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drm/fb-helper: Keep references for the current set of used connectors
[linux/fpc-iii.git] / net / sched / sch_fq.c
blobe5458b99e09cb4d4226a1ef49a7ec81f2e20d94a
1 /*
2 * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing)
3 *
4 * Copyright (C) 2013-2015 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 locally 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 #include <net/tcp.h>
56
57 /*
58 * Per flow structure, dynamically allocated
59 */
60 struct fq_flow {
61 struct sk_buff *head; /* list of skbs for this flow : first skb */
62 union {
63 struct sk_buff *tail; /* last skb in the list */
64 unsigned long age; /* jiffies when flow was emptied, for gc */
65 };
66 struct rb_node fq_node; /* anchor in fq_root[] trees */
67 struct sock *sk;
68 int qlen; /* number of packets in flow queue */
69 int credit;
70 u32 socket_hash; /* sk_hash */
71 struct fq_flow *next; /* next pointer in RR lists, or &detached */
72
73 struct rb_node rate_node; /* anchor in q->delayed tree */
74 u64 time_next_packet;
75 };
76
77 struct fq_flow_head {
78 struct fq_flow *first;
79 struct fq_flow *last;
80 };
81
82 struct fq_sched_data {
83 struct fq_flow_head new_flows;
84
85 struct fq_flow_head old_flows;
86
87 struct rb_root delayed; /* for rate limited flows */
88 u64 time_next_delayed_flow;
89
90 struct fq_flow internal; /* for non classified or high prio packets */
91 u32 quantum;
92 u32 initial_quantum;
93 u32 flow_refill_delay;
94 u32 flow_max_rate; /* optional max rate per flow */
95 u32 flow_plimit; /* max packets per flow */
96 u32 orphan_mask; /* mask for orphaned skb */
97 struct rb_root *fq_root;
98 u8 rate_enable;
99 u8 fq_trees_log;
100
101 u32 flows;
102 u32 inactive_flows;
103 u32 throttled_flows;
104
105 u64 stat_gc_flows;
106 u64 stat_internal_packets;
107 u64 stat_tcp_retrans;
108 u64 stat_throttled;
109 u64 stat_flows_plimit;
110 u64 stat_pkts_too_long;
111 u64 stat_allocation_errors;
112 struct qdisc_watchdog watchdog;
113 };
114
115 /* special value to mark a detached flow (not on old/new list) */
116 static struct fq_flow detached, throttled;
117
118 static void fq_flow_set_detached(struct fq_flow *f)
119 {
120 f->next = &detached;
121 f->age = jiffies;
122 }
123
124 static bool fq_flow_is_detached(const struct fq_flow *f)
125 {
126 return f->next == &detached;
127 }
128
129 static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f)
130 {
131 struct rb_node **p = &q->delayed.rb_node, *parent = NULL;
132
133 while (*p) {
134 struct fq_flow *aux;
135
136 parent = *p;
137 aux = container_of(parent, struct fq_flow, rate_node);
138 if (f->time_next_packet >= aux->time_next_packet)
139 p = &parent->rb_right;
140 else
141 p = &parent->rb_left;
142 }
143 rb_link_node(&f->rate_node, parent, p);
144 rb_insert_color(&f->rate_node, &q->delayed);
145 q->throttled_flows++;
146 q->stat_throttled++;
147
148 f->next = &throttled;
149 if (q->time_next_delayed_flow > f->time_next_packet)
150 q->time_next_delayed_flow = f->time_next_packet;
151 }
152
153
154 static struct kmem_cache *fq_flow_cachep __read_mostly;
155
156 static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow)
157 {
158 if (head->first)
159 head->last->next = flow;
160 else
161 head->first = flow;
162 head->last = flow;
163 flow->next = NULL;
164 }
165
166 /* limit number of collected flows per round */
167 #define FQ_GC_MAX 8
168 #define FQ_GC_AGE (3*HZ)
169
170 static bool fq_gc_candidate(const struct fq_flow *f)
171 {
172 return fq_flow_is_detached(f) &&
173 time_after(jiffies, f->age + FQ_GC_AGE);
174 }
175
176 static void fq_gc(struct fq_sched_data *q,
177 struct rb_root *root,
178 struct sock *sk)
179 {
180 struct fq_flow *f, *tofree[FQ_GC_MAX];
181 struct rb_node **p, *parent;
182 int fcnt = 0;
183
184 p = &root->rb_node;
185 parent = NULL;
186 while (*p) {
187 parent = *p;
188
189 f = container_of(parent, struct fq_flow, fq_node);
190 if (f->sk == sk)
191 break;
192
193 if (fq_gc_candidate(f)) {
194 tofree[fcnt++] = f;
195 if (fcnt == FQ_GC_MAX)
196 break;
197 }
198
199 if (f->sk > sk)
200 p = &parent->rb_right;
201 else
202 p = &parent->rb_left;
203 }
204
205 q->flows -= fcnt;
206 q->inactive_flows -= fcnt;
207 q->stat_gc_flows += fcnt;
208 while (fcnt) {
209 struct fq_flow *f = tofree[--fcnt];
210
211 rb_erase(&f->fq_node, root);
212 kmem_cache_free(fq_flow_cachep, f);
213 }
214 }
215
216 static 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
223 /* warning: no starvation prevention... */
224 if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
225 return &q->internal;
226
227 /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket
228 * or a listener (SYNCOOKIE mode)
229 * 1) request sockets are not full blown,
230 * they do not contain sk_pacing_rate
231 * 2) They are not part of a 'flow' yet
232 * 3) We do not want to rate limit them (eg SYNFLOOD attack),
233 * especially if the listener set SO_MAX_PACING_RATE
234 * 4) We pretend they are orphaned
235 */
236 if (!sk || sk_listener(sk)) {
237 unsigned long hash = skb_get_hash(skb) & q->orphan_mask;
238
239 /* By forcing low order bit to 1, we make sure to not
240 * collide with a local flow (socket pointers are word aligned)
241 */
242 sk = (struct sock *)((hash << 1) | 1UL);
243 skb_orphan(skb);
244 }
245
246 root = &q->fq_root[hash_32((u32)(long)sk, q->fq_trees_log)];
247
248 if (q->flows >= (2U << q->fq_trees_log) &&
249 q->inactive_flows > q->flows/2)
250 fq_gc(q, root, sk);
251
252 p = &root->rb_node;
253 parent = NULL;
254 while (*p) {
255 parent = *p;
256
257 f = container_of(parent, struct fq_flow, fq_node);
258 if (f->sk == sk) {
259 /* socket might have been reallocated, so check
260 * if its sk_hash is the same.
261 * It not, we need to refill credit with
262 * initial quantum
263 */
264 if (unlikely(skb->sk &&
265 f->socket_hash != sk->sk_hash)) {
266 f->credit = q->initial_quantum;
267 f->socket_hash = sk->sk_hash;
268 f->time_next_packet = 0ULL;
269 }
270 return f;
271 }
272 if (f->sk > sk)
273 p = &parent->rb_right;
274 else
275 p = &parent->rb_left;
276 }
277
278 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN);
279 if (unlikely(!f)) {
280 q->stat_allocation_errors++;
281 return &q->internal;
282 }
283 fq_flow_set_detached(f);
284 f->sk = sk;
285 if (skb->sk)
286 f->socket_hash = sk->sk_hash;
287 f->credit = q->initial_quantum;
288
289 rb_link_node(&f->fq_node, parent, p);
290 rb_insert_color(&f->fq_node, root);
291
292 q->flows++;
293 q->inactive_flows++;
294 return f;
295 }
296
297
298 /* remove one skb from head of flow queue */
299 static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
300 {
301 struct sk_buff *skb = flow->head;
302
303 if (skb) {
304 flow->head = skb->next;
305 skb->next = NULL;
306 flow->qlen--;
307 qdisc_qstats_backlog_dec(sch, skb);
308 sch->q.qlen--;
309 }
310 return skb;
311 }
312
313 /* We might add in the future detection of retransmits
314 * For the time being, just return false
315 */
316 static bool skb_is_retransmit(struct sk_buff *skb)
317 {
318 return false;
319 }
320
321 /* add skb to flow queue
322 * flow queue is a linked list, kind of FIFO, except for TCP retransmits
323 * We special case tcp retransmits to be transmitted before other packets.
324 * We rely on fact that TCP retransmits are unlikely, so we do not waste
325 * a separate queue or a pointer.
326 * head-> [retrans pkt 1]
327 * [retrans pkt 2]
328 * [ normal pkt 1]
329 * [ normal pkt 2]
330 * [ normal pkt 3]
331 * tail-> [ normal pkt 4]
332 */
333 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb)
334 {
335 struct sk_buff *prev, *head = flow->head;
336
337 skb->next = NULL;
338 if (!head) {
339 flow->head = skb;
340 flow->tail = skb;
341 return;
342 }
343 if (likely(!skb_is_retransmit(skb))) {
344 flow->tail->next = skb;
345 flow->tail = skb;
346 return;
347 }
348
349 /* This skb is a tcp retransmit,
350 * find the last retrans packet in the queue
351 */
352 prev = NULL;
353 while (skb_is_retransmit(head)) {
354 prev = head;
355 head = head->next;
356 if (!head)
357 break;
358 }
359 if (!prev) { /* no rtx packet in queue, become the new head */
360 skb->next = flow->head;
361 flow->head = skb;
362 } else {
363 if (prev == flow->tail)
364 flow->tail = skb;
365 else
366 skb->next = prev->next;
367 prev->next = skb;
368 }
369 }
370
371 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch,
372 struct sk_buff **to_free)
373 {
374 struct fq_sched_data *q = qdisc_priv(sch);
375 struct fq_flow *f;
376
377 if (unlikely(sch->q.qlen >= sch->limit))
378 return qdisc_drop(skb, sch, to_free);
379
380 f = fq_classify(skb, q);
381 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) {
382 q->stat_flows_plimit++;
383 return qdisc_drop(skb, sch, to_free);
384 }
385
386 f->qlen++;
387 if (skb_is_retransmit(skb))
388 q->stat_tcp_retrans++;
389 qdisc_qstats_backlog_inc(sch, skb);
390 if (fq_flow_is_detached(f)) {
391 fq_flow_add_tail(&q->new_flows, f);
392 if (time_after(jiffies, f->age + q->flow_refill_delay))
393 f->credit = max_t(u32, f->credit, q->quantum);
394 q->inactive_flows--;
395 }
396
397 /* Note: this overwrites f->age */
398 flow_queue_add(f, skb);
399
400 if (unlikely(f == &q->internal)) {
401 q->stat_internal_packets++;
402 }
403 sch->q.qlen++;
404
405 return NET_XMIT_SUCCESS;
406 }
407
408 static void fq_check_throttled(struct fq_sched_data *q, u64 now)
409 {
410 struct rb_node *p;
411
412 if (q->time_next_delayed_flow > now)
413 return;
414
415 q->time_next_delayed_flow = ~0ULL;
416 while ((p = rb_first(&q->delayed)) != NULL) {
417 struct fq_flow *f = container_of(p, struct fq_flow, rate_node);
418
419 if (f->time_next_packet > now) {
420 q->time_next_delayed_flow = f->time_next_packet;
421 break;
422 }
423 rb_erase(p, &q->delayed);
424 q->throttled_flows--;
425 fq_flow_add_tail(&q->old_flows, f);
426 }
427 }
428
429 static struct sk_buff *fq_dequeue(struct Qdisc *sch)
430 {
431 struct fq_sched_data *q = qdisc_priv(sch);
432 u64 now = ktime_get_ns();
433 struct fq_flow_head *head;
434 struct sk_buff *skb;
435 struct fq_flow *f;
436 u32 rate;
437
438 skb = fq_dequeue_head(sch, &q->internal);
439 if (skb)
440 goto out;
441 fq_check_throttled(q, now);
442 begin:
443 head = &q->new_flows;
444 if (!head->first) {
445 head = &q->old_flows;
446 if (!head->first) {
447 if (q->time_next_delayed_flow != ~0ULL)
448 qdisc_watchdog_schedule_ns(&q->watchdog,
449 q->time_next_delayed_flow);
450 return NULL;
451 }
452 }
453 f = head->first;
454
455 if (f->credit <= 0) {
456 f->credit += q->quantum;
457 head->first = f->next;
458 fq_flow_add_tail(&q->old_flows, f);
459 goto begin;
460 }
461
462 skb = f->head;
463 if (unlikely(skb && now < f->time_next_packet &&
464 !skb_is_tcp_pure_ack(skb))) {
465 head->first = f->next;
466 fq_flow_set_throttled(q, f);
467 goto begin;
468 }
469
470 skb = fq_dequeue_head(sch, f);
471 if (!skb) {
472 head->first = f->next;
473 /* force a pass through old_flows to prevent starvation */
474 if ((head == &q->new_flows) && q->old_flows.first) {
475 fq_flow_add_tail(&q->old_flows, f);
476 } else {
477 fq_flow_set_detached(f);
478 q->inactive_flows++;
479 }
480 goto begin;
481 }
482 prefetch(&skb->end);
483 f->credit -= qdisc_pkt_len(skb);
484
485 if (f->credit > 0 || !q->rate_enable)
486 goto out;
487
488 /* Do not pace locally generated ack packets */
489 if (skb_is_tcp_pure_ack(skb))
490 goto out;
491
492 rate = q->flow_max_rate;
493 if (skb->sk)
494 rate = min(skb->sk->sk_pacing_rate, rate);
495
496 if (rate != ~0U) {
497 u32 plen = max(qdisc_pkt_len(skb), q->quantum);
498 u64 len = (u64)plen * NSEC_PER_SEC;
499
500 if (likely(rate))
501 do_div(len, rate);
502 /* Since socket rate can change later,
503 * clamp the delay to 1 second.
504 * Really, providers of too big packets should be fixed !
505 */
506 if (unlikely(len > NSEC_PER_SEC)) {
507 len = NSEC_PER_SEC;
508 q->stat_pkts_too_long++;
509 }
510
511 f->time_next_packet = now + len;
512 }
513 out:
514 qdisc_bstats_update(sch, skb);
515 return skb;
516 }
517
518 static void fq_flow_purge(struct fq_flow *flow)
519 {
520 rtnl_kfree_skbs(flow->head, flow->tail);
521 flow->head = NULL;
522 flow->qlen = 0;
523 }
524
525 static void fq_reset(struct Qdisc *sch)
526 {
527 struct fq_sched_data *q = qdisc_priv(sch);
528 struct rb_root *root;
529 struct rb_node *p;
530 struct fq_flow *f;
531 unsigned int idx;
532
533 sch->q.qlen = 0;
534 sch->qstats.backlog = 0;
535
536 fq_flow_purge(&q->internal);
537
538 if (!q->fq_root)
539 return;
540
541 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
542 root = &q->fq_root[idx];
543 while ((p = rb_first(root)) != NULL) {
544 f = container_of(p, struct fq_flow, fq_node);
545 rb_erase(p, root);
546
547 fq_flow_purge(f);
548
549 kmem_cache_free(fq_flow_cachep, f);
550 }
551 }
552 q->new_flows.first = NULL;
553 q->old_flows.first = NULL;
554 q->delayed = RB_ROOT;
555 q->flows = 0;
556 q->inactive_flows = 0;
557 q->throttled_flows = 0;
558 }
559
560 static void fq_rehash(struct fq_sched_data *q,
561 struct rb_root *old_array, u32 old_log,
562 struct rb_root *new_array, u32 new_log)
563 {
564 struct rb_node *op, **np, *parent;
565 struct rb_root *oroot, *nroot;
566 struct fq_flow *of, *nf;
567 int fcnt = 0;
568 u32 idx;
569
570 for (idx = 0; idx < (1U << old_log); idx++) {
571 oroot = &old_array[idx];
572 while ((op = rb_first(oroot)) != NULL) {
573 rb_erase(op, oroot);
574 of = container_of(op, struct fq_flow, fq_node);
575 if (fq_gc_candidate(of)) {
576 fcnt++;
577 kmem_cache_free(fq_flow_cachep, of);
578 continue;
579 }
580 nroot = &new_array[hash_32((u32)(long)of->sk, new_log)];
581
582 np = &nroot->rb_node;
583 parent = NULL;
584 while (*np) {
585 parent = *np;
586
587 nf = container_of(parent, struct fq_flow, fq_node);
588 BUG_ON(nf->sk == of->sk);
589
590 if (nf->sk > of->sk)
591 np = &parent->rb_right;
592 else
593 np = &parent->rb_left;
594 }
595
596 rb_link_node(&of->fq_node, parent, np);
597 rb_insert_color(&of->fq_node, nroot);
598 }
599 }
600 q->flows -= fcnt;
601 q->inactive_flows -= fcnt;
602 q->stat_gc_flows += fcnt;
603 }
604
605 static void *fq_alloc_node(size_t sz, int node)
606 {
607 void *ptr;
608
609 ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node);
610 if (!ptr)
611 ptr = vmalloc_node(sz, node);
612 return ptr;
613 }
614
615 static void fq_free(void *addr)
616 {
617 kvfree(addr);
618 }
619
620 static int fq_resize(struct Qdisc *sch, u32 log)
621 {
622 struct fq_sched_data *q = qdisc_priv(sch);
623 struct rb_root *array;
624 void *old_fq_root;
625 u32 idx;
626
627 if (q->fq_root && log == q->fq_trees_log)
628 return 0;
629
630 /* If XPS was setup, we can allocate memory on right NUMA node */
631 array = fq_alloc_node(sizeof(struct rb_root) << log,
632 netdev_queue_numa_node_read(sch->dev_queue));
633 if (!array)
634 return -ENOMEM;
635
636 for (idx = 0; idx < (1U << log); idx++)
637 array[idx] = RB_ROOT;
638
639 sch_tree_lock(sch);
640
641 old_fq_root = q->fq_root;
642 if (old_fq_root)
643 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
644
645 q->fq_root = array;
646 q->fq_trees_log = log;
647
648 sch_tree_unlock(sch);
649
650 fq_free(old_fq_root);
651
652 return 0;
653 }
654
655 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
656 [TCA_FQ_PLIMIT] = { .type = NLA_U32 },
657 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 },
658 [TCA_FQ_QUANTUM] = { .type = NLA_U32 },
659 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 },
660 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 },
661 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 },
662 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 },
663 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 },
664 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 },
665 };
666
667 static int fq_change(struct Qdisc *sch, struct nlattr *opt)
668 {
669 struct fq_sched_data *q = qdisc_priv(sch);
670 struct nlattr *tb[TCA_FQ_MAX + 1];
671 int err, drop_count = 0;
672 unsigned drop_len = 0;
673 u32 fq_log;
674
675 if (!opt)
676 return -EINVAL;
677
678 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy);
679 if (err < 0)
680 return err;
681
682 sch_tree_lock(sch);
683
684 fq_log = q->fq_trees_log;
685
686 if (tb[TCA_FQ_BUCKETS_LOG]) {
687 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);
688
689 if (nval >= 1 && nval <= ilog2(256*1024))
690 fq_log = nval;
691 else
692 err = -EINVAL;
693 }
694 if (tb[TCA_FQ_PLIMIT])
695 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
696
697 if (tb[TCA_FQ_FLOW_PLIMIT])
698 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
699
700 if (tb[TCA_FQ_QUANTUM]) {
701 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
702
703 if (quantum > 0)
704 q->quantum = quantum;
705 else
706 err = -EINVAL;
707 }
708
709 if (tb[TCA_FQ_INITIAL_QUANTUM])
710 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
711
712 if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
713 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n",
714 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]));
715
716 if (tb[TCA_FQ_FLOW_MAX_RATE])
717 q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);
718
719 if (tb[TCA_FQ_RATE_ENABLE]) {
720 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);
721
722 if (enable <= 1)
723 q->rate_enable = enable;
724 else
725 err = -EINVAL;
726 }
727
728 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) {
729 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ;
730
731 q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
732 }
733
734 if (tb[TCA_FQ_ORPHAN_MASK])
735 q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]);
736
737 if (!err) {
738 sch_tree_unlock(sch);
739 err = fq_resize(sch, fq_log);
740 sch_tree_lock(sch);
741 }
742 while (sch->q.qlen > sch->limit) {
743 struct sk_buff *skb = fq_dequeue(sch);
744
745 if (!skb)
746 break;
747 drop_len += qdisc_pkt_len(skb);
748 rtnl_kfree_skbs(skb, skb);
749 drop_count++;
750 }
751 qdisc_tree_reduce_backlog(sch, drop_count, drop_len);
752
753 sch_tree_unlock(sch);
754 return err;
755 }
756
757 static void fq_destroy(struct Qdisc *sch)
758 {
759 struct fq_sched_data *q = qdisc_priv(sch);
760
761 fq_reset(sch);
762 fq_free(q->fq_root);
763 qdisc_watchdog_cancel(&q->watchdog);
764 }
765
766 static int fq_init(struct Qdisc *sch, struct nlattr *opt)
767 {
768 struct fq_sched_data *q = qdisc_priv(sch);
769 int err;
770
771 sch->limit = 10000;
772 q->flow_plimit = 100;
773 q->quantum = 2 * psched_mtu(qdisc_dev(sch));
774 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
775 q->flow_refill_delay = msecs_to_jiffies(40);
776 q->flow_max_rate = ~0U;
777 q->rate_enable = 1;
778 q->new_flows.first = NULL;
779 q->old_flows.first = NULL;
780 q->delayed = RB_ROOT;
781 q->fq_root = NULL;
782 q->fq_trees_log = ilog2(1024);
783 q->orphan_mask = 1024 - 1;
784 qdisc_watchdog_init(&q->watchdog, sch);
785
786 if (opt)
787 err = fq_change(sch, opt);
788 else
789 err = fq_resize(sch, q->fq_trees_log);
790
791 return err;
792 }
793
794 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
795 {
796 struct fq_sched_data *q = qdisc_priv(sch);
797 struct nlattr *opts;
798
799 opts = nla_nest_start(skb, TCA_OPTIONS);
800 if (opts == NULL)
801 goto nla_put_failure;
802
803 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */
804
805 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
806 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
807 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
808 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
809 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
810 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
811 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY,
812 jiffies_to_usecs(q->flow_refill_delay)) ||
813 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) ||
814 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
815 goto nla_put_failure;
816
817 return nla_nest_end(skb, opts);
818
819 nla_put_failure:
820 return -1;
821 }
822
823 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
824 {
825 struct fq_sched_data *q = qdisc_priv(sch);
826 u64 now = ktime_get_ns();
827 struct tc_fq_qd_stats st = {
828 .gc_flows = q->stat_gc_flows,
829 .highprio_packets = q->stat_internal_packets,
830 .tcp_retrans = q->stat_tcp_retrans,
831 .throttled = q->stat_throttled,
832 .flows_plimit = q->stat_flows_plimit,
833 .pkts_too_long = q->stat_pkts_too_long,
834 .allocation_errors = q->stat_allocation_errors,
835 .flows = q->flows,
836 .inactive_flows = q->inactive_flows,
837 .throttled_flows = q->throttled_flows,
838 .time_next_delayed_flow = q->time_next_delayed_flow - now,
839 };
840
841 return gnet_stats_copy_app(d, &st, sizeof(st));
842 }
843
844 static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
845 .id = "fq",
846 .priv_size = sizeof(struct fq_sched_data),
847
848 .enqueue = fq_enqueue,
849 .dequeue = fq_dequeue,
850 .peek = qdisc_peek_dequeued,
851 .init = fq_init,
852 .reset = fq_reset,
853 .destroy = fq_destroy,
854 .change = fq_change,
855 .dump = fq_dump,
856 .dump_stats = fq_dump_stats,
857 .owner = THIS_MODULE,
858 };
859
860 static int __init fq_module_init(void)
861 {
862 int ret;
863
864 fq_flow_cachep = kmem_cache_create("fq_flow_cache",
865 sizeof(struct fq_flow),
866 0, 0, NULL);
867 if (!fq_flow_cachep)
868 return -ENOMEM;
869
870 ret = register_qdisc(&fq_qdisc_ops);
871 if (ret)
872 kmem_cache_destroy(fq_flow_cachep);
873 return ret;
874 }
875
876 static void __exit fq_module_exit(void)
877 {
878 unregister_qdisc(&fq_qdisc_ops);
879 kmem_cache_destroy(fq_flow_cachep);
880 }
881
882 module_init(fq_module_init)
883 module_exit(fq_module_exit)
884 MODULE_AUTHOR("Eric Dumazet");
885 MODULE_LICENSE("GPL");
Linux with added FPC-III support