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 (q->rate_enable) 305 smp_store_release(&sk->sk_pacing_status, 306 SK_PACING_FQ); 307 if (fq_flow_is_throttled(f)) 308 fq_flow_unset_throttled(q, f); 309 f->time_next_packet = 0ULL; 310 } 311 return f; 312 } 313 if (f->sk > sk) 314 p = &parent->rb_right; 315 else 316 p = &parent->rb_left; 317 } 318 319 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); 320 if (unlikely(!f)) { 321 q->stat_allocation_errors++; 322 return &q->internal; 323 } 324 /* f->t_root is already zeroed after kmem_cache_zalloc() */ 325 326 fq_flow_set_detached(f); 327 f->sk = sk; 328 if (skb->sk == sk) { 329 f->socket_hash = sk->sk_hash; 330 if (q->rate_enable) 331 smp_store_release(&sk->sk_pacing_status, 332 SK_PACING_FQ); 333 } 334 f->credit = q->initial_quantum; 335 336 rb_link_node(&f->fq_node, parent, p); 337 rb_insert_color(&f->fq_node, root); 338 339 q->flows++; 340 q->inactive_flows++; 341 return f; 342 } 343 344 static struct sk_buff *fq_peek(struct fq_flow *flow) 345 { 346 struct sk_buff *skb = skb_rb_first(&flow->t_root); 347 struct sk_buff *head = flow->head; 348 349 if (!skb) 350 return head; 351 352 if (!head) 353 return skb; 354 355 if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send) 356 return skb; 357 return head; 358 } 359 360 static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow, 361 struct sk_buff *skb) 362 { 363 if (skb == flow->head) { 364 flow->head = skb->next; 365 } else { 366 rb_erase(&skb->rbnode, &flow->t_root); 367 skb->dev = qdisc_dev(sch); 368 } 369 } 370 371 /* remove one skb from head of flow queue */ 372 static struct sk_buff *fq_dequeue_head(struct Qdisc *sch, struct fq_flow *flow) 373 { 374 struct sk_buff *skb = fq_peek(flow); 375 376 if (skb) { 377 fq_erase_head(sch, flow, skb); 378 skb_mark_not_on_list(skb); 379 flow->qlen--; 380 qdisc_qstats_backlog_dec(sch, skb); 381 sch->q.qlen--; 382 } 383 return skb; 384 } 385 386 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 387 { 388 struct rb_node **p, *parent; 389 struct sk_buff *head, *aux; 390 391 fq_skb_cb(skb)->time_to_send = skb->tstamp ?: ktime_get_ns(); 392 393 head = flow->head; 394 if (!head || 395 fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) { 396 if (!head) 397 flow->head = skb; 398 else 399 flow->tail->next = skb; 400 flow->tail = skb; 401 skb->next = NULL; 402 return; 403 } 404 405 p = &flow->t_root.rb_node; 406 parent = NULL; 407 408 while (*p) { 409 parent = *p; 410 aux = rb_to_skb(parent); 411 if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send) 412 p = &parent->rb_right; 413 else 414 p = &parent->rb_left; 415 } 416 rb_link_node(&skb->rbnode, parent, p); 417 rb_insert_color(&skb->rbnode, &flow->t_root); 418 } 419 420 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 421 struct sk_buff **to_free) 422 { 423 struct fq_sched_data *q = qdisc_priv(sch); 424 struct fq_flow *f; 425 426 if (unlikely(sch->q.qlen >= sch->limit)) 427 return qdisc_drop(skb, sch, to_free); 428 429 f = fq_classify(skb, q); 430 if (unlikely(f->qlen >= q->flow_plimit && f != &q->internal)) { 431 q->stat_flows_plimit++; 432 return qdisc_drop(skb, sch, to_free); 433 } 434 435 f->qlen++; 436 qdisc_qstats_backlog_inc(sch, skb); 437 if (fq_flow_is_detached(f)) { 438 fq_flow_add_tail(&q->new_flows, f); 439 if (time_after(jiffies, f->age + q->flow_refill_delay)) 440 f->credit = max_t(u32, f->credit, q->quantum); 441 q->inactive_flows--; 442 } 443 444 /* Note: this overwrites f->age */ 445 flow_queue_add(f, skb); 446 447 if (unlikely(f == &q->internal)) { 448 q->stat_internal_packets++; 449 } 450 sch->q.qlen++; 451 452 return NET_XMIT_SUCCESS; 453 } 454 455 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 456 { 457 unsigned long sample; 458 struct rb_node *p; 459 460 if (q->time_next_delayed_flow > now) 461 return; 462 463 /* Update unthrottle latency EWMA. 464 * This is cheap and can help diagnosing timer/latency problems. 465 */ 466 sample = (unsigned long)(now - q->time_next_delayed_flow); 467 q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; 468 q->unthrottle_latency_ns += sample >> 3; 469 470 q->time_next_delayed_flow = ~0ULL; 471 while ((p = rb_first(&q->delayed)) != NULL) { 472 struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node); 473 474 if (f->time_next_packet > now) { 475 q->time_next_delayed_flow = f->time_next_packet; 476 break; 477 } 478 fq_flow_unset_throttled(q, f); 479 } 480 } 481 482 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 483 { 484 struct fq_sched_data *q = qdisc_priv(sch); 485 struct fq_flow_head *head; 486 struct sk_buff *skb; 487 struct fq_flow *f; 488 unsigned long rate; 489 u32 plen; 490 u64 now; 491 492 if (!sch->q.qlen) 493 return NULL; 494 495 skb = fq_dequeue_head(sch, &q->internal); 496 if (skb) 497 goto out; 498 499 now = ktime_get_ns(); 500 fq_check_throttled(q, now); 501 begin: 502 head = &q->new_flows; 503 if (!head->first) { 504 head = &q->old_flows; 505 if (!head->first) { 506 if (q->time_next_delayed_flow != ~0ULL) 507 qdisc_watchdog_schedule_ns(&q->watchdog, 508 q->time_next_delayed_flow); 509 return NULL; 510 } 511 } 512 f = head->first; 513 514 if (f->credit <= 0) { 515 f->credit += q->quantum; 516 head->first = f->next; 517 fq_flow_add_tail(&q->old_flows, f); 518 goto begin; 519 } 520 521 skb = fq_peek(f); 522 if (skb) { 523 u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send, 524 f->time_next_packet); 525 526 if (now < time_next_packet) { 527 head->first = f->next; 528 f->time_next_packet = time_next_packet; 529 fq_flow_set_throttled(q, f); 530 goto begin; 531 } 532 if ((s64)(now - time_next_packet - q->ce_threshold) > 0) { 533 INET_ECN_set_ce(skb); 534 q->stat_ce_mark++; 535 } 536 } 537 538 skb = fq_dequeue_head(sch, f); 539 if (!skb) { 540 head->first = f->next; 541 /* force a pass through old_flows to prevent starvation */ 542 if ((head == &q->new_flows) && q->old_flows.first) { 543 fq_flow_add_tail(&q->old_flows, f); 544 } else { 545 fq_flow_set_detached(f); 546 q->inactive_flows++; 547 } 548 goto begin; 549 } 550 prefetch(&skb->end); 551 plen = qdisc_pkt_len(skb); 552 f->credit -= plen; 553 554 if (!q->rate_enable) 555 goto out; 556 557 rate = q->flow_max_rate; 558 559 /* If EDT time was provided for this skb, we need to 560 * update f->time_next_packet only if this qdisc enforces 561 * a flow max rate. 562 */ 563 if (!skb->tstamp) { 564 if (skb->sk) 565 rate = min(skb->sk->sk_pacing_rate, rate); 566 567 if (rate <= q->low_rate_threshold) { 568 f->credit = 0; 569 } else { 570 plen = max(plen, q->quantum); 571 if (f->credit > 0) 572 goto out; 573 } 574 } 575 if (rate != ~0UL) { 576 u64 len = (u64)plen * NSEC_PER_SEC; 577 578 if (likely(rate)) 579 len = div64_ul(len, rate); 580 /* Since socket rate can change later, 581 * clamp the delay to 1 second. 582 * Really, providers of too big packets should be fixed ! 583 */ 584 if (unlikely(len > NSEC_PER_SEC)) { 585 len = NSEC_PER_SEC; 586 q->stat_pkts_too_long++; 587 } 588 /* Account for schedule/timers drifts. 589 * f->time_next_packet was set when prior packet was sent, 590 * and current time (@now) can be too late by tens of us. 591 */ 592 if (f->time_next_packet) 593 len -= min(len/2, now - f->time_next_packet); 594 f->time_next_packet = now + len; 595 } 596 out: 597 qdisc_bstats_update(sch, skb); 598 return skb; 599 } 600 601 static void fq_flow_purge(struct fq_flow *flow) 602 { 603 struct rb_node *p = rb_first(&flow->t_root); 604 605 while (p) { 606 struct sk_buff *skb = rb_to_skb(p); 607 608 p = rb_next(p); 609 rb_erase(&skb->rbnode, &flow->t_root); 610 rtnl_kfree_skbs(skb, skb); 611 } 612 rtnl_kfree_skbs(flow->head, flow->tail); 613 flow->head = NULL; 614 flow->qlen = 0; 615 } 616 617 static void fq_reset(struct Qdisc *sch) 618 { 619 struct fq_sched_data *q = qdisc_priv(sch); 620 struct rb_root *root; 621 struct rb_node *p; 622 struct fq_flow *f; 623 unsigned int idx; 624 625 sch->q.qlen = 0; 626 sch->qstats.backlog = 0; 627 628 fq_flow_purge(&q->internal); 629 630 if (!q->fq_root) 631 return; 632 633 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 634 root = &q->fq_root[idx]; 635 while ((p = rb_first(root)) != NULL) { 636 f = rb_entry(p, struct fq_flow, fq_node); 637 rb_erase(p, root); 638 639 fq_flow_purge(f); 640 641 kmem_cache_free(fq_flow_cachep, f); 642 } 643 } 644 q->new_flows.first = NULL; 645 q->old_flows.first = NULL; 646 q->delayed = RB_ROOT; 647 q->flows = 0; 648 q->inactive_flows = 0; 649 q->throttled_flows = 0; 650 } 651 652 static void fq_rehash(struct fq_sched_data *q, 653 struct rb_root *old_array, u32 old_log, 654 struct rb_root *new_array, u32 new_log) 655 { 656 struct rb_node *op, **np, *parent; 657 struct rb_root *oroot, *nroot; 658 struct fq_flow *of, *nf; 659 int fcnt = 0; 660 u32 idx; 661 662 for (idx = 0; idx < (1U << old_log); idx++) { 663 oroot = &old_array[idx]; 664 while ((op = rb_first(oroot)) != NULL) { 665 rb_erase(op, oroot); 666 of = rb_entry(op, struct fq_flow, fq_node); 667 if (fq_gc_candidate(of)) { 668 fcnt++; 669 kmem_cache_free(fq_flow_cachep, of); 670 continue; 671 } 672 nroot = &new_array[hash_ptr(of->sk, new_log)]; 673 674 np = &nroot->rb_node; 675 parent = NULL; 676 while (*np) { 677 parent = *np; 678 679 nf = rb_entry(parent, struct fq_flow, fq_node); 680 BUG_ON(nf->sk == of->sk); 681 682 if (nf->sk > of->sk) 683 np = &parent->rb_right; 684 else 685 np = &parent->rb_left; 686 } 687 688 rb_link_node(&of->fq_node, parent, np); 689 rb_insert_color(&of->fq_node, nroot); 690 } 691 } 692 q->flows -= fcnt; 693 q->inactive_flows -= fcnt; 694 q->stat_gc_flows += fcnt; 695 } 696 697 static void fq_free(void *addr) 698 { 699 kvfree(addr); 700 } 701 702 static int fq_resize(struct Qdisc *sch, u32 log) 703 { 704 struct fq_sched_data *q = qdisc_priv(sch); 705 struct rb_root *array; 706 void *old_fq_root; 707 u32 idx; 708 709 if (q->fq_root && log == q->fq_trees_log) 710 return 0; 711 712 /* If XPS was setup, we can allocate memory on right NUMA node */ 713 array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, 714 netdev_queue_numa_node_read(sch->dev_queue)); 715 if (!array) 716 return -ENOMEM; 717 718 for (idx = 0; idx < (1U << log); idx++) 719 array[idx] = RB_ROOT; 720 721 sch_tree_lock(sch); 722 723 old_fq_root = q->fq_root; 724 if (old_fq_root) 725 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); 726 727 q->fq_root = array; 728 q->fq_trees_log = log; 729 730 sch_tree_unlock(sch); 731 732 fq_free(old_fq_root); 733 734 return 0; 735 } 736 737 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 738 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 739 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 740 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 741 [TCA_FQ_INITIAL_QUANTUM] = { .type = NLA_U32 }, 742 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 743 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 744 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 745 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 746 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, 747 [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, 748 [TCA_FQ_CE_THRESHOLD] = { .type = NLA_U32 }, 749 }; 750 751 static int fq_change(struct Qdisc *sch, struct nlattr *opt, 752 struct netlink_ext_ack *extack) 753 { 754 struct fq_sched_data *q = qdisc_priv(sch); 755 struct nlattr *tb[TCA_FQ_MAX + 1]; 756 int err, drop_count = 0; 757 unsigned drop_len = 0; 758 u32 fq_log; 759 760 if (!opt) 761 return -EINVAL; 762 763 err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy, 764 NULL); 765 if (err < 0) 766 return err; 767 768 sch_tree_lock(sch); 769 770 fq_log = q->fq_trees_log; 771 772 if (tb[TCA_FQ_BUCKETS_LOG]) { 773 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 774 775 if (nval >= 1 && nval <= ilog2(256*1024)) 776 fq_log = nval; 777 else 778 err = -EINVAL; 779 } 780 if (tb[TCA_FQ_PLIMIT]) 781 sch->limit = nla_get_u32(tb[TCA_FQ_PLIMIT]); 782 783 if (tb[TCA_FQ_FLOW_PLIMIT]) 784 q->flow_plimit = nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT]); 785 786 if (tb[TCA_FQ_QUANTUM]) { 787 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 788 789 if (quantum > 0) 790 q->quantum = quantum; 791 else 792 err = -EINVAL; 793 } 794 795 if (tb[TCA_FQ_INITIAL_QUANTUM]) 796 q->initial_quantum = nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM]); 797 798 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 799 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", 800 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); 801 802 if (tb[TCA_FQ_FLOW_MAX_RATE]) { 803 u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); 804 805 q->flow_max_rate = (rate == ~0U) ? ~0UL : rate; 806 } 807 if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) 808 q->low_rate_threshold = 809 nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD]); 810 811 if (tb[TCA_FQ_RATE_ENABLE]) { 812 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); 813 814 if (enable <= 1) 815 q->rate_enable = enable; 816 else 817 err = -EINVAL; 818 } 819 820 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { 821 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; 822 823 q->flow_refill_delay = usecs_to_jiffies(usecs_delay); 824 } 825 826 if (tb[TCA_FQ_ORPHAN_MASK]) 827 q->orphan_mask = nla_get_u32(tb[TCA_FQ_ORPHAN_MASK]); 828 829 if (tb[TCA_FQ_CE_THRESHOLD]) 830 q->ce_threshold = (u64)NSEC_PER_USEC * 831 nla_get_u32(tb[TCA_FQ_CE_THRESHOLD]); 832 833 if (!err) { 834 sch_tree_unlock(sch); 835 err = fq_resize(sch, fq_log); 836 sch_tree_lock(sch); 837 } 838 while (sch->q.qlen > sch->limit) { 839 struct sk_buff *skb = fq_dequeue(sch); 840 841 if (!skb) 842 break; 843 drop_len += qdisc_pkt_len(skb); 844 rtnl_kfree_skbs(skb, skb); 845 drop_count++; 846 } 847 qdisc_tree_reduce_backlog(sch, drop_count, drop_len); 848 849 sch_tree_unlock(sch); 850 return err; 851 } 852 853 static void fq_destroy(struct Qdisc *sch) 854 { 855 struct fq_sched_data *q = qdisc_priv(sch); 856 857 fq_reset(sch); 858 fq_free(q->fq_root); 859 qdisc_watchdog_cancel(&q->watchdog); 860 } 861 862 static int fq_init(struct Qdisc *sch, struct nlattr *opt, 863 struct netlink_ext_ack *extack) 864 { 865 struct fq_sched_data *q = qdisc_priv(sch); 866 int err; 867 868 sch->limit = 10000; 869 q->flow_plimit = 100; 870 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 871 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 872 q->flow_refill_delay = msecs_to_jiffies(40); 873 q->flow_max_rate = ~0UL; 874 q->time_next_delayed_flow = ~0ULL; 875 q->rate_enable = 1; 876 q->new_flows.first = NULL; 877 q->old_flows.first = NULL; 878 q->delayed = RB_ROOT; 879 q->fq_root = NULL; 880 q->fq_trees_log = ilog2(1024); 881 q->orphan_mask = 1024 - 1; 882 q->low_rate_threshold = 550000 / 8; 883 884 /* Default ce_threshold of 4294 seconds */ 885 q->ce_threshold = (u64)NSEC_PER_USEC * ~0U; 886 887 qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC); 888 889 if (opt) 890 err = fq_change(sch, opt, extack); 891 else 892 err = fq_resize(sch, q->fq_trees_log); 893 894 return err; 895 } 896 897 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 898 { 899 struct fq_sched_data *q = qdisc_priv(sch); 900 u64 ce_threshold = q->ce_threshold; 901 struct nlattr *opts; 902 903 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 904 if (opts == NULL) 905 goto nla_put_failure; 906 907 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ 908 909 do_div(ce_threshold, NSEC_PER_USEC); 910 911 if (nla_put_u32(skb, TCA_FQ_PLIMIT, sch->limit) || 912 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, q->flow_plimit) || 913 nla_put_u32(skb, TCA_FQ_QUANTUM, q->quantum) || 914 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, q->initial_quantum) || 915 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, q->rate_enable) || 916 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, 917 min_t(unsigned long, q->flow_max_rate, ~0U)) || 918 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, 919 jiffies_to_usecs(q->flow_refill_delay)) || 920 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, q->orphan_mask) || 921 nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, 922 q->low_rate_threshold) || 923 nla_put_u32(skb, TCA_FQ_CE_THRESHOLD, (u32)ce_threshold) || 924 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, q->fq_trees_log)) 925 goto nla_put_failure; 926 927 return nla_nest_end(skb, opts); 928 929 nla_put_failure: 930 return -1; 931 } 932 933 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 934 { 935 struct fq_sched_data *q = qdisc_priv(sch); 936 struct tc_fq_qd_stats st; 937 938 sch_tree_lock(sch); 939 940 st.gc_flows = q->stat_gc_flows; 941 st.highprio_packets = q->stat_internal_packets; 942 st.tcp_retrans = 0; 943 st.throttled = q->stat_throttled; 944 st.flows_plimit = q->stat_flows_plimit; 945 st.pkts_too_long = q->stat_pkts_too_long; 946 st.allocation_errors = q->stat_allocation_errors; 947 st.time_next_delayed_flow = q->time_next_delayed_flow - ktime_get_ns(); 948 st.flows = q->flows; 949 st.inactive_flows = q->inactive_flows; 950 st.throttled_flows = q->throttled_flows; 951 st.unthrottle_latency_ns = min_t(unsigned long, 952 q->unthrottle_latency_ns, ~0U); 953 st.ce_mark = q->stat_ce_mark; 954 sch_tree_unlock(sch); 955 956 return gnet_stats_copy_app(d, &st, sizeof(st)); 957 } 958 959 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 960 .id = "fq", 961 .priv_size = sizeof(struct fq_sched_data), 962 963 .enqueue = fq_enqueue, 964 .dequeue = fq_dequeue, 965 .peek = qdisc_peek_dequeued, 966 .init = fq_init, 967 .reset = fq_reset, 968 .destroy = fq_destroy, 969 .change = fq_change, 970 .dump = fq_dump, 971 .dump_stats = fq_dump_stats, 972 .owner = THIS_MODULE, 973 }; 974 975 static int __init fq_module_init(void) 976 { 977 int ret; 978 979 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 980 sizeof(struct fq_flow), 981 0, 0, NULL); 982 if (!fq_flow_cachep) 983 return -ENOMEM; 984 985 ret = register_qdisc(&fq_qdisc_ops); 986 if (ret) 987 kmem_cache_destroy(fq_flow_cachep); 988 return ret; 989 } 990 991 static void __exit fq_module_exit(void) 992 { 993 unregister_qdisc(&fq_qdisc_ops); 994 kmem_cache_destroy(fq_flow_cachep); 995 } 996 997 module_init(fq_module_init) 998 module_exit(fq_module_exit) 999 MODULE_AUTHOR("Eric Dumazet"); 1000 MODULE_LICENSE("GPL"); 1001