1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Fair Queue CoDel discipline 4 * 5 * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/types.h> 10 #include <linux/kernel.h> 11 #include <linux/jiffies.h> 12 #include <linux/string.h> 13 #include <linux/in.h> 14 #include <linux/errno.h> 15 #include <linux/init.h> 16 #include <linux/skbuff.h> 17 #include <linux/jhash.h> 18 #include <linux/slab.h> 19 #include <linux/vmalloc.h> 20 #include <net/netlink.h> 21 #include <net/pkt_sched.h> 22 #include <net/pkt_cls.h> 23 #include <net/codel.h> 24 #include <net/codel_impl.h> 25 #include <net/codel_qdisc.h> 26 27 /* Fair Queue CoDel. 28 * 29 * Principles : 30 * Packets are classified (internal classifier or external) on flows. 31 * This is a Stochastic model (as we use a hash, several flows 32 * might be hashed on same slot) 33 * Each flow has a CoDel managed queue. 34 * Flows are linked onto two (Round Robin) lists, 35 * so that new flows have priority on old ones. 36 * 37 * For a given flow, packets are not reordered (CoDel uses a FIFO) 38 * head drops only. 39 * ECN capability is on by default. 40 * Low memory footprint (64 bytes per flow) 41 */ 42 43 struct fq_codel_flow { 44 struct sk_buff *head; 45 struct sk_buff *tail; 46 struct list_head flowchain; 47 int deficit; 48 struct codel_vars cvars; 49 }; /* please try to keep this structure <= 64 bytes */ 50 51 struct fq_codel_sched_data { 52 struct tcf_proto __rcu *filter_list; /* optional external classifier */ 53 struct tcf_block *block; 54 struct fq_codel_flow *flows; /* Flows table [flows_cnt] */ 55 u32 *backlogs; /* backlog table [flows_cnt] */ 56 u32 flows_cnt; /* number of flows */ 57 u32 quantum; /* psched_mtu(qdisc_dev(sch)); */ 58 u32 drop_batch_size; 59 u32 memory_limit; 60 struct codel_params cparams; 61 struct codel_stats cstats; 62 u32 memory_usage; 63 u32 drop_overmemory; 64 u32 drop_overlimit; 65 u32 new_flow_count; 66 67 struct list_head new_flows; /* list of new flows */ 68 struct list_head old_flows; /* list of old flows */ 69 }; 70 71 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q, 72 struct sk_buff *skb) 73 { 74 return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); 75 } 76 77 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, 78 int *qerr) 79 { 80 struct fq_codel_sched_data *q = qdisc_priv(sch); 81 struct tcf_proto *filter; 82 struct tcf_result res; 83 int result; 84 85 if (TC_H_MAJ(skb->priority) == sch->handle && 86 TC_H_MIN(skb->priority) > 0 && 87 TC_H_MIN(skb->priority) <= q->flows_cnt) 88 return TC_H_MIN(skb->priority); 89 90 filter = rcu_dereference_bh(q->filter_list); 91 if (!filter) 92 return fq_codel_hash(q, skb) + 1; 93 94 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 95 result = tcf_classify(skb, filter, &res, false); 96 if (result >= 0) { 97 #ifdef CONFIG_NET_CLS_ACT 98 switch (result) { 99 case TC_ACT_STOLEN: 100 case TC_ACT_QUEUED: 101 case TC_ACT_TRAP: 102 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 103 /* fall through */ 104 case TC_ACT_SHOT: 105 return 0; 106 } 107 #endif 108 if (TC_H_MIN(res.classid) <= q->flows_cnt) 109 return TC_H_MIN(res.classid); 110 } 111 return 0; 112 } 113 114 /* helper functions : might be changed when/if skb use a standard list_head */ 115 116 /* remove one skb from head of slot queue */ 117 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow) 118 { 119 struct sk_buff *skb = flow->head; 120 121 flow->head = skb->next; 122 skb_mark_not_on_list(skb); 123 return skb; 124 } 125 126 /* add skb to flow queue (tail add) */ 127 static inline void flow_queue_add(struct fq_codel_flow *flow, 128 struct sk_buff *skb) 129 { 130 if (flow->head == NULL) 131 flow->head = skb; 132 else 133 flow->tail->next = skb; 134 flow->tail = skb; 135 skb->next = NULL; 136 } 137 138 static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets, 139 struct sk_buff **to_free) 140 { 141 struct fq_codel_sched_data *q = qdisc_priv(sch); 142 struct sk_buff *skb; 143 unsigned int maxbacklog = 0, idx = 0, i, len; 144 struct fq_codel_flow *flow; 145 unsigned int threshold; 146 unsigned int mem = 0; 147 148 /* Queue is full! Find the fat flow and drop packet(s) from it. 149 * This might sound expensive, but with 1024 flows, we scan 150 * 4KB of memory, and we dont need to handle a complex tree 151 * in fast path (packet queue/enqueue) with many cache misses. 152 * In stress mode, we'll try to drop 64 packets from the flow, 153 * amortizing this linear lookup to one cache line per drop. 154 */ 155 for (i = 0; i < q->flows_cnt; i++) { 156 if (q->backlogs[i] > maxbacklog) { 157 maxbacklog = q->backlogs[i]; 158 idx = i; 159 } 160 } 161 162 /* Our goal is to drop half of this fat flow backlog */ 163 threshold = maxbacklog >> 1; 164 165 flow = &q->flows[idx]; 166 len = 0; 167 i = 0; 168 do { 169 skb = dequeue_head(flow); 170 len += qdisc_pkt_len(skb); 171 mem += get_codel_cb(skb)->mem_usage; 172 __qdisc_drop(skb, to_free); 173 } while (++i < max_packets && len < threshold); 174 175 /* Tell codel to increase its signal strength also */ 176 flow->cvars.count += i; 177 q->backlogs[idx] -= len; 178 q->memory_usage -= mem; 179 sch->qstats.drops += i; 180 sch->qstats.backlog -= len; 181 sch->q.qlen -= i; 182 return idx; 183 } 184 185 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, 186 struct sk_buff **to_free) 187 { 188 struct fq_codel_sched_data *q = qdisc_priv(sch); 189 unsigned int idx, prev_backlog, prev_qlen; 190 struct fq_codel_flow *flow; 191 int uninitialized_var(ret); 192 unsigned int pkt_len; 193 bool memory_limited; 194 195 idx = fq_codel_classify(skb, sch, &ret); 196 if (idx == 0) { 197 if (ret & __NET_XMIT_BYPASS) 198 qdisc_qstats_drop(sch); 199 __qdisc_drop(skb, to_free); 200 return ret; 201 } 202 idx--; 203 204 codel_set_enqueue_time(skb); 205 flow = &q->flows[idx]; 206 flow_queue_add(flow, skb); 207 q->backlogs[idx] += qdisc_pkt_len(skb); 208 qdisc_qstats_backlog_inc(sch, skb); 209 210 if (list_empty(&flow->flowchain)) { 211 list_add_tail(&flow->flowchain, &q->new_flows); 212 q->new_flow_count++; 213 flow->deficit = q->quantum; 214 } 215 get_codel_cb(skb)->mem_usage = skb->truesize; 216 q->memory_usage += get_codel_cb(skb)->mem_usage; 217 memory_limited = q->memory_usage > q->memory_limit; 218 if (++sch->q.qlen <= sch->limit && !memory_limited) 219 return NET_XMIT_SUCCESS; 220 221 prev_backlog = sch->qstats.backlog; 222 prev_qlen = sch->q.qlen; 223 224 /* save this packet length as it might be dropped by fq_codel_drop() */ 225 pkt_len = qdisc_pkt_len(skb); 226 /* fq_codel_drop() is quite expensive, as it performs a linear search 227 * in q->backlogs[] to find a fat flow. 228 * So instead of dropping a single packet, drop half of its backlog 229 * with a 64 packets limit to not add a too big cpu spike here. 230 */ 231 ret = fq_codel_drop(sch, q->drop_batch_size, to_free); 232 233 prev_qlen -= sch->q.qlen; 234 prev_backlog -= sch->qstats.backlog; 235 q->drop_overlimit += prev_qlen; 236 if (memory_limited) 237 q->drop_overmemory += prev_qlen; 238 239 /* As we dropped packet(s), better let upper stack know this. 240 * If we dropped a packet for this flow, return NET_XMIT_CN, 241 * but in this case, our parents wont increase their backlogs. 242 */ 243 if (ret == idx) { 244 qdisc_tree_reduce_backlog(sch, prev_qlen - 1, 245 prev_backlog - pkt_len); 246 return NET_XMIT_CN; 247 } 248 qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); 249 return NET_XMIT_SUCCESS; 250 } 251 252 /* This is the specific function called from codel_dequeue() 253 * to dequeue a packet from queue. Note: backlog is handled in 254 * codel, we dont need to reduce it here. 255 */ 256 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 257 { 258 struct Qdisc *sch = ctx; 259 struct fq_codel_sched_data *q = qdisc_priv(sch); 260 struct fq_codel_flow *flow; 261 struct sk_buff *skb = NULL; 262 263 flow = container_of(vars, struct fq_codel_flow, cvars); 264 if (flow->head) { 265 skb = dequeue_head(flow); 266 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 267 q->memory_usage -= get_codel_cb(skb)->mem_usage; 268 sch->q.qlen--; 269 sch->qstats.backlog -= qdisc_pkt_len(skb); 270 } 271 return skb; 272 } 273 274 static void drop_func(struct sk_buff *skb, void *ctx) 275 { 276 struct Qdisc *sch = ctx; 277 278 kfree_skb(skb); 279 qdisc_qstats_drop(sch); 280 } 281 282 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 283 { 284 struct fq_codel_sched_data *q = qdisc_priv(sch); 285 struct sk_buff *skb; 286 struct fq_codel_flow *flow; 287 struct list_head *head; 288 289 begin: 290 head = &q->new_flows; 291 if (list_empty(head)) { 292 head = &q->old_flows; 293 if (list_empty(head)) 294 return NULL; 295 } 296 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 297 298 if (flow->deficit <= 0) { 299 flow->deficit += q->quantum; 300 list_move_tail(&flow->flowchain, &q->old_flows); 301 goto begin; 302 } 303 304 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 305 &flow->cvars, &q->cstats, qdisc_pkt_len, 306 codel_get_enqueue_time, drop_func, dequeue_func); 307 308 if (!skb) { 309 /* force a pass through old_flows to prevent starvation */ 310 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 311 list_move_tail(&flow->flowchain, &q->old_flows); 312 else 313 list_del_init(&flow->flowchain); 314 goto begin; 315 } 316 qdisc_bstats_update(sch, skb); 317 flow->deficit -= qdisc_pkt_len(skb); 318 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 319 * or HTB crashes. Defer it for next round. 320 */ 321 if (q->cstats.drop_count && sch->q.qlen) { 322 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 323 q->cstats.drop_len); 324 q->cstats.drop_count = 0; 325 q->cstats.drop_len = 0; 326 } 327 return skb; 328 } 329 330 static void fq_codel_flow_purge(struct fq_codel_flow *flow) 331 { 332 rtnl_kfree_skbs(flow->head, flow->tail); 333 flow->head = NULL; 334 } 335 336 static void fq_codel_reset(struct Qdisc *sch) 337 { 338 struct fq_codel_sched_data *q = qdisc_priv(sch); 339 int i; 340 341 INIT_LIST_HEAD(&q->new_flows); 342 INIT_LIST_HEAD(&q->old_flows); 343 for (i = 0; i < q->flows_cnt; i++) { 344 struct fq_codel_flow *flow = q->flows + i; 345 346 fq_codel_flow_purge(flow); 347 INIT_LIST_HEAD(&flow->flowchain); 348 codel_vars_init(&flow->cvars); 349 } 350 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 351 sch->q.qlen = 0; 352 sch->qstats.backlog = 0; 353 q->memory_usage = 0; 354 } 355 356 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 357 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 358 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 359 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 360 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 361 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 362 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 363 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 364 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 365 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 366 }; 367 368 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt, 369 struct netlink_ext_ack *extack) 370 { 371 struct fq_codel_sched_data *q = qdisc_priv(sch); 372 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 373 int err; 374 375 if (!opt) 376 return -EINVAL; 377 378 err = nla_parse_nested_deprecated(tb, TCA_FQ_CODEL_MAX, opt, 379 fq_codel_policy, NULL); 380 if (err < 0) 381 return err; 382 if (tb[TCA_FQ_CODEL_FLOWS]) { 383 if (q->flows) 384 return -EINVAL; 385 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 386 if (!q->flows_cnt || 387 q->flows_cnt > 65536) 388 return -EINVAL; 389 } 390 sch_tree_lock(sch); 391 392 if (tb[TCA_FQ_CODEL_TARGET]) { 393 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 394 395 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 396 } 397 398 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 399 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 400 401 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 402 } 403 404 if (tb[TCA_FQ_CODEL_INTERVAL]) { 405 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 406 407 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 408 } 409 410 if (tb[TCA_FQ_CODEL_LIMIT]) 411 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 412 413 if (tb[TCA_FQ_CODEL_ECN]) 414 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 415 416 if (tb[TCA_FQ_CODEL_QUANTUM]) 417 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 418 419 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 420 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 421 422 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 423 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 424 425 while (sch->q.qlen > sch->limit || 426 q->memory_usage > q->memory_limit) { 427 struct sk_buff *skb = fq_codel_dequeue(sch); 428 429 q->cstats.drop_len += qdisc_pkt_len(skb); 430 rtnl_kfree_skbs(skb, skb); 431 q->cstats.drop_count++; 432 } 433 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 434 q->cstats.drop_count = 0; 435 q->cstats.drop_len = 0; 436 437 sch_tree_unlock(sch); 438 return 0; 439 } 440 441 static void fq_codel_destroy(struct Qdisc *sch) 442 { 443 struct fq_codel_sched_data *q = qdisc_priv(sch); 444 445 tcf_block_put(q->block); 446 kvfree(q->backlogs); 447 kvfree(q->flows); 448 } 449 450 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt, 451 struct netlink_ext_ack *extack) 452 { 453 struct fq_codel_sched_data *q = qdisc_priv(sch); 454 int i; 455 int err; 456 457 sch->limit = 10*1024; 458 q->flows_cnt = 1024; 459 q->memory_limit = 32 << 20; /* 32 MBytes */ 460 q->drop_batch_size = 64; 461 q->quantum = psched_mtu(qdisc_dev(sch)); 462 INIT_LIST_HEAD(&q->new_flows); 463 INIT_LIST_HEAD(&q->old_flows); 464 codel_params_init(&q->cparams); 465 codel_stats_init(&q->cstats); 466 q->cparams.ecn = true; 467 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 468 469 if (opt) { 470 err = fq_codel_change(sch, opt, extack); 471 if (err) 472 goto init_failure; 473 } 474 475 err = tcf_block_get(&q->block, &q->filter_list, sch, extack); 476 if (err) 477 goto init_failure; 478 479 if (!q->flows) { 480 q->flows = kvcalloc(q->flows_cnt, 481 sizeof(struct fq_codel_flow), 482 GFP_KERNEL); 483 if (!q->flows) { 484 err = -ENOMEM; 485 goto init_failure; 486 } 487 q->backlogs = kvcalloc(q->flows_cnt, sizeof(u32), GFP_KERNEL); 488 if (!q->backlogs) { 489 err = -ENOMEM; 490 goto alloc_failure; 491 } 492 for (i = 0; i < q->flows_cnt; i++) { 493 struct fq_codel_flow *flow = q->flows + i; 494 495 INIT_LIST_HEAD(&flow->flowchain); 496 codel_vars_init(&flow->cvars); 497 } 498 } 499 if (sch->limit >= 1) 500 sch->flags |= TCQ_F_CAN_BYPASS; 501 else 502 sch->flags &= ~TCQ_F_CAN_BYPASS; 503 return 0; 504 505 alloc_failure: 506 kvfree(q->flows); 507 q->flows = NULL; 508 init_failure: 509 q->flows_cnt = 0; 510 return err; 511 } 512 513 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 514 { 515 struct fq_codel_sched_data *q = qdisc_priv(sch); 516 struct nlattr *opts; 517 518 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 519 if (opts == NULL) 520 goto nla_put_failure; 521 522 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 523 codel_time_to_us(q->cparams.target)) || 524 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 525 sch->limit) || 526 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 527 codel_time_to_us(q->cparams.interval)) || 528 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 529 q->cparams.ecn) || 530 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 531 q->quantum) || 532 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 533 q->drop_batch_size) || 534 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 535 q->memory_limit) || 536 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 537 q->flows_cnt)) 538 goto nla_put_failure; 539 540 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 541 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 542 codel_time_to_us(q->cparams.ce_threshold))) 543 goto nla_put_failure; 544 545 return nla_nest_end(skb, opts); 546 547 nla_put_failure: 548 return -1; 549 } 550 551 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 552 { 553 struct fq_codel_sched_data *q = qdisc_priv(sch); 554 struct tc_fq_codel_xstats st = { 555 .type = TCA_FQ_CODEL_XSTATS_QDISC, 556 }; 557 struct list_head *pos; 558 559 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 560 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 561 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 562 st.qdisc_stats.new_flow_count = q->new_flow_count; 563 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 564 st.qdisc_stats.memory_usage = q->memory_usage; 565 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 566 567 sch_tree_lock(sch); 568 list_for_each(pos, &q->new_flows) 569 st.qdisc_stats.new_flows_len++; 570 571 list_for_each(pos, &q->old_flows) 572 st.qdisc_stats.old_flows_len++; 573 sch_tree_unlock(sch); 574 575 return gnet_stats_copy_app(d, &st, sizeof(st)); 576 } 577 578 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 579 { 580 return NULL; 581 } 582 583 static unsigned long fq_codel_find(struct Qdisc *sch, u32 classid) 584 { 585 return 0; 586 } 587 588 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 589 u32 classid) 590 { 591 return 0; 592 } 593 594 static void fq_codel_unbind(struct Qdisc *q, unsigned long cl) 595 { 596 } 597 598 static struct tcf_block *fq_codel_tcf_block(struct Qdisc *sch, unsigned long cl, 599 struct netlink_ext_ack *extack) 600 { 601 struct fq_codel_sched_data *q = qdisc_priv(sch); 602 603 if (cl) 604 return NULL; 605 return q->block; 606 } 607 608 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 609 struct sk_buff *skb, struct tcmsg *tcm) 610 { 611 tcm->tcm_handle |= TC_H_MIN(cl); 612 return 0; 613 } 614 615 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 616 struct gnet_dump *d) 617 { 618 struct fq_codel_sched_data *q = qdisc_priv(sch); 619 u32 idx = cl - 1; 620 struct gnet_stats_queue qs = { 0 }; 621 struct tc_fq_codel_xstats xstats; 622 623 if (idx < q->flows_cnt) { 624 const struct fq_codel_flow *flow = &q->flows[idx]; 625 const struct sk_buff *skb; 626 627 memset(&xstats, 0, sizeof(xstats)); 628 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 629 xstats.class_stats.deficit = flow->deficit; 630 xstats.class_stats.ldelay = 631 codel_time_to_us(flow->cvars.ldelay); 632 xstats.class_stats.count = flow->cvars.count; 633 xstats.class_stats.lastcount = flow->cvars.lastcount; 634 xstats.class_stats.dropping = flow->cvars.dropping; 635 if (flow->cvars.dropping) { 636 codel_tdiff_t delta = flow->cvars.drop_next - 637 codel_get_time(); 638 639 xstats.class_stats.drop_next = (delta >= 0) ? 640 codel_time_to_us(delta) : 641 -codel_time_to_us(-delta); 642 } 643 if (flow->head) { 644 sch_tree_lock(sch); 645 skb = flow->head; 646 while (skb) { 647 qs.qlen++; 648 skb = skb->next; 649 } 650 sch_tree_unlock(sch); 651 } 652 qs.backlog = q->backlogs[idx]; 653 qs.drops = 0; 654 } 655 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) 656 return -1; 657 if (idx < q->flows_cnt) 658 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 659 return 0; 660 } 661 662 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 663 { 664 struct fq_codel_sched_data *q = qdisc_priv(sch); 665 unsigned int i; 666 667 if (arg->stop) 668 return; 669 670 for (i = 0; i < q->flows_cnt; i++) { 671 if (list_empty(&q->flows[i].flowchain) || 672 arg->count < arg->skip) { 673 arg->count++; 674 continue; 675 } 676 if (arg->fn(sch, i + 1, arg) < 0) { 677 arg->stop = 1; 678 break; 679 } 680 arg->count++; 681 } 682 } 683 684 static const struct Qdisc_class_ops fq_codel_class_ops = { 685 .leaf = fq_codel_leaf, 686 .find = fq_codel_find, 687 .tcf_block = fq_codel_tcf_block, 688 .bind_tcf = fq_codel_bind, 689 .unbind_tcf = fq_codel_unbind, 690 .dump = fq_codel_dump_class, 691 .dump_stats = fq_codel_dump_class_stats, 692 .walk = fq_codel_walk, 693 }; 694 695 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = { 696 .cl_ops = &fq_codel_class_ops, 697 .id = "fq_codel", 698 .priv_size = sizeof(struct fq_codel_sched_data), 699 .enqueue = fq_codel_enqueue, 700 .dequeue = fq_codel_dequeue, 701 .peek = qdisc_peek_dequeued, 702 .init = fq_codel_init, 703 .reset = fq_codel_reset, 704 .destroy = fq_codel_destroy, 705 .change = fq_codel_change, 706 .dump = fq_codel_dump, 707 .dump_stats = fq_codel_dump_stats, 708 .owner = THIS_MODULE, 709 }; 710 711 static int __init fq_codel_module_init(void) 712 { 713 return register_qdisc(&fq_codel_qdisc_ops); 714 } 715 716 static void __exit fq_codel_module_exit(void) 717 { 718 unregister_qdisc(&fq_codel_qdisc_ops); 719 } 720 721 module_init(fq_codel_module_init) 722 module_exit(fq_codel_module_exit) 723 MODULE_AUTHOR("Eric Dumazet"); 724 MODULE_LICENSE("GPL"); 725