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