) {
439 q->stats.forced_mark++;
443 q->stats.forced_drop++;
444 goto congestion_drop;
448 if (slot->qlen >= q->maxdepth) {
450 if (!sfq_headdrop(q))
451 return qdisc_drop(skb, sch);
453 /* We know we have at least one packet in queue */
454 head = slot_dequeue_head(slot);
455 delta = qdisc_pkt_len(head) - qdisc_pkt_len(skb);
456 sch->qstats.backlog -= delta;
457 slot->backlog -= delta;
458 qdisc_drop(head, sch);
460 slot_queue_add(slot, skb);
465 sch->qstats.backlog += qdisc_pkt_len(skb);
466 slot->backlog += qdisc_pkt_len(skb);
467 slot_queue_add(slot, skb);
469 if (slot->qlen == 1) { /* The flow is new */
470 if (q->tail == NULL) { /* It is the first flow */
474 slot->next = q->tail->next;
477 /* We could use a bigger initial quantum for new flows */
478 slot->allot = q->scaled_quantum;
480 if (++sch->q.qlen <= q->limit)
481 return NET_XMIT_SUCCESS;
485 /* Return Congestion Notification only if we dropped a packet
488 if (qlen != slot->qlen)
491 /* As we dropped a packet, better let upper stack know this */
492 qdisc_tree_decrease_qlen(sch, 1);
493 return NET_XMIT_SUCCESS;
496 static struct sk_buff *
497 sfq_dequeue(struct Qdisc *sch)
499 struct sfq_sched_data *q = qdisc_priv(sch);
502 struct sfq_slot *slot;
504 /* No active slots */
511 if (slot->allot <= 0) {
513 slot->allot += q->scaled_quantum;
516 skb = slot_dequeue_head(slot);
518 qdisc_bstats_update(sch, skb);
520 sch->qstats.backlog -= qdisc_pkt_len(skb);
521 slot->backlog -= qdisc_pkt_len(skb);
522 /* Is the slot empty? */
523 if (slot->qlen == 0) {
524 q->ht[slot->hash] = SFQ_EMPTY_SLOT;
527 q->tail = NULL; /* no more active slots */
530 q->tail->next = next_a;
532 slot->allot -= SFQ_ALLOT_SIZE(qdisc_pkt_len(skb));
538 sfq_reset(struct Qdisc *sch)
542 while ((skb = sfq_dequeue(sch)) != NULL)
547 * When q->perturbation is changed, we rehash all queued skbs
548 * to avoid OOO (Out Of Order) effects.
549 * We dont use sfq_dequeue()/sfq_enqueue() because we dont want to change
552 static void sfq_rehash(struct Qdisc *sch)
554 struct sfq_sched_data *q = qdisc_priv(sch);
557 struct sfq_slot *slot;
558 struct sk_buff_head list;
561 __skb_queue_head_init(&list);
563 for (i = 0; i < q->maxflows; i++) {
568 skb = slot_dequeue_head(slot);
570 __skb_queue_tail(&list, skb);
573 red_set_vars(&slot->vars);
574 q->ht[slot->hash] = SFQ_EMPTY_SLOT;
578 while ((skb = __skb_dequeue(&list)) != NULL) {
579 unsigned int hash = sfq_hash(q, skb);
580 sfq_index x = q->ht[hash];
583 if (x == SFQ_EMPTY_SLOT) {
584 x = q->dep[0].next; /* get a free slot */
585 if (x >= SFQ_MAX_FLOWS) {
586 drop: sch->qstats.backlog -= qdisc_pkt_len(skb);
595 if (slot->qlen >= q->maxdepth)
597 slot_queue_add(slot, skb);
599 slot->vars.qavg = red_calc_qavg(q->red_parms,
602 slot->backlog += qdisc_pkt_len(skb);
604 if (slot->qlen == 1) { /* The flow is new */
605 if (q->tail == NULL) { /* It is the first flow */
608 slot->next = q->tail->next;
612 slot->allot = q->scaled_quantum;
615 sch->q.qlen -= dropped;
616 qdisc_tree_decrease_qlen(sch, dropped);
619 static void sfq_perturbation(unsigned long arg)
621 struct Qdisc *sch = (struct Qdisc *)arg;
622 struct sfq_sched_data *q = qdisc_priv(sch);
623 spinlock_t *root_lock = qdisc_lock(qdisc_root_sleeping(sch));
625 spin_lock(root_lock);
626 q->perturbation = net_random();
627 if (!q->filter_list && q->tail)
629 spin_unlock(root_lock);
631 if (q->perturb_period)
632 mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
635 static int sfq_change(struct Qdisc *sch, struct nlattr *opt)
637 struct sfq_sched_data *q = qdisc_priv(sch);
638 struct tc_sfq_qopt *ctl = nla_data(opt);
639 struct tc_sfq_qopt_v1 *ctl_v1 = NULL;
641 struct red_parms *p = NULL;
643 if (opt->nla_len < nla_attr_size(sizeof(*ctl)))
645 if (opt->nla_len >= nla_attr_size(sizeof(*ctl_v1)))
646 ctl_v1 = nla_data(opt);
648 (!is_power_of_2(ctl->divisor) || ctl->divisor > 65536))
650 if (ctl_v1 && ctl_v1->qth_min) {
651 p = kmalloc(sizeof(*p), GFP_KERNEL);
657 q->quantum = ctl->quantum;
658 q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
660 q->perturb_period = ctl->perturb_period * HZ;
662 q->maxflows = min_t(u32, ctl->flows, SFQ_MAX_FLOWS);
664 q->divisor = ctl->divisor;
665 q->maxflows = min_t(u32, q->maxflows, q->divisor);
669 q->maxdepth = min_t(u32, ctl_v1->depth, SFQ_MAX_DEPTH);
671 swap(q->red_parms, p);
672 red_set_parms(q->red_parms,
673 ctl_v1->qth_min, ctl_v1->qth_max,
675 ctl_v1->Plog, ctl_v1->Scell_log,
679 q->flags = ctl_v1->flags;
680 q->headdrop = ctl_v1->headdrop;
683 q->limit = min_t(u32, ctl->limit, q->maxdepth * q->maxflows);
684 q->maxflows = min_t(u32, q->maxflows, q->limit);
688 while (sch->q.qlen > q->limit)
690 qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
692 del_timer(&q->perturb_timer);
693 if (q->perturb_period) {
694 mod_timer(&q->perturb_timer, jiffies + q->perturb_period);
695 q->perturbation = net_random();
697 sch_tree_unlock(sch);
702 static void *sfq_alloc(size_t sz)
704 void *ptr = kmalloc(sz, GFP_KERNEL | __GFP_NOWARN);
711 static void sfq_free(void *addr)
714 if (is_vmalloc_addr(addr))
721 static void sfq_destroy(struct Qdisc *sch)
723 struct sfq_sched_data *q = qdisc_priv(sch);
725 tcf_destroy_chain(&q->filter_list);
726 q->perturb_period = 0;
727 del_timer_sync(&q->perturb_timer);
733 static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
735 struct sfq_sched_data *q = qdisc_priv(sch);
738 q->perturb_timer.function = sfq_perturbation;
739 q->perturb_timer.data = (unsigned long)sch;
740 init_timer_deferrable(&q->perturb_timer);
742 for (i = 0; i < SFQ_MAX_DEPTH + 1; i++) {
743 q->dep[i].next = i + SFQ_MAX_FLOWS;
744 q->dep[i].prev = i + SFQ_MAX_FLOWS;
747 q->limit = SFQ_MAX_DEPTH;
748 q->maxdepth = SFQ_MAX_DEPTH;
751 q->divisor = SFQ_DEFAULT_HASH_DIVISOR;
752 q->maxflows = SFQ_DEFAULT_FLOWS;
753 q->quantum = psched_mtu(qdisc_dev(sch));
754 q->scaled_quantum = SFQ_ALLOT_SIZE(q->quantum);
755 q->perturb_period = 0;
756 q->perturbation = net_random();
759 int err = sfq_change(sch, opt);
764 q->ht = sfq_alloc(sizeof(q->ht[0]) * q->divisor);
765 q->slots = sfq_alloc(sizeof(q->slots[0]) * q->maxflows);
766 if (!q->ht || !q->slots) {
770 for (i = 0; i < q->divisor; i++)
771 q->ht[i] = SFQ_EMPTY_SLOT;
773 for (i = 0; i < q->maxflows; i++) {
774 slot_queue_init(&q->slots[i]);
778 sch->flags |= TCQ_F_CAN_BYPASS;
780 sch->flags &= ~TCQ_F_CAN_BYPASS;
784 static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb)
786 struct sfq_sched_data *q = qdisc_priv(sch);
787 unsigned char *b = skb_tail_pointer(skb);
788 struct tc_sfq_qopt_v1 opt;
789 struct red_parms *p = q->red_parms;
791 memset(&opt, 0, sizeof(opt));
792 opt.v0.quantum = q->quantum;
793 opt.v0.perturb_period = q->perturb_period / HZ;
794 opt.v0.limit = q->limit;
795 opt.v0.divisor = q->divisor;
796 opt.v0.flows = q->maxflows;
797 opt.depth = q->maxdepth;
798 opt.headdrop = q->headdrop;
801 opt.qth_min = p->qth_min >> p->Wlog;
802 opt.qth_max = p->qth_max >> p->Wlog;
805 opt.Scell_log = p->Scell_log;
806 opt.max_P = p->max_P;
808 memcpy(&opt.stats, &q->stats, sizeof(opt.stats));
809 opt.flags = q->flags;
811 NLA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
820 static struct Qdisc *sfq_leaf(struct Qdisc *sch, unsigned long arg)
825 static unsigned long sfq_get(struct Qdisc *sch, u32 classid)
830 static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent,
833 /* we cannot bypass queue discipline anymore */
834 sch->flags &= ~TCQ_F_CAN_BYPASS;
838 static void sfq_put(struct Qdisc *q, unsigned long cl)
842 static struct tcf_proto **sfq_find_tcf(struct Qdisc *sch, unsigned long cl)
844 struct sfq_sched_data *q = qdisc_priv(sch);
848 return &q->filter_list;
851 static int sfq_dump_class(struct Qdisc *sch, unsigned long cl,
852 struct sk_buff *skb, struct tcmsg *tcm)
854 tcm->tcm_handle |= TC_H_MIN(cl);
858 static int sfq_dump_class_stats(struct Qdisc *sch, unsigned long cl,
861 struct sfq_sched_data *q = qdisc_priv(sch);
862 sfq_index idx = q->ht[cl - 1];
863 struct gnet_stats_queue qs = { 0 };
864 struct tc_sfq_xstats xstats = { 0 };
866 if (idx != SFQ_EMPTY_SLOT) {
867 const struct sfq_slot *slot = &q->slots[idx];
869 xstats.allot = slot->allot << SFQ_ALLOT_SHIFT;
870 qs.qlen = slot->qlen;
871 qs.backlog = slot->backlog;
873 if (gnet_stats_copy_queue(d, &qs) < 0)
875 return gnet_stats_copy_app(d, &xstats, sizeof(xstats));
878 static void sfq_walk(struct Qdisc *sch, struct qdisc_walker *arg)
880 struct sfq_sched_data *q = qdisc_priv(sch);
886 for (i = 0; i < q->divisor; i++) {
887 if (q->ht[i] == SFQ_EMPTY_SLOT ||
888 arg->count < arg->skip) {
892 if (arg->fn(sch, i + 1, arg) < 0) {
900 static const struct Qdisc_class_ops sfq_class_ops = {
904 .tcf_chain = sfq_find_tcf,
905 .bind_tcf = sfq_bind,
906 .unbind_tcf = sfq_put,
907 .dump = sfq_dump_class,
908 .dump_stats = sfq_dump_class_stats,
912 static struct Qdisc_ops sfq_qdisc_ops __read_mostly = {
913 .cl_ops = &sfq_class_ops,
915 .priv_size = sizeof(struct sfq_sched_data),
916 .enqueue = sfq_enqueue,
917 .dequeue = sfq_dequeue,
918 .peek = qdisc_peek_dequeued,
922 .destroy = sfq_destroy,
925 .owner = THIS_MODULE,
928 static int __init sfq_module_init(void)
930 return register_qdisc(&sfq_qdisc_ops);
932 static void __exit sfq_module_exit(void)
934 unregister_qdisc(&sfq_qdisc_ops);
936 module_init(sfq_module_init)
937 module_exit(sfq_module_exit)
938 MODULE_LICENSE("GPL");