1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * net/sched/sch_fq.c Fair Queue Packet Scheduler (per flow pacing) 4 * 5 * Copyright (C) 2013-2015 Eric Dumazet <edumazet@google.com> 6 * 7 * Meant to be mostly used for locally generated traffic : 8 * Fast classification depends on skb->sk being set before reaching us. 9 * If not, (router workload), we use rxhash as fallback, with 32 bits wide hash. 10 * All packets belonging to a socket are considered as a 'flow'. 11 * 12 * Flows are dynamically allocated and stored in a hash table of RB trees 13 * They are also part of one Round Robin 'queues' (new or old flows) 14 * 15 * Burst avoidance (aka pacing) capability : 16 * 17 * Transport (eg TCP) can set in sk->sk_pacing_rate a rate, enqueue a 18 * bunch of packets, and this packet scheduler adds delay between 19 * packets to respect rate limitation. 20 * 21 * enqueue() : 22 * - lookup one RB tree (out of 1024 or more) to find the flow. 23 * If non existent flow, create it, add it to the tree. 24 * Add skb to the per flow list of skb (fifo). 25 * - Use a special fifo for high prio packets 26 * 27 * dequeue() : serves flows in Round Robin 28 * Note : When a flow becomes empty, we do not immediately remove it from 29 * rb trees, for performance reasons (its expected to send additional packets, 30 * or SLAB cache will reuse socket for another flow) 31 */ 32 33 #include <linux/module.h> 34 #include <linux/types.h> 35 #include <linux/kernel.h> 36 #include <linux/jiffies.h> 37 #include <linux/string.h> 38 #include <linux/in.h> 39 #include <linux/errno.h> 40 #include <linux/init.h> 41 #include <linux/skbuff.h> 42 #include <linux/slab.h> 43 #include <linux/rbtree.h> 44 #include <linux/hash.h> 45 #include <linux/prefetch.h> 46 #include <linux/vmalloc.h> 47 #include <net/netlink.h> 48 #include <net/pkt_sched.h> 49 #include <net/sock.h> 50 #include <net/tcp_states.h> 51 #include <net/tcp.h> 52 53 struct fq_skb_cb { 54 u64 time_to_send; 55 }; 56 57 static inline struct fq_skb_cb *fq_skb_cb(struct sk_buff *skb) 58 { 59 qdisc_cb_private_validate(skb, sizeof(struct fq_skb_cb)); 60 return (struct fq_skb_cb *)qdisc_skb_cb(skb)->data; 61 } 62 63 /* 64 * Per flow structure, dynamically allocated. 65 * If packets have monotically increasing time_to_send, they are placed in O(1) 66 * in linear list (head,tail), otherwise are placed in a rbtree (t_root). 67 */ 68 struct fq_flow { 69 struct rb_root t_root; 70 struct sk_buff *head; /* list of skbs for this flow : first skb */ 71 union { 72 struct sk_buff *tail; /* last skb in the list */ 73 unsigned long age; /* jiffies when flow was emptied, for gc */ 74 }; 75 struct rb_node fq_node; /* anchor in fq_root[] trees */ 76 struct sock *sk; 77 int qlen; /* number of packets in flow queue */ 78 int credit; 79 u32 socket_hash; /* sk_hash */ 80 struct fq_flow *next; /* next pointer in RR lists, or &detached */ 81 82 struct rb_node rate_node; /* anchor in q->delayed tree */ 83 u64 time_next_packet; 84 }; 85 86 struct fq_flow_head { 87 struct fq_flow *first; 88 struct fq_flow *last; 89 }; 90 91 struct fq_sched_data { 92 struct fq_flow_head new_flows; 93 94 struct fq_flow_head old_flows; 95 96 struct rb_root delayed; /* for rate limited flows */ 97 u64 time_next_delayed_flow; 98 unsigned long unthrottle_latency_ns; 99 100 struct fq_flow internal; /* for non classified or high prio packets */ 101 u32 quantum; 102 u32 initial_quantum; 103 u32 flow_refill_delay; 104 u32 flow_plimit; /* max packets per flow */ 105 unsigned long flow_max_rate; /* optional max rate per flow */ 106 u64 ce_threshold; 107 u32 orphan_mask; /* mask for orphaned skb */ 108 u32 low_rate_threshold; 109 struct rb_root *fq_root; 110 u8 rate_enable; 111 u8 fq_trees_log; 112 113 u32 flows; 114 u32 inactive_flows; 115 u32 throttled_flows; 116 117 u64 stat_gc_flows; 118 u64 stat_internal_packets; 119 u64 stat_throttled; 120 u64 stat_ce_mark; 121 u64 stat_flows_plimit; 122 u64 stat_pkts_too_long; 123 u64 stat_allocation_errors; 124 struct qdisc_watchdog watchdog; 125 }; 126 127 /* special value to mark a detached flow (not on old/new list) */ 128 static struct fq_flow detached, throttled; 129 130 static void fq_flow_set_detached(struct fq_flow *f) 131 { 132 f->next = &detached; 133 f->age = jiffies; 134 } 135 136 static bool fq_flow_is_detached(const struct fq_flow *f) 137 { 138 return f->next == &detached; 139 } 140 141 static bool fq_flow_is_throttled(const struct fq_flow *f) 142 { 143 return f->next == &throttled; 144 } 145 146 static void fq_flow_add_tail(struct fq_flow_head *head, struct fq_flow *flow) 147 { 148 if (head->first) 149 head->last->next = flow; 150 else 151 head->first = flow; 152 head->last = flow; 153 flow->next = NULL; 154 } 155 156 static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f) 157 { 158 rb_erase(&f->rate_node, &q->delayed); 159 q->throttled_flows--; 160 fq_flow_add_tail(&q->old_flows, f); 161 } 162 163 static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f) 164 { 165 struct rb_node **p = &q->delayed.rb_node, *parent = NULL; 166 167 while (*p) { 168 struct fq_flow *aux; 169 170 parent = *p; 171 aux = rb_entry(parent, struct fq_flow, rate_node); 172 if (f->time_next_packet >= aux->time_next_packet) 173 p = &parent->rb_right; 174 else 175 p = &parent->rb_left; 176 } 177 rb_link_node(&f->rate_node, parent, p); 178 rb_insert_color(&f->rate_node, &q->delayed); 179 q->throttled_flows++; 180 q->stat_throttled++; 181 182 f->next = &throttled; 183 if (q->time_next_delayed_flow > f->time_next_packet) 184 q->time_next_delayed_flow = f->time_next_packet; 185 } 186 187 188 static struct kmem_cache *fq_flow_cachep __read_mostly; 189 190 191 /* limit number of collected flows per round */ 192 #define FQ_GC_MAX 8 193 #define FQ_GC_AGE (3*HZ) 194 195 static bool fq_gc_candidate(const struct fq_flow *f) 196 { 197 return fq_flow_is_detached(f) && 198 time_after(jiffies, f->age + FQ_GC_AGE); 199 } 200 201 static void fq_gc(struct fq_sched_data *q, 202 struct rb_root *root, 203 struct sock *sk) 204 { 205 struct fq_flow *f, *tofree[FQ_GC_MAX]; 206 struct rb_node **p, *parent; 207 int fcnt = 0; 208 209 p = &root->rb_node; 210 parent = NULL; 211 while (*p) { 212 parent = *p; 213 214 f = rb_entry(parent, struct fq_flow, fq_node); 215 if (f->sk == sk) 216 break; 217 218 if (fq_gc_candidate(f)) { 219 tofree[fcnt++] = f; 220 if (fcnt == FQ_GC_MAX) 221 break; 222 } 223 224 if (f->sk > sk) 225 p = &parent->rb_right; 226 else 227 p = &parent->rb_left; 228 } 229 230 q->flows -= fcnt; 231 q->inactive_flows -= fcnt; 232 q->stat_gc_flows += fcnt; 233 while (fcnt) { 234 struct fq_flow *f = tofree[--fcnt]; 235 236 rb_erase(&f->fq_node, root); 237 kmem_cache_free(fq_flow_cachep, f); 238 } 239 } 240 241 static struct fq_flow *fq_classify(struct sk_buff *skb, struct fq_sched_data *q) 242 { 243 struct rb_node **p, *parent; 244 struct sock *sk = skb->sk; 245 struct rb_root *root; 246 struct fq_flow *f; 247 248 /* warning: no starvation prevention... */ 249 if (unlikely((skb->priority & TC_PRIO_MAX) == TC_PRIO_CONTROL)) 250 return &q->internal; 251 252 /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket 253 * or a listener (SYNCOOKIE mode) 254 * 1) request sockets are not full blown, 255 * they do not contain sk_pacing_rate 256 * 2) They are not part of a 'flow' yet 257 * 3) We do not want to rate limit them (eg SYNFLOOD attack), 258 * especially if the listener set SO_MAX_PACING_RATE 259 * 4) We pretend they are orphaned 260 */ 261 if (!sk || sk_listener(sk)) { 262 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 263 264 /* By forcing low order bit to 1, we make sure to not 265 * collide with a local flow (socket pointers are word aligned) 266 */ 267 sk = (struct sock *)((hash << 1) | 1UL); 268 skb_orphan(skb); 269 } else if (sk->sk_state == TCP_CLOSE) { 270 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 271 /* 272 * Sockets in TCP_CLOSE are non connected. 273 * Typical use case is UDP sockets, they can send packets 274 * with sendto() to many different destinations. 275 * We probably could use a generic bit advertising 276 * non connected sockets, instead of sk_state == TCP_CLOSE, 277 * if we care enough. 278 */ 279 sk = (struct sock *)((hash << 1) | 1UL); 280 } 281 282 root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)]; 283 284 if (q->flows >= (2U << q->fq_trees_log) && 285 q->inactive_flows > q->flows/2) 286 fq_gc(q, root, sk); 287 288 p = &root->rb_node; 289 parent = NULL; 290 while (*p) { 291 parent = *p; 292 293 f = rb_entry(parent, struct fq_flow, fq_node); 294 if (f->sk == sk) { 295 /* socket might have been reallocated, so check 296 * if its sk_hash is the same. 297 * It not, we need to refill credit with 298 * initial quantum 299 */ 300 if (unlikely(skb->sk == sk && 301 f->socket_hash != sk->sk_hash)) { 302 f->credit = q->initial_quantum; 303 f->socket_hash = sk->sk_hash; 304 if (fq_flow_is_throttled(f)) 305 fq_flow_unset_throttled(q, f); 306 f->time_next_packet = 0ULL; 307 } 308 return f; 309 } 310 if (f->sk > sk) 311 p = &parent->rb_right; 312 else 313 p = &parent->rb_left; 314 } 315 316 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); 317 if (unlikely(!f)) { 318 q->stat_allocation_errors++; 319 return &q->internal; 320 } 321 /* f->t_root is already zeroed after kmem_cache_zalloc() */ 322 323 fq_flow_set_detached(f); 324 f->sk = sk; 325 if (skb->sk == sk) 326 f->socket_hash = sk->sk_hash; 327 f->credit = q->initial_quantum; 328 329 rb_link_node(&f->fq_node, parent, p); 330 rb_insert_color(&f->fq_node, root); 331 332 q->flows++; 333 q->inactive_flows++; 334 return f; 335 } 336 337 static struct sk_buff *fq_peek(struct fq_flow *flow) 338 { 339 struct sk_buff *skb = skb_rb_first(&flow->t_root); 340 struct sk_buff *head = flow->head; 341 342 if (!skb) 343 return head; 344 345 if (!head) 346 return skb; 347 348 if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send) 349 return skb; 350 return head; 351 } 352 353 static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow, 354 struct sk_buff *skb) 355 { 356 if (skb == flow->head) { 357 flow->head = skb->next; 358 } else { 359 rb_erase(&skb->rbnode, &flow->t_root); 360 skb->dev = qdisc_dev(sch); 361 } 362 } 363 364 /* remove one skb from head of flow queue */ 365 static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow) 366 { 367 struct sk_buff *skb = fq_peek(flow); 368 369 if (skb) { 370 fq_erase_head(sch, flow, skb); 371 skb_mark_not_on_list(skb); 372 flow->qlen--; 373 qdisc_qstats_backlog_dec(sch, skb); 374 sch->q.qlen--; 375 } 376 return skb; 377 } 378 379 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 380 { 381 struct rb_node **p, *parent; 382 struct sk_buff *head, *aux; 383 384 fq_skb_cb(skb)->time_to_send = skb->tstamp ?: ktime_get_ns(); 385 386 head = flow->head; 387 if (!head || 388 fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) { 389 if (!head) 390 flow->head = skb; 391 else 392 flow->tail->next = skb; 393 flow->tail = skb; 394 skb->next = NULL; 395 return; 396 } 397 398 p = &flow->t_root.rb_node; 399 parent = NULL; 400 401 while (*p) { 402 parent = *p; 403 aux = rb_to_skb(parent); 404 if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send) 405 p = &parent->rb_right; 406 else 407 p = &parent->rb_left; 408 } 409 rb_link_node(&skb->rbnode, parent, p); 410 rb_insert_color(&skb->rbnode, &flow->t_root); 411 } 412 413 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 414 struct sk_buff **to_free) 415 { 416 struct fq_sched_data *q = qdisc_priv(sch); 417 struct fq_flow *f; 418 419 if (unlikely(sch->q.qlen >= sch->limit)) 420 return qdisc_drop(skb, sch, to_free); 421 422 f = fq_classify(skb, q); 423 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) { 424 q->stat_flows_plimit++; 425 return qdisc_drop(skb, sch, to_free); 426 } 427 428 f->qlen++; 429 qdisc_qstats_backlog_inc(sch, skb); 430 if (fq_flow_is_detached(f)) { 431 struct sock *sk = skb->sk; 432 433 fq_flow_add_tail(&q->new_flows, f); 434 if (time_after(jiffies, f->age + q->flow_refill_delay)) 435 f->credit = max_t(u32, f->credit, q->quantum); 436 if (sk && q->rate_enable) { 437 if (unlikely(smp_load_acquire(&sk->sk_pacing_status) != 438 SK_PACING_FQ)) 439 smp_store_release(&sk->sk_pacing_status, 440 SK_PACING_FQ); 441 } 442 q->inactive_flows--; 443 } 444 445 /* Note: this overwrites f->age */ 446 flow_queue_add(f, skb); 447 448 if (unlikely(f == &q->internal)) { 449 q->stat_internal_packets++; 450 } 451 sch->q.qlen++; 452 453 return NET_XMIT_SUCCESS; 454 } 455 456 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 457 { 458 unsigned long sample; 459 struct rb_node *p; 460 461 if (q->time_next_delayed_flow > now) 462 return; 463 464 /* Update unthrottle latency EWMA. 465 * This is cheap and can help diagnosing timer/latency problems. 466 */ 467 sample = (unsigned long)(now - q->time_next_delayed_flow); 468 q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; 469 q->unthrottle_latency_ns += sample >> 3; 470 471 q->time_next_delayed_flow = ~0ULL; 472 while ((p = rb_first(&q->delayed)) != NULL) { 473 struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node); 474 475 if (f->time_next_packet > now) { 476 q->time_next_delayed_flow = f->time_next_packet; 477 break; 478 } 479 fq_flow_unset_throttled(q, f); 480 } 481 } 482 483 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 484 { 485 struct fq_sched_data *q = qdisc_priv(sch); 486 struct fq_flow_head *head; 487 struct sk_buff *skb; 488 struct fq_flow *f; 489 unsigned long rate; 490 u32 plen; 491 u64 now; 492 493 if (!sch->q.qlen) 494 return NULL; 495 496 skb = fq_dequeue_head(sch, &q->internal); 497 if (skb) 498 goto out; 499 500 now = ktime_get_ns(); 501 fq_check_throttled(q, now); 502 begin: 503 head = &q->new_flows; 504 if (!head->first) { 505 head = &q->old_flows; 506 if (!head->first) { 507 if (q->time_next_delayed_flow != ~0ULL) 508 qdisc_watchdog_schedule_ns(&q->watchdog, 509 q->time_next_delayed_flow); 510 return NULL; 511 } 512 } 513 f = head->first; 514 515 if (f->credit <= 0) { 516 f->credit += q->quantum; 517 head->first = f->next; 518 fq_flow_add_tail(&q->old_flows, f); 519 goto begin; 520 } 521 522 skb = fq_peek(f); 523 if (skb) { 524 u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send, 525 f->time_next_packet); 526 527 if (now < time_next_packet) { 528 head->first = f->next; 529 f->time_next_packet = time_next_packet; 530 fq_flow_set_throttled(q, f); 531 goto begin; 532 } 533 if ((s64)(now - time_next_packet - q->ce_threshold) > 0) { 534 INET_ECN_set_ce(skb); 535 q->stat_ce_mark++; 536 } 537 } 538 539 skb = fq_dequeue_head(sch, f); 540 if (!skb) { 541 head->first = f->next; 542 /* force a pass through old_flows to prevent starvation */ 543 if ((head == &q->new_flows) && q->old_flows.first) { 544 fq_flow_add_tail(&q->old_flows, f); 545 } else { 546 fq_flow_set_detached(f); 547 q->inactive_flows++; 548 } 549 goto begin; 550 } 551 prefetch(&skb->end); 552 plen = qdisc_pkt_len(skb); 553 f->credit -= plen; 554 555 if (!q->rate_enable) 556 goto out; 557 558 rate = q->flow_max_rate; 559 560 /* If EDT time was provided for this skb, we need to 561 * update f->time_next_packet only if this qdisc enforces 562 * a flow max rate. 563 */ 564 if (!skb->tstamp) { 565 if (skb->sk) 566 rate = min(skb->sk->sk_pacing_rate, rate); 567 568 if (rate <= q->low_rate_threshold) { 569 f->credit = 0; 570 } else { 571 plen = max(plen, q->quantum); 572 if (f->credit > 0) 573 goto out; 574 } 575 } 576 if (rate != ~0UL) { 577 u64 len = (u64)plen * NSEC_PER_SEC; 578 579 if (likely(rate)) 580 len = div64_ul(len, rate); 581 /* Since socket rate can change later, 582 * clamp the delay to 1 second. 583 * Really, providers of too big packets should be fixed ! 584 */ 585 if (unlikely(len > NSEC_PER_SEC)) { 586 len = NSEC_PER_SEC; 587 q->stat_pkts_too_long++; 588 } 589 /* Account for schedule/timers drifts. 590 * f->time_next_packet was set when prior packet was sent, 591 * and current time (@now) can be too late by tens of us. 592 */ 593 if (f->time_next_packet) 594 len -= min(len/2, now - f->time_next_packet); 595 f->time_next_packet = now + len; 596 } 597 out: 598 qdisc_bstats_update(sch, skb); 599 return skb; 600 } 601 602 static void fq_flow_purge(struct fq_flow *flow) 603 { 604 struct rb_node *p = rb_first(&flow->t_root); 605 606 while (p) { 607 struct sk_buff *skb = rb_to_skb(p); 608 609 p = rb_next(p); 610 rb_erase(&skb->rbnode, &flow->t_root); 611 rtnl_kfree_skbs(skb, skb); 612 } 613 rtnl_kfree_skbs(flow->head, flow->tail); 614 flow->head = NULL; 615 flow->qlen = 0; 616 } 617 618 static void fq_reset(struct Qdisc *sch) 619 { 620 struct fq_sched_data *q = qdisc_priv(sch); 621 struct rb_root *root; 622 struct rb_node *p; 623 struct fq_flow *f; 624 unsigned int idx; 625 626 sch->q.qlen = 0; 627 sch->qstats.backlog = 0; 628 629 fq_flow_purge(&q->internal); 630 631 if (!q->fq_root) 632 return; 633 634 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 635 root = &q->fq_root[idx]; 636 while ((p = rb_first(root)) != NULL) { 637 f = rb_entry(p, struct fq_flow, fq_node); 638 rb_erase(p, root); 639 640 fq_flow_purge(f); 641 642 kmem_cache_free(fq_flow_cachep, f); 643 } 644 } 645 q->new_flows.first = NULL; 646 q->old_flows.first = NULL; 647 q->delayed = RB_ROOT; 648 q->flows = 0; 649 q->inactive_flows = 0; 650 q->throttled_flows = 0; 651 } 652 653 static void fq_rehash(struct fq_sched_data *q, 654 struct rb_root *old_array, u32 old_log, 655 struct rb_root *new_array, u32 new_log) 656 { 657 struct rb_node *op, **np, *parent; 658 struct rb_root *oroot, *nroot; 659 struct fq_flow *of, *nf; 660 int fcnt = 0; 661 u32 idx; 662 663 for (idx = 0; idx < (1U << old_log); idx++) { 664 oroot = &old_array[idx]; 665 while ((op = rb_first(oroot)) != NULL) { 666 rb_erase(op, oroot); 667 of = rb_entry(op, struct fq_flow, fq_node); 668 if (fq_gc_candidate(of)) { 669 fcnt++; 670 kmem_cache_free(fq_flow_cachep, of); 671 continue; 672 } 673 nroot = &new_array[hash_ptr(of->sk, new_log)]; 674 675 np = &nroot->rb_node; 676 parent = NULL; 677 while (*np) { 678 parent = *np; 679 680 nf = rb_entry(parent, struct fq_flow, fq_node); 681 BUG_ON(nf->sk == of->sk); 682 683 if (nf->sk > of->sk) 684 np = &parent->rb_right; 685 else 686 np = &parent->rb_left; 687 } 688 689 rb_link_node(&of->fq_node, parent, np); 690 rb_insert_color(&of->fq_node, nroot); 691 } 692 } 693 q->flows -= fcnt; 694 q->inactive_flows -= fcnt; 695 q->stat_gc_flows += fcnt; 696 } 697 698 static void fq_free(void *addr) 699 { 700 kvfree(addr); 701 } 702 703 static int fq_resize(struct Qdisc *sch, u32 log) 704 { 705 struct fq_sched_data *q = qdisc_priv(sch); 706 struct rb_root *array; 707 void *old_fq_root; 708 u32 idx; 709 710 if (q->fq_root && log == q->fq_trees_log) 711 return 0; 712 713 /* If XPS was setup, we can allocate memory on right NUMA node */ 714 array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, 715 netdev_queue_numa_node_read(sch->dev_queue)); 716 if (!array) 717 return -ENOMEM; 718 719 for (idx = 0; idx < (1U << log); idx++) 720 array[idx] = RB_ROOT; 721 722 sch_tree_lock(sch); 723 724 old_fq_root = q->fq_root; 725 if (old_fq_root) 726 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); 727 728 q->fq_root = array; 729 q->fq_trees_log = log; 730 731 sch_tree_unlock(sch); 732 733 fq_free(old_fq_root); 734 735 return 0; 736 } 737 738 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 739 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 740 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 741 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 742 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, 743 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 744 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 745 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 746 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 747 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, 748 [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, 749 [TCA_FQ_CE_THRESHOLD] = { .type = NLA_U32 }, 750 }; 751 752 static int fq_change(struct Qdisc *sch, struct nlattr *opt, 753 struct netlink_ext_ack *extack) 754 { 755 struct fq_sched_data *q = qdisc_priv(sch); 756 struct nlattr *tb[TCA_FQ_MAX + 1]; 757 int err, drop_count = 0; 758 unsigned drop_len = 0; 759 u32 fq_log; 760 761 if (!opt) 762 return -EINVAL; 763 764 err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy, 765 NULL); 766 if (err < 0) 767 return err; 768 769 sch_tree_lock(sch); 770 771 fq_log = q->fq_trees_log; 772 773 if (tb[TCA_FQ_BUCKETS_LOG]) { 774 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 775 776 if (nval >= 1 && nval <= ilog2(256*1024)) 777 fq_log = nval; 778 else 779 err = -EINVAL; 780 } 781 if (tb[TCA_FQ_PLIMIT]) 782 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]); 783 784 if (tb[TCA_FQ_FLOW_PLIMIT]) 785 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); 786 787 if (tb[TCA_FQ_QUANTUM]) { 788 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 789 790 if (quantum > 0) 791 q->quantum = quantum; 792 else 793 err = -EINVAL; 794 } 795 796 if (tb[TCA_FQ_INITIAL_QUANTUM]) 797 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); 798 799 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 800 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", 801 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); 802 803 if (tb[TCA_FQ_FLOW_MAX_RATE]) { 804 u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); 805 806 q->flow_max_rate = (rate == ~0U) ? ~0UL : rate; 807 } 808 if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) 809 q->low_rate_threshold = 810 nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD]); 811 812 if (tb[TCA_FQ_RATE_ENABLE]) { 813 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); 814 815 if (enable <= 1) 816 q->rate_enable = enable; 817 else 818 err = -EINVAL; 819 } 820 821 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { 822 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; 823 824 q->flow_refill_delay = usecs_to_jiffies(usecs_delay); 825 } 826 827 if (tb[TCA_FQ_ORPHAN_MASK]) 828 q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]); 829 830 if (tb[TCA_FQ_CE_THRESHOLD]) 831 q->ce_threshold = (u64)NSEC_PER_USEC * 832 nla_get_u32(tb[TCA_FQ_CE_THRESHOLD]); 833 834 if (!err) { 835 sch_tree_unlock(sch); 836 err = fq_resize(sch, fq_log); 837 sch_tree_lock(sch); 838 } 839 while (sch->q.qlen > sch->limit) { 840 struct sk_buff *skb = fq_dequeue(sch); 841 842 if (!skb) 843 break; 844 drop_len += qdisc_pkt_len(skb); 845 rtnl_kfree_skbs(skb, skb); 846 drop_count++; 847 } 848 qdisc_tree_reduce_backlog(sch, drop_count, drop_len); 849 850 sch_tree_unlock(sch); 851 return err; 852 } 853 854 static void fq_destroy(struct Qdisc *sch) 855 { 856 struct fq_sched_data *q = qdisc_priv(sch); 857 858 fq_reset(sch); 859 fq_free(q->fq_root); 860 qdisc_watchdog_cancel(&q->watchdog); 861 } 862 863 static int fq_init(struct Qdisc *sch, struct nlattr *opt, 864 struct netlink_ext_ack *extack) 865 { 866 struct fq_sched_data *q = qdisc_priv(sch); 867 int err; 868 869 sch->limit = 10000; 870 q->flow_plimit = 100; 871 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 872 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 873 q->flow_refill_delay = msecs_to_jiffies(40); 874 q->flow_max_rate = ~0UL; 875 q->time_next_delayed_flow = ~0ULL; 876 q->rate_enable = 1; 877 q->new_flows.first = NULL; 878 q->old_flows.first = NULL; 879 q->delayed = RB_ROOT; 880 q->fq_root = NULL; 881 q->fq_trees_log = ilog2(1024); 882 q->orphan_mask = 1024 - 1; 883 q->low_rate_threshold = 550000 / 8; 884 885 /* Default ce_threshold of 4294 seconds */ 886 q->ce_threshold = (u64)NSEC_PER_USEC * ~0U; 887 888 qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC); 889 890 if (opt) 891 err = fq_change(sch, opt, extack); 892 else 893 err = fq_resize(sch, q->fq_trees_log); 894 895 return err; 896 } 897 898 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 899 { 900 struct fq_sched_data *q = qdisc_priv(sch); 901 u64 ce_threshold = q->ce_threshold; 902 struct nlattr *opts; 903 904 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 905 if (opts == NULL) 906 goto nla_put_failure; 907 908 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ 909 910 do_div(ce_threshold, NSEC_PER_USEC); 911 912 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) || 913 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) || 914 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) || 915 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) || 916 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) || 917 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, 918 min_t(unsigned long, q->flow_max_rate, ~0U)) || 919 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, 920 jiffies_to_usecs(q->flow_refill_delay)) || 921 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) || 922 nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, 923 q->low_rate_threshold) || 924 nla_put_u32(skb, TCA_FQ_CE_THRESHOLD, (u32)ce_threshold) || 925 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log)) 926 goto nla_put_failure; 927 928 return nla_nest_end(skb, opts); 929 930 nla_put_failure: 931 return -1; 932 } 933 934 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 935 { 936 struct fq_sched_data *q = qdisc_priv(sch); 937 struct tc_fq_qd_stats st; 938 939 sch_tree_lock(sch); 940 941 st.gc_flows = q->stat_gc_flows; 942 st.highprio_packets = q->stat_internal_packets; 943 st.tcp_retrans = 0; 944 st.throttled = q->stat_throttled; 945 st.flows_plimit = q->stat_flows_plimit; 946 st.pkts_too_long = q->stat_pkts_too_long; 947 st.allocation_errors = q->stat_allocation_errors; 948 st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); 949 st.flows = q->flows; 950 st.inactive_flows = q->inactive_flows; 951 st.throttled_flows = q->throttled_flows; 952 st.unthrottle_latency_ns = min_t(unsigned long, 953 q->unthrottle_latency_ns, ~0U); 954 st.ce_mark = q->stat_ce_mark; 955 sch_tree_unlock(sch); 956 957 return gnet_stats_copy_app(d, &st, sizeof(st)); 958 } 959 960 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 961 .id = "fq", 962 .priv_size = sizeof(struct fq_sched_data), 963 964 .enqueue = fq_enqueue, 965 .dequeue = fq_dequeue, 966 .peek = qdisc_peek_dequeued, 967 .init = fq_init, 968 .reset = fq_reset, 969 .destroy = fq_destroy, 970 .change = fq_change, 971 .dump = fq_dump, 972 .dump_stats = fq_dump_stats, 973 .owner = THIS_MODULE, 974 }; 975 976 static int __init fq_module_init(void) 977 { 978 int ret; 979 980 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 981 sizeof(struct fq_flow), 982 0, 0, NULL); 983 if (!fq_flow_cachep) 984 return -ENOMEM; 985 986 ret = register_qdisc(&fq_qdisc_ops); 987 if (ret) 988 kmem_cache_destroy(fq_flow_cachep); 989 return ret; 990 } 991 992 static void __exit fq_module_exit(void) 993 { 994 unregister_qdisc(&fq_qdisc_ops); 995 kmem_cache_destroy(fq_flow_cachep); 996 } 997 998 module_init(fq_module_init) 999 module_exit(fq_module_exit) 1000 MODULE_AUTHOR("Eric Dumazet"); 1001 MODULE_LICENSE("GPL"); 1002