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1/*
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>
49#include <linux/prefetch.h>
50#include <linux/vmalloc.h>
51#include <net/netlink.h>
52#include <net/pkt_sched.h>
53#include <net/sock.h>
54#include <net/tcp_states.h>
55
56/*
57 * Per flow structure, dynamically allocated
58 */
59struct fq_flow {
60 struct sk_buff *head; /* list of skbs for this flow : first skb */
61 union {
62 struct sk_buff *tail; /* last skb in the list */
63 unsigned long age; /* jiffies when flow was emptied, for gc */
64 };
65 struct rb_node fq_node; /* anchor in fq_root[] trees */
66 struct sock *sk;
67 int qlen; /* number of packets in flow queue */
68 int credit;
69 u32 socket_hash; /* sk_hash */
70 struct fq_flow *next; /* next pointer in RR lists, or &detached */
71
72 struct rb_node rate_node; /* anchor in q->delayed tree */
73 u64 time_next_packet;
74};
75
76struct fq_flow_head {
77 struct fq_flow *first;
78 struct fq_flow *last;
79};
80
81struct fq_sched_data {
82 struct fq_flow_head new_flows;
83
84 struct fq_flow_head old_flows;
85
86 struct rb_root delayed; /* for rate limited flows */
87 u64 time_next_delayed_flow;
88
89 struct fq_flow internal; /* for non classified or high prio packets */
90 u32 quantum;
91 u32 initial_quantum;
92 u32 flow_refill_delay;
93 u32 flow_max_rate; /* optional max rate per flow */
94 u32 flow_plimit; /* max packets per flow */
95 struct rb_root *fq_root;
96 u8 rate_enable;
97 u8 fq_trees_log;
98
99 u32 flows;
100 u32 inactive_flows;
101 u32 throttled_flows;
102
103 u64 stat_gc_flows;
104 u64 stat_internal_packets;
105 u64 stat_tcp_retrans;
106 u64 stat_throttled;
107 u64 stat_flows_plimit;
108 u64 stat_pkts_too_long;
109 u64 stat_allocation_errors;
110 struct qdisc_watchdog watchdog;
111};
112
113/* special value to mark a detached flow (not on old/new list) */
114static struct fq_flow detached, throttled;
115
116static void fq_flow_set_detached(struct fq_flow *f)
117{
118 f->next = &detached;
119 f->age = jiffies;
120}
121
122static bool fq_flow_is_detached(const struct fq_flow *f)
123{
124 return f->next == &detached;
125}
126
127static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
128{
129 struct rb_node **p = &q->delayed.rb_node, *parent = NULL;
130
131 while (*p) {
132 struct fq_flow *aux;
133
134 parent = *p;
135 aux = container_of(parent, struct fq_flow, rate_node);
136 if (f->time_next_packet >= aux->time_next_packet)
137 p = &parent->rb_right;
138 else
139 p = &parent->rb_left;
140 }
141 rb_link_node(&f->rate_node, parent, p);
142 rb_insert_color(&f->rate_node, &q->delayed);
143 q->throttled_flows++;
144 q->stat_throttled++;
145
146 f->next = &throttled;
147 if (q->time_next_delayed_flow > f->time_next_packet)
148 q->time_next_delayed_flow = f->time_next_packet;
149}
150
151
152static struct kmem_cache *fq_flow_cachep __read_mostly;
153
154static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
155{
156 if (head->first)
157 head->last->next = flow;
158 else
159 head->first = flow;
160 head->last = flow;
161 flow->next = NULL;
162}
163
164/* limit number of collected flows per round */
165#define FQ_GC_MAX 8
166#define FQ_GC_AGE (3*HZ)
167
168static bool fq_gc_candidate(const struct fq_flow *f)
169{
170 return fq_flow_is_detached(f) &&
171 time_after(jiffies, f->age + FQ_GC_AGE);
172}
173
174static void fq_gc(struct fq_sched_data *q,
175 struct rb_root *root,
176 struct sock *sk)
177{
178 struct fq_flow *f, *tofree[FQ_GC_MAX];
179 struct rb_node **p, *parent;
180 int fcnt = 0;
181
182 p = &root->rb_node;
183 parent = NULL;
184 while (*p) {
185 parent = *p;
186
187 f = container_of(parent, struct fq_flow, fq_node);
188 if (f->sk == sk)
189 break;
190
191 if (fq_gc_candidate(f)) {
192 tofree[fcnt++] = f;
193 if (fcnt == FQ_GC_MAX)
194 break;
195 }
196
197 if (f->sk > sk)
198 p = &parent->rb_right;
199 else
200 p = &parent->rb_left;
201 }
202
203 q->flows -= fcnt;
204 q->inactive_flows -= fcnt;
205 q->stat_gc_flows += fcnt;
206 while (fcnt) {
207 struct fq_flow *f = tofree[--fcnt];
208
209 rb_erase(&f->fq_node, root);
210 kmem_cache_free(fq_flow_cachep, f);
211 }
212}
213
214static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q)
215{
216 struct rb_node **p, *parent;
217 struct sock *sk = skb->sk;
218 struct rb_root *root;
219 struct fq_flow *f;
220
221 /* warning: no starvation prevention... */
222 if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
223 return &q->internal;
224
225 if (unlikely(!sk)) {
226 /* By forcing low order bit to 1, we make sure to not
227 * collide with a local flow (socket pointers are word aligned)
228 */
229 sk = (struct sock *)(skb_get_hash(skb) | 1L);
230 }
231
232 root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];
233
234 if (q->flows >= (2U << q->fq_trees_log) &&
235 q->inactive_flows > q->flows/2)
236 fq_gc(q, root, sk);
237
238 p = &root->rb_node;
239 parent = NULL;
240 while (*p) {
241 parent = *p;
242
243 f = container_of(parent, struct fq_flow, fq_node);
244 if (f->sk == sk) {
245 /* socket might have been reallocated, so check
246 * if its sk_hash is the same.
247 * It not, we need to refill credit with
248 * initial quantum
249 */
250 if (unlikely(skb->sk &&
251 f->socket_hash != sk->sk_hash)) {
252 f->credit = q->initial_quantum;
253 f->socket_hash = sk->sk_hash;
254 f->time_next_packet = 0ULL;
255 }
256 return f;
257 }
258 if (f->sk > sk)
259 p = &parent->rb_right;
260 else
261 p = &parent->rb_left;
262 }
263
264 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
265 if (unlikely(!f)) {
266 q->stat_allocation_errors++;
267 return &q->internal;
268 }
269 fq_flow_set_detached(f);
270 f->sk = sk;
271 if (skb->sk)
272 f->socket_hash = sk->sk_hash;
273 f->credit = q->initial_quantum;
274
275 rb_link_node(&f->fq_node, parent, p);
276 rb_insert_color(&f->fq_node, root);
277
278 q->flows++;
279 q->inactive_flows++;
280 return f;
281}
282
283
284/* remove one skb from head of flow queue */
285static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
286{
287 struct sk_buff *skb = flow->head;
288
289 if (skb) {
290 flow->head = skb->next;
291 skb->next = NULL;
292 flow->qlen--;
293 sch->qstats.backlog -= qdisc_pkt_len(skb);
294 sch->q.qlen--;
295 }
296 return skb;
297}
298
299/* We might add in the future detection of retransmits
300 * For the time being, just return false
301 */
302static bool skb_is_retransmit(struct sk_buff *skb)
303{
304 return false;
305}
306
307/* add skb to flow queue
308 * flow queue is a linked list, kind of FIFO, except for TCP retransmits
309 * We special case tcp retransmits to be transmitted before other packets.
310 * We rely on fact that TCP retransmits are unlikely, so we do not waste
311 * a separate queue or a pointer.
312 * head-> [retrans pkt 1]
313 * [retrans pkt 2]
314 * [ normal pkt 1]
315 * [ normal pkt 2]
316 * [ normal pkt 3]
317 * tail-> [ normal pkt 4]
318 */
319static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
320{
321 struct sk_buff *prev, *head = flow->head;
322
323 skb->next = NULL;
324 if (!head) {
325 flow->head = skb;
326 flow->tail = skb;
327 return;
328 }
329 if (likely(!skb_is_retransmit(skb))) {
330 flow->tail->next = skb;
331 flow->tail = skb;
332 return;
333 }
334
335 /* This skb is a tcp retransmit,
336 * find the last retrans packet in the queue
337 */
338 prev = NULL;
339 while (skb_is_retransmit(head)) {
340 prev = head;
341 head = head->next;
342 if (!head)
343 break;
344 }
345 if (!prev) { /* no rtx packet in queue, become the new head */
346 skb->next = flow->head;
347 flow->head = skb;
348 } else {
349 if (prev == flow->tail)
350 flow->tail = skb;
351 else
352 skb->next = prev->next;
353 prev->next = skb;
354 }
355}
356
357static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
358{
359 struct fq_sched_data *q = qdisc_priv(sch);
360 struct fq_flow *f;
361
362 if (unlikely(sch->q.qlen >= sch->limit))
363 return qdisc_drop(skb, sch);
364
365 f = fq_classify(skb, q);
366 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
367 q->stat_flows_plimit++;
368 return qdisc_drop(skb, sch);
369 }
370
371 f->qlen++;
372 if (skb_is_retransmit(skb))
373 q->stat_tcp_retrans++;
374 sch->qstats.backlog += qdisc_pkt_len(skb);
375 if (fq_flow_is_detached(f)) {
376 fq_flow_add_tail(&q->new_flows, f);
377 if (time_after(jiffies, f->age + q->flow_refill_delay))
378 f->credit = max_t(u32, f->credit, q->quantum);
379 q->inactive_flows--;
380 qdisc_unthrottled(sch);
381 }
382
383 /* Note: this overwrites f->age */
384 flow_queue_add(f, skb);
385
386 if (unlikely(f == &q->internal)) {
387 q->stat_internal_packets++;
388 qdisc_unthrottled(sch);
389 }
390 sch->q.qlen++;
391
392 return NET_XMIT_SUCCESS;
393}
394
395static void fq_check_throttled(struct fq_sched_data *q, u64 now)
396{
397 struct rb_node *p;
398
399 if (q->time_next_delayed_flow > now)
400 return;
401
402 q->time_next_delayed_flow = ~0ULL;
403 while ((p = rb_first(&q->delayed)) != NULL) {
404 struct fq_flow *f = container_of(p, struct fq_flow, rate_node);
405
406 if (f->time_next_packet > now) {
407 q->time_next_delayed_flow = f->time_next_packet;
408 break;
409 }
410 rb_erase(p, &q->delayed);
411 q->throttled_flows--;
412 fq_flow_add_tail(&q->old_flows, f);
413 }
414}
415
416static struct sk_buff *fq_dequeue(struct Qdisc *sch)
417{
418 struct fq_sched_data *q = qdisc_priv(sch);
419 u64 now = ktime_to_ns(ktime_get());
420 struct fq_flow_head *head;
421 struct sk_buff *skb;
422 struct fq_flow *f;
423 u32 rate;
424
425 skb = fq_dequeue_head(sch, &q->internal);
426 if (skb)
427 goto out;
428 fq_check_throttled(q, now);
429begin:
430 head = &q->new_flows;
431 if (!head->first) {
432 head = &q->old_flows;
433 if (!head->first) {
434 if (q->time_next_delayed_flow != ~0ULL)
435 qdisc_watchdog_schedule_ns(&q->watchdog,
436 q->time_next_delayed_flow);
437 return NULL;
438 }
439 }
440 f = head->first;
441
442 if (f->credit <= 0) {
443 f->credit += q->quantum;
444 head->first = f->next;
445 fq_flow_add_tail(&q->old_flows, f);
446 goto begin;
447 }
448
449 if (unlikely(f->head && now < f->time_next_packet)) {
450 head->first = f->next;
451 fq_flow_set_throttled(q, f);
452 goto begin;
453 }
454
455 skb = fq_dequeue_head(sch, f);
456 if (!skb) {
457 head->first = f->next;
458 /* force a pass through old_flows to prevent starvation */
459 if ((head == &q->new_flows) && q->old_flows.first) {
460 fq_flow_add_tail(&q->old_flows, f);
461 } else {
462 fq_flow_set_detached(f);
463 q->inactive_flows++;
464 }
465 goto begin;
466 }
467 prefetch(&skb->end);
468 f->time_next_packet = now;
469 f->credit -= qdisc_pkt_len(skb);
470
471 if (f->credit > 0 || !q->rate_enable)
472 goto out;
473
474 rate = q->flow_max_rate;
475 if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT)
476 rate = min(skb->sk->sk_pacing_rate, rate);
477
478 if (rate != ~0U) {
479 u32 plen = max(qdisc_pkt_len(skb), q->quantum);
480 u64 len = (u64)plen * NSEC_PER_SEC;
481
482 if (likely(rate))
483 do_div(len, rate);
484 /* Since socket rate can change later,
485 * clamp the delay to 125 ms.
486 * TODO: maybe segment the too big skb, as in commit
487 * e43ac79a4bc ("sch_tbf: segment too big GSO packets")
488 */
489 if (unlikely(len > 125 * NSEC_PER_MSEC)) {
490 len = 125 * NSEC_PER_MSEC;
491 q->stat_pkts_too_long++;
492 }
493
494 f->time_next_packet = now + len;
495 }
496out:
497 qdisc_bstats_update(sch, skb);
498 qdisc_unthrottled(sch);
499 return skb;
500}
501
502static void fq_reset(struct Qdisc *sch)
503{
504 struct fq_sched_data *q = qdisc_priv(sch);
505 struct rb_root *root;
506 struct sk_buff *skb;
507 struct rb_node *p;
508 struct fq_flow *f;
509 unsigned int idx;
510
511 while ((skb = fq_dequeue_head(sch, &q->internal)) != NULL)
512 kfree_skb(skb);
513
514 if (!q->fq_root)
515 return;
516
517 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
518 root = &q->fq_root[idx];
519 while ((p = rb_first(root)) != NULL) {
520 f = container_of(p, struct fq_flow, fq_node);
521 rb_erase(p, root);
522
523 while ((skb = fq_dequeue_head(sch, f)) != NULL)
524 kfree_skb(skb);
525
526 kmem_cache_free(fq_flow_cachep, f);
527 }
528 }
529 q->new_flows.first = NULL;
530 q->old_flows.first = NULL;
531 q->delayed = RB_ROOT;
532 q->flows = 0;
533 q->inactive_flows = 0;
534 q->throttled_flows = 0;
535}
536
537static void fq_rehash(struct fq_sched_data *q,
538 struct rb_root *old_array, u32 old_log,
539 struct rb_root *new_array, u32 new_log)
540{
541 struct rb_node *op, **np, *parent;
542 struct rb_root *oroot, *nroot;
543 struct fq_flow *of, *nf;
544 int fcnt = 0;
545 u32 idx;
546
547 for (idx = 0; idx < (1U << old_log); idx++) {
548 oroot = &old_array[idx];
549 while ((op = rb_first(oroot)) != NULL) {
550 rb_erase(op, oroot);
551 of = container_of(op, struct fq_flow, fq_node);
552 if (fq_gc_candidate(of)) {
553 fcnt++;
554 kmem_cache_free(fq_flow_cachep, of);
555 continue;
556 }
557 nroot = &new_array[hash_32((u32)(long)of->sk, new_log)];
558
559 np = &nroot->rb_node;
560 parent = NULL;
561 while (*np) {
562 parent = *np;
563
564 nf = container_of(parent, struct fq_flow, fq_node);
565 BUG_ON(nf->sk == of->sk);
566
567 if (nf->sk > of->sk)
568 np = &parent->rb_right;
569 else
570 np = &parent->rb_left;
571 }
572
573 rb_link_node(&of->fq_node, parent, np);
574 rb_insert_color(&of->fq_node, nroot);
575 }
576 }
577 q->flows -= fcnt;
578 q->inactive_flows -= fcnt;
579 q->stat_gc_flows += fcnt;
580}
581
582static void *fq_alloc_node(size_t sz, int node)
583{
584 void *ptr;
585
586 ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node);
587 if (!ptr)
588 ptr = vmalloc_node(sz, node);
589 return ptr;
590}
591
592static void fq_free(void *addr)
593{
594 if (addr && is_vmalloc_addr(addr))
595 vfree(addr);
596 else
597 kfree(addr);
598}
599
600static int fq_resize(struct Qdisc *sch, u32 log)
601{
602 struct fq_sched_data *q = qdisc_priv(sch);
603 struct rb_root *array;
604 void *old_fq_root;
605 u32 idx;
606
607 if (q->fq_root && log == q->fq_trees_log)
608 return 0;
609
610 /* If XPS was setup, we can allocate memory on right NUMA node */
611 array = fq_alloc_node(sizeof(struct rb_root) << log,
612 netdev_queue_numa_node_read(sch->dev_queue));
613 if (!array)
614 return -ENOMEM;
615
616 for (idx = 0; idx < (1U << log); idx++)
617 array[idx] = RB_ROOT;
618
619 sch_tree_lock(sch);
620
621 old_fq_root = q->fq_root;
622 if (old_fq_root)
623 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
624
625 q->fq_root = array;
626 q->fq_trees_log = log;
627
628 sch_tree_unlock(sch);
629
630 fq_free(old_fq_root);
631
632 return 0;
633}
634
635static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
636 [TCA_FQ_PLIMIT] = { .type = NLA_U32 },
637 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 },
638 [TCA_FQ_QUANTUM] = { .type = NLA_U32 },
639 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 },
640 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 },
641 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 },
642 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 },
643 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 },
644 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 },
645};
646
647static int fq_change(struct Qdisc *sch, struct nlattr *opt)
648{
649 struct fq_sched_data *q = qdisc_priv(sch);
650 struct nlattr *tb[TCA_FQ_MAX + 1];
651 int err, drop_count = 0;
652 u32 fq_log;
653
654 if (!opt)
655 return -EINVAL;
656
657 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy);
658 if (err < 0)
659 return err;
660
661 sch_tree_lock(sch);
662
663 fq_log = q->fq_trees_log;
664
665 if (tb[TCA_FQ_BUCKETS_LOG]) {
666 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);
667
668 if (nval >= 1 && nval <= ilog2(256*1024))
669 fq_log = nval;
670 else
671 err = -EINVAL;
672 }
673 if (tb[TCA_FQ_PLIMIT])
674 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
675
676 if (tb[TCA_FQ_FLOW_PLIMIT])
677 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
678
679 if (tb[TCA_FQ_QUANTUM])
680 q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
681
682 if (tb[TCA_FQ_INITIAL_QUANTUM])
683 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
684
685 if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
686 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n",
687 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]));
688
689 if (tb[TCA_FQ_FLOW_MAX_RATE])
690 q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);
691
692 if (tb[TCA_FQ_RATE_ENABLE]) {
693 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);
694
695 if (enable <= 1)
696 q->rate_enable = enable;
697 else
698 err = -EINVAL;
699 }
700
701 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) {
702 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ;
703
704 q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
705 }
706
707 if (!err) {
708 sch_tree_unlock(sch);
709 err = fq_resize(sch, fq_log);
710 sch_tree_lock(sch);
711 }
712 while (sch->q.qlen > sch->limit) {
713 struct sk_buff *skb = fq_dequeue(sch);
714
715 if (!skb)
716 break;
717 kfree_skb(skb);
718 drop_count++;
719 }
720 qdisc_tree_decrease_qlen(sch, drop_count);
721
722 sch_tree_unlock(sch);
723 return err;
724}
725
726static void fq_destroy(struct Qdisc *sch)
727{
728 struct fq_sched_data *q = qdisc_priv(sch);
729
730 fq_reset(sch);
731 fq_free(q->fq_root);
732 qdisc_watchdog_cancel(&q->watchdog);
733}
734
735static int fq_init(struct Qdisc *sch, struct nlattr *opt)
736{
737 struct fq_sched_data *q = qdisc_priv(sch);
738 int err;
739
740 sch->limit = 10000;
741 q->flow_plimit = 100;
742 q->quantum = 2 * psched_mtu(qdisc_dev(sch));
743 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
744 q->flow_refill_delay = msecs_to_jiffies(40);
745 q->flow_max_rate = ~0U;
746 q->rate_enable = 1;
747 q->new_flows.first = NULL;
748 q->old_flows.first = NULL;
749 q->delayed = RB_ROOT;
750 q->fq_root = NULL;
751 q->fq_trees_log = ilog2(1024);
752 qdisc_watchdog_init(&q->watchdog, sch);
753
754 if (opt)
755 err = fq_change(sch, opt);
756 else
757 err = fq_resize(sch, q->fq_trees_log);
758
759 return err;
760}
761
762static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
763{
764 struct fq_sched_data *q = qdisc_priv(sch);
765 struct nlattr *opts;
766
767 opts = nla_nest_start(skb, TCA_OPTIONS);
768 if (opts == NULL)
769 goto nla_put_failure;
770
771 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */
772
773 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
774 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
775 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
776 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
777 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
778 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
779 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY,
780 jiffies_to_usecs(q->flow_refill_delay)) ||
781 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
782 goto nla_put_failure;
783
784 return nla_nest_end(skb, opts);
785
786nla_put_failure:
787 return -1;
788}
789
790static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
791{
792 struct fq_sched_data *q = qdisc_priv(sch);
793 u64 now = ktime_to_ns(ktime_get());
794 struct tc_fq_qd_stats st = {
795 .gc_flows = q->stat_gc_flows,
796 .highprio_packets = q->stat_internal_packets,
797 .tcp_retrans = q->stat_tcp_retrans,
798 .throttled = q->stat_throttled,
799 .flows_plimit = q->stat_flows_plimit,
800 .pkts_too_long = q->stat_pkts_too_long,
801 .allocation_errors = q->stat_allocation_errors,
802 .flows = q->flows,
803 .inactive_flows = q->inactive_flows,
804 .throttled_flows = q->throttled_flows,
805 .time_next_delayed_flow = q->time_next_delayed_flow - now,
806 };
807
808 return gnet_stats_copy_app(d, &st, sizeof(st));
809}
810
811static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
812 .id = "fq",
813 .priv_size = sizeof(struct fq_sched_data),
814
815 .enqueue = fq_enqueue,
816 .dequeue = fq_dequeue,
817 .peek = qdisc_peek_dequeued,
818 .init = fq_init,
819 .reset = fq_reset,
820 .destroy = fq_destroy,
821 .change = fq_change,
822 .dump = fq_dump,
823 .dump_stats = fq_dump_stats,
824 .owner = THIS_MODULE,
825};
826
827static int __init fq_module_init(void)
828{
829 int ret;
830
831 fq_flow_cachep = kmem_cache_create("fq_flow_cache",
832 sizeof(struct fq_flow),
833 0, 0, NULL);
834 if (!fq_flow_cachep)
835 return -ENOMEM;
836
837 ret = register_qdisc(&fq_qdisc_ops);
838 if (ret)
839 kmem_cache_destroy(fq_flow_cachep);
840 return ret;
841}
842
843static void __exit fq_module_exit(void)
844{
845 unregister_qdisc(&fq_qdisc_ops);
846 kmem_cache_destroy(fq_flow_cachep);
847}
848
849module_init(fq_module_init)
850module_exit(fq_module_exit)
851MODULE_AUTHOR("Eric Dumazet");
852MODULE_LICENSE("GPL");