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 Qdisc *sch, 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 sch->qstats.backlog -= qdisc_pkt_len(skb); 297 sch->q.qlen--; 298 } 299 return skb; 300 } 301 302 /* We might add in the future detection of retransmits 303 * For the time being, just return false 304 */ 305 static bool skb_is_retransmit(struct sk_buff *skb) 306 { 307 return false; 308 } 309 310 /* add skb to flow queue 311 * flow queue is a linked list, kind of FIFO, except for TCP retransmits 312 * We special case tcp retransmits to be transmitted before other packets. 313 * We rely on fact that TCP retransmits are unlikely, so we do not waste 314 * a separate queue or a pointer. 315 * head-> [retrans pkt 1] 316 * [retrans pkt 2] 317 * [ normal pkt 1] 318 * [ normal pkt 2] 319 * [ normal pkt 3] 320 * tail-> [ normal pkt 4] 321 */ 322 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 323 { 324 struct sk_buff *prev, *head = flow->head; 325 326 skb->next = NULL; 327 if (!head) { 328 flow->head = skb; 329 flow->tail = skb; 330 return; 331 } 332 if (likely(!skb_is_retransmit(skb))) { 333 flow->tail->next = skb; 334 flow->tail = skb; 335 return; 336 } 337 338 /* This skb is a tcp retransmit, 339 * find the last retrans packet in the queue 340 */ 341 prev = NULL; 342 while (skb_is_retransmit(head)) { 343 prev = head; 344 head = head->next; 345 if (!head) 346 break; 347 } 348 if (!prev) { /* no rtx packet in queue, become the new head */ 349 skb->next = flow->head; 350 flow->head = skb; 351 } else { 352 if (prev == flow->tail) 353 flow->tail = skb; 354 else 355 skb->next = prev->next; 356 prev->next = skb; 357 } 358 } 359 360 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch) 361 { 362 struct fq_sched_data *q = qdisc_priv(sch); 363 struct fq_flow *f; 364 365 if (unlikely(sch->q.qlen >= sch->limit)) 366 return qdisc_drop(skb, sch); 367 368 f = fq_classify(skb, q); 369 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) { 370 q->stat_flows_plimit++; 371 return qdisc_drop(skb, sch); 372 } 373 374 f->qlen++; 375 flow_queue_add(f, skb); 376 if (skb_is_retransmit(skb)) 377 q->stat_tcp_retrans++; 378 sch->qstats.backlog += qdisc_pkt_len(skb); 379 if (fq_flow_is_detached(f)) { 380 fq_flow_add_tail(&q->new_flows, f); 381 if (q->quantum > f->credit) 382 f->credit = q->quantum; 383 q->inactive_flows--; 384 qdisc_unthrottled(sch); 385 } 386 if (unlikely(f == &q->internal)) { 387 q->stat_internal_packets++; 388 qdisc_unthrottled(sch); 389 } 390 sch->q.qlen++; 391 392 return NET_XMIT_SUCCESS; 393 } 394 395 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 396 { 397 struct rb_node *p; 398 399 if (q->time_next_delayed_flow > now) 400 return; 401 402 q->time_next_delayed_flow = ~0ULL; 403 while ((p = rb_first(&q->delayed)) != NULL) { 404 struct fq_flow *f = container_of(p, struct fq_flow, rate_node); 405 406 if (f->time_next_packet > now) { 407 q->time_next_delayed_flow = f->time_next_packet; 408 break; 409 } 410 rb_erase(p, &q->delayed); 411 q->throttled_flows--; 412 fq_flow_add_tail(&q->old_flows, f); 413 } 414 } 415 416 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 417 { 418 struct fq_sched_data *q = qdisc_priv(sch); 419 u64 now = ktime_to_ns(ktime_get()); 420 struct fq_flow_head *head; 421 struct sk_buff *skb; 422 struct fq_flow *f; 423 u32 rate; 424 425 skb = fq_dequeue_head(sch, &q->internal); 426 if (skb) 427 goto out; 428 fq_check_throttled(q, now); 429 begin: 430 head = &q->new_flows; 431 if (!head->first) { 432 head = &q->old_flows; 433 if (!head->first) { 434 if (q->time_next_delayed_flow != ~0ULL) 435 qdisc_watchdog_schedule_ns(&q->watchdog, 436 q->time_next_delayed_flow); 437 return NULL; 438 } 439 } 440 f = head->first; 441 442 if (f->credit <= 0) { 443 f->credit += q->quantum; 444 head->first = f->next; 445 fq_flow_add_tail(&q->old_flows, f); 446 goto begin; 447 } 448 449 if (unlikely(f->head && now < f->time_next_packet)) { 450 head->first = f->next; 451 fq_flow_set_throttled(q, f); 452 goto begin; 453 } 454 455 skb = fq_dequeue_head(sch, f); 456 if (!skb) { 457 head->first = f->next; 458 /* force a pass through old_flows to prevent starvation */ 459 if ((head == &q->new_flows) && q->old_flows.first) { 460 fq_flow_add_tail(&q->old_flows, f); 461 } else { 462 fq_flow_set_detached(f); 463 f->age = jiffies; 464 q->inactive_flows++; 465 } 466 goto begin; 467 } 468 prefetch(&skb->end); 469 f->time_next_packet = now; 470 f->credit -= qdisc_pkt_len(skb); 471 472 if (f->credit > 0 || !q->rate_enable) 473 goto out; 474 475 rate = q->flow_max_rate; 476 if (skb->sk && skb->sk->sk_state != TCP_TIME_WAIT) 477 rate = min(skb->sk->sk_pacing_rate, rate); 478 479 if (rate != ~0U) { 480 u32 plen = max(qdisc_pkt_len(skb), q->quantum); 481 u64 len = (u64)plen * NSEC_PER_SEC; 482 483 if (likely(rate)) 484 do_div(len, rate); 485 /* Since socket rate can change later, 486 * clamp the delay to 125 ms. 487 * TODO: maybe segment the too big skb, as in commit 488 * e43ac79a4bc ("sch_tbf: segment too big GSO packets") 489 */ 490 if (unlikely(len > 125 * NSEC_PER_MSEC)) { 491 len = 125 * NSEC_PER_MSEC; 492 q->stat_pkts_too_long++; 493 } 494 495 f->time_next_packet = now + len; 496 } 497 out: 498 qdisc_bstats_update(sch, skb); 499 qdisc_unthrottled(sch); 500 return skb; 501 } 502 503 static void fq_reset(struct Qdisc *sch) 504 { 505 struct fq_sched_data *q = qdisc_priv(sch); 506 struct rb_root *root; 507 struct sk_buff *skb; 508 struct rb_node *p; 509 struct fq_flow *f; 510 unsigned int idx; 511 512 while ((skb = fq_dequeue_head(sch, &q->internal)) != NULL) 513 kfree_skb(skb); 514 515 if (!q->fq_root) 516 return; 517 518 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 519 root = &q->fq_root[idx]; 520 while ((p = rb_first(root)) != NULL) { 521 f = container_of(p, struct fq_flow, fq_node); 522 rb_erase(p, root); 523 524 while ((skb = fq_dequeue_head(sch, f)) != NULL) 525 kfree_skb(skb); 526 527 kmem_cache_free(fq_flow_cachep, f); 528 } 529 } 530 q->new_flows.first = NULL; 531 q->old_flows.first = NULL; 532 q->delayed = RB_ROOT; 533 q->flows = 0; 534 q->inactive_flows = 0; 535 q->throttled_flows = 0; 536 } 537 538 static void fq_rehash(struct fq_sched_data *q, 539 struct rb_root *old_array, u32 old_log, 540 struct rb_root *new_array, u32 new_log) 541 { 542 struct rb_node *op, **np, *parent; 543 struct rb_root *oroot, *nroot; 544 struct fq_flow *of, *nf; 545 int fcnt = 0; 546 u32 idx; 547 548 for (idx = 0; idx < (1U << old_log); idx++) { 549 oroot = &old_array[idx]; 550 while ((op = rb_first(oroot)) != NULL) { 551 rb_erase(op, oroot); 552 of = container_of(op, struct fq_flow, fq_node); 553 if (fq_gc_candidate(of)) { 554 fcnt++; 555 kmem_cache_free(fq_flow_cachep, of); 556 continue; 557 } 558 nroot = &new_array[hash_32((u32)(long)of->sk, new_log)]; 559 560 np = &nroot->rb_node; 561 parent = NULL; 562 while (*np) { 563 parent = *np; 564 565 nf = container_of(parent, struct fq_flow, fq_node); 566 BUG_ON(nf->sk == of->sk); 567 568 if (nf->sk > of->sk) 569 np = &parent->rb_right; 570 else 571 np = &parent->rb_left; 572 } 573 574 rb_link_node(&of->fq_node, parent, np); 575 rb_insert_color(&of->fq_node, nroot); 576 } 577 } 578 q->flows -= fcnt; 579 q->inactive_flows -= fcnt; 580 q->stat_gc_flows += fcnt; 581 } 582 583 static int fq_resize(struct fq_sched_data *q, u32 log) 584 { 585 struct rb_root *array; 586 u32 idx; 587 588 if (q->fq_root && log == q->fq_trees_log) 589 return 0; 590 591 array = kmalloc(sizeof(struct rb_root) << log, GFP_KERNEL); 592 if (!array) 593 return -ENOMEM; 594 595 for (idx = 0; idx < (1U << log); idx++) 596 array[idx] = RB_ROOT; 597 598 if (q->fq_root) { 599 fq_rehash(q, q->fq_root, q->fq_trees_log, array, log); 600 kfree(q->fq_root); 601 } 602 q->fq_root = array; 603 q->fq_trees_log = log; 604 605 return 0; 606 } 607 608 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 609 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 610 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 611 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 612 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, 613 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 614 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 615 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 616 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 617 }; 618 619 static int fq_change(struct Qdisc *sch, struct nlattr *opt) 620 { 621 struct fq_sched_data *q = qdisc_priv(sch); 622 struct nlattr *tb[TCA_FQ_MAX + 1]; 623 int err, drop_count = 0; 624 u32 fq_log; 625 626 if (!opt) 627 return -EINVAL; 628 629 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy); 630 if (err < 0) 631 return err; 632 633 sch_tree_lock(sch); 634 635 fq_log = q->fq_trees_log; 636 637 if (tb[TCA_FQ_BUCKETS_LOG]) { 638 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 639 640 if (nval >= 1 && nval <= ilog2(256*1024)) 641 fq_log = nval; 642 else 643 err = -EINVAL; 644 } 645 if (tb[TCA_FQ_PLIMIT]) 646 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]); 647 648 if (tb[TCA_FQ_FLOW_PLIMIT]) 649 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); 650 651 if (tb[TCA_FQ_QUANTUM]) 652 q->quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 653 654 if (tb[TCA_FQ_INITIAL_QUANTUM]) 655 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); 656 657 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 658 q->flow_default_rate = 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 (!err) 673 err = fq_resize(q, fq_log); 674 675 while (sch->q.qlen > sch->limit) { 676 struct sk_buff *skb = fq_dequeue(sch); 677 678 if (!skb) 679 break; 680 kfree_skb(skb); 681 drop_count++; 682 } 683 qdisc_tree_decrease_qlen(sch, drop_count); 684 685 sch_tree_unlock(sch); 686 return err; 687 } 688 689 static void fq_destroy(struct Qdisc *sch) 690 { 691 struct fq_sched_data *q = qdisc_priv(sch); 692 693 fq_reset(sch); 694 kfree(q->fq_root); 695 qdisc_watchdog_cancel(&q->watchdog); 696 } 697 698 static int fq_init(struct Qdisc *sch, struct nlattr *opt) 699 { 700 struct fq_sched_data *q = qdisc_priv(sch); 701 int err; 702 703 sch->limit = 10000; 704 q->flow_plimit = 100; 705 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 706 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 707 q->flow_default_rate = 0; 708 q->flow_max_rate = ~0U; 709 q->rate_enable = 1; 710 q->new_flows.first = NULL; 711 q->old_flows.first = NULL; 712 q->delayed = RB_ROOT; 713 q->fq_root = NULL; 714 q->fq_trees_log = ilog2(1024); 715 qdisc_watchdog_init(&q->watchdog, sch); 716 717 if (opt) 718 err = fq_change(sch, opt); 719 else 720 err = fq_resize(q, q->fq_trees_log); 721 722 return err; 723 } 724 725 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 726 { 727 struct fq_sched_data *q = qdisc_priv(sch); 728 struct nlattr *opts; 729 730 opts = nla_nest_start(skb, TCA_OPTIONS); 731 if (opts == NULL) 732 goto nla_put_failure; 733 734 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore, 735 * do not bother giving its value 736 */ 737 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) || 738 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) || 739 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) || 740 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) || 741 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) || 742 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, q->flow_max_rate) || 743 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log)) 744 goto nla_put_failure; 745 746 nla_nest_end(skb, opts); 747 return skb->len; 748 749 nla_put_failure: 750 return -1; 751 } 752 753 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 754 { 755 struct fq_sched_data *q = qdisc_priv(sch); 756 u64 now = ktime_to_ns(ktime_get()); 757 struct tc_fq_qd_stats st = { 758 .gc_flows = q->stat_gc_flows, 759 .highprio_packets = q->stat_internal_packets, 760 .tcp_retrans = q->stat_tcp_retrans, 761 .throttled = q->stat_throttled, 762 .flows_plimit = q->stat_flows_plimit, 763 .pkts_too_long = q->stat_pkts_too_long, 764 .allocation_errors = q->stat_allocation_errors, 765 .flows = q->flows, 766 .inactive_flows = q->inactive_flows, 767 .throttled_flows = q->throttled_flows, 768 .time_next_delayed_flow = q->time_next_delayed_flow - now, 769 }; 770 771 return gnet_stats_copy_app(d, &st, sizeof(st)); 772 } 773 774 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 775 .id = "fq", 776 .priv_size = sizeof(struct fq_sched_data), 777 778 .enqueue = fq_enqueue, 779 .dequeue = fq_dequeue, 780 .peek = qdisc_peek_dequeued, 781 .init = fq_init, 782 .reset = fq_reset, 783 .destroy = fq_destroy, 784 .change = fq_change, 785 .dump = fq_dump, 786 .dump_stats = fq_dump_stats, 787 .owner = THIS_MODULE, 788 }; 789 790 static int __init fq_module_init(void) 791 { 792 int ret; 793 794 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 795 sizeof(struct fq_flow), 796 0, 0, NULL); 797 if (!fq_flow_cachep) 798 return -ENOMEM; 799 800 ret = register_qdisc(&fq_qdisc_ops); 801 if (ret) 802 kmem_cache_destroy(fq_flow_cachep); 803 return ret; 804 } 805 806 static void __exit fq_module_exit(void) 807 { 808 unregister_qdisc(&fq_qdisc_ops); 809 kmem_cache_destroy(fq_flow_cachep); 810 } 811 812 module_init(fq_module_init) 813 module_exit(fq_module_exit) 814 MODULE_AUTHOR("Eric Dumazet"); 815 MODULE_LICENSE("GPL"); 816