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