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afe4fd06 ED |
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> | |
08f89b98 | 49 | #include <linux/prefetch.h> |
afe4fd06 ED |
50 | #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 | */ | |
58 | struct 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 | ||
75 | struct fq_flow_head { | |
76 | struct fq_flow *first; | |
77 | struct fq_flow *last; | |
78 | }; | |
79 | ||
80 | struct 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) */ | |
113 | static struct fq_flow detached, throttled; | |
114 | ||
115 | static void fq_flow_set_detached(struct fq_flow *f) | |
116 | { | |
117 | f->next = &detached; | |
118 | } | |
119 | ||
120 | static bool fq_flow_is_detached(const struct fq_flow *f) | |
121 | { | |
122 | return f->next == &detached; | |
123 | } | |
124 | ||
125 | static 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 | ||
150 | static struct kmem_cache *fq_flow_cachep __read_mostly; | |
151 | ||
152 | static 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 | ||
166 | static 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 | ||
172 | static 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 | ||
212 | static 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 | ||
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 | 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 */ | |
288 | static 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 | */ | |
303 | static 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 | */ | |
320 | static 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 | ||
358 | static 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 | ||
393 | static 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 | ||
414 | static 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); | |
426 | begin: | |
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 | } | |
08f89b98 | 465 | prefetch(&skb->end); |
afe4fd06 ED |
466 | 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 | } | |
492 | out: | |
afe4fd06 ED |
493 | 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 | ||
500 | static 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 | ||
508 | static 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 | ||
553 | static 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 | ||
578 | static 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 | ||
589 | static 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 | ||
657 | static 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 | ||
678 | static 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 | ||
705 | static 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 | ||
727 | nla_put_failure: | |
728 | return -1; | |
729 | } | |
730 | ||
731 | static 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 | ||
752 | static 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 | ||
768 | static 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 | ||
784 | static void __exit fq_module_exit(void) | |
785 | { | |
786 | unregister_qdisc(&fq_qdisc_ops); | |
787 | kmem_cache_destroy(fq_flow_cachep); | |
788 | } | |
789 | ||
790 | module_init(fq_module_init) | |
791 | module_exit(fq_module_exit) | |
792 | MODULE_AUTHOR("Eric Dumazet"); | |
793 | MODULE_LICENSE("GPL"); |