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 #define FQ_GC_AGE (3*HZ) 249 250 static bool fq_gc_candidate(const struct fq_flow *f) 251 { 252 return fq_flow_is_detached(f) && 253 time_after(jiffies, f->age + FQ_GC_AGE); 254 } 255 256 static void fq_gc(struct fq_sched_data *q, 257 struct rb_root *root, 258 struct sock *sk) 259 { 260 struct fq_flow *f, *tofree = NULL; 261 struct rb_node **p, *parent; 262 int fcnt; 263 264 p = &root->rb_node; 265 parent = NULL; 266 while (*p) { 267 parent = *p; 268 269 f = rb_entry(parent, struct fq_flow, fq_node); 270 if (f->sk == sk) 271 break; 272 273 if (fq_gc_candidate(f)) { 274 f->next = tofree; 275 tofree = f; 276 } 277 278 if (f->sk > sk) 279 p = &parent->rb_right; 280 else 281 p = &parent->rb_left; 282 } 283 284 if (!tofree) 285 return; 286 287 fcnt = 0; 288 while (tofree) { 289 f = tofree; 290 tofree = f->next; 291 rb_erase(&f->fq_node, root); 292 kmem_cache_free(fq_flow_cachep, f); 293 fcnt++; 294 } 295 q->flows -= fcnt; 296 q->inactive_flows -= fcnt; 297 q->stat_gc_flows += fcnt; 298 } 299 300 /* Fast path can be used if : 301 * 1) Packet tstamp is in the past, or within the pacing offload horizon. 302 * 2) FQ qlen == 0 OR 303 * (no flow is currently eligible for transmit, 304 * AND fast path queue has less than 8 packets) 305 * 3) No SO_MAX_PACING_RATE on the socket (if any). 306 * 4) No @maxrate attribute on this qdisc, 307 * 308 * FQ can not use generic TCQ_F_CAN_BYPASS infrastructure. 309 */ 310 static bool fq_fastpath_check(const struct Qdisc *sch, struct sk_buff *skb, 311 u64 now) 312 { 313 const struct fq_sched_data *q = qdisc_priv(sch); 314 const struct sock *sk; 315 316 if (fq_skb_cb(skb)->time_to_send > now + q->offload_horizon) 317 return false; 318 319 if (sch->q.qlen != 0) { 320 /* Even if some packets are stored in this qdisc, 321 * we can still enable fast path if all of them are 322 * scheduled in the future (ie no flows are eligible) 323 * or in the fast path queue. 324 */ 325 if (q->flows != q->inactive_flows + q->throttled_flows) 326 return false; 327 328 /* Do not allow fast path queue to explode, we want Fair Queue mode 329 * under pressure. 330 */ 331 if (q->internal.qlen >= 8) 332 return false; 333 334 /* Ordering invariants fall apart if some delayed flows 335 * are ready but we haven't serviced them, yet. 336 */ 337 if (q->time_next_delayed_flow <= now + q->offload_horizon) 338 return false; 339 } 340 341 sk = skb->sk; 342 if (sk && sk_fullsock(sk) && !sk_is_tcp(sk) && 343 sk->sk_max_pacing_rate != ~0UL) 344 return false; 345 346 if (q->flow_max_rate != ~0UL) 347 return false; 348 349 return true; 350 } 351 352 static struct fq_flow *fq_classify(struct Qdisc *sch, struct sk_buff *skb, 353 u64 now) 354 { 355 struct fq_sched_data *q = qdisc_priv(sch); 356 struct rb_node **p, *parent; 357 struct sock *sk = skb->sk; 358 struct rb_root *root; 359 struct fq_flow *f; 360 361 /* SYNACK messages are attached to a TCP_NEW_SYN_RECV request socket 362 * or a listener (SYNCOOKIE mode) 363 * 1) request sockets are not full blown, 364 * they do not contain sk_pacing_rate 365 * 2) They are not part of a 'flow' yet 366 * 3) We do not want to rate limit them (eg SYNFLOOD attack), 367 * especially if the listener set SO_MAX_PACING_RATE 368 * 4) We pretend they are orphaned 369 * TCP can also associate TIME_WAIT sockets with RST or ACK packets. 370 */ 371 if (!sk || sk_listener_or_tw(sk)) { 372 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 373 374 /* By forcing low order bit to 1, we make sure to not 375 * collide with a local flow (socket pointers are word aligned) 376 */ 377 sk = (struct sock *)((hash << 1) | 1UL); 378 skb_orphan(skb); 379 } else if (sk->sk_state == TCP_CLOSE) { 380 unsigned long hash = skb_get_hash(skb) & q->orphan_mask; 381 /* 382 * Sockets in TCP_CLOSE are non connected. 383 * Typical use case is UDP sockets, they can send packets 384 * with sendto() to many different destinations. 385 * We probably could use a generic bit advertising 386 * non connected sockets, instead of sk_state == TCP_CLOSE, 387 * if we care enough. 388 */ 389 sk = (struct sock *)((hash << 1) | 1UL); 390 } 391 392 if (fq_fastpath_check(sch, skb, now)) { 393 q->internal.stat_fastpath_packets++; 394 if (skb->sk == sk && q->rate_enable && 395 READ_ONCE(sk->sk_pacing_status) != SK_PACING_FQ) 396 smp_store_release(&sk->sk_pacing_status, 397 SK_PACING_FQ); 398 return &q->internal; 399 } 400 401 root = &q->fq_root[hash_ptr(sk, q->fq_trees_log)]; 402 403 fq_gc(q, root, sk); 404 405 p = &root->rb_node; 406 parent = NULL; 407 while (*p) { 408 parent = *p; 409 410 f = rb_entry(parent, struct fq_flow, fq_node); 411 if (f->sk == sk) { 412 /* socket might have been reallocated, so check 413 * if its sk_hash is the same. 414 * It not, we need to refill credit with 415 * initial quantum 416 */ 417 if (unlikely(skb->sk == sk && 418 f->socket_hash != sk->sk_hash)) { 419 f->credit = q->initial_quantum; 420 f->socket_hash = sk->sk_hash; 421 if (q->rate_enable) 422 smp_store_release(&sk->sk_pacing_status, 423 SK_PACING_FQ); 424 if (fq_flow_is_throttled(f)) 425 fq_flow_unset_throttled(q, f); 426 f->time_next_packet = 0ULL; 427 } 428 return f; 429 } 430 if (f->sk > sk) 431 p = &parent->rb_right; 432 else 433 p = &parent->rb_left; 434 } 435 436 f = kmem_cache_zalloc(fq_flow_cachep, GFP_ATOMIC | __GFP_NOWARN); 437 if (unlikely(!f)) { 438 q->stat_allocation_errors++; 439 return &q->internal; 440 } 441 /* f->t_root is already zeroed after kmem_cache_zalloc() */ 442 443 fq_flow_set_detached(f); 444 f->sk = sk; 445 if (skb->sk == sk) { 446 f->socket_hash = sk->sk_hash; 447 if (q->rate_enable) 448 smp_store_release(&sk->sk_pacing_status, 449 SK_PACING_FQ); 450 } 451 f->credit = q->initial_quantum; 452 453 rb_link_node(&f->fq_node, parent, p); 454 rb_insert_color(&f->fq_node, root); 455 456 q->flows++; 457 q->inactive_flows++; 458 return f; 459 } 460 461 static struct sk_buff *fq_peek(struct fq_flow *flow) 462 { 463 struct sk_buff *skb = skb_rb_first(&flow->t_root); 464 struct sk_buff *head = flow->head; 465 466 if (!skb) 467 return head; 468 469 if (!head) 470 return skb; 471 472 if (fq_skb_cb(skb)->time_to_send < fq_skb_cb(head)->time_to_send) 473 return skb; 474 return head; 475 } 476 477 static void fq_erase_head(struct Qdisc *sch, struct fq_flow *flow, 478 struct sk_buff *skb) 479 { 480 if (skb == flow->head) { 481 struct sk_buff *next = skb->next; 482 483 prefetch(next); 484 flow->head = next; 485 } else { 486 rb_erase(&skb->rbnode, &flow->t_root); 487 skb->dev = qdisc_dev(sch); 488 } 489 } 490 491 /* Remove one skb from flow queue. 492 * This skb must be the return value of prior fq_peek(). 493 */ 494 static void fq_dequeue_skb(struct Qdisc *sch, struct fq_flow *flow, 495 struct sk_buff *skb) 496 { 497 fq_erase_head(sch, flow, skb); 498 skb_mark_not_on_list(skb); 499 qdisc_qstats_backlog_dec(sch, skb); 500 sch->q.qlen--; 501 qdisc_bstats_update(sch, skb); 502 } 503 504 static void flow_queue_add(struct fq_flow *flow, struct sk_buff *skb) 505 { 506 struct rb_node **p, *parent; 507 struct sk_buff *head, *aux; 508 509 head = flow->head; 510 if (!head || 511 fq_skb_cb(skb)->time_to_send >= fq_skb_cb(flow->tail)->time_to_send) { 512 if (!head) 513 flow->head = skb; 514 else 515 flow->tail->next = skb; 516 flow->tail = skb; 517 skb->next = NULL; 518 return; 519 } 520 521 p = &flow->t_root.rb_node; 522 parent = NULL; 523 524 while (*p) { 525 parent = *p; 526 aux = rb_to_skb(parent); 527 if (fq_skb_cb(skb)->time_to_send >= fq_skb_cb(aux)->time_to_send) 528 p = &parent->rb_right; 529 else 530 p = &parent->rb_left; 531 } 532 rb_link_node(&skb->rbnode, parent, p); 533 rb_insert_color(&skb->rbnode, &flow->t_root); 534 } 535 536 static bool fq_packet_beyond_horizon(const struct sk_buff *skb, 537 const struct fq_sched_data *q, u64 now) 538 { 539 return unlikely((s64)skb->tstamp > (s64)(now + q->horizon)); 540 } 541 542 static int fq_enqueue(struct sk_buff *skb, struct Qdisc *sch, 543 struct sk_buff **to_free) 544 { 545 struct fq_sched_data *q = qdisc_priv(sch); 546 struct fq_flow *f; 547 u64 now; 548 u8 band; 549 550 band = fq_prio2band(q->prio2band, skb->priority & TC_PRIO_MAX); 551 if (unlikely(q->band_pkt_count[band] >= sch->limit)) { 552 q->stat_band_drops[band]++; 553 return qdisc_drop_reason(skb, sch, to_free, QDISC_DROP_BAND_LIMIT); 554 } 555 556 now = ktime_get_ns(); 557 if (!skb->tstamp) { 558 fq_skb_cb(skb)->time_to_send = now; 559 } else { 560 /* Check if packet timestamp is too far in the future. */ 561 if (fq_packet_beyond_horizon(skb, q, now)) { 562 if (q->horizon_drop) { 563 q->stat_horizon_drops++; 564 return qdisc_drop_reason(skb, sch, to_free, 565 QDISC_DROP_HORIZON_LIMIT); 566 } 567 q->stat_horizon_caps++; 568 skb->tstamp = now + q->horizon; 569 } 570 fq_skb_cb(skb)->time_to_send = skb->tstamp; 571 } 572 573 f = fq_classify(sch, skb, now); 574 575 if (f != &q->internal) { 576 if (unlikely(f->qlen >= q->flow_plimit)) { 577 q->stat_flows_plimit++; 578 return qdisc_drop_reason(skb, sch, to_free, 579 QDISC_DROP_FLOW_LIMIT); 580 } 581 582 if (fq_flow_is_detached(f)) { 583 fq_flow_add_tail(q, f, NEW_FLOW); 584 if (time_after(jiffies, f->age + q->flow_refill_delay)) 585 f->credit = max_t(u32, f->credit, q->quantum); 586 } 587 588 f->band = band; 589 q->band_pkt_count[band]++; 590 fq_skb_cb(skb)->band = band; 591 if (f->qlen == 0) 592 q->inactive_flows--; 593 } 594 595 f->qlen++; 596 /* Note: this overwrites f->age */ 597 flow_queue_add(f, skb); 598 599 qdisc_qstats_backlog_inc(sch, skb); 600 sch->q.qlen++; 601 602 return NET_XMIT_SUCCESS; 603 } 604 605 static void fq_check_throttled(struct fq_sched_data *q, u64 now) 606 { 607 unsigned long sample; 608 struct rb_node *p; 609 610 if (q->time_next_delayed_flow > now + q->offload_horizon) 611 return; 612 613 /* Update unthrottle latency EWMA. 614 * This is cheap and can help diagnosing timer/latency problems. 615 */ 616 sample = (unsigned long)(now - q->time_next_delayed_flow); 617 if ((long)sample > 0) { 618 q->unthrottle_latency_ns -= q->unthrottle_latency_ns >> 3; 619 q->unthrottle_latency_ns += sample >> 3; 620 } 621 now += q->offload_horizon; 622 623 q->time_next_delayed_flow = ~0ULL; 624 while ((p = rb_first(&q->delayed)) != NULL) { 625 struct fq_flow *f = rb_entry(p, struct fq_flow, rate_node); 626 627 if (f->time_next_packet > now) { 628 q->time_next_delayed_flow = f->time_next_packet; 629 break; 630 } 631 fq_flow_unset_throttled(q, f); 632 } 633 } 634 635 static struct fq_flow_head *fq_pband_head_select(struct fq_perband_flows *pband) 636 { 637 if (pband->credit <= 0) 638 return NULL; 639 640 if (pband->new_flows.first) 641 return &pband->new_flows; 642 643 return pband->old_flows.first ? &pband->old_flows : NULL; 644 } 645 646 static struct sk_buff *fq_dequeue(struct Qdisc *sch) 647 { 648 struct fq_sched_data *q = qdisc_priv(sch); 649 struct fq_perband_flows *pband; 650 struct fq_flow_head *head; 651 struct sk_buff *skb; 652 struct fq_flow *f; 653 unsigned long rate; 654 int retry; 655 u32 plen; 656 u64 now; 657 658 if (!sch->q.qlen) 659 return NULL; 660 661 skb = fq_peek(&q->internal); 662 if (skb) { 663 q->internal.qlen--; 664 fq_dequeue_skb(sch, &q->internal, skb); 665 goto out; 666 } 667 668 now = ktime_get_ns(); 669 fq_check_throttled(q, now); 670 retry = 0; 671 pband = &q->band_flows[q->band_nr]; 672 begin: 673 head = fq_pband_head_select(pband); 674 if (!head) { 675 while (++retry <= FQ_BANDS) { 676 if (++q->band_nr == FQ_BANDS) 677 q->band_nr = 0; 678 pband = &q->band_flows[q->band_nr]; 679 pband->credit = min(pband->credit + pband->quantum, 680 pband->quantum); 681 if (pband->credit > 0) 682 goto begin; 683 retry = 0; 684 } 685 if (q->time_next_delayed_flow != ~0ULL) 686 qdisc_watchdog_schedule_range_ns(&q->watchdog, 687 q->time_next_delayed_flow, 688 q->timer_slack); 689 return NULL; 690 } 691 f = head->first; 692 retry = 0; 693 if (f->credit <= 0) { 694 f->credit += q->quantum; 695 head->first = f->next; 696 fq_flow_add_tail(q, f, OLD_FLOW); 697 goto begin; 698 } 699 700 skb = fq_peek(f); 701 if (skb) { 702 u64 time_next_packet = max_t(u64, fq_skb_cb(skb)->time_to_send, 703 f->time_next_packet); 704 705 if (now + q->offload_horizon < time_next_packet) { 706 head->first = f->next; 707 f->time_next_packet = time_next_packet; 708 fq_flow_set_throttled(q, f); 709 goto begin; 710 } 711 prefetch(&skb->end); 712 fq_dequeue_skb(sch, f, skb); 713 if (unlikely((s64)(now - time_next_packet - q->ce_threshold) > 0)) { 714 INET_ECN_set_ce(skb); 715 q->stat_ce_mark++; 716 } 717 if (--f->qlen == 0) 718 q->inactive_flows++; 719 q->band_pkt_count[fq_skb_cb(skb)->band]--; 720 } else { 721 head->first = f->next; 722 /* force a pass through old_flows to prevent starvation */ 723 if (head == &pband->new_flows) { 724 fq_flow_add_tail(q, f, OLD_FLOW); 725 } else { 726 fq_flow_set_detached(f); 727 } 728 goto begin; 729 } 730 plen = qdisc_pkt_len(skb); 731 f->credit -= plen; 732 pband->credit -= plen; 733 734 if (!q->rate_enable) 735 goto out; 736 737 rate = q->flow_max_rate; 738 739 /* If EDT time was provided for this skb, we need to 740 * update f->time_next_packet only if this qdisc enforces 741 * a flow max rate. 742 */ 743 if (!skb->tstamp) { 744 if (skb->sk) 745 rate = min(READ_ONCE(skb->sk->sk_pacing_rate), rate); 746 747 if (rate <= q->low_rate_threshold) { 748 f->credit = 0; 749 } else { 750 plen = max(plen, q->quantum); 751 if (f->credit > 0) 752 goto out; 753 } 754 } 755 if (rate != ~0UL) { 756 u64 len = (u64)plen * NSEC_PER_SEC; 757 758 if (likely(rate)) 759 len = div64_ul(len, rate); 760 /* Since socket rate can change later, 761 * clamp the delay to 1 second. 762 * Really, providers of too big packets should be fixed ! 763 */ 764 if (unlikely(len > NSEC_PER_SEC)) { 765 len = NSEC_PER_SEC; 766 q->stat_pkts_too_long++; 767 } 768 /* Account for schedule/timers drifts. 769 * f->time_next_packet was set when prior packet was sent, 770 * and current time (@now) can be too late by tens of us. 771 */ 772 if (f->time_next_packet) 773 len -= min(len/2, now - f->time_next_packet); 774 f->time_next_packet = now + len; 775 } 776 out: 777 return skb; 778 } 779 780 static void fq_flow_purge(struct fq_flow *flow) 781 { 782 struct rb_node *p = rb_first(&flow->t_root); 783 784 while (p) { 785 struct sk_buff *skb = rb_to_skb(p); 786 787 p = rb_next(p); 788 rb_erase(&skb->rbnode, &flow->t_root); 789 rtnl_kfree_skbs(skb, skb); 790 } 791 rtnl_kfree_skbs(flow->head, flow->tail); 792 flow->head = NULL; 793 flow->qlen = 0; 794 } 795 796 static void fq_reset(struct Qdisc *sch) 797 { 798 struct fq_sched_data *q = qdisc_priv(sch); 799 struct rb_root *root; 800 struct rb_node *p; 801 struct fq_flow *f; 802 unsigned int idx; 803 804 sch->q.qlen = 0; 805 sch->qstats.backlog = 0; 806 807 fq_flow_purge(&q->internal); 808 809 if (!q->fq_root) 810 return; 811 812 for (idx = 0; idx < (1U << q->fq_trees_log); idx++) { 813 root = &q->fq_root[idx]; 814 while ((p = rb_first(root)) != NULL) { 815 f = rb_entry(p, struct fq_flow, fq_node); 816 rb_erase(p, root); 817 818 fq_flow_purge(f); 819 820 kmem_cache_free(fq_flow_cachep, f); 821 } 822 } 823 for (idx = 0; idx < FQ_BANDS; idx++) { 824 q->band_flows[idx].new_flows.first = NULL; 825 q->band_flows[idx].old_flows.first = NULL; 826 } 827 q->delayed = RB_ROOT; 828 q->flows = 0; 829 q->inactive_flows = 0; 830 q->throttled_flows = 0; 831 } 832 833 static void fq_rehash(struct fq_sched_data *q, 834 struct rb_root *old_array, u32 old_log, 835 struct rb_root *new_array, u32 new_log) 836 { 837 struct rb_node *op, **np, *parent; 838 struct rb_root *oroot, *nroot; 839 struct fq_flow *of, *nf; 840 int fcnt = 0; 841 u32 idx; 842 843 for (idx = 0; idx < (1U << old_log); idx++) { 844 oroot = &old_array[idx]; 845 while ((op = rb_first(oroot)) != NULL) { 846 rb_erase(op, oroot); 847 of = rb_entry(op, struct fq_flow, fq_node); 848 if (fq_gc_candidate(of)) { 849 fcnt++; 850 kmem_cache_free(fq_flow_cachep, of); 851 continue; 852 } 853 nroot = &new_array[hash_ptr(of->sk, new_log)]; 854 855 np = &nroot->rb_node; 856 parent = NULL; 857 while (*np) { 858 parent = *np; 859 860 nf = rb_entry(parent, struct fq_flow, fq_node); 861 BUG_ON(nf->sk == of->sk); 862 863 if (nf->sk > of->sk) 864 np = &parent->rb_right; 865 else 866 np = &parent->rb_left; 867 } 868 869 rb_link_node(&of->fq_node, parent, np); 870 rb_insert_color(&of->fq_node, nroot); 871 } 872 } 873 q->flows -= fcnt; 874 q->inactive_flows -= fcnt; 875 q->stat_gc_flows += fcnt; 876 } 877 878 static void fq_free(void *addr) 879 { 880 kvfree(addr); 881 } 882 883 static int fq_resize(struct Qdisc *sch, u32 log) 884 { 885 struct fq_sched_data *q = qdisc_priv(sch); 886 struct rb_root *array; 887 void *old_fq_root; 888 u32 idx; 889 890 if (q->fq_root && log == q->fq_trees_log) 891 return 0; 892 893 /* If XPS was setup, we can allocate memory on right NUMA node */ 894 array = kvmalloc_node(sizeof(struct rb_root) << log, GFP_KERNEL | __GFP_RETRY_MAYFAIL, 895 netdev_queue_numa_node_read(sch->dev_queue)); 896 if (!array) 897 return -ENOMEM; 898 899 for (idx = 0; idx < (1U << log); idx++) 900 array[idx] = RB_ROOT; 901 902 sch_tree_lock(sch); 903 904 old_fq_root = q->fq_root; 905 if (old_fq_root) 906 fq_rehash(q, old_fq_root, q->fq_trees_log, array, log); 907 908 q->fq_root = array; 909 WRITE_ONCE(q->fq_trees_log, log); 910 911 sch_tree_unlock(sch); 912 913 fq_free(old_fq_root); 914 915 return 0; 916 } 917 918 static const struct netlink_range_validation iq_range = { 919 .max = INT_MAX, 920 }; 921 922 static const struct nla_policy fq_policy[TCA_FQ_MAX + 1] = { 923 [TCA_FQ_UNSPEC] = { .strict_start_type = TCA_FQ_TIMER_SLACK }, 924 925 [TCA_FQ_PLIMIT] = { .type = NLA_U32 }, 926 [TCA_FQ_FLOW_PLIMIT] = { .type = NLA_U32 }, 927 [TCA_FQ_QUANTUM] = { .type = NLA_U32 }, 928 [TCA_FQ_INITIAL_QUANTUM] = NLA_POLICY_FULL_RANGE(NLA_U32, &iq_range), 929 [TCA_FQ_RATE_ENABLE] = { .type = NLA_U32 }, 930 [TCA_FQ_FLOW_DEFAULT_RATE] = { .type = NLA_U32 }, 931 [TCA_FQ_FLOW_MAX_RATE] = { .type = NLA_U32 }, 932 [TCA_FQ_BUCKETS_LOG] = { .type = NLA_U32 }, 933 [TCA_FQ_FLOW_REFILL_DELAY] = { .type = NLA_U32 }, 934 [TCA_FQ_ORPHAN_MASK] = { .type = NLA_U32 }, 935 [TCA_FQ_LOW_RATE_THRESHOLD] = { .type = NLA_U32 }, 936 [TCA_FQ_CE_THRESHOLD] = { .type = NLA_U32 }, 937 [TCA_FQ_TIMER_SLACK] = { .type = NLA_U32 }, 938 [TCA_FQ_HORIZON] = { .type = NLA_U32 }, 939 [TCA_FQ_HORIZON_DROP] = { .type = NLA_U8 }, 940 [TCA_FQ_PRIOMAP] = NLA_POLICY_EXACT_LEN(sizeof(struct tc_prio_qopt)), 941 [TCA_FQ_WEIGHTS] = NLA_POLICY_EXACT_LEN(FQ_BANDS * sizeof(s32)), 942 [TCA_FQ_OFFLOAD_HORIZON] = { .type = NLA_U32 }, 943 }; 944 945 /* compress a u8 array with all elems <= 3 to an array of 2-bit fields */ 946 static void fq_prio2band_compress_crumb(const u8 *in, u8 *out) 947 { 948 const int num_elems = TC_PRIO_MAX + 1; 949 u8 tmp[FQ_PRIO2BAND_CRUMB_SIZE]; 950 int i; 951 952 memset(tmp, 0, sizeof(tmp)); 953 for (i = 0; i < num_elems; i++) 954 tmp[i / 4] |= in[i] << (2 * (i & 0x3)); 955 956 for (i = 0; i < FQ_PRIO2BAND_CRUMB_SIZE; i++) 957 WRITE_ONCE(out[i], tmp[i]); 958 } 959 960 static void fq_prio2band_decompress_crumb(const u8 *in, u8 *out) 961 { 962 const int num_elems = TC_PRIO_MAX + 1; 963 int i; 964 965 for (i = 0; i < num_elems; i++) 966 out[i] = fq_prio2band(in, i); 967 } 968 969 static int fq_load_weights(struct fq_sched_data *q, 970 const struct nlattr *attr, 971 struct netlink_ext_ack *extack) 972 { 973 s32 *weights = nla_data(attr); 974 int i; 975 976 for (i = 0; i < FQ_BANDS; i++) { 977 if (weights[i] < FQ_MIN_WEIGHT) { 978 NL_SET_ERR_MSG_FMT_MOD(extack, "Weight %d less that minimum allowed %d", 979 weights[i], FQ_MIN_WEIGHT); 980 return -EINVAL; 981 } 982 } 983 for (i = 0; i < FQ_BANDS; i++) 984 WRITE_ONCE(q->band_flows[i].quantum, weights[i]); 985 return 0; 986 } 987 988 static int fq_load_priomap(struct fq_sched_data *q, 989 const struct nlattr *attr, 990 struct netlink_ext_ack *extack) 991 { 992 const struct tc_prio_qopt *map = nla_data(attr); 993 int i; 994 995 if (map->bands != FQ_BANDS) { 996 NL_SET_ERR_MSG_MOD(extack, "FQ only supports 3 bands"); 997 return -EINVAL; 998 } 999 for (i = 0; i < TC_PRIO_MAX + 1; i++) { 1000 if (map->priomap[i] >= FQ_BANDS) { 1001 NL_SET_ERR_MSG_FMT_MOD(extack, "FQ priomap field %d maps to a too high band %d", 1002 i, map->priomap[i]); 1003 return -EINVAL; 1004 } 1005 } 1006 fq_prio2band_compress_crumb(map->priomap, q->prio2band); 1007 return 0; 1008 } 1009 1010 static int fq_change(struct Qdisc *sch, struct nlattr *opt, 1011 struct netlink_ext_ack *extack) 1012 { 1013 unsigned int dropped_pkts = 0, dropped_bytes = 0; 1014 struct fq_sched_data *q = qdisc_priv(sch); 1015 struct nlattr *tb[TCA_FQ_MAX + 1]; 1016 u32 fq_log; 1017 int err; 1018 1019 err = nla_parse_nested_deprecated(tb, TCA_FQ_MAX, opt, fq_policy, 1020 NULL); 1021 if (err < 0) 1022 return err; 1023 1024 sch_tree_lock(sch); 1025 1026 fq_log = q->fq_trees_log; 1027 1028 if (tb[TCA_FQ_BUCKETS_LOG]) { 1029 u32 nval = nla_get_u32(tb[TCA_FQ_BUCKETS_LOG]); 1030 1031 if (nval >= 1 && nval <= ilog2(256*1024)) 1032 fq_log = nval; 1033 else 1034 err = -EINVAL; 1035 } 1036 if (tb[TCA_FQ_PLIMIT]) 1037 WRITE_ONCE(sch->limit, 1038 nla_get_u32(tb[TCA_FQ_PLIMIT])); 1039 1040 if (tb[TCA_FQ_FLOW_PLIMIT]) 1041 WRITE_ONCE(q->flow_plimit, 1042 nla_get_u32(tb[TCA_FQ_FLOW_PLIMIT])); 1043 1044 if (tb[TCA_FQ_QUANTUM]) { 1045 u32 quantum = nla_get_u32(tb[TCA_FQ_QUANTUM]); 1046 1047 if (quantum > 0 && quantum <= (1 << 20)) { 1048 WRITE_ONCE(q->quantum, quantum); 1049 } else { 1050 NL_SET_ERR_MSG_MOD(extack, "invalid quantum"); 1051 err = -EINVAL; 1052 } 1053 } 1054 1055 if (tb[TCA_FQ_INITIAL_QUANTUM]) 1056 WRITE_ONCE(q->initial_quantum, 1057 nla_get_u32(tb[TCA_FQ_INITIAL_QUANTUM])); 1058 1059 if (tb[TCA_FQ_FLOW_DEFAULT_RATE]) 1060 pr_warn_ratelimited("sch_fq: defrate %u ignored.\n", 1061 nla_get_u32(tb[TCA_FQ_FLOW_DEFAULT_RATE])); 1062 1063 if (tb[TCA_FQ_FLOW_MAX_RATE]) { 1064 u32 rate = nla_get_u32(tb[TCA_FQ_FLOW_MAX_RATE]); 1065 1066 WRITE_ONCE(q->flow_max_rate, 1067 (rate == ~0U) ? ~0UL : rate); 1068 } 1069 if (tb[TCA_FQ_LOW_RATE_THRESHOLD]) 1070 WRITE_ONCE(q->low_rate_threshold, 1071 nla_get_u32(tb[TCA_FQ_LOW_RATE_THRESHOLD])); 1072 1073 if (tb[TCA_FQ_RATE_ENABLE]) { 1074 u32 enable = nla_get_u32(tb[TCA_FQ_RATE_ENABLE]); 1075 1076 if (enable <= 1) 1077 WRITE_ONCE(q->rate_enable, 1078 enable); 1079 else 1080 err = -EINVAL; 1081 } 1082 1083 if (tb[TCA_FQ_FLOW_REFILL_DELAY]) { 1084 u32 usecs_delay = nla_get_u32(tb[TCA_FQ_FLOW_REFILL_DELAY]) ; 1085 1086 WRITE_ONCE(q->flow_refill_delay, 1087 usecs_to_jiffies(usecs_delay)); 1088 } 1089 1090 if (!err && tb[TCA_FQ_PRIOMAP]) 1091 err = fq_load_priomap(q, tb[TCA_FQ_PRIOMAP], extack); 1092 1093 if (!err && tb[TCA_FQ_WEIGHTS]) 1094 err = fq_load_weights(q, tb[TCA_FQ_WEIGHTS], extack); 1095 1096 if (tb[TCA_FQ_ORPHAN_MASK]) 1097 WRITE_ONCE(q->orphan_mask, 1098 nla_get_u32(tb[TCA_FQ_ORPHAN_MASK])); 1099 1100 if (tb[TCA_FQ_CE_THRESHOLD]) 1101 WRITE_ONCE(q->ce_threshold, 1102 (u64)NSEC_PER_USEC * 1103 nla_get_u32(tb[TCA_FQ_CE_THRESHOLD])); 1104 1105 if (tb[TCA_FQ_TIMER_SLACK]) 1106 WRITE_ONCE(q->timer_slack, 1107 nla_get_u32(tb[TCA_FQ_TIMER_SLACK])); 1108 1109 if (tb[TCA_FQ_HORIZON]) 1110 WRITE_ONCE(q->horizon, 1111 (u64)NSEC_PER_USEC * 1112 nla_get_u32(tb[TCA_FQ_HORIZON])); 1113 1114 if (tb[TCA_FQ_HORIZON_DROP]) 1115 WRITE_ONCE(q->horizon_drop, 1116 nla_get_u8(tb[TCA_FQ_HORIZON_DROP])); 1117 1118 if (tb[TCA_FQ_OFFLOAD_HORIZON]) { 1119 u64 offload_horizon = (u64)NSEC_PER_USEC * 1120 nla_get_u32(tb[TCA_FQ_OFFLOAD_HORIZON]); 1121 1122 if (offload_horizon <= qdisc_dev(sch)->max_pacing_offload_horizon) { 1123 WRITE_ONCE(q->offload_horizon, offload_horizon); 1124 } else { 1125 NL_SET_ERR_MSG_MOD(extack, "invalid offload_horizon"); 1126 err = -EINVAL; 1127 } 1128 } 1129 if (!err) { 1130 1131 sch_tree_unlock(sch); 1132 err = fq_resize(sch, fq_log); 1133 sch_tree_lock(sch); 1134 } 1135 1136 while (sch->q.qlen > sch->limit) { 1137 struct sk_buff *skb = qdisc_dequeue_internal(sch, false); 1138 1139 if (!skb) 1140 break; 1141 1142 dropped_pkts++; 1143 dropped_bytes += qdisc_pkt_len(skb); 1144 rtnl_kfree_skbs(skb, skb); 1145 } 1146 qdisc_tree_reduce_backlog(sch, dropped_pkts, dropped_bytes); 1147 1148 sch_tree_unlock(sch); 1149 return err; 1150 } 1151 1152 static void fq_destroy(struct Qdisc *sch) 1153 { 1154 struct fq_sched_data *q = qdisc_priv(sch); 1155 1156 fq_reset(sch); 1157 fq_free(q->fq_root); 1158 qdisc_watchdog_cancel(&q->watchdog); 1159 } 1160 1161 static int fq_init(struct Qdisc *sch, struct nlattr *opt, 1162 struct netlink_ext_ack *extack) 1163 { 1164 struct fq_sched_data *q = qdisc_priv(sch); 1165 int i, err; 1166 1167 sch->limit = 10000; 1168 q->flow_plimit = 100; 1169 q->quantum = 2 * psched_mtu(qdisc_dev(sch)); 1170 q->initial_quantum = 10 * psched_mtu(qdisc_dev(sch)); 1171 q->flow_refill_delay = msecs_to_jiffies(40); 1172 q->flow_max_rate = ~0UL; 1173 q->time_next_delayed_flow = ~0ULL; 1174 q->rate_enable = 1; 1175 for (i = 0; i < FQ_BANDS; i++) { 1176 q->band_flows[i].new_flows.first = NULL; 1177 q->band_flows[i].old_flows.first = NULL; 1178 } 1179 q->band_flows[0].quantum = 9 << 16; 1180 q->band_flows[1].quantum = 3 << 16; 1181 q->band_flows[2].quantum = 1 << 16; 1182 q->delayed = RB_ROOT; 1183 q->fq_root = NULL; 1184 q->fq_trees_log = ilog2(1024); 1185 q->orphan_mask = 1024 - 1; 1186 q->low_rate_threshold = 550000 / 8; 1187 1188 q->timer_slack = 10 * NSEC_PER_USEC; /* 10 usec of hrtimer slack */ 1189 1190 q->horizon = 10ULL * NSEC_PER_SEC; /* 10 seconds */ 1191 q->horizon_drop = 1; /* by default, drop packets beyond horizon */ 1192 1193 /* Default ce_threshold of 4294 seconds */ 1194 q->ce_threshold = (u64)NSEC_PER_USEC * ~0U; 1195 1196 fq_prio2band_compress_crumb(sch_default_prio2band, q->prio2band); 1197 qdisc_watchdog_init_clockid(&q->watchdog, sch, CLOCK_MONOTONIC); 1198 1199 if (opt) 1200 err = fq_change(sch, opt, extack); 1201 else 1202 err = fq_resize(sch, q->fq_trees_log); 1203 1204 return err; 1205 } 1206 1207 static int fq_dump(struct Qdisc *sch, struct sk_buff *skb) 1208 { 1209 struct fq_sched_data *q = qdisc_priv(sch); 1210 struct tc_prio_qopt prio = { 1211 .bands = FQ_BANDS, 1212 }; 1213 struct nlattr *opts; 1214 u64 offload_horizon; 1215 u64 ce_threshold; 1216 s32 weights[3]; 1217 u64 horizon; 1218 1219 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 1220 if (opts == NULL) 1221 goto nla_put_failure; 1222 1223 /* TCA_FQ_FLOW_DEFAULT_RATE is not used anymore */ 1224 1225 ce_threshold = READ_ONCE(q->ce_threshold); 1226 do_div(ce_threshold, NSEC_PER_USEC); 1227 1228 horizon = READ_ONCE(q->horizon); 1229 do_div(horizon, NSEC_PER_USEC); 1230 1231 offload_horizon = READ_ONCE(q->offload_horizon); 1232 do_div(offload_horizon, NSEC_PER_USEC); 1233 1234 if (nla_put_u32(skb, TCA_FQ_PLIMIT, 1235 READ_ONCE(sch->limit)) || 1236 nla_put_u32(skb, TCA_FQ_FLOW_PLIMIT, 1237 READ_ONCE(q->flow_plimit)) || 1238 nla_put_u32(skb, TCA_FQ_QUANTUM, 1239 READ_ONCE(q->quantum)) || 1240 nla_put_u32(skb, TCA_FQ_INITIAL_QUANTUM, 1241 READ_ONCE(q->initial_quantum)) || 1242 nla_put_u32(skb, TCA_FQ_RATE_ENABLE, 1243 READ_ONCE(q->rate_enable)) || 1244 nla_put_u32(skb, TCA_FQ_FLOW_MAX_RATE, 1245 min_t(unsigned long, 1246 READ_ONCE(q->flow_max_rate), ~0U)) || 1247 nla_put_u32(skb, TCA_FQ_FLOW_REFILL_DELAY, 1248 jiffies_to_usecs(READ_ONCE(q->flow_refill_delay))) || 1249 nla_put_u32(skb, TCA_FQ_ORPHAN_MASK, 1250 READ_ONCE(q->orphan_mask)) || 1251 nla_put_u32(skb, TCA_FQ_LOW_RATE_THRESHOLD, 1252 READ_ONCE(q->low_rate_threshold)) || 1253 nla_put_u32(skb, TCA_FQ_CE_THRESHOLD, (u32)ce_threshold) || 1254 nla_put_u32(skb, TCA_FQ_BUCKETS_LOG, 1255 READ_ONCE(q->fq_trees_log)) || 1256 nla_put_u32(skb, TCA_FQ_TIMER_SLACK, 1257 READ_ONCE(q->timer_slack)) || 1258 nla_put_u32(skb, TCA_FQ_HORIZON, (u32)horizon) || 1259 nla_put_u32(skb, TCA_FQ_OFFLOAD_HORIZON, (u32)offload_horizon) || 1260 nla_put_u8(skb, TCA_FQ_HORIZON_DROP, 1261 READ_ONCE(q->horizon_drop))) 1262 goto nla_put_failure; 1263 1264 fq_prio2band_decompress_crumb(q->prio2band, prio.priomap); 1265 if (nla_put(skb, TCA_FQ_PRIOMAP, sizeof(prio), &prio)) 1266 goto nla_put_failure; 1267 1268 weights[0] = READ_ONCE(q->band_flows[0].quantum); 1269 weights[1] = READ_ONCE(q->band_flows[1].quantum); 1270 weights[2] = READ_ONCE(q->band_flows[2].quantum); 1271 if (nla_put(skb, TCA_FQ_WEIGHTS, sizeof(weights), &weights)) 1272 goto nla_put_failure; 1273 1274 return nla_nest_end(skb, opts); 1275 1276 nla_put_failure: 1277 return -1; 1278 } 1279 1280 static int fq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 1281 { 1282 struct fq_sched_data *q = qdisc_priv(sch); 1283 struct tc_fq_qd_stats st; 1284 int i; 1285 1286 st.pad = 0; 1287 1288 sch_tree_lock(sch); 1289 1290 st.gc_flows = q->stat_gc_flows; 1291 st.highprio_packets = 0; 1292 st.fastpath_packets = q->internal.stat_fastpath_packets; 1293 st.tcp_retrans = 0; 1294 st.throttled = q->stat_throttled; 1295 st.flows_plimit = q->stat_flows_plimit; 1296 st.pkts_too_long = q->stat_pkts_too_long; 1297 st.allocation_errors = q->stat_allocation_errors; 1298 st.time_next_delayed_flow = q->time_next_delayed_flow + q->timer_slack - 1299 ktime_get_ns(); 1300 st.flows = q->flows; 1301 st.inactive_flows = q->inactive_flows; 1302 st.throttled_flows = q->throttled_flows; 1303 st.unthrottle_latency_ns = min_t(unsigned long, 1304 q->unthrottle_latency_ns, ~0U); 1305 st.ce_mark = q->stat_ce_mark; 1306 st.horizon_drops = q->stat_horizon_drops; 1307 st.horizon_caps = q->stat_horizon_caps; 1308 for (i = 0; i < FQ_BANDS; i++) { 1309 st.band_drops[i] = q->stat_band_drops[i]; 1310 st.band_pkt_count[i] = q->band_pkt_count[i]; 1311 } 1312 sch_tree_unlock(sch); 1313 1314 return gnet_stats_copy_app(d, &st, sizeof(st)); 1315 } 1316 1317 static struct Qdisc_ops fq_qdisc_ops __read_mostly = { 1318 .id = "fq", 1319 .priv_size = sizeof(struct fq_sched_data), 1320 1321 .enqueue = fq_enqueue, 1322 .dequeue = fq_dequeue, 1323 .peek = qdisc_peek_dequeued, 1324 .init = fq_init, 1325 .reset = fq_reset, 1326 .destroy = fq_destroy, 1327 .change = fq_change, 1328 .dump = fq_dump, 1329 .dump_stats = fq_dump_stats, 1330 .owner = THIS_MODULE, 1331 }; 1332 MODULE_ALIAS_NET_SCH("fq"); 1333 1334 static int __init fq_module_init(void) 1335 { 1336 int ret; 1337 1338 fq_flow_cachep = kmem_cache_create("fq_flow_cache", 1339 sizeof(struct fq_flow), 1340 0, SLAB_HWCACHE_ALIGN, NULL); 1341 if (!fq_flow_cachep) 1342 return -ENOMEM; 1343 1344 ret = register_qdisc(&fq_qdisc_ops); 1345 if (ret) 1346 kmem_cache_destroy(fq_flow_cachep); 1347 return ret; 1348 } 1349 1350 static void __exit fq_module_exit(void) 1351 { 1352 unregister_qdisc(&fq_qdisc_ops); 1353 kmem_cache_destroy(fq_flow_cachep); 1354 } 1355 1356 module_init(fq_module_init) 1357 module_exit(fq_module_exit) 1358 MODULE_AUTHOR("Eric Dumazet"); 1359 MODULE_LICENSE("GPL"); 1360 MODULE_DESCRIPTION("Fair Queue Packet Scheduler"); 1361