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) 2013-2023 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 u8 band; 56 }; 57 58 static inline struct fq_skb_cb *fq_skb_cb(struct sk_buff *skb) 59 { 60 qdisc_cb_private_validate(skb, sizeof(struct fq_skb_cb)); 61 return (struct fq_skb_cb *)qdisc_skb_cb(skb)->data; 62 } 63 64 /* 65 * Per flow structure, dynamically allocated. 66 * If packets have monotically increasing time_to_send, they are placed in O(1) 67 * in linear list (head,tail), otherwise are placed in a rbtree (t_root). 68 */ 69 struct fq_flow { 70 /* First cache line : used in fq_gc(), fq_enqueue(), fq_dequeue() */ 71 struct rb_root t_root; 72 struct sk_buff *head; /* list of skbs for this flow : first skb */ 73 union { 74 struct sk_buff *tail; /* last skb in the list */ 75 unsigned long age; /* (jiffies | 1UL) when flow was emptied, for gc */ 76 }; 77 union { 78 struct rb_node fq_node; /* anchor in fq_root[] trees */ 79 /* Following field is only used for q->internal, 80 * because q->internal is not hashed in fq_root[] 81 */ 82 u64 stat_fastpath_packets; 83 }; 84 struct sock *sk; 85 u32 socket_hash; /* sk_hash */ 86 int qlen; /* number of packets in flow queue */ 87 88 /* Second cache line */ 89 int credit; 90 int band; 91 struct fq_flow *next; /* next pointer in RR lists */ 92 93 struct rb_node rate_node; /* anchor in q->delayed tree */ 94 u64 time_next_packet; 95 }; 96 97 struct fq_flow_head { 98 struct fq_flow *first; 99 struct fq_flow *last; 100 }; 101 102 struct fq_perband_flows { 103 struct fq_flow_head new_flows; 104 struct fq_flow_head old_flows; 105 int credit; 106 int quantum; /* based on band nr : 576KB, 192KB, 64KB */ 107 }; 108 109 #define FQ_PRIO2BAND_CRUMB_SIZE ((TC_PRIO_MAX + 1) >> 2) 110 111 struct fq_sched_data { 112 /* Read mostly cache line */ 113 114 u64 offload_horizon; 115 u32 quantum; 116 u32 initial_quantum; 117 u32 flow_refill_delay; 118 u32 flow_plimit; /* max packets per flow */ 119 unsigned long flow_max_rate; /* optional max rate per flow */ 120 u64 ce_threshold; 121 u64 horizon; /* horizon in ns */ 122 u32 orphan_mask; /* mask for orphaned skb */ 123 u32 low_rate_threshold; 124 struct rb_root *fq_root; 125 u8 rate_enable; 126 u8 fq_trees_log; 127 u8 horizon_drop; 128 u8 prio2band[FQ_PRIO2BAND_CRUMB_SIZE]; 129 u32 timer_slack; /* hrtimer slack in ns */ 130 131 /* Read/Write fields. */ 132 133 unsigned int band_nr; /* band being serviced in fq_dequeue() */ 134 135 struct fq_perband_flows band_flows[FQ_BANDS]; 136 137 struct fq_flow internal; /* fastpath queue. */ 138 struct rb_root delayed; /* for rate limited flows */ 139 u64 time_next_delayed_flow; 140 unsigned long unthrottle_latency_ns; 141 142 u32 band_pkt_count[FQ_BANDS]; 143 u32 flows; 144 u32 inactive_flows; /* Flows with no packet to send. */ 145 u32 throttled_flows; 146 147 u64 stat_throttled; 148 struct qdisc_watchdog watchdog; 149 u64 stat_gc_flows; 150 151 /* Seldom used fields. */ 152 153 u64 stat_band_drops[FQ_BANDS]; 154 u64 stat_ce_mark; 155 u64 stat_horizon_drops; 156 u64 stat_horizon_caps; 157 u64 stat_flows_plimit; 158 u64 stat_pkts_too_long; 159 u64 stat_allocation_errors; 160 }; 161 162 /* return the i-th 2-bit value ("crumb") */ 163 static u8 fq_prio2band(const u8 *prio2band, unsigned int prio) 164 { 165 return (READ_ONCE(prio2band[prio / 4]) >> (2 * (prio & 0x3))) & 0x3; 166 } 167 168 /* 169 * f->tail and f->age share the same location. 170 * We can use the low order bit to differentiate if this location points 171 * to a sk_buff or contains a jiffies value, if we force this value to be odd. 172 * This assumes f->tail low order bit must be 0 since alignof(struct sk_buff) >= 2 173 */ 174 static void fq_flow_set_detached(struct fq_flow *f) 175 { 176 f->age = jiffies | 1UL; 177 } 178 179 static bool fq_flow_is_detached(const struct fq_flow *f) 180 { 181 return !!(f->age & 1UL); 182 } 183 184 /* special value to mark a throttled flow (not on old/new list) */ 185 static struct fq_flow throttled; 186 187 static bool fq_flow_is_throttled(const struct fq_flow *f) 188 { 189 return f->next == &throttled; 190 } 191 192 enum new_flow { 193 NEW_FLOW, 194 OLD_FLOW 195 }; 196 197 static void fq_flow_add_tail(struct fq_sched_data *q, struct fq_flow *flow, 198 enum new_flow list_sel) 199 { 200 struct fq_perband_flows *pband = &q->band_flows[flow->band]; 201 struct fq_flow_head *head = (list_sel == NEW_FLOW) ? 202 &pband->new_flows : 203 &pband->old_flows; 204 205 if (head->first) 206 head->last->next = flow; 207 else 208 head->first = flow; 209 head->last = flow; 210 flow->next = NULL; 211 } 212 213 static void fq_flow_unset_throttled(struct fq_sched_data *q, struct fq_flow *f) 214 { 215 rb_erase(&f->rate_node, &q->delayed); 216 q->throttled_flows--; 217 fq_flow_add_tail(q, f, OLD_FLOW); 218 } 219 220 static void fq_flow_set_throttled(struct fq_sched_data *q, struct fq_flow *f) 221 { 222 struct rb_node **p = &q->delayed.rb_node, *parent = NULL; 223 224 while (*p) { 225 struct fq_flow *aux; 226 227 parent = *p; 228 aux = rb_entry(parent, struct fq_flow, rate_node); 229 if (f->time_next_packet >= aux->time_next_packet) 230 p = &parent->rb_right; 231 else 232 p = &parent->rb_left; 233 } 234 rb_link_node(&f->rate_node, parent, p); 235 rb_insert_color(&f->rate_node, &q->delayed); 236 q->throttled_flows++; 237 q->stat_throttled++; 238 239 f->next = &throttled; 240 if (q->time_next_delayed_flow > f->time_next_packet) 241 q->time_next_delayed_flow = f->time_next_packet; 242 } 243 244 245 static struct kmem_cache *fq_flow_cachep __read_mostly; 246 247 248 /* limit number of collected flows per round */ 249 #define FQ_GC_MAX 8 250 #define FQ_GC_AGE (3*HZ) 251 252 static bool fq_gc_candidate(const struct fq_flow *f) 253 { 254 return fq_flow_is_detached(f) && 255 time_after(jiffies, f->age + FQ_GC_AGE); 256 } 257 258 static void fq_gc(struct fq_sched_data *q, 259 struct rb_root *root, 260 struct sock *sk) 261 { 262 struct rb_node **p, *parent; 263 void *tofree[FQ_GC_MAX]; 264 struct fq_flow *f; 265 int i, fcnt = 0; 266 267 p = &root->rb_node; 268 parent = NULL; 269 while (*p) { 270 parent = *p; 271 272 f = rb_entry(parent, struct fq_flow, fq_node); 273 if (f->sk == sk) 274 break; 275 276 if (fq_gc_candidate(f)) { 277 tofree[fcnt++] = f; 278 if (fcnt == FQ_GC_MAX) 279 break; 280 } 281 282 if (f->sk > sk) 283 p = &parent->rb_right; 284 else 285 p = &parent->rb_left; 286 } 287 288 if (!fcnt) 289 return; 290 291 for (i = fcnt; i > 0; ) { 292 f = tofree[--i]; 293 rb_erase(&f->fq_node, root); 294 } 295 q->flows -= fcnt; 296 q->inactive_flows -= fcnt; 297 q->stat_gc_flows += fcnt; 298 299 kmem_cache_free_bulk(fq_flow_cachep, fcnt, tofree); 300 } 301 302 /* Fast path can be used if : 303 * 1) Packet tstamp is in the past, or within the pacing offload horizon. 304 * 2) FQ qlen == 0 OR 305 * (no flow is currently eligible for transmit, 306 * AND fast path queue has less than 8 packets) 307 * 3) No SO_MAX_PACING_RATE on the socket (if any). 308 * 4) No @maxrate attribute on this qdisc, 309 * 310 * FQ can not use generic TCQ_F_CAN_BYPASS infrastructure. 311 */ 312 static bool fq_fastpath_check(const struct Qdisc *sch, struct sk_buff *skb, 313 u64 now) 314 { 315 const struct fq_sched_data *q = qdisc_priv(sch); 316 const struct sock *sk; 317 318 if (fq_skb_cb(skb)->time_to_send > now + q->offload_horizon) 319 return false; 320 321 if (sch->q.qlen != 0) { 322 /* Even if some packets are stored in this qdisc, 323 * we can still enable fast path if all of them are 324 * scheduled in the future (ie no flows are eligible) 325 * or in the fast path queue. 326 */ 327 if (q->flows != q->inactive_flows + q->throttled_flows) 328 return false; 329 330 /* Do not allow fast path queue to explode, we want Fair Queue mode 331 * under pressure. 332 */ 333 if (q->internal.qlen >= 8) 334 return false; 335 336 /* Ordering invariants fall apart if some delayed flows 337 * are ready but we haven't serviced them, yet. 338 */ 339 if (q->time_next_delayed_flow <= now + q->offload_horizon) 340 return false; 341 } 342 343 sk = skb->sk; 344 if (sk && sk_fullsock(sk) && !sk_is_tcp(sk) && 345 sk->sk_max_pacing_rate != ~0UL) 346 return false; 347 348 if (q->flow_max_rate != ~0UL) 349 return false; 350 351 return true; 352 } 353 354 static struct fq_flow *fq_classify(struct Qdisc *sch, struct sk_buff *skb, 355 u64 now) 356 { 357 struct fq_sched_data *q = qdisc_priv(sch); 358 struct rb_node **p, *parent; 359 struct sock *sk = skb->sk; 360 struct rb_root *root; 361 struct fq_flow *f; 362 363 /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket 364 * or a listener (SYNCOOKIE mode) 365 * 1) request sockets are not full blown, 366 * they do not contain sk_pacing_rate 367 * 2) They are not part of a 'flow' yet 368 * 3) We do not want to rate limit them (eg SYNFLOOD attack), 369 * especially if the listener set SO_MAX_PACING_RATE 370 * 4) We pretend they are orphaned 371 * TCP can also associate TIME_WAIT sockets with RST or ACK packets. 372 */ 373 if (!sk || sk_listener_or_tw(sk)) { 374 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 375 376 /* By forcing low order bit to 1, we make sure to not 377 * collide with a local flow (socket pointers are word aligned) 378 */ 379 sk = (struct sock *)((hash << 1) | 1UL); 380 skb_orphan(skb); 381 } else if (sk->sk_state == TCP_CLOSE) { 382 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 383 /* 384 * Sockets in TCP_CLOSE are non connected. 385 * Typical use case is UDP sockets, they can send packets 386 * with sendto() to many different destinations. 387 * We probably could use a generic bit advertising 388 * non connected sockets, instead of sk_state == TCP_CLOSE, 389 * if we care enough. 390 */ 391 sk = (struct sock *)((hash << 1) | 1UL); 392 } 393 394 if (fq_fastpath_check(sch, skb, now)) { 395 q->internal.stat_fastpath_packets++; 396 if (skb->sk == sk && q->rate_enable && 397 READ_ONCE(sk->sk_pacing_status) != SK_PACING_FQ) 398 smp_store_release(&sk->sk_pacing_status, 399 SK_PACING_FQ); 400 return &q->internal; 401 } 402 403 root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)]; 404 405 fq_gc(q, root, sk); 406 407 p = &root->rb_node; 408 parent = NULL; 409 while (*p) { 410 parent = *p; 411 412 f = rb_entry(parent, struct fq_flow, fq_node); 413 if (f->sk == sk) { 414 /* socket might have been reallocated, so check 415 * if its sk_hash is the same. 416 * It not, we need to refill credit with 417 * initial quantum 418 */ 419 if (unlikely(skb->sk == sk && 420 f->socket_hash != sk->sk_hash)) { 421 f->credit = q->initial_quantum; 422 f->socket_hash = sk->sk_hash; 423 if (q->rate_enable) 424 smp_store_release(&sk->sk_pacing_status, 425 SK_PACING_FQ); 426 if (fq_flow_is_throttled(f)) 427 fq_flow_unset_throttled(q, f); 428 f->time_next_packet = 0ULL; 429 } 430 return f; 431 } 432 if (f->sk > sk) 433 p = &parent->rb_right; 434 else 435 p = &parent->rb_left; 436 } 437 438 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); 439 if (unlikely(!f)) { 440 q->stat_allocation_errors++; 441 return &q->internal; 442 } 443 /* f->t_root is already zeroed after kmem_cache_zalloc() */ 444 445 fq_flow_set_detached(f); 446 f->sk = sk; 447 if (skb->sk == sk) { 448 f->socket_hash = sk->sk_hash; 449 if (q->rate_enable) 450 smp_store_release(&sk->sk_pacing_status, 451 SK_PACING_FQ); 452 } 453 f->credit = q->initial_quantum; 454 455 rb_link_node(&f->fq_node, parent, p); 456 rb_insert_color(&f->fq_node, root); 457 458 q->flows++; 459 q->inactive_flows++; 460 return f; 461 } 462 463 static struct sk_buff *fq_peek(struct fq_flow *flow) 464 { 465 struct sk_buff *skb = skb_rb_first(&flow->t_root); 466 struct sk_buff *head = flow->head; 467 468 if (!skb) 469 return head; 470 471 if (!head) 472 return skb; 473 474 if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send) 475 return skb; 476 return head; 477 } 478 479 static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow, 480 struct sk_buff *skb) 481 { 482 if (skb == flow->head) { 483 flow->head = skb->next; 484 } else { 485 rb_erase(&skb->rbnode, &flow->t_root); 486 skb->dev = qdisc_dev(sch); 487 } 488 } 489 490 /* Remove one skb from flow queue. 491 * This skb must be the return value of prior fq_peek(). 492 */ 493 static void fq_dequeue_skb(struct Qdisc *sch, struct fq_flow *flow, 494 struct sk_buff *skb) 495 { 496 fq_erase_head(sch, flow, skb); 497 skb_mark_not_on_list(skb); 498 qdisc_qstats_backlog_dec(sch, skb); 499 sch->q.qlen--; 500 } 501 502 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 503 { 504 struct rb_node **p, *parent; 505 struct sk_buff *head, *aux; 506 507 head = flow->head; 508 if (!head || 509 fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) { 510 if (!head) 511 flow->head = skb; 512 else 513 flow->tail->next = skb; 514 flow->tail = skb; 515 skb->next = NULL; 516 return; 517 } 518 519 p = &flow->t_root.rb_node; 520 parent = NULL; 521 522 while (*p) { 523 parent = *p; 524 aux = rb_to_skb(parent); 525 if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send) 526 p = &parent->rb_right; 527 else 528 p = &parent->rb_left; 529 } 530 rb_link_node(&skb->rbnode, parent, p); 531 rb_insert_color(&skb->rbnode, &flow->t_root); 532 } 533 534 static bool fq_packet_beyond_horizon(const struct sk_buff *skb, 535 const struct fq_sched_data *q, u64 now) 536 { 537 return unlikely((s64)skb->tstamp > (s64)(now + q->horizon)); 538 } 539 540 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 541 struct sk_buff **to_free) 542 { 543 struct fq_sched_data *q = qdisc_priv(sch); 544 struct fq_flow *f; 545 u64 now; 546 u8 band; 547 548 band = fq_prio2band(q->prio2band, skb->priority & TC_PRIO_MAX); 549 if (unlikely(q->band_pkt_count[band] >= sch->limit)) { 550 q->stat_band_drops[band]++; 551 return qdisc_drop(skb, sch, to_free); 552 } 553 554 now = ktime_get_ns(); 555 if (!skb->tstamp) { 556 fq_skb_cb(skb)->time_to_send = now; 557 } else { 558 /* Check if packet timestamp is too far in the future. */ 559 if (fq_packet_beyond_horizon(skb, q, now)) { 560 if (q->horizon_drop) { 561 q->stat_horizon_drops++; 562 return qdisc_drop(skb, sch, to_free); 563 } 564 q->stat_horizon_caps++; 565 skb->tstamp = now + q->horizon; 566 } 567 fq_skb_cb(skb)->time_to_send = skb->tstamp; 568 } 569 570 f = fq_classify(sch, skb, now); 571 572 if (f != &q->internal) { 573 if (unlikely(f->qlen >= q->flow_plimit)) { 574 q->stat_flows_plimit++; 575 return qdisc_drop(skb, sch, to_free); 576 } 577 578 if (fq_flow_is_detached(f)) { 579 fq_flow_add_tail(q, f, NEW_FLOW); 580 if (time_after(jiffies, f->age + q->flow_refill_delay)) 581 f->credit = max_t(u32, f->credit, q->quantum); 582 } 583 584 f->band = band; 585 q->band_pkt_count[band]++; 586 fq_skb_cb(skb)->band = band; 587 if (f->qlen == 0) 588 q->inactive_flows--; 589 } 590 591 f->qlen++; 592 /* Note: this overwrites f->age */ 593 flow_queue_add(f, skb); 594 595 qdisc_qstats_backlog_inc(sch, skb); 596 sch->q.qlen++; 597 598 return NET_XMIT_SUCCESS; 599 } 600 601 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 602 { 603 unsigned long sample; 604 struct rb_node *p; 605 606 if (q->time_next_delayed_flow > now + q->offload_horizon) 607 return; 608 609 /* Update unthrottle latency EWMA. 610 * This is cheap and can help diagnosing timer/latency problems. 611 */ 612 sample = (unsigned long)(now - q->time_next_delayed_flow); 613 if ((long)sample > 0) { 614 q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; 615 q->unthrottle_latency_ns += sample >> 3; 616 } 617 now += q->offload_horizon; 618 619 q->time_next_delayed_flow = ~0ULL; 620 while ((p = rb_first(&q->delayed)) != NULL) { 621 struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node); 622 623 if (f->time_next_packet > now) { 624 q->time_next_delayed_flow = f->time_next_packet; 625 break; 626 } 627 fq_flow_unset_throttled(q, f); 628 } 629 } 630 631 static struct fq_flow_head *fq_pband_head_select(struct fq_perband_flows *pband) 632 { 633 if (pband->credit <= 0) 634 return NULL; 635 636 if (pband->new_flows.first) 637 return &pband->new_flows; 638 639 return pband->old_flows.first ? &pband->old_flows : NULL; 640 } 641 642 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 643 { 644 struct fq_sched_data *q = qdisc_priv(sch); 645 struct fq_perband_flows *pband; 646 struct fq_flow_head *head; 647 struct sk_buff *skb; 648 struct fq_flow *f; 649 unsigned long rate; 650 int retry; 651 u32 plen; 652 u64 now; 653 654 if (!sch->q.qlen) 655 return NULL; 656 657 skb = fq_peek(&q->internal); 658 if (unlikely(skb)) { 659 q->internal.qlen--; 660 fq_dequeue_skb(sch, &q->internal, skb); 661 goto out; 662 } 663 664 now = ktime_get_ns(); 665 fq_check_throttled(q, now); 666 retry = 0; 667 pband = &q->band_flows[q->band_nr]; 668 begin: 669 head = fq_pband_head_select(pband); 670 if (!head) { 671 while (++retry <= FQ_BANDS) { 672 if (++q->band_nr == FQ_BANDS) 673 q->band_nr = 0; 674 pband = &q->band_flows[q->band_nr]; 675 pband->credit = min(pband->credit + pband->quantum, 676 pband->quantum); 677 if (pband->credit > 0) 678 goto begin; 679 retry = 0; 680 } 681 if (q->time_next_delayed_flow != ~0ULL) 682 qdisc_watchdog_schedule_range_ns(&q->watchdog, 683 q->time_next_delayed_flow, 684 q->timer_slack); 685 return NULL; 686 } 687 f = head->first; 688 retry = 0; 689 if (f->credit <= 0) { 690 f->credit += q->quantum; 691 head->first = f->next; 692 fq_flow_add_tail(q, f, OLD_FLOW); 693 goto begin; 694 } 695 696 skb = fq_peek(f); 697 if (skb) { 698 u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send, 699 f->time_next_packet); 700 701 if (now + q->offload_horizon < time_next_packet) { 702 head->first = f->next; 703 f->time_next_packet = time_next_packet; 704 fq_flow_set_throttled(q, f); 705 goto begin; 706 } 707 prefetch(&skb->end); 708 if ((s64)(now - time_next_packet - q->ce_threshold) > 0) { 709 INET_ECN_set_ce(skb); 710 q->stat_ce_mark++; 711 } 712 if (--f->qlen == 0) 713 q->inactive_flows++; 714 q->band_pkt_count[fq_skb_cb(skb)->band]--; 715 fq_dequeue_skb(sch, f, skb); 716 } else { 717 head->first = f->next; 718 /* force a pass through old_flows to prevent starvation */ 719 if (head == &pband->new_flows) { 720 fq_flow_add_tail(q, f, OLD_FLOW); 721 } else { 722 fq_flow_set_detached(f); 723 } 724 goto begin; 725 } 726 plen = qdisc_pkt_len(skb); 727 f->credit -= plen; 728 pband->credit -= plen; 729 730 if (!q->rate_enable) 731 goto out; 732 733 rate = q->flow_max_rate; 734 735 /* If EDT time was provided for this skb, we need to 736 * update f->time_next_packet only if this qdisc enforces 737 * a flow max rate. 738 */ 739 if (!skb->tstamp) { 740 if (skb->sk) 741 rate = min(READ_ONCE(skb->sk->sk_pacing_rate), rate); 742 743 if (rate <= q->low_rate_threshold) { 744 f->credit = 0; 745 } else { 746 plen = max(plen, q->quantum); 747 if (f->credit > 0) 748 goto out; 749 } 750 } 751 if (rate != ~0UL) { 752 u64 len = (u64)plen * NSEC_PER_SEC; 753 754 if (likely(rate)) 755 len = div64_ul(len, rate); 756 /* Since socket rate can change later, 757 * clamp the delay to 1 second. 758 * Really, providers of too big packets should be fixed ! 759 */ 760 if (unlikely(len > NSEC_PER_SEC)) { 761 len = NSEC_PER_SEC; 762 q->stat_pkts_too_long++; 763 } 764 /* Account for schedule/timers drifts. 765 * f->time_next_packet was set when prior packet was sent, 766 * and current time (@now) can be too late by tens of us. 767 */ 768 if (f->time_next_packet) 769 len -= min(len/2, now - f->time_next_packet); 770 f->time_next_packet = now + len; 771 } 772 out: 773 qdisc_bstats_update(sch, skb); 774 return skb; 775 } 776 777 static void fq_flow_purge(struct fq_flow *flow) 778 { 779 struct rb_node *p = rb_first(&flow->t_root); 780 781 while (p) { 782 struct sk_buff *skb = rb_to_skb(p); 783 784 p = rb_next(p); 785 rb_erase(&skb->rbnode, &flow->t_root); 786 rtnl_kfree_skbs(skb, skb); 787 } 788 rtnl_kfree_skbs(flow->head, flow->tail); 789 flow->head = NULL; 790 flow->qlen = 0; 791 } 792 793 static void fq_reset(struct Qdisc *sch) 794 { 795 struct fq_sched_data *q = qdisc_priv(sch); 796 struct rb_root *root; 797 struct rb_node *p; 798 struct fq_flow *f; 799 unsigned int idx; 800 801 sch->q.qlen = 0; 802 sch->qstats.backlog = 0; 803 804 fq_flow_purge(&q->internal); 805 806 if (!q->fq_root) 807 return; 808 809 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 810 root = &q->fq_root[idx]; 811 while ((p = rb_first(root)) != NULL) { 812 f = rb_entry(p, struct fq_flow, fq_node); 813 rb_erase(p, root); 814 815 fq_flow_purge(f); 816 817 kmem_cache_free(fq_flow_cachep, f); 818 } 819 } 820 for (idx = 0; idx < FQ_BANDS; idx++) { 821 q->band_flows[idx].new_flows.first = NULL; 822 q->band_flows[idx].old_flows.first = NULL; 823 } 824 q->delayed = RB_ROOT; 825 q->flows = 0; 826 q->inactive_flows = 0; 827 q->throttled_flows = 0; 828 } 829 830 static void fq_rehash(struct fq_sched_data *q, 831 struct rb_root *old_array, u32 old_log, 832 struct rb_root *new_array, u32 new_log) 833 { 834 struct rb_node *op, **np, *parent; 835 struct rb_root *oroot, *nroot; 836 struct fq_flow *of, *nf; 837 int fcnt = 0; 838 u32 idx; 839 840 for (idx = 0; idx < (1U << old_log); idx++) { 841 oroot = &old_array[idx]; 842 while ((op = rb_first(oroot)) != NULL) { 843 rb_erase(op, oroot); 844 of = rb_entry(op, struct fq_flow, fq_node); 845 if (fq_gc_candidate(of)) { 846 fcnt++; 847 kmem_cache_free(fq_flow_cachep, of); 848 continue; 849 } 850 nroot = &new_array[hash_ptr(of->sk, new_log)]; 851 852 np = &nroot->rb_node; 853 parent = NULL; 854 while (*np) { 855 parent = *np; 856 857 nf = rb_entry(parent, struct fq_flow, fq_node); 858 BUG_ON(nf->sk == of->sk); 859 860 if (nf->sk > of->sk) 861 np = &parent->rb_right; 862 else 863 np = &parent->rb_left; 864 } 865 866 rb_link_node(&of->fq_node, parent, np); 867 rb_insert_color(&of->fq_node, nroot); 868 } 869 } 870 q->flows -= fcnt; 871 q->inactive_flows -= fcnt; 872 q->stat_gc_flows += fcnt; 873 } 874 875 static void fq_free(void *addr) 876 { 877 kvfree(addr); 878 } 879 880 static int fq_resize(struct Qdisc *sch, u32 log) 881 { 882 struct fq_sched_data *q = qdisc_priv(sch); 883 struct rb_root *array; 884 void *old_fq_root; 885 u32 idx; 886 887 if (q->fq_root && log == q->fq_trees_log) 888 return 0; 889 890 /* If XPS was setup, we can allocate memory on right NUMA node */ 891 array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, 892 netdev_queue_numa_node_read(sch->dev_queue)); 893 if (!array) 894 return -ENOMEM; 895 896 for (idx = 0; idx < (1U << log); idx++) 897 array[idx] = RB_ROOT; 898 899 sch_tree_lock(sch); 900 901 old_fq_root = q->fq_root; 902 if (old_fq_root) 903 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); 904 905 q->fq_root = array; 906 WRITE_ONCE(q->fq_trees_log, log); 907 908 sch_tree_unlock(sch); 909 910 fq_free(old_fq_root); 911 912 return 0; 913 } 914 915 static const struct netlink_range_validation iq_range = { 916 .max = INT_MAX, 917 }; 918 919 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 920 [TCA_FQ_UNSPEC] = { .strict_start_type = TCA_FQ_TIMER_SLACK }, 921 922 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 923 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 924 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 925 [TCA_FQ_INITIAL_QUANTUM] = NLA_POLICY_FULL_RANGE(NLA_U32, &iq_range), 926 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 927 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 928 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 929 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 930 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, 931 [TCA_FQ_ORPHAN_MASK] = { .type = NLA_U32 }, 932 [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, 933 [TCA_FQ_CE_THRESHOLD] = { .type = NLA_U32 }, 934 [TCA_FQ_TIMER_SLACK] = { .type = NLA_U32 }, 935 [TCA_FQ_HORIZON] = { .type = NLA_U32 }, 936 [TCA_FQ_HORIZON_DROP] = { .type = NLA_U8 }, 937 [TCA_FQ_PRIOMAP] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_prio_qopt)), 938 [TCA_FQ_WEIGHTS] = NLA_POLICY_EXACT_LEN(FQ_BANDS * sizeof(s32)), 939 [TCA_FQ_OFFLOAD_HORIZON] = { .type = NLA_U32 }, 940 }; 941 942 /* compress a u8 array with all elems <= 3 to an array of 2-bit fields */ 943 static void fq_prio2band_compress_crumb(const u8 *in, u8 *out) 944 { 945 const int num_elems = TC_PRIO_MAX + 1; 946 u8 tmp[FQ_PRIO2BAND_CRUMB_SIZE]; 947 int i; 948 949 memset(tmp, 0, sizeof(tmp)); 950 for (i = 0; i < num_elems; i++) 951 tmp[i / 4] |= in[i] << (2 * (i & 0x3)); 952 953 for (i = 0; i < FQ_PRIO2BAND_CRUMB_SIZE; i++) 954 WRITE_ONCE(out[i], tmp[i]); 955 } 956 957 static void fq_prio2band_decompress_crumb(const u8 *in, u8 *out) 958 { 959 const int num_elems = TC_PRIO_MAX + 1; 960 int i; 961 962 for (i = 0; i < num_elems; i++) 963 out[i] = fq_prio2band(in, i); 964 } 965 966 static int fq_load_weights(struct fq_sched_data *q, 967 const struct nlattr *attr, 968 struct netlink_ext_ack *extack) 969 { 970 s32 *weights = nla_data(attr); 971 int i; 972 973 for (i = 0; i < FQ_BANDS; i++) { 974 if (weights[i] < FQ_MIN_WEIGHT) { 975 NL_SET_ERR_MSG_FMT_MOD(extack, "Weight %d less that minimum allowed %d", 976 weights[i], FQ_MIN_WEIGHT); 977 return -EINVAL; 978 } 979 } 980 for (i = 0; i < FQ_BANDS; i++) 981 WRITE_ONCE(q->band_flows[i].quantum, weights[i]); 982 return 0; 983 } 984 985 static int fq_load_priomap(struct fq_sched_data *q, 986 const struct nlattr *attr, 987 struct netlink_ext_ack *extack) 988 { 989 const struct tc_prio_qopt *map = nla_data(attr); 990 int i; 991 992 if (map->bands != FQ_BANDS) { 993 NL_SET_ERR_MSG_MOD(extack, "FQ only supports 3 bands"); 994 return -EINVAL; 995 } 996 for (i = 0; i < TC_PRIO_MAX + 1; i++) { 997 if (map->priomap[i] >= FQ_BANDS) { 998 NL_SET_ERR_MSG_FMT_MOD(extack, "FQ priomap field %d maps to a too high band %d", 999 i, map->priomap[i]); 1000 return -EINVAL; 1001 } 1002 } 1003 fq_prio2band_compress_crumb(map->priomap, q->prio2band); 1004 return 0; 1005 } 1006 1007 static int fq_change(struct Qdisc *sch, struct nlattr *opt, 1008 struct netlink_ext_ack *extack) 1009 { 1010 struct fq_sched_data *q = qdisc_priv(sch); 1011 struct nlattr *tb[TCA_FQ_MAX + 1]; 1012 int err, drop_count = 0; 1013 unsigned drop_len = 0; 1014 u32 fq_log; 1015 1016 err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy, 1017 NULL); 1018 if (err < 0) 1019 return err; 1020 1021 sch_tree_lock(sch); 1022 1023 fq_log = q->fq_trees_log; 1024 1025 if (tb[TCA_FQ_BUCKETS_LOG]) { 1026 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 1027 1028 if (nval >= 1 && nval <= ilog2(256*1024)) 1029 fq_log = nval; 1030 else 1031 err = -EINVAL; 1032 } 1033 if (tb[TCA_FQ_PLIMIT]) 1034 WRITE_ONCE(sch->limit, 1035 nla_get_u32(tb[TCA_FQ_PLIMIT])); 1036 1037 if (tb[TCA_FQ_FLOW_PLIMIT]) 1038 WRITE_ONCE(q->flow_plimit, 1039 nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT])); 1040 1041 if (tb[TCA_FQ_QUANTUM]) { 1042 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 1043 1044 if (quantum > 0 && quantum <= (1 << 20)) { 1045 WRITE_ONCE(q->quantum, quantum); 1046 } else { 1047 NL_SET_ERR_MSG_MOD(extack, "invalid quantum"); 1048 err = -EINVAL; 1049 } 1050 } 1051 1052 if (tb[TCA_FQ_INITIAL_QUANTUM]) 1053 WRITE_ONCE(q->initial_quantum, 1054 nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM])); 1055 1056 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 1057 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", 1058 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); 1059 1060 if (tb[TCA_FQ_FLOW_MAX_RATE]) { 1061 u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); 1062 1063 WRITE_ONCE(q->flow_max_rate, 1064 (rate == ~0U) ? ~0UL : rate); 1065 } 1066 if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) 1067 WRITE_ONCE(q->low_rate_threshold, 1068 nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD])); 1069 1070 if (tb[TCA_FQ_RATE_ENABLE]) { 1071 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); 1072 1073 if (enable <= 1) 1074 WRITE_ONCE(q->rate_enable, 1075 enable); 1076 else 1077 err = -EINVAL; 1078 } 1079 1080 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { 1081 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; 1082 1083 WRITE_ONCE(q->flow_refill_delay, 1084 usecs_to_jiffies(usecs_delay)); 1085 } 1086 1087 if (!err && tb[TCA_FQ_PRIOMAP]) 1088 err = fq_load_priomap(q, tb[TCA_FQ_PRIOMAP], extack); 1089 1090 if (!err && tb[TCA_FQ_WEIGHTS]) 1091 err = fq_load_weights(q, tb[TCA_FQ_WEIGHTS], extack); 1092 1093 if (tb[TCA_FQ_ORPHAN_MASK]) 1094 WRITE_ONCE(q->orphan_mask, 1095 nla_get_u32(tb[TCA_FQ_ORPHAN_MASK])); 1096 1097 if (tb[TCA_FQ_CE_THRESHOLD]) 1098 WRITE_ONCE(q->ce_threshold, 1099 (u64)NSEC_PER_USEC * 1100 nla_get_u32(tb[TCA_FQ_CE_THRESHOLD])); 1101 1102 if (tb[TCA_FQ_TIMER_SLACK]) 1103 WRITE_ONCE(q->timer_slack, 1104 nla_get_u32(tb[TCA_FQ_TIMER_SLACK])); 1105 1106 if (tb[TCA_FQ_HORIZON]) 1107 WRITE_ONCE(q->horizon, 1108 (u64)NSEC_PER_USEC * 1109 nla_get_u32(tb[TCA_FQ_HORIZON])); 1110 1111 if (tb[TCA_FQ_HORIZON_DROP]) 1112 WRITE_ONCE(q->horizon_drop, 1113 nla_get_u8(tb[TCA_FQ_HORIZON_DROP])); 1114 1115 if (tb[TCA_FQ_OFFLOAD_HORIZON]) { 1116 u64 offload_horizon = (u64)NSEC_PER_USEC * 1117 nla_get_u32(tb[TCA_FQ_OFFLOAD_HORIZON]); 1118 1119 if (offload_horizon <= qdisc_dev(sch)->max_pacing_offload_horizon) { 1120 WRITE_ONCE(q->offload_horizon, offload_horizon); 1121 } else { 1122 NL_SET_ERR_MSG_MOD(extack, "invalid offload_horizon"); 1123 err = -EINVAL; 1124 } 1125 } 1126 if (!err) { 1127 1128 sch_tree_unlock(sch); 1129 err = fq_resize(sch, fq_log); 1130 sch_tree_lock(sch); 1131 } 1132 while (sch->q.qlen > sch->limit) { 1133 struct sk_buff *skb = fq_dequeue(sch); 1134 1135 if (!skb) 1136 break; 1137 drop_len += qdisc_pkt_len(skb); 1138 rtnl_kfree_skbs(skb, skb); 1139 drop_count++; 1140 } 1141 qdisc_tree_reduce_backlog(sch, drop_count, drop_len); 1142 1143 sch_tree_unlock(sch); 1144 return err; 1145 } 1146 1147 static void fq_destroy(struct Qdisc *sch) 1148 { 1149 struct fq_sched_data *q = qdisc_priv(sch); 1150 1151 fq_reset(sch); 1152 fq_free(q->fq_root); 1153 qdisc_watchdog_cancel(&q->watchdog); 1154 } 1155 1156 static int fq_init(struct Qdisc *sch, struct nlattr *opt, 1157 struct netlink_ext_ack *extack) 1158 { 1159 struct fq_sched_data *q = qdisc_priv(sch); 1160 int i, err; 1161 1162 sch->limit = 10000; 1163 q->flow_plimit = 100; 1164 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 1165 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 1166 q->flow_refill_delay = msecs_to_jiffies(40); 1167 q->flow_max_rate = ~0UL; 1168 q->time_next_delayed_flow = ~0ULL; 1169 q->rate_enable = 1; 1170 for (i = 0; i < FQ_BANDS; i++) { 1171 q->band_flows[i].new_flows.first = NULL; 1172 q->band_flows[i].old_flows.first = NULL; 1173 } 1174 q->band_flows[0].quantum = 9 << 16; 1175 q->band_flows[1].quantum = 3 << 16; 1176 q->band_flows[2].quantum = 1 << 16; 1177 q->delayed = RB_ROOT; 1178 q->fq_root = NULL; 1179 q->fq_trees_log = ilog2(1024); 1180 q->orphan_mask = 1024 - 1; 1181 q->low_rate_threshold = 550000 / 8; 1182 1183 q->timer_slack = 10 * NSEC_PER_USEC; /* 10 usec of hrtimer slack */ 1184 1185 q->horizon = 10ULL * NSEC_PER_SEC; /* 10 seconds */ 1186 q->horizon_drop = 1; /* by default, drop packets beyond horizon */ 1187 1188 /* Default ce_threshold of 4294 seconds */ 1189 q->ce_threshold = (u64)NSEC_PER_USEC * ~0U; 1190 1191 fq_prio2band_compress_crumb(sch_default_prio2band, q->prio2band); 1192 qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC); 1193 1194 if (opt) 1195 err = fq_change(sch, opt, extack); 1196 else 1197 err = fq_resize(sch, q->fq_trees_log); 1198 1199 return err; 1200 } 1201 1202 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 1203 { 1204 struct fq_sched_data *q = qdisc_priv(sch); 1205 struct tc_prio_qopt prio = { 1206 .bands = FQ_BANDS, 1207 }; 1208 struct nlattr *opts; 1209 u64 offload_horizon; 1210 u64 ce_threshold; 1211 s32 weights[3]; 1212 u64 horizon; 1213 1214 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 1215 if (opts == NULL) 1216 goto nla_put_failure; 1217 1218 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ 1219 1220 ce_threshold = READ_ONCE(q->ce_threshold); 1221 do_div(ce_threshold, NSEC_PER_USEC); 1222 1223 horizon = READ_ONCE(q->horizon); 1224 do_div(horizon, NSEC_PER_USEC); 1225 1226 offload_horizon = READ_ONCE(q->offload_horizon); 1227 do_div(offload_horizon, NSEC_PER_USEC); 1228 1229 if (nla_put_u32(skb, TCA_FQ_PLIMIT, 1230 READ_ONCE(sch->limit)) || 1231 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, 1232 READ_ONCE(q->flow_plimit)) || 1233 nla_put_u32(skb, TCA_FQ_QUANTUM, 1234 READ_ONCE(q->quantum)) || 1235 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, 1236 READ_ONCE(q->initial_quantum)) || 1237 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, 1238 READ_ONCE(q->rate_enable)) || 1239 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, 1240 min_t(unsigned long, 1241 READ_ONCE(q->flow_max_rate), ~0U)) || 1242 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, 1243 jiffies_to_usecs(READ_ONCE(q->flow_refill_delay))) || 1244 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, 1245 READ_ONCE(q->orphan_mask)) || 1246 nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, 1247 READ_ONCE(q->low_rate_threshold)) || 1248 nla_put_u32(skb, TCA_FQ_CE_THRESHOLD, (u32)ce_threshold) || 1249 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, 1250 READ_ONCE(q->fq_trees_log)) || 1251 nla_put_u32(skb, TCA_FQ_TIMER_SLACK, 1252 READ_ONCE(q->timer_slack)) || 1253 nla_put_u32(skb, TCA_FQ_HORIZON, (u32)horizon) || 1254 nla_put_u32(skb, TCA_FQ_OFFLOAD_HORIZON, (u32)offload_horizon) || 1255 nla_put_u8(skb, TCA_FQ_HORIZON_DROP, 1256 READ_ONCE(q->horizon_drop))) 1257 goto nla_put_failure; 1258 1259 fq_prio2band_decompress_crumb(q->prio2band, prio.priomap); 1260 if (nla_put(skb, TCA_FQ_PRIOMAP, sizeof(prio), &prio)) 1261 goto nla_put_failure; 1262 1263 weights[0] = READ_ONCE(q->band_flows[0].quantum); 1264 weights[1] = READ_ONCE(q->band_flows[1].quantum); 1265 weights[2] = READ_ONCE(q->band_flows[2].quantum); 1266 if (nla_put(skb, TCA_FQ_WEIGHTS, sizeof(weights), &weights)) 1267 goto nla_put_failure; 1268 1269 return nla_nest_end(skb, opts); 1270 1271 nla_put_failure: 1272 return -1; 1273 } 1274 1275 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 1276 { 1277 struct fq_sched_data *q = qdisc_priv(sch); 1278 struct tc_fq_qd_stats st; 1279 int i; 1280 1281 st.pad = 0; 1282 1283 sch_tree_lock(sch); 1284 1285 st.gc_flows = q->stat_gc_flows; 1286 st.highprio_packets = 0; 1287 st.fastpath_packets = q->internal.stat_fastpath_packets; 1288 st.tcp_retrans = 0; 1289 st.throttled = q->stat_throttled; 1290 st.flows_plimit = q->stat_flows_plimit; 1291 st.pkts_too_long = q->stat_pkts_too_long; 1292 st.allocation_errors = q->stat_allocation_errors; 1293 st.time_next_delayed_flow = q->time_next_delayed_flow + q->timer_slack - 1294 ktime_get_ns(); 1295 st.flows = q->flows; 1296 st.inactive_flows = q->inactive_flows; 1297 st.throttled_flows = q->throttled_flows; 1298 st.unthrottle_latency_ns = min_t(unsigned long, 1299 q->unthrottle_latency_ns, ~0U); 1300 st.ce_mark = q->stat_ce_mark; 1301 st.horizon_drops = q->stat_horizon_drops; 1302 st.horizon_caps = q->stat_horizon_caps; 1303 for (i = 0; i < FQ_BANDS; i++) { 1304 st.band_drops[i] = q->stat_band_drops[i]; 1305 st.band_pkt_count[i] = q->band_pkt_count[i]; 1306 } 1307 sch_tree_unlock(sch); 1308 1309 return gnet_stats_copy_app(d, &st, sizeof(st)); 1310 } 1311 1312 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 1313 .id = "fq", 1314 .priv_size = sizeof(struct fq_sched_data), 1315 1316 .enqueue = fq_enqueue, 1317 .dequeue = fq_dequeue, 1318 .peek = qdisc_peek_dequeued, 1319 .init = fq_init, 1320 .reset = fq_reset, 1321 .destroy = fq_destroy, 1322 .change = fq_change, 1323 .dump = fq_dump, 1324 .dump_stats = fq_dump_stats, 1325 .owner = THIS_MODULE, 1326 }; 1327 MODULE_ALIAS_NET_SCH("fq"); 1328 1329 static int __init fq_module_init(void) 1330 { 1331 int ret; 1332 1333 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 1334 sizeof(struct fq_flow), 1335 0, SLAB_HWCACHE_ALIGN, NULL); 1336 if (!fq_flow_cachep) 1337 return -ENOMEM; 1338 1339 ret = register_qdisc(&fq_qdisc_ops); 1340 if (ret) 1341 kmem_cache_destroy(fq_flow_cachep); 1342 return ret; 1343 } 1344 1345 static void __exit fq_module_exit(void) 1346 { 1347 unregister_qdisc(&fq_qdisc_ops); 1348 kmem_cache_destroy(fq_flow_cachep); 1349 } 1350 1351 module_init(fq_module_init) 1352 module_exit(fq_module_exit) 1353 MODULE_AUTHOR("Eric Dumazet"); 1354 MODULE_LICENSE("GPL"); 1355 MODULE_DESCRIPTION("Fair Queue Packet Scheduler"); 1356