1 /* 2 * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing) 3 * 4 * Copyright (C) 2013-2015 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 locally 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 <linux/vmalloc.h> 51 #include <net/netlink.h> 52 #include <net/pkt_sched.h> 53 #include <net/sock.h> 54 #include <net/tcp_states.h> 55 #include <net/tcp.h> 56 57 /* 58 * Per flow structure, dynamically allocated 59 */ 60 struct fq_flow { 61 struct sk_buff *head; /* list of skbs for this flow : first skb */ 62 union { 63 struct sk_buff *tail; /* last skb in the list */ 64 unsigned long age; /* jiffies when flow was emptied, for gc */ 65 }; 66 struct rb_node fq_node; /* anchor in fq_root[] trees */ 67 struct sock *sk; 68 int qlen; /* number of packets in flow queue */ 69 int credit; 70 u32 socket_hash; /* sk_hash */ 71 struct fq_flow *next; /* next pointer in RR lists, or &detached */ 72 73 struct rb_node rate_node; /* anchor in q->delayed tree */ 74 u64 time_next_packet; 75 }; 76 77 struct fq_flow_head { 78 struct fq_flow *first; 79 struct fq_flow *last; 80 }; 81 82 struct fq_sched_data { 83 struct fq_flow_head new_flows; 84 85 struct fq_flow_head old_flows; 86 87 struct rb_root delayed; /* for rate limited flows */ 88 u64 time_next_delayed_flow; 89 unsigned long unthrottle_latency_ns; 90 91 struct fq_flow internal; /* for non classified or high prio packets */ 92 u32 quantum; 93 u32 initial_quantum; 94 u32 flow_refill_delay; 95 u32 flow_plimit; /* max packets per flow */ 96 unsigned long flow_max_rate; /* optional max rate per flow */ 97 u32 orphan_mask; /* mask for orphaned skb */ 98 u32 low_rate_threshold; 99 struct rb_root *fq_root; 100 u8 rate_enable; 101 u8 fq_trees_log; 102 103 u32 flows; 104 u32 inactive_flows; 105 u32 throttled_flows; 106 107 u64 stat_gc_flows; 108 u64 stat_internal_packets; 109 u64 stat_throttled; 110 u64 stat_flows_plimit; 111 u64 stat_pkts_too_long; 112 u64 stat_allocation_errors; 113 struct qdisc_watchdog watchdog; 114 }; 115 116 /* special value to mark a detached flow (not on old/new list) */ 117 static struct fq_flow detached, throttled; 118 119 static void fq_flow_set_detached(struct fq_flow *f) 120 { 121 f->next = &detached; 122 f->age = jiffies; 123 } 124 125 static bool fq_flow_is_detached(const struct fq_flow *f) 126 { 127 return f->next == &detached; 128 } 129 130 static bool fq_flow_is_throttled(const struct fq_flow *f) 131 { 132 return f->next == &throttled; 133 } 134 135 static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow) 136 { 137 if (head->first) 138 head->last->next = flow; 139 else 140 head->first = flow; 141 head->last = flow; 142 flow->next = NULL; 143 } 144 145 static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f) 146 { 147 rb_erase(&f->rate_node, &q->delayed); 148 q->throttled_flows--; 149 fq_flow_add_tail(&q->old_flows, f); 150 } 151 152 static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f) 153 { 154 struct rb_node **p = &q->delayed.rb_node, *parent = NULL; 155 156 while (*p) { 157 struct fq_flow *aux; 158 159 parent = *p; 160 aux = rb_entry(parent, struct fq_flow, rate_node); 161 if (f->time_next_packet >= aux->time_next_packet) 162 p = &parent->rb_right; 163 else 164 p = &parent->rb_left; 165 } 166 rb_link_node(&f->rate_node, parent, p); 167 rb_insert_color(&f->rate_node, &q->delayed); 168 q->throttled_flows++; 169 q->stat_throttled++; 170 171 f->next = &throttled; 172 if (q->time_next_delayed_flow > f->time_next_packet) 173 q->time_next_delayed_flow = f->time_next_packet; 174 } 175 176 177 static struct kmem_cache *fq_flow_cachep __read_mostly; 178 179 180 /* limit number of collected flows per round */ 181 #define FQ_GC_MAX 8 182 #define FQ_GC_AGE (3*HZ) 183 184 static bool fq_gc_candidate(const struct fq_flow *f) 185 { 186 return fq_flow_is_detached(f) && 187 time_after(jiffies, f->age + FQ_GC_AGE); 188 } 189 190 static void fq_gc(struct fq_sched_data *q, 191 struct rb_root *root, 192 struct sock *sk) 193 { 194 struct fq_flow *f, *tofree[FQ_GC_MAX]; 195 struct rb_node **p, *parent; 196 int fcnt = 0; 197 198 p = &root->rb_node; 199 parent = NULL; 200 while (*p) { 201 parent = *p; 202 203 f = rb_entry(parent, struct fq_flow, fq_node); 204 if (f->sk == sk) 205 break; 206 207 if (fq_gc_candidate(f)) { 208 tofree[fcnt++] = f; 209 if (fcnt == FQ_GC_MAX) 210 break; 211 } 212 213 if (f->sk > sk) 214 p = &parent->rb_right; 215 else 216 p = &parent->rb_left; 217 } 218 219 q->flows -= fcnt; 220 q->inactive_flows -= fcnt; 221 q->stat_gc_flows += fcnt; 222 while (fcnt) { 223 struct fq_flow *f = tofree[--fcnt]; 224 225 rb_erase(&f->fq_node, root); 226 kmem_cache_free(fq_flow_cachep, f); 227 } 228 } 229 230 static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q) 231 { 232 struct rb_node **p, *parent; 233 struct sock *sk = skb->sk; 234 struct rb_root *root; 235 struct fq_flow *f; 236 237 /* warning: no starvation prevention... */ 238 if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL)) 239 return &q->internal; 240 241 /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket 242 * or a listener (SYNCOOKIE mode) 243 * 1) request sockets are not full blown, 244 * they do not contain sk_pacing_rate 245 * 2) They are not part of a 'flow' yet 246 * 3) We do not want to rate limit them (eg SYNFLOOD attack), 247 * especially if the listener set SO_MAX_PACING_RATE 248 * 4) We pretend they are orphaned 249 */ 250 if (!sk || sk_listener(sk)) { 251 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 252 253 /* By forcing low order bit to 1, we make sure to not 254 * collide with a local flow (socket pointers are word aligned) 255 */ 256 sk = (struct sock *)((hash << 1) | 1UL); 257 skb_orphan(skb); 258 } 259 260 root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)]; 261 262 if (q->flows >= (2U << q->fq_trees_log) && 263 q->inactive_flows > q->flows/2) 264 fq_gc(q, root, sk); 265 266 p = &root->rb_node; 267 parent = NULL; 268 while (*p) { 269 parent = *p; 270 271 f = rb_entry(parent, struct fq_flow, fq_node); 272 if (f->sk == sk) { 273 /* socket might have been reallocated, so check 274 * if its sk_hash is the same. 275 * It not, we need to refill credit with 276 * initial quantum 277 */ 278 if (unlikely(skb->sk && 279 f->socket_hash != sk->sk_hash)) { 280 f->credit = q->initial_quantum; 281 f->socket_hash = sk->sk_hash; 282 if (fq_flow_is_throttled(f)) 283 fq_flow_unset_throttled(q, f); 284 f->time_next_packet = 0ULL; 285 } 286 return f; 287 } 288 if (f->sk > sk) 289 p = &parent->rb_right; 290 else 291 p = &parent->rb_left; 292 } 293 294 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); 295 if (unlikely(!f)) { 296 q->stat_allocation_errors++; 297 return &q->internal; 298 } 299 fq_flow_set_detached(f); 300 f->sk = sk; 301 if (skb->sk) 302 f->socket_hash = sk->sk_hash; 303 f->credit = q->initial_quantum; 304 305 rb_link_node(&f->fq_node, parent, p); 306 rb_insert_color(&f->fq_node, root); 307 308 q->flows++; 309 q->inactive_flows++; 310 return f; 311 } 312 313 314 /* remove one skb from head of flow queue */ 315 static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow) 316 { 317 struct sk_buff *skb = flow->head; 318 319 if (skb) { 320 flow->head = skb->next; 321 skb_mark_not_on_list(skb); 322 flow->qlen--; 323 qdisc_qstats_backlog_dec(sch, skb); 324 sch->q.qlen--; 325 } 326 return skb; 327 } 328 329 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 330 { 331 struct sk_buff *head = flow->head; 332 333 skb->next = NULL; 334 if (!head) 335 flow->head = skb; 336 else 337 flow->tail->next = skb; 338 339 flow->tail = skb; 340 } 341 342 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 343 struct sk_buff **to_free) 344 { 345 struct fq_sched_data *q = qdisc_priv(sch); 346 struct fq_flow *f; 347 348 if (unlikely(sch->q.qlen >= sch->limit)) 349 return qdisc_drop(skb, sch, to_free); 350 351 f = fq_classify(skb, q); 352 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) { 353 q->stat_flows_plimit++; 354 return qdisc_drop(skb, sch, to_free); 355 } 356 357 f->qlen++; 358 qdisc_qstats_backlog_inc(sch, skb); 359 if (fq_flow_is_detached(f)) { 360 struct sock *sk = skb->sk; 361 362 fq_flow_add_tail(&q->new_flows, f); 363 if (time_after(jiffies, f->age + q->flow_refill_delay)) 364 f->credit = max_t(u32, f->credit, q->quantum); 365 if (sk && q->rate_enable) { 366 if (unlikely(smp_load_acquire(&sk->sk_pacing_status) != 367 SK_PACING_FQ)) 368 smp_store_release(&sk->sk_pacing_status, 369 SK_PACING_FQ); 370 } 371 q->inactive_flows--; 372 } 373 374 /* Note: this overwrites f->age */ 375 flow_queue_add(f, skb); 376 377 if (unlikely(f == &q->internal)) { 378 q->stat_internal_packets++; 379 } 380 sch->q.qlen++; 381 382 return NET_XMIT_SUCCESS; 383 } 384 385 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 386 { 387 unsigned long sample; 388 struct rb_node *p; 389 390 if (q->time_next_delayed_flow > now) 391 return; 392 393 /* Update unthrottle latency EWMA. 394 * This is cheap and can help diagnosing timer/latency problems. 395 */ 396 sample = (unsigned long)(now - q->time_next_delayed_flow); 397 q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; 398 q->unthrottle_latency_ns += sample >> 3; 399 400 q->time_next_delayed_flow = ~0ULL; 401 while ((p = rb_first(&q->delayed)) != NULL) { 402 struct fq_flow *f = rb_entry(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 fq_flow_unset_throttled(q, f); 409 } 410 } 411 412 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 413 { 414 struct fq_sched_data *q = qdisc_priv(sch); 415 u64 now = ktime_get_ns(); 416 struct fq_flow_head *head; 417 struct sk_buff *skb; 418 struct fq_flow *f; 419 unsigned long rate; 420 u32 plen; 421 422 skb = fq_dequeue_head(sch, &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 skb = f->head; 447 if (skb) { 448 u64 time_next_packet = max_t(u64, ktime_to_ns(skb->tstamp), 449 f->time_next_packet); 450 451 if (now < time_next_packet) { 452 head->first = f->next; 453 f->time_next_packet = time_next_packet; 454 fq_flow_set_throttled(q, f); 455 goto begin; 456 } 457 } 458 459 skb = fq_dequeue_head(sch, f); 460 if (!skb) { 461 head->first = f->next; 462 /* force a pass through old_flows to prevent starvation */ 463 if ((head == &q->new_flows) && q->old_flows.first) { 464 fq_flow_add_tail(&q->old_flows, f); 465 } else { 466 fq_flow_set_detached(f); 467 q->inactive_flows++; 468 } 469 goto begin; 470 } 471 prefetch(&skb->end); 472 plen = qdisc_pkt_len(skb); 473 f->credit -= plen; 474 475 if (!q->rate_enable) 476 goto out; 477 478 rate = q->flow_max_rate; 479 480 /* If EDT time was provided for this skb, we need to 481 * update f->time_next_packet only if this qdisc enforces 482 * a flow max rate. 483 */ 484 if (!skb->tstamp) { 485 if (skb->sk) 486 rate = min(skb->sk->sk_pacing_rate, rate); 487 488 if (rate <= q->low_rate_threshold) { 489 f->credit = 0; 490 } else { 491 plen = max(plen, q->quantum); 492 if (f->credit > 0) 493 goto out; 494 } 495 } 496 if (rate != ~0UL) { 497 u64 len = (u64)plen * NSEC_PER_SEC; 498 499 if (likely(rate)) 500 len = div64_ul(len, rate); 501 /* Since socket rate can change later, 502 * clamp the delay to 1 second. 503 * Really, providers of too big packets should be fixed ! 504 */ 505 if (unlikely(len > NSEC_PER_SEC)) { 506 len = NSEC_PER_SEC; 507 q->stat_pkts_too_long++; 508 } 509 /* Account for schedule/timers drifts. 510 * f->time_next_packet was set when prior packet was sent, 511 * and current time (@now) can be too late by tens of us. 512 */ 513 if (f->time_next_packet) 514 len -= min(len/2, now - f->time_next_packet); 515 f->time_next_packet = now + len; 516 } 517 out: 518 qdisc_bstats_update(sch, skb); 519 return skb; 520 } 521 522 static void fq_flow_purge(struct fq_flow *flow) 523 { 524 rtnl_kfree_skbs(flow->head, flow->tail); 525 flow->head = NULL; 526 flow->qlen = 0; 527 } 528 529 static void fq_reset(struct Qdisc *sch) 530 { 531 struct fq_sched_data *q = qdisc_priv(sch); 532 struct rb_root *root; 533 struct rb_node *p; 534 struct fq_flow *f; 535 unsigned int idx; 536 537 sch->q.qlen = 0; 538 sch->qstats.backlog = 0; 539 540 fq_flow_purge(&q->internal); 541 542 if (!q->fq_root) 543 return; 544 545 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 546 root = &q->fq_root[idx]; 547 while ((p = rb_first(root)) != NULL) { 548 f = rb_entry(p, struct fq_flow, fq_node); 549 rb_erase(p, root); 550 551 fq_flow_purge(f); 552 553 kmem_cache_free(fq_flow_cachep, f); 554 } 555 } 556 q->new_flows.first = NULL; 557 q->old_flows.first = NULL; 558 q->delayed = RB_ROOT; 559 q->flows = 0; 560 q->inactive_flows = 0; 561 q->throttled_flows = 0; 562 } 563 564 static void fq_rehash(struct fq_sched_data *q, 565 struct rb_root *old_array, u32 old_log, 566 struct rb_root *new_array, u32 new_log) 567 { 568 struct rb_node *op, **np, *parent; 569 struct rb_root *oroot, *nroot; 570 struct fq_flow *of, *nf; 571 int fcnt = 0; 572 u32 idx; 573 574 for (idx = 0; idx < (1U << old_log); idx++) { 575 oroot = &old_array[idx]; 576 while ((op = rb_first(oroot)) != NULL) { 577 rb_erase(op, oroot); 578 of = rb_entry(op, struct fq_flow, fq_node); 579 if (fq_gc_candidate(of)) { 580 fcnt++; 581 kmem_cache_free(fq_flow_cachep, of); 582 continue; 583 } 584 nroot = &new_array[hash_ptr(of->sk, new_log)]; 585 586 np = &nroot->rb_node; 587 parent = NULL; 588 while (*np) { 589 parent = *np; 590 591 nf = rb_entry(parent, struct fq_flow, fq_node); 592 BUG_ON(nf->sk == of->sk); 593 594 if (nf->sk > of->sk) 595 np = &parent->rb_right; 596 else 597 np = &parent->rb_left; 598 } 599 600 rb_link_node(&of->fq_node, parent, np); 601 rb_insert_color(&of->fq_node, nroot); 602 } 603 } 604 q->flows -= fcnt; 605 q->inactive_flows -= fcnt; 606 q->stat_gc_flows += fcnt; 607 } 608 609 static void fq_free(void *addr) 610 { 611 kvfree(addr); 612 } 613 614 static int fq_resize(struct Qdisc *sch, u32 log) 615 { 616 struct fq_sched_data *q = qdisc_priv(sch); 617 struct rb_root *array; 618 void *old_fq_root; 619 u32 idx; 620 621 if (q->fq_root && log == q->fq_trees_log) 622 return 0; 623 624 /* If XPS was setup, we can allocate memory on right NUMA node */ 625 array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, 626 netdev_queue_numa_node_read(sch->dev_queue)); 627 if (!array) 628 return -ENOMEM; 629 630 for (idx = 0; idx < (1U << log); idx++) 631 array[idx] = RB_ROOT; 632 633 sch_tree_lock(sch); 634 635 old_fq_root = q->fq_root; 636 if (old_fq_root) 637 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); 638 639 q->fq_root = array; 640 q->fq_trees_log = log; 641 642 sch_tree_unlock(sch); 643 644 fq_free(old_fq_root); 645 646 return 0; 647 } 648 649 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 650 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 651 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 652 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 653 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, 654 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 655 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 656 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 657 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 658 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, 659 [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, 660 }; 661 662 static int fq_change(struct Qdisc *sch, struct nlattr *opt, 663 struct netlink_ext_ack *extack) 664 { 665 struct fq_sched_data *q = qdisc_priv(sch); 666 struct nlattr *tb[TCA_FQ_MAX + 1]; 667 int err, drop_count = 0; 668 unsigned drop_len = 0; 669 u32 fq_log; 670 671 if (!opt) 672 return -EINVAL; 673 674 err = nla_parse_nested(tb, TCA_FQ_MAX, opt, fq_policy, NULL); 675 if (err < 0) 676 return err; 677 678 sch_tree_lock(sch); 679 680 fq_log = q->fq_trees_log; 681 682 if (tb[TCA_FQ_BUCKETS_LOG]) { 683 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 684 685 if (nval >= 1 && nval <= ilog2(256*1024)) 686 fq_log = nval; 687 else 688 err = -EINVAL; 689 } 690 if (tb[TCA_FQ_PLIMIT]) 691 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]); 692 693 if (tb[TCA_FQ_FLOW_PLIMIT]) 694 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); 695 696 if (tb[TCA_FQ_QUANTUM]) { 697 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 698 699 if (quantum > 0) 700 q->quantum = quantum; 701 else 702 err = -EINVAL; 703 } 704 705 if (tb[TCA_FQ_INITIAL_QUANTUM]) 706 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); 707 708 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 709 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", 710 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); 711 712 if (tb[TCA_FQ_FLOW_MAX_RATE]) { 713 u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); 714 715 q->flow_max_rate = (rate == ~0U) ? ~0UL : rate; 716 } 717 if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) 718 q->low_rate_threshold = 719 nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD]); 720 721 if (tb[TCA_FQ_RATE_ENABLE]) { 722 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); 723 724 if (enable <= 1) 725 q->rate_enable = enable; 726 else 727 err = -EINVAL; 728 } 729 730 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { 731 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; 732 733 q->flow_refill_delay = usecs_to_jiffies(usecs_delay); 734 } 735 736 if (tb[TCA_FQ_ORPHAN_MASK]) 737 q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]); 738 739 if (!err) { 740 sch_tree_unlock(sch); 741 err = fq_resize(sch, fq_log); 742 sch_tree_lock(sch); 743 } 744 while (sch->q.qlen > sch->limit) { 745 struct sk_buff *skb = fq_dequeue(sch); 746 747 if (!skb) 748 break; 749 drop_len += qdisc_pkt_len(skb); 750 rtnl_kfree_skbs(skb, skb); 751 drop_count++; 752 } 753 qdisc_tree_reduce_backlog(sch, drop_count, drop_len); 754 755 sch_tree_unlock(sch); 756 return err; 757 } 758 759 static void fq_destroy(struct Qdisc *sch) 760 { 761 struct fq_sched_data *q = qdisc_priv(sch); 762 763 fq_reset(sch); 764 fq_free(q->fq_root); 765 qdisc_watchdog_cancel(&q->watchdog); 766 } 767 768 static int fq_init(struct Qdisc *sch, struct nlattr *opt, 769 struct netlink_ext_ack *extack) 770 { 771 struct fq_sched_data *q = qdisc_priv(sch); 772 int err; 773 774 sch->limit = 10000; 775 q->flow_plimit = 100; 776 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 777 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 778 q->flow_refill_delay = msecs_to_jiffies(40); 779 q->flow_max_rate = ~0UL; 780 q->time_next_delayed_flow = ~0ULL; 781 q->rate_enable = 1; 782 q->new_flows.first = NULL; 783 q->old_flows.first = NULL; 784 q->delayed = RB_ROOT; 785 q->fq_root = NULL; 786 q->fq_trees_log = ilog2(1024); 787 q->orphan_mask = 1024 - 1; 788 q->low_rate_threshold = 550000 / 8; 789 qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC); 790 791 if (opt) 792 err = fq_change(sch, opt, extack); 793 else 794 err = fq_resize(sch, q->fq_trees_log); 795 796 return err; 797 } 798 799 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 800 { 801 struct fq_sched_data *q = qdisc_priv(sch); 802 struct nlattr *opts; 803 804 opts = nla_nest_start(skb, TCA_OPTIONS); 805 if (opts == NULL) 806 goto nla_put_failure; 807 808 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ 809 810 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) || 811 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) || 812 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) || 813 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) || 814 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) || 815 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, 816 min_t(unsigned long, q->flow_max_rate, ~0U)) || 817 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, 818 jiffies_to_usecs(q->flow_refill_delay)) || 819 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) || 820 nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, 821 q->low_rate_threshold) || 822 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log)) 823 goto nla_put_failure; 824 825 return nla_nest_end(skb, opts); 826 827 nla_put_failure: 828 return -1; 829 } 830 831 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 832 { 833 struct fq_sched_data *q = qdisc_priv(sch); 834 struct tc_fq_qd_stats st; 835 836 sch_tree_lock(sch); 837 838 st.gc_flows = q->stat_gc_flows; 839 st.highprio_packets = q->stat_internal_packets; 840 st.tcp_retrans = 0; 841 st.throttled = q->stat_throttled; 842 st.flows_plimit = q->stat_flows_plimit; 843 st.pkts_too_long = q->stat_pkts_too_long; 844 st.allocation_errors = q->stat_allocation_errors; 845 st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); 846 st.flows = q->flows; 847 st.inactive_flows = q->inactive_flows; 848 st.throttled_flows = q->throttled_flows; 849 st.unthrottle_latency_ns = min_t(unsigned long, 850 q->unthrottle_latency_ns, ~0U); 851 sch_tree_unlock(sch); 852 853 return gnet_stats_copy_app(d, &st, sizeof(st)); 854 } 855 856 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 857 .id = "fq", 858 .priv_size = sizeof(struct fq_sched_data), 859 860 .enqueue = fq_enqueue, 861 .dequeue = fq_dequeue, 862 .peek = qdisc_peek_dequeued, 863 .init = fq_init, 864 .reset = fq_reset, 865 .destroy = fq_destroy, 866 .change = fq_change, 867 .dump = fq_dump, 868 .dump_stats = fq_dump_stats, 869 .owner = THIS_MODULE, 870 }; 871 872 static int __init fq_module_init(void) 873 { 874 int ret; 875 876 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 877 sizeof(struct fq_flow), 878 0, 0, NULL); 879 if (!fq_flow_cachep) 880 return -ENOMEM; 881 882 ret = register_qdisc(&fq_qdisc_ops); 883 if (ret) 884 kmem_cache_destroy(fq_flow_cachep); 885 return ret; 886 } 887 888 static void __exit fq_module_exit(void) 889 { 890 unregister_qdisc(&fq_qdisc_ops); 891 kmem_cache_destroy(fq_flow_cachep); 892 } 893 894 module_init(fq_module_init) 895 module_exit(fq_module_exit) 896 MODULE_AUTHOR("Eric Dumazet"); 897 MODULE_LICENSE("GPL"); 898