blob: 32ad015ee8ce4a9c5b967c22dd90631881f2362b [file] [log] [blame]
Eric Dumazetafe4fd02013-08-29 15:49:55 -07001/*
2 * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing)
3 *
4 * Copyright (C) 2013 Eric Dumazet <edumazet@google.com>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 *
11 * Meant to be mostly used for localy generated traffic :
12 * Fast classification depends on skb->sk being set before reaching us.
13 * If not, (router workload), we use rxhash as fallback, with 32 bits wide hash.
14 * All packets belonging to a socket are considered as a 'flow'.
15 *
16 * Flows are dynamically allocated and stored in a hash table of RB trees
17 * They are also part of one Round Robin 'queues' (new or old flows)
18 *
19 * Burst avoidance (aka pacing) capability :
20 *
21 * Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a
22 * bunch of packets, and this packet scheduler adds delay between
23 * packets to respect rate limitation.
24 *
25 * enqueue() :
26 * - lookup one RB tree (out of 1024 or more) to find the flow.
27 * If non existent flow, create it, add it to the tree.
28 * Add skb to the per flow list of skb (fifo).
29 * - Use a special fifo for high prio packets
30 *
31 * dequeue() : serves flows in Round Robin
32 * Note : When a flow becomes empty, we do not immediately remove it from
33 * rb trees, for performance reasons (its expected to send additional packets,
34 * or SLAB cache will reuse socket for another flow)
35 */
36
37#include <linux/module.h>
38#include <linux/types.h>
39#include <linux/kernel.h>
40#include <linux/jiffies.h>
41#include <linux/string.h>
42#include <linux/in.h>
43#include <linux/errno.h>
44#include <linux/init.h>
45#include <linux/skbuff.h>
46#include <linux/slab.h>
47#include <linux/rbtree.h>
48#include <linux/hash.h>
Eric Dumazet08f89b92013-08-30 09:46:43 -070049#include <linux/prefetch.h>
Eric Dumazetafe4fd02013-08-29 15:49:55 -070050#include <net/netlink.h>
51#include <net/pkt_sched.h>
52#include <net/sock.h>
53#include <net/tcp_states.h>
54
55/*
56 * Per flow structure, dynamically allocated
57 */
58struct fq_flow {
59 struct sk_buff *head; /* list of skbs for this flow : first skb */
60 union {
61 struct sk_buff *tail; /* last skb in the list */
62 unsigned long age; /* jiffies when flow was emptied, for gc */
63 };
64 struct rb_node fq_node; /* anchor in fq_root[] trees */
65 struct sock *sk;
66 int qlen; /* number of packets in flow queue */
67 int credit;
68 u32 socket_hash; /* sk_hash */
69 struct fq_flow *next; /* next pointer in RR lists, or &detached */
70
71 struct rb_node rate_node; /* anchor in q->delayed tree */
72 u64 time_next_packet;
73};
74
75struct fq_flow_head {
76 struct fq_flow *first;
77 struct fq_flow *last;
78};
79
80struct fq_sched_data {
81 struct fq_flow_head new_flows;
82
83 struct fq_flow_head old_flows;
84
85 struct rb_root delayed; /* for rate limited flows */
86 u64 time_next_delayed_flow;
87
88 struct fq_flow internal; /* for non classified or high prio packets */
89 u32 quantum;
90 u32 initial_quantum;
91 u32 flow_default_rate;/* rate per flow : bytes per second */
92 u32 flow_max_rate; /* optional max rate per flow */
93 u32 flow_plimit; /* max packets per flow */
94 struct rb_root *fq_root;
95 u8 rate_enable;
96 u8 fq_trees_log;
97
98 u32 flows;
99 u32 inactive_flows;
100 u32 throttled_flows;
101
102 u64 stat_gc_flows;
103 u64 stat_internal_packets;
104 u64 stat_tcp_retrans;
105 u64 stat_throttled;
106 u64 stat_flows_plimit;
107 u64 stat_pkts_too_long;
108 u64 stat_allocation_errors;
109 struct qdisc_watchdog watchdog;
110};
111
112/* special value to mark a detached flow (not on old/new list) */
113static struct fq_flow detached, throttled;
114
115static void fq_flow_set_detached(struct fq_flow *f)
116{
117 f->next = &detached;
118}
119
120static bool fq_flow_is_detached(const struct fq_flow *f)
121{
122 return f->next == &detached;
123}
124
125static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
126{
127 struct rb_node **p = &q->delayed.rb_node, *parent = NULL;
128
129 while (*p) {
130 struct fq_flow *aux;
131
132 parent = *p;
133 aux = container_of(parent, struct fq_flow, rate_node);
134 if (f->time_next_packet >= aux->time_next_packet)
135 p = &parent->rb_right;
136 else
137 p = &parent->rb_left;
138 }
139 rb_link_node(&f->rate_node, parent, p);
140 rb_insert_color(&f->rate_node, &q->delayed);
141 q->throttled_flows++;
142 q->stat_throttled++;
143
144 f->next = &throttled;
145 if (q->time_next_delayed_flow > f->time_next_packet)
146 q->time_next_delayed_flow = f->time_next_packet;
147}
148
149
150static struct kmem_cache *fq_flow_cachep __read_mostly;
151
152static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
153{
154 if (head->first)
155 head->last->next = flow;
156 else
157 head->first = flow;
158 head->last = flow;
159 flow->next = NULL;
160}
161
162/* limit number of collected flows per round */
163#define FQ_GC_MAX 8
164#define FQ_GC_AGE (3*HZ)
165
166static bool fq_gc_candidate(const struct fq_flow *f)
167{
168 return fq_flow_is_detached(f) &&
169 time_after(jiffies, f->age + FQ_GC_AGE);
170}
171
172static void fq_gc(struct fq_sched_data *q,
173 struct rb_root *root,
174 struct sock *sk)
175{
176 struct fq_flow *f, *tofree[FQ_GC_MAX];
177 struct rb_node **p, *parent;
178 int fcnt = 0;
179
180 p = &root->rb_node;
181 parent = NULL;
182 while (*p) {
183 parent = *p;
184
185 f = container_of(parent, struct fq_flow, fq_node);
186 if (f->sk == sk)
187 break;
188
189 if (fq_gc_candidate(f)) {
190 tofree[fcnt++] = f;
191 if (fcnt == FQ_GC_MAX)
192 break;
193 }
194
195 if (f->sk > sk)
196 p = &parent->rb_right;
197 else
198 p = &parent->rb_left;
199 }
200
201 q->flows -= fcnt;
202 q->inactive_flows -= fcnt;
203 q->stat_gc_flows += fcnt;
204 while (fcnt) {
205 struct fq_flow *f = tofree[--fcnt];
206
207 rb_erase(&f->fq_node, root);
208 kmem_cache_free(fq_flow_cachep, f);
209 }
210}
211
212static const u8 prio2band[TC_PRIO_MAX + 1] = {
213 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
214};
215
216static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
217{
218 struct rb_node **p, *parent;
219 struct sock *sk = skb->sk;
220 struct rb_root *root;
221 struct fq_flow *f;
222 int band;
223
224 /* warning: no starvation prevention... */
225 band = prio2band[skb->priority & TC_PRIO_MAX];
226 if (unlikely(band == 0))
227 return &q->internal;
228
229 if (unlikely(!sk)) {
230 /* By forcing low order bit to 1, we make sure to not
231 * collide with a local flow (socket pointers are word aligned)
232 */
233 sk = (struct sock *)(skb_get_rxhash(skb) | 1L);
234 }
235
236 root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];
237
238 if (q->flows >= (2U << q->fq_trees_log) &&
239 q->inactive_flows > q->flows/2)
240 fq_gc(q, root, sk);
241
242 p = &root->rb_node;
243 parent = NULL;
244 while (*p) {
245 parent = *p;
246
247 f = container_of(parent, struct fq_flow, fq_node);
248 if (f->sk == sk) {
249 /* socket might have been reallocated, so check
250 * if its sk_hash is the same.
251 * It not, we need to refill credit with
252 * initial quantum
253 */
254 if (unlikely(skb->sk &&
255 f->socket_hash != sk->sk_hash)) {
256 f->credit = q->initial_quantum;
257 f->socket_hash = sk->sk_hash;
258 }
259 return f;
260 }
261 if (f->sk > sk)
262 p = &parent->rb_right;
263 else
264 p = &parent->rb_left;
265 }
266
267 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
268 if (unlikely(!f)) {
269 q->stat_allocation_errors++;
270 return &q->internal;
271 }
272 fq_flow_set_detached(f);
273 f->sk = sk;
274 if (skb->sk)
275 f->socket_hash = sk->sk_hash;
276 f->credit = q->initial_quantum;
277
278 rb_link_node(&f->fq_node, parent, p);
279 rb_insert_color(&f->fq_node, root);
280
281 q->flows++;
282 q->inactive_flows++;
283 return f;
284}
285
286
287/* remove one skb from head of flow queue */
288static struct sk_buff *fq_dequeue_head(struct fq_flow *flow)
289{
290 struct sk_buff *skb = flow->head;
291
292 if (skb) {
293 flow->head = skb->next;
294 skb->next = NULL;
295 flow->qlen--;
296 }
297 return skb;
298}
299
300/* We might add in the future detection of retransmits
301 * For the time being, just return false
302 */
303static bool skb_is_retransmit(struct sk_buff *skb)
304{
305 return false;
306}
307
308/* add skb to flow queue
309 * flow queue is a linked list, kind of FIFO, except for TCP retransmits
310 * We special case tcp retransmits to be transmitted before other packets.
311 * We rely on fact that TCP retransmits are unlikely, so we do not waste
312 * a separate queue or a pointer.
313 * head-> [retrans pkt 1]
314 * [retrans pkt 2]
315 * [ normal pkt 1]
316 * [ normal pkt 2]
317 * [ normal pkt 3]
318 * tail-> [ normal pkt 4]
319 */
320static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
321{
322 struct sk_buff *prev, *head = flow->head;
323
324 skb->next = NULL;
325 if (!head) {
326 flow->head = skb;
327 flow->tail = skb;
328 return;
329 }
330 if (likely(!skb_is_retransmit(skb))) {
331 flow->tail->next = skb;
332 flow->tail = skb;
333 return;
334 }
335
336 /* This skb is a tcp retransmit,
337 * find the last retrans packet in the queue
338 */
339 prev = NULL;
340 while (skb_is_retransmit(head)) {
341 prev = head;
342 head = head->next;
343 if (!head)
344 break;
345 }
346 if (!prev) { /* no rtx packet in queue, become the new head */
347 skb->next = flow->head;
348 flow->head = skb;
349 } else {
350 if (prev == flow->tail)
351 flow->tail = skb;
352 else
353 skb->next = prev->next;
354 prev->next = skb;
355 }
356}
357
358static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
359{
360 struct fq_sched_data *q = qdisc_priv(sch);
361 struct fq_flow *f;
362
363 if (unlikely(sch->q.qlen >= sch->limit))
364 return qdisc_drop(skb, sch);
365
366 f = fq_classify(skb, q);
367 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
368 q->stat_flows_plimit++;
369 return qdisc_drop(skb, sch);
370 }
371
372 f->qlen++;
373 flow_queue_add(f, skb);
374 if (skb_is_retransmit(skb))
375 q->stat_tcp_retrans++;
376 sch->qstats.backlog += qdisc_pkt_len(skb);
377 if (fq_flow_is_detached(f)) {
378 fq_flow_add_tail(&q->new_flows, f);
379 if (q->quantum > f->credit)
380 f->credit = q->quantum;
381 q->inactive_flows--;
382 qdisc_unthrottled(sch);
383 }
384 if (unlikely(f == &q->internal)) {
385 q->stat_internal_packets++;
386 qdisc_unthrottled(sch);
387 }
388 sch->q.qlen++;
389
390 return NET_XMIT_SUCCESS;
391}
392
393static void fq_check_throttled(struct fq_sched_data *q, u64 now)
394{
395 struct rb_node *p;
396
397 if (q->time_next_delayed_flow > now)
398 return;
399
400 q->time_next_delayed_flow = ~0ULL;
401 while ((p = rb_first(&q->delayed)) != NULL) {
402 struct fq_flow *f = container_of(p, struct fq_flow, rate_node);
403
404 if (f->time_next_packet > now) {
405 q->time_next_delayed_flow = f->time_next_packet;
406 break;
407 }
408 rb_erase(p, &q->delayed);
409 q->throttled_flows--;
410 fq_flow_add_tail(&q->old_flows, f);
411 }
412}
413
414static struct sk_buff *fq_dequeue(struct Qdisc *sch)
415{
416 struct fq_sched_data *q = qdisc_priv(sch);
417 u64 now = ktime_to_ns(ktime_get());
418 struct fq_flow_head *head;
419 struct sk_buff *skb;
420 struct fq_flow *f;
421
422 skb = fq_dequeue_head(&q->internal);
423 if (skb)
424 goto out;
425 fq_check_throttled(q, now);
426begin:
427 head = &q->new_flows;
428 if (!head->first) {
429 head = &q->old_flows;
430 if (!head->first) {
431 if (q->time_next_delayed_flow != ~0ULL)
432 qdisc_watchdog_schedule_ns(&q->watchdog,
433 q->time_next_delayed_flow);
434 return NULL;
435 }
436 }
437 f = head->first;
438
439 if (f->credit <= 0) {
440 f->credit += q->quantum;
441 head->first = f->next;
442 fq_flow_add_tail(&q->old_flows, f);
443 goto begin;
444 }
445
446 if (unlikely(f->head && now < f->time_next_packet)) {
447 head->first = f->next;
448 fq_flow_set_throttled(q, f);
449 goto begin;
450 }
451
452 skb = fq_dequeue_head(f);
453 if (!skb) {
454 head->first = f->next;
455 /* force a pass through old_flows to prevent starvation */
456 if ((head == &q->new_flows) && q->old_flows.first) {
457 fq_flow_add_tail(&q->old_flows, f);
458 } else {
459 fq_flow_set_detached(f);
460 f->age = jiffies;
461 q->inactive_flows++;
462 }
463 goto begin;
464 }
Eric Dumazet08f89b92013-08-30 09:46:43 -0700465 prefetch(&skb->end);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700466 f->time_next_packet = now;
467 f->credit -= qdisc_pkt_len(skb);
468
469 if (f->credit <= 0 &&
470 q->rate_enable &&
471 skb->sk && skb->sk->sk_state != TCP_TIME_WAIT) {
472 u32 rate = skb->sk->sk_pacing_rate ?: q->flow_default_rate;
473
474 rate = min(rate, q->flow_max_rate);
475 if (rate) {
476 u64 len = (u64)qdisc_pkt_len(skb) * NSEC_PER_SEC;
477
478 do_div(len, rate);
479 /* Since socket rate can change later,
480 * clamp the delay to 125 ms.
481 * TODO: maybe segment the too big skb, as in commit
482 * e43ac79a4bc ("sch_tbf: segment too big GSO packets")
483 */
484 if (unlikely(len > 125 * NSEC_PER_MSEC)) {
485 len = 125 * NSEC_PER_MSEC;
486 q->stat_pkts_too_long++;
487 }
488
489 f->time_next_packet = now + len;
490 }
491 }
492out:
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700493 sch->qstats.backlog -= qdisc_pkt_len(skb);
494 qdisc_bstats_update(sch, skb);
495 sch->q.qlen--;
496 qdisc_unthrottled(sch);
497 return skb;
498}
499
500static void fq_reset(struct Qdisc *sch)
501{
502 struct sk_buff *skb;
503
504 while ((skb = fq_dequeue(sch)) != NULL)
505 kfree_skb(skb);
506}
507
508static void fq_rehash(struct fq_sched_data *q,
509 struct rb_root *old_array, u32 old_log,
510 struct rb_root *new_array, u32 new_log)
511{
512 struct rb_node *op, **np, *parent;
513 struct rb_root *oroot, *nroot;
514 struct fq_flow *of, *nf;
515 int fcnt = 0;
516 u32 idx;
517
518 for (idx = 0; idx < (1U << old_log); idx++) {
519 oroot = &old_array[idx];
520 while ((op = rb_first(oroot)) != NULL) {
521 rb_erase(op, oroot);
522 of = container_of(op, struct fq_flow, fq_node);
523 if (fq_gc_candidate(of)) {
524 fcnt++;
525 kmem_cache_free(fq_flow_cachep, of);
526 continue;
527 }
528 nroot = &new_array[hash_32((u32)(long)of->sk, new_log)];
529
530 np = &nroot->rb_node;
531 parent = NULL;
532 while (*np) {
533 parent = *np;
534
535 nf = container_of(parent, struct fq_flow, fq_node);
536 BUG_ON(nf->sk == of->sk);
537
538 if (nf->sk > of->sk)
539 np = &parent->rb_right;
540 else
541 np = &parent->rb_left;
542 }
543
544 rb_link_node(&of->fq_node, parent, np);
545 rb_insert_color(&of->fq_node, nroot);
546 }
547 }
548 q->flows -= fcnt;
549 q->inactive_flows -= fcnt;
550 q->stat_gc_flows += fcnt;
551}
552
553static int fq_resize(struct fq_sched_data *q, u32 log)
554{
555 struct rb_root *array;
556 u32 idx;
557
558 if (q->fq_root && log == q->fq_trees_log)
559 return 0;
560
561 array = kmalloc(sizeof(struct rb_root) << log, GFP_KERNEL);
562 if (!array)
563 return -ENOMEM;
564
565 for (idx = 0; idx < (1U << log); idx++)
566 array[idx] = RB_ROOT;
567
568 if (q->fq_root) {
569 fq_rehash(q, q->fq_root, q->fq_trees_log, array, log);
570 kfree(q->fq_root);
571 }
572 q->fq_root = array;
573 q->fq_trees_log = log;
574
575 return 0;
576}
577
578static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
579 [TCA_FQ_PLIMIT] = { .type = NLA_U32 },
580 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 },
581 [TCA_FQ_QUANTUM] = { .type = NLA_U32 },
582 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 },
583 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 },
584 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 },
585 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 },
586 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 },
587};
588
589static int fq_change(struct Qdisc *sch, struct nlattr *opt)
590{
591 struct fq_sched_data *q = qdisc_priv(sch);
592 struct nlattr *tb[TCA_FQ_MAX + 1];
593 int err, drop_count = 0;
594 u32 fq_log;
595
596 if (!opt)
597 return -EINVAL;
598
599 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy);
600 if (err < 0)
601 return err;
602
603 sch_tree_lock(sch);
604
605 fq_log = q->fq_trees_log;
606
607 if (tb[TCA_FQ_BUCKETS_LOG]) {
608 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);
609
610 if (nval >= 1 && nval <= ilog2(256*1024))
611 fq_log = nval;
612 else
613 err = -EINVAL;
614 }
615 if (tb[TCA_FQ_PLIMIT])
616 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
617
618 if (tb[TCA_FQ_FLOW_PLIMIT])
619 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
620
621 if (tb[TCA_FQ_QUANTUM])
622 q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
623
624 if (tb[TCA_FQ_INITIAL_QUANTUM])
625 q->quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
626
627 if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
628 q->flow_default_rate = nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]);
629
630 if (tb[TCA_FQ_FLOW_MAX_RATE])
631 q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);
632
633 if (tb[TCA_FQ_RATE_ENABLE]) {
634 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);
635
636 if (enable <= 1)
637 q->rate_enable = enable;
638 else
639 err = -EINVAL;
640 }
641
642 if (!err)
643 err = fq_resize(q, fq_log);
644
645 while (sch->q.qlen > sch->limit) {
646 struct sk_buff *skb = fq_dequeue(sch);
647
648 kfree_skb(skb);
649 drop_count++;
650 }
651 qdisc_tree_decrease_qlen(sch, drop_count);
652
653 sch_tree_unlock(sch);
654 return err;
655}
656
657static void fq_destroy(struct Qdisc *sch)
658{
659 struct fq_sched_data *q = qdisc_priv(sch);
660 struct rb_root *root;
661 struct rb_node *p;
662 unsigned int idx;
663
664 if (q->fq_root) {
665 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
666 root = &q->fq_root[idx];
667 while ((p = rb_first(root)) != NULL) {
668 rb_erase(p, root);
669 kmem_cache_free(fq_flow_cachep,
670 container_of(p, struct fq_flow, fq_node));
671 }
672 }
673 kfree(q->fq_root);
674 }
675 qdisc_watchdog_cancel(&q->watchdog);
676}
677
678static int fq_init(struct Qdisc *sch, struct nlattr *opt)
679{
680 struct fq_sched_data *q = qdisc_priv(sch);
681 int err;
682
683 sch->limit = 10000;
684 q->flow_plimit = 100;
685 q->quantum = 2 * psched_mtu(qdisc_dev(sch));
686 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
687 q->flow_default_rate = 0;
688 q->flow_max_rate = ~0U;
689 q->rate_enable = 1;
690 q->new_flows.first = NULL;
691 q->old_flows.first = NULL;
692 q->delayed = RB_ROOT;
693 q->fq_root = NULL;
694 q->fq_trees_log = ilog2(1024);
695 qdisc_watchdog_init(&q->watchdog, sch);
696
697 if (opt)
698 err = fq_change(sch, opt);
699 else
700 err = fq_resize(q, q->fq_trees_log);
701
702 return err;
703}
704
705static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
706{
707 struct fq_sched_data *q = qdisc_priv(sch);
708 struct nlattr *opts;
709
710 opts = nla_nest_start(skb, TCA_OPTIONS);
711 if (opts == NULL)
712 goto nla_put_failure;
713
714 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
715 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
716 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
717 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
718 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
719 nla_put_u32(skb, TCA_FQ_FLOW_DEFAULT_RATE, q->flow_default_rate) ||
720 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
721 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
722 goto nla_put_failure;
723
724 nla_nest_end(skb, opts);
725 return skb->len;
726
727nla_put_failure:
728 return -1;
729}
730
731static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
732{
733 struct fq_sched_data *q = qdisc_priv(sch);
734 u64 now = ktime_to_ns(ktime_get());
735 struct tc_fq_qd_stats st = {
736 .gc_flows = q->stat_gc_flows,
737 .highprio_packets = q->stat_internal_packets,
738 .tcp_retrans = q->stat_tcp_retrans,
739 .throttled = q->stat_throttled,
740 .flows_plimit = q->stat_flows_plimit,
741 .pkts_too_long = q->stat_pkts_too_long,
742 .allocation_errors = q->stat_allocation_errors,
743 .flows = q->flows,
744 .inactive_flows = q->inactive_flows,
745 .throttled_flows = q->throttled_flows,
746 .time_next_delayed_flow = q->time_next_delayed_flow - now,
747 };
748
749 return gnet_stats_copy_app(d, &st, sizeof(st));
750}
751
752static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
753 .id = "fq",
754 .priv_size = sizeof(struct fq_sched_data),
755
756 .enqueue = fq_enqueue,
757 .dequeue = fq_dequeue,
758 .peek = qdisc_peek_dequeued,
759 .init = fq_init,
760 .reset = fq_reset,
761 .destroy = fq_destroy,
762 .change = fq_change,
763 .dump = fq_dump,
764 .dump_stats = fq_dump_stats,
765 .owner = THIS_MODULE,
766};
767
768static int __init fq_module_init(void)
769{
770 int ret;
771
772 fq_flow_cachep = kmem_cache_create("fq_flow_cache",
773 sizeof(struct fq_flow),
774 0, 0, NULL);
775 if (!fq_flow_cachep)
776 return -ENOMEM;
777
778 ret = register_qdisc(&fq_qdisc_ops);
779 if (ret)
780 kmem_cache_destroy(fq_flow_cachep);
781 return ret;
782}
783
784static void __exit fq_module_exit(void)
785{
786 unregister_qdisc(&fq_qdisc_ops);
787 kmem_cache_destroy(fq_flow_cachep);
788}
789
790module_init(fq_module_init)
791module_exit(fq_module_exit)
792MODULE_AUTHOR("Eric Dumazet");
793MODULE_LICENSE("GPL");