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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 Dumazetc3bd8542013-12-15 13:15:25 -080050#include <linux/vmalloc.h>
Eric Dumazetafe4fd02013-08-29 15:49:55 -070051#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;
Eric Dumazetf52ed892013-11-15 08:58:14 -080092 u32 flow_refill_delay;
Eric Dumazetafe4fd02013-08-29 15:49:55 -070093 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;
Eric Dumazetf52ed892013-11-15 08:58:14 -0800119 f->age = jiffies;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700120}
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
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700214static 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;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700220
221 /* warning: no starvation prevention... */
Maciej Żenczykowski2abc2f02013-11-14 08:50:43 -0800222 if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL))
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700223 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 */
Tom Herbert3958afa1b2013-12-15 22:12:06 -0800229 sk = (struct sock *)(skb_get_hash(skb) | 1L);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700230 }
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;
Eric Dumazetfc59d5b2013-10-27 16:26:43 -0700254 f->time_next_packet = 0ULL;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700255 }
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 */
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700285static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow)
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700286{
287 struct sk_buff *skb = flow->head;
288
289 if (skb) {
290 flow->head = skb->next;
291 skb->next = NULL;
292 flow->qlen--;
John Fastabend25331d62014-09-28 11:53:29 -0700293 qdisc_qstats_backlog_dec(sch, skb);
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700294 sch->q.qlen--;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700295 }
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++;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700372 if (skb_is_retransmit(skb))
373 q->stat_tcp_retrans++;
John Fastabend25331d62014-09-28 11:53:29 -0700374 qdisc_qstats_backlog_inc(sch, skb);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700375 if (fq_flow_is_detached(f)) {
376 fq_flow_add_tail(&q->new_flows, f);
Eric Dumazetf52ed892013-11-15 08:58:14 -0800377 if (time_after(jiffies, f->age + q->flow_refill_delay))
378 f->credit = max_t(u32, f->credit, q->quantum);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700379 q->inactive_flows--;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700380 }
Eric Dumazetf52ed892013-11-15 08:58:14 -0800381
382 /* Note: this overwrites f->age */
383 flow_queue_add(f, skb);
384
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700385 if (unlikely(f == &q->internal)) {
386 q->stat_internal_packets++;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700387 }
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);
Eric Dumazetd2de8752014-08-22 18:32:09 -0700417 u64 now = ktime_get_ns();
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700418 struct fq_flow_head *head;
419 struct sk_buff *skb;
420 struct fq_flow *f;
Eric Dumazet0eab5eb2013-10-01 09:10:16 -0700421 u32 rate;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700422
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700423 skb = fq_dequeue_head(sch, &q->internal);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700424 if (skb)
425 goto out;
426 fq_check_throttled(q, now);
427begin:
428 head = &q->new_flows;
429 if (!head->first) {
430 head = &q->old_flows;
431 if (!head->first) {
432 if (q->time_next_delayed_flow != ~0ULL)
433 qdisc_watchdog_schedule_ns(&q->watchdog,
Eric Dumazetf2600cf2014-10-04 10:11:31 -0700434 q->time_next_delayed_flow,
435 false);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700436 return NULL;
437 }
438 }
439 f = head->first;
440
441 if (f->credit <= 0) {
442 f->credit += q->quantum;
443 head->first = f->next;
444 fq_flow_add_tail(&q->old_flows, f);
445 goto begin;
446 }
447
448 if (unlikely(f->head && now < f->time_next_packet)) {
449 head->first = f->next;
450 fq_flow_set_throttled(q, f);
451 goto begin;
452 }
453
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700454 skb = fq_dequeue_head(sch, f);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700455 if (!skb) {
456 head->first = f->next;
457 /* force a pass through old_flows to prevent starvation */
458 if ((head == &q->new_flows) && q->old_flows.first) {
459 fq_flow_add_tail(&q->old_flows, f);
460 } else {
461 fq_flow_set_detached(f);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700462 q->inactive_flows++;
463 }
464 goto begin;
465 }
Eric Dumazet08f89b92013-08-30 09:46:43 -0700466 prefetch(&skb->end);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700467 f->time_next_packet = now;
468 f->credit -= qdisc_pkt_len(skb);
469
Eric Dumazet0eab5eb2013-10-01 09:10:16 -0700470 if (f->credit > 0 || !q->rate_enable)
471 goto out;
472
Eric Dumazet7eec4172013-10-08 15:16:00 -0700473 rate = q->flow_max_rate;
474 if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT)
475 rate = min(skb->sk->sk_pacing_rate, rate);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700476
Eric Dumazet7eec4172013-10-08 15:16:00 -0700477 if (rate != ~0U) {
Eric Dumazet0eab5eb2013-10-01 09:10:16 -0700478 u32 plen = max(qdisc_pkt_len(skb), q->quantum);
479 u64 len = (u64)plen * NSEC_PER_SEC;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700480
Eric Dumazet7eec4172013-10-08 15:16:00 -0700481 if (likely(rate))
482 do_div(len, rate);
Eric Dumazet0eab5eb2013-10-01 09:10:16 -0700483 /* Since socket rate can change later,
484 * clamp the delay to 125 ms.
485 * TODO: maybe segment the too big skb, as in commit
486 * e43ac79a4bc ("sch_tbf: segment too big GSO packets")
487 */
488 if (unlikely(len > 125 * NSEC_PER_MSEC)) {
489 len = 125 * NSEC_PER_MSEC;
490 q->stat_pkts_too_long++;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700491 }
Eric Dumazet0eab5eb2013-10-01 09:10:16 -0700492
493 f->time_next_packet = now + len;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700494 }
495out:
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700496 qdisc_bstats_update(sch, skb);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700497 return skb;
498}
499
500static void fq_reset(struct Qdisc *sch)
501{
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700502 struct fq_sched_data *q = qdisc_priv(sch);
503 struct rb_root *root;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700504 struct sk_buff *skb;
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700505 struct rb_node *p;
506 struct fq_flow *f;
507 unsigned int idx;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700508
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700509 while ((skb = fq_dequeue_head(sch, &q->internal)) != NULL)
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700510 kfree_skb(skb);
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700511
512 if (!q->fq_root)
513 return;
514
515 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) {
516 root = &q->fq_root[idx];
517 while ((p = rb_first(root)) != NULL) {
518 f = container_of(p, struct fq_flow, fq_node);
519 rb_erase(p, root);
520
521 while ((skb = fq_dequeue_head(sch, f)) != NULL)
522 kfree_skb(skb);
523
524 kmem_cache_free(fq_flow_cachep, f);
525 }
526 }
527 q->new_flows.first = NULL;
528 q->old_flows.first = NULL;
529 q->delayed = RB_ROOT;
530 q->flows = 0;
531 q->inactive_flows = 0;
532 q->throttled_flows = 0;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700533}
534
535static void fq_rehash(struct fq_sched_data *q,
536 struct rb_root *old_array, u32 old_log,
537 struct rb_root *new_array, u32 new_log)
538{
539 struct rb_node *op, **np, *parent;
540 struct rb_root *oroot, *nroot;
541 struct fq_flow *of, *nf;
542 int fcnt = 0;
543 u32 idx;
544
545 for (idx = 0; idx < (1U << old_log); idx++) {
546 oroot = &old_array[idx];
547 while ((op = rb_first(oroot)) != NULL) {
548 rb_erase(op, oroot);
549 of = container_of(op, struct fq_flow, fq_node);
550 if (fq_gc_candidate(of)) {
551 fcnt++;
552 kmem_cache_free(fq_flow_cachep, of);
553 continue;
554 }
555 nroot = &new_array[hash_32((u32)(long)of->sk, new_log)];
556
557 np = &nroot->rb_node;
558 parent = NULL;
559 while (*np) {
560 parent = *np;
561
562 nf = container_of(parent, struct fq_flow, fq_node);
563 BUG_ON(nf->sk == of->sk);
564
565 if (nf->sk > of->sk)
566 np = &parent->rb_right;
567 else
568 np = &parent->rb_left;
569 }
570
571 rb_link_node(&of->fq_node, parent, np);
572 rb_insert_color(&of->fq_node, nroot);
573 }
574 }
575 q->flows -= fcnt;
576 q->inactive_flows -= fcnt;
577 q->stat_gc_flows += fcnt;
578}
579
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800580static void *fq_alloc_node(size_t sz, int node)
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700581{
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800582 void *ptr;
583
584 ptr = kmalloc_node(sz, GFP_KERNEL | __GFP_REPEAT | __GFP_NOWARN, node);
585 if (!ptr)
586 ptr = vmalloc_node(sz, node);
587 return ptr;
588}
589
590static void fq_free(void *addr)
591{
WANG Cong4cb28972014-06-02 15:55:22 -0700592 kvfree(addr);
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800593}
594
595static int fq_resize(struct Qdisc *sch, u32 log)
596{
597 struct fq_sched_data *q = qdisc_priv(sch);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700598 struct rb_root *array;
Eric Dumazet2d8d40a2014-03-06 22:57:52 -0800599 void *old_fq_root;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700600 u32 idx;
601
602 if (q->fq_root && log == q->fq_trees_log)
603 return 0;
604
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800605 /* If XPS was setup, we can allocate memory on right NUMA node */
606 array = fq_alloc_node(sizeof(struct rb_root) << log,
607 netdev_queue_numa_node_read(sch->dev_queue));
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700608 if (!array)
609 return -ENOMEM;
610
611 for (idx = 0; idx < (1U << log); idx++)
612 array[idx] = RB_ROOT;
613
Eric Dumazet2d8d40a2014-03-06 22:57:52 -0800614 sch_tree_lock(sch);
615
616 old_fq_root = q->fq_root;
617 if (old_fq_root)
618 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log);
619
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700620 q->fq_root = array;
621 q->fq_trees_log = log;
622
Eric Dumazet2d8d40a2014-03-06 22:57:52 -0800623 sch_tree_unlock(sch);
624
625 fq_free(old_fq_root);
626
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700627 return 0;
628}
629
630static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = {
631 [TCA_FQ_PLIMIT] = { .type = NLA_U32 },
632 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 },
633 [TCA_FQ_QUANTUM] = { .type = NLA_U32 },
634 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 },
635 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 },
636 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 },
637 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 },
638 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 },
Eric Dumazetf52ed892013-11-15 08:58:14 -0800639 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 },
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700640};
641
642static int fq_change(struct Qdisc *sch, struct nlattr *opt)
643{
644 struct fq_sched_data *q = qdisc_priv(sch);
645 struct nlattr *tb[TCA_FQ_MAX + 1];
646 int err, drop_count = 0;
647 u32 fq_log;
648
649 if (!opt)
650 return -EINVAL;
651
652 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy);
653 if (err < 0)
654 return err;
655
656 sch_tree_lock(sch);
657
658 fq_log = q->fq_trees_log;
659
660 if (tb[TCA_FQ_BUCKETS_LOG]) {
661 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]);
662
663 if (nval >= 1 && nval <= ilog2(256*1024))
664 fq_log = nval;
665 else
666 err = -EINVAL;
667 }
668 if (tb[TCA_FQ_PLIMIT])
669 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]);
670
671 if (tb[TCA_FQ_FLOW_PLIMIT])
672 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]);
673
674 if (tb[TCA_FQ_QUANTUM])
675 q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]);
676
677 if (tb[TCA_FQ_INITIAL_QUANTUM])
Eric Dumazetede869c2013-10-07 12:50:18 -0700678 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700679
680 if (tb[TCA_FQ_FLOW_DEFAULT_RATE])
Eric Dumazet65c5189a2013-11-15 08:57:26 -0800681 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n",
682 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE]));
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700683
684 if (tb[TCA_FQ_FLOW_MAX_RATE])
685 q->flow_max_rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]);
686
687 if (tb[TCA_FQ_RATE_ENABLE]) {
688 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]);
689
690 if (enable <= 1)
691 q->rate_enable = enable;
692 else
693 err = -EINVAL;
694 }
695
Eric Dumazetf52ed892013-11-15 08:58:14 -0800696 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) {
697 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ;
698
699 q->flow_refill_delay = usecs_to_jiffies(usecs_delay);
700 }
701
Eric Dumazet2d8d40a2014-03-06 22:57:52 -0800702 if (!err) {
703 sch_tree_unlock(sch);
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800704 err = fq_resize(sch, fq_log);
Eric Dumazet2d8d40a2014-03-06 22:57:52 -0800705 sch_tree_lock(sch);
706 }
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700707 while (sch->q.qlen > sch->limit) {
708 struct sk_buff *skb = fq_dequeue(sch);
709
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700710 if (!skb)
711 break;
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700712 kfree_skb(skb);
713 drop_count++;
714 }
715 qdisc_tree_decrease_qlen(sch, drop_count);
716
717 sch_tree_unlock(sch);
718 return err;
719}
720
721static void fq_destroy(struct Qdisc *sch)
722{
723 struct fq_sched_data *q = qdisc_priv(sch);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700724
Eric Dumazet8d34ce12013-09-27 14:20:01 -0700725 fq_reset(sch);
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800726 fq_free(q->fq_root);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700727 qdisc_watchdog_cancel(&q->watchdog);
728}
729
730static int fq_init(struct Qdisc *sch, struct nlattr *opt)
731{
732 struct fq_sched_data *q = qdisc_priv(sch);
733 int err;
734
735 sch->limit = 10000;
736 q->flow_plimit = 100;
737 q->quantum = 2 * psched_mtu(qdisc_dev(sch));
738 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch));
Eric Dumazetf52ed892013-11-15 08:58:14 -0800739 q->flow_refill_delay = msecs_to_jiffies(40);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700740 q->flow_max_rate = ~0U;
741 q->rate_enable = 1;
742 q->new_flows.first = NULL;
743 q->old_flows.first = NULL;
744 q->delayed = RB_ROOT;
745 q->fq_root = NULL;
746 q->fq_trees_log = ilog2(1024);
747 qdisc_watchdog_init(&q->watchdog, sch);
748
749 if (opt)
750 err = fq_change(sch, opt);
751 else
Eric Dumazetc3bd8542013-12-15 13:15:25 -0800752 err = fq_resize(sch, q->fq_trees_log);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700753
754 return err;
755}
756
757static int fq_dump(struct Qdisc *sch, struct sk_buff *skb)
758{
759 struct fq_sched_data *q = qdisc_priv(sch);
760 struct nlattr *opts;
761
762 opts = nla_nest_start(skb, TCA_OPTIONS);
763 if (opts == NULL)
764 goto nla_put_failure;
765
Eric Dumazet65c5189a2013-11-15 08:57:26 -0800766 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */
767
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700768 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) ||
769 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) ||
770 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) ||
771 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) ||
772 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) ||
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700773 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) ||
Eric Dumazetf52ed892013-11-15 08:58:14 -0800774 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY,
775 jiffies_to_usecs(q->flow_refill_delay)) ||
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700776 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log))
777 goto nla_put_failure;
778
Yang Yingliangd59b7d82014-03-12 10:20:32 +0800779 return nla_nest_end(skb, opts);
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700780
781nla_put_failure:
782 return -1;
783}
784
785static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
786{
787 struct fq_sched_data *q = qdisc_priv(sch);
Eric Dumazetd2de8752014-08-22 18:32:09 -0700788 u64 now = ktime_get_ns();
Eric Dumazetafe4fd02013-08-29 15:49:55 -0700789 struct tc_fq_qd_stats st = {
790 .gc_flows = q->stat_gc_flows,
791 .highprio_packets = q->stat_internal_packets,
792 .tcp_retrans = q->stat_tcp_retrans,
793 .throttled = q->stat_throttled,
794 .flows_plimit = q->stat_flows_plimit,
795 .pkts_too_long = q->stat_pkts_too_long,
796 .allocation_errors = q->stat_allocation_errors,
797 .flows = q->flows,
798 .inactive_flows = q->inactive_flows,
799 .throttled_flows = q->throttled_flows,
800 .time_next_delayed_flow = q->time_next_delayed_flow - now,
801 };
802
803 return gnet_stats_copy_app(d, &st, sizeof(st));
804}
805
806static struct Qdisc_ops fq_qdisc_ops __read_mostly = {
807 .id = "fq",
808 .priv_size = sizeof(struct fq_sched_data),
809
810 .enqueue = fq_enqueue,
811 .dequeue = fq_dequeue,
812 .peek = qdisc_peek_dequeued,
813 .init = fq_init,
814 .reset = fq_reset,
815 .destroy = fq_destroy,
816 .change = fq_change,
817 .dump = fq_dump,
818 .dump_stats = fq_dump_stats,
819 .owner = THIS_MODULE,
820};
821
822static int __init fq_module_init(void)
823{
824 int ret;
825
826 fq_flow_cachep = kmem_cache_create("fq_flow_cache",
827 sizeof(struct fq_flow),
828 0, 0, NULL);
829 if (!fq_flow_cachep)
830 return -ENOMEM;
831
832 ret = register_qdisc(&fq_qdisc_ops);
833 if (ret)
834 kmem_cache_destroy(fq_flow_cachep);
835 return ret;
836}
837
838static void __exit fq_module_exit(void)
839{
840 unregister_qdisc(&fq_qdisc_ops);
841 kmem_cache_destroy(fq_flow_cachep);
842}
843
844module_init(fq_module_init)
845module_exit(fq_module_exit)
846MODULE_AUTHOR("Eric Dumazet");
847MODULE_LICENSE("GPL");