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 <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 } 465 prefetch(&skb->end); 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: 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"); 794