1 /* 2 * Fair Queue CoDel discipline 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation; either version 7 * 2 of the License, or (at your option) any later version. 8 * 9 * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> 10 */ 11 12 #include <linux/module.h> 13 #include <linux/types.h> 14 #include <linux/kernel.h> 15 #include <linux/jiffies.h> 16 #include <linux/string.h> 17 #include <linux/in.h> 18 #include <linux/errno.h> 19 #include <linux/init.h> 20 #include <linux/skbuff.h> 21 #include <linux/jhash.h> 22 #include <linux/slab.h> 23 #include <linux/vmalloc.h> 24 #include <net/netlink.h> 25 #include <net/pkt_sched.h> 26 #include <net/codel.h> 27 #include <net/codel_impl.h> 28 #include <net/codel_qdisc.h> 29 30 /* Fair Queue CoDel. 31 * 32 * Principles : 33 * Packets are classified (internal classifier or external) on flows. 34 * This is a Stochastic model (as we use a hash, several flows 35 * might be hashed on same slot) 36 * Each flow has a CoDel managed queue. 37 * Flows are linked onto two (Round Robin) lists, 38 * so that new flows have priority on old ones. 39 * 40 * For a given flow, packets are not reordered (CoDel uses a FIFO) 41 * head drops only. 42 * ECN capability is on by default. 43 * Low memory footprint (64 bytes per flow) 44 */ 45 46 struct fq_codel_flow { 47 struct sk_buff *head; 48 struct sk_buff *tail; 49 struct list_head flowchain; 50 int deficit; 51 u32 dropped; /* number of drops (or ECN marks) on this flow */ 52 struct codel_vars cvars; 53 }; /* please try to keep this structure <= 64 bytes */ 54 55 struct fq_codel_sched_data { 56 struct tcf_proto __rcu *filter_list; /* optional external classifier */ 57 struct fq_codel_flow *flows; /* Flows table [flows_cnt] */ 58 u32 *backlogs; /* backlog table [flows_cnt] */ 59 u32 flows_cnt; /* number of flows */ 60 u32 perturbation; /* hash perturbation */ 61 u32 quantum; /* psched_mtu(qdisc_dev(sch)); */ 62 u32 drop_batch_size; 63 u32 memory_limit; 64 struct codel_params cparams; 65 struct codel_stats cstats; 66 u32 memory_usage; 67 u32 drop_overmemory; 68 u32 drop_overlimit; 69 u32 new_flow_count; 70 71 struct list_head new_flows; /* list of new flows */ 72 struct list_head old_flows; /* list of old flows */ 73 }; 74 75 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q, 76 struct sk_buff *skb) 77 { 78 u32 hash = skb_get_hash_perturb(skb, q->perturbation); 79 80 return reciprocal_scale(hash, q->flows_cnt); 81 } 82 83 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, 84 int *qerr) 85 { 86 struct fq_codel_sched_data *q = qdisc_priv(sch); 87 struct tcf_proto *filter; 88 struct tcf_result res; 89 int result; 90 91 if (TC_H_MAJ(skb->priority) == sch->handle && 92 TC_H_MIN(skb->priority) > 0 && 93 TC_H_MIN(skb->priority) <= q->flows_cnt) 94 return TC_H_MIN(skb->priority); 95 96 filter = rcu_dereference_bh(q->filter_list); 97 if (!filter) 98 return fq_codel_hash(q, skb) + 1; 99 100 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 101 result = tc_classify(skb, filter, &res, false); 102 if (result >= 0) { 103 #ifdef CONFIG_NET_CLS_ACT 104 switch (result) { 105 case TC_ACT_STOLEN: 106 case TC_ACT_QUEUED: 107 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 108 case TC_ACT_SHOT: 109 return 0; 110 } 111 #endif 112 if (TC_H_MIN(res.classid) <= q->flows_cnt) 113 return TC_H_MIN(res.classid); 114 } 115 return 0; 116 } 117 118 /* helper functions : might be changed when/if skb use a standard list_head */ 119 120 /* remove one skb from head of slot queue */ 121 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow) 122 { 123 struct sk_buff *skb = flow->head; 124 125 flow->head = skb->next; 126 skb->next = NULL; 127 return skb; 128 } 129 130 /* add skb to flow queue (tail add) */ 131 static inline void flow_queue_add(struct fq_codel_flow *flow, 132 struct sk_buff *skb) 133 { 134 if (flow->head == NULL) 135 flow->head = skb; 136 else 137 flow->tail->next = skb; 138 flow->tail = skb; 139 skb->next = NULL; 140 } 141 142 static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets) 143 { 144 struct fq_codel_sched_data *q = qdisc_priv(sch); 145 struct sk_buff *skb; 146 unsigned int maxbacklog = 0, idx = 0, i, len; 147 struct fq_codel_flow *flow; 148 unsigned int threshold; 149 unsigned int mem = 0; 150 151 /* Queue is full! Find the fat flow and drop packet(s) from it. 152 * This might sound expensive, but with 1024 flows, we scan 153 * 4KB of memory, and we dont need to handle a complex tree 154 * in fast path (packet queue/enqueue) with many cache misses. 155 * In stress mode, we'll try to drop 64 packets from the flow, 156 * amortizing this linear lookup to one cache line per drop. 157 */ 158 for (i = 0; i < q->flows_cnt; i++) { 159 if (q->backlogs[i] > maxbacklog) { 160 maxbacklog = q->backlogs[i]; 161 idx = i; 162 } 163 } 164 165 /* Our goal is to drop half of this fat flow backlog */ 166 threshold = maxbacklog >> 1; 167 168 flow = &q->flows[idx]; 169 len = 0; 170 i = 0; 171 do { 172 skb = dequeue_head(flow); 173 len += qdisc_pkt_len(skb); 174 mem += skb->truesize; 175 kfree_skb(skb); 176 } while (++i < max_packets && len < threshold); 177 178 flow->dropped += i; 179 q->backlogs[idx] -= len; 180 q->memory_usage -= mem; 181 sch->qstats.drops += i; 182 sch->qstats.backlog -= len; 183 sch->q.qlen -= i; 184 return idx; 185 } 186 187 static unsigned int fq_codel_qdisc_drop(struct Qdisc *sch) 188 { 189 unsigned int prev_backlog; 190 191 prev_backlog = sch->qstats.backlog; 192 fq_codel_drop(sch, 1U); 193 return prev_backlog - sch->qstats.backlog; 194 } 195 196 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch) 197 { 198 struct fq_codel_sched_data *q = qdisc_priv(sch); 199 unsigned int idx, prev_backlog, prev_qlen; 200 struct fq_codel_flow *flow; 201 int uninitialized_var(ret); 202 bool memory_limited; 203 204 idx = fq_codel_classify(skb, sch, &ret); 205 if (idx == 0) { 206 if (ret & __NET_XMIT_BYPASS) 207 qdisc_qstats_drop(sch); 208 kfree_skb(skb); 209 return ret; 210 } 211 idx--; 212 213 codel_set_enqueue_time(skb); 214 flow = &q->flows[idx]; 215 flow_queue_add(flow, skb); 216 q->backlogs[idx] += qdisc_pkt_len(skb); 217 qdisc_qstats_backlog_inc(sch, skb); 218 219 if (list_empty(&flow->flowchain)) { 220 list_add_tail(&flow->flowchain, &q->new_flows); 221 q->new_flow_count++; 222 flow->deficit = q->quantum; 223 flow->dropped = 0; 224 } 225 q->memory_usage += skb->truesize; 226 memory_limited = q->memory_usage > q->memory_limit; 227 if (++sch->q.qlen <= sch->limit && !memory_limited) 228 return NET_XMIT_SUCCESS; 229 230 prev_backlog = sch->qstats.backlog; 231 prev_qlen = sch->q.qlen; 232 233 /* fq_codel_drop() is quite expensive, as it performs a linear search 234 * in q->backlogs[] to find a fat flow. 235 * So instead of dropping a single packet, drop half of its backlog 236 * with a 64 packets limit to not add a too big cpu spike here. 237 */ 238 ret = fq_codel_drop(sch, q->drop_batch_size); 239 240 q->drop_overlimit += prev_qlen - sch->q.qlen; 241 if (memory_limited) 242 q->drop_overmemory += prev_qlen - sch->q.qlen; 243 /* As we dropped packet(s), better let upper stack know this */ 244 qdisc_tree_reduce_backlog(sch, prev_qlen - sch->q.qlen, 245 prev_backlog - sch->qstats.backlog); 246 247 return ret == idx ? NET_XMIT_CN : NET_XMIT_SUCCESS; 248 } 249 250 /* This is the specific function called from codel_dequeue() 251 * to dequeue a packet from queue. Note: backlog is handled in 252 * codel, we dont need to reduce it here. 253 */ 254 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 255 { 256 struct Qdisc *sch = ctx; 257 struct fq_codel_sched_data *q = qdisc_priv(sch); 258 struct fq_codel_flow *flow; 259 struct sk_buff *skb = NULL; 260 261 flow = container_of(vars, struct fq_codel_flow, cvars); 262 if (flow->head) { 263 skb = dequeue_head(flow); 264 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 265 q->memory_usage -= skb->truesize; 266 sch->q.qlen--; 267 sch->qstats.backlog -= qdisc_pkt_len(skb); 268 } 269 return skb; 270 } 271 272 static void drop_func(struct sk_buff *skb, void *ctx) 273 { 274 struct Qdisc *sch = ctx; 275 276 qdisc_drop(skb, sch); 277 } 278 279 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 280 { 281 struct fq_codel_sched_data *q = qdisc_priv(sch); 282 struct sk_buff *skb; 283 struct fq_codel_flow *flow; 284 struct list_head *head; 285 u32 prev_drop_count, prev_ecn_mark; 286 unsigned int prev_backlog; 287 288 begin: 289 head = &q->new_flows; 290 if (list_empty(head)) { 291 head = &q->old_flows; 292 if (list_empty(head)) 293 return NULL; 294 } 295 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 296 297 if (flow->deficit <= 0) { 298 flow->deficit += q->quantum; 299 list_move_tail(&flow->flowchain, &q->old_flows); 300 goto begin; 301 } 302 303 prev_drop_count = q->cstats.drop_count; 304 prev_ecn_mark = q->cstats.ecn_mark; 305 prev_backlog = sch->qstats.backlog; 306 307 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 308 &flow->cvars, &q->cstats, qdisc_pkt_len, 309 codel_get_enqueue_time, drop_func, dequeue_func); 310 311 flow->dropped += q->cstats.drop_count - prev_drop_count; 312 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; 313 314 if (!skb) { 315 /* force a pass through old_flows to prevent starvation */ 316 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 317 list_move_tail(&flow->flowchain, &q->old_flows); 318 else 319 list_del_init(&flow->flowchain); 320 goto begin; 321 } 322 qdisc_bstats_update(sch, skb); 323 flow->deficit -= qdisc_pkt_len(skb); 324 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 325 * or HTB crashes. Defer it for next round. 326 */ 327 if (q->cstats.drop_count && sch->q.qlen) { 328 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 329 q->cstats.drop_len); 330 q->cstats.drop_count = 0; 331 q->cstats.drop_len = 0; 332 } 333 return skb; 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 while (flow->head) { 347 struct sk_buff *skb = dequeue_head(flow); 348 349 qdisc_qstats_backlog_dec(sch, skb); 350 kfree_skb(skb); 351 } 352 353 INIT_LIST_HEAD(&flow->flowchain); 354 codel_vars_init(&flow->cvars); 355 } 356 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 357 sch->q.qlen = 0; 358 q->memory_usage = 0; 359 } 360 361 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 362 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 363 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 364 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 365 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 366 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 367 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 368 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 369 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 370 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 371 }; 372 373 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt) 374 { 375 struct fq_codel_sched_data *q = qdisc_priv(sch); 376 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 377 int err; 378 379 if (!opt) 380 return -EINVAL; 381 382 err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy); 383 if (err < 0) 384 return err; 385 if (tb[TCA_FQ_CODEL_FLOWS]) { 386 if (q->flows) 387 return -EINVAL; 388 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 389 if (!q->flows_cnt || 390 q->flows_cnt > 65536) 391 return -EINVAL; 392 } 393 sch_tree_lock(sch); 394 395 if (tb[TCA_FQ_CODEL_TARGET]) { 396 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 397 398 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 399 } 400 401 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 402 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 403 404 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 405 } 406 407 if (tb[TCA_FQ_CODEL_INTERVAL]) { 408 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 409 410 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 411 } 412 413 if (tb[TCA_FQ_CODEL_LIMIT]) 414 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 415 416 if (tb[TCA_FQ_CODEL_ECN]) 417 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 418 419 if (tb[TCA_FQ_CODEL_QUANTUM]) 420 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 421 422 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 423 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 424 425 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 426 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 427 428 while (sch->q.qlen > sch->limit || 429 q->memory_usage > q->memory_limit) { 430 struct sk_buff *skb = fq_codel_dequeue(sch); 431 432 q->cstats.drop_len += qdisc_pkt_len(skb); 433 kfree_skb(skb); 434 q->cstats.drop_count++; 435 } 436 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 437 q->cstats.drop_count = 0; 438 q->cstats.drop_len = 0; 439 440 sch_tree_unlock(sch); 441 return 0; 442 } 443 444 static void *fq_codel_zalloc(size_t sz) 445 { 446 void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN); 447 448 if (!ptr) 449 ptr = vzalloc(sz); 450 return ptr; 451 } 452 453 static void fq_codel_free(void *addr) 454 { 455 kvfree(addr); 456 } 457 458 static void fq_codel_destroy(struct Qdisc *sch) 459 { 460 struct fq_codel_sched_data *q = qdisc_priv(sch); 461 462 tcf_destroy_chain(&q->filter_list); 463 fq_codel_free(q->backlogs); 464 fq_codel_free(q->flows); 465 } 466 467 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) 468 { 469 struct fq_codel_sched_data *q = qdisc_priv(sch); 470 int i; 471 472 sch->limit = 10*1024; 473 q->flows_cnt = 1024; 474 q->memory_limit = 32 << 20; /* 32 MBytes */ 475 q->drop_batch_size = 64; 476 q->quantum = psched_mtu(qdisc_dev(sch)); 477 q->perturbation = prandom_u32(); 478 INIT_LIST_HEAD(&q->new_flows); 479 INIT_LIST_HEAD(&q->old_flows); 480 codel_params_init(&q->cparams); 481 codel_stats_init(&q->cstats); 482 q->cparams.ecn = true; 483 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 484 485 if (opt) { 486 int err = fq_codel_change(sch, opt); 487 if (err) 488 return err; 489 } 490 491 if (!q->flows) { 492 q->flows = fq_codel_zalloc(q->flows_cnt * 493 sizeof(struct fq_codel_flow)); 494 if (!q->flows) 495 return -ENOMEM; 496 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32)); 497 if (!q->backlogs) { 498 fq_codel_free(q->flows); 499 return -ENOMEM; 500 } 501 for (i = 0; i < q->flows_cnt; i++) { 502 struct fq_codel_flow *flow = q->flows + i; 503 504 INIT_LIST_HEAD(&flow->flowchain); 505 codel_vars_init(&flow->cvars); 506 } 507 } 508 if (sch->limit >= 1) 509 sch->flags |= TCQ_F_CAN_BYPASS; 510 else 511 sch->flags &= ~TCQ_F_CAN_BYPASS; 512 return 0; 513 } 514 515 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 516 { 517 struct fq_codel_sched_data *q = qdisc_priv(sch); 518 struct nlattr *opts; 519 520 opts = nla_nest_start(skb, TCA_OPTIONS); 521 if (opts == NULL) 522 goto nla_put_failure; 523 524 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 525 codel_time_to_us(q->cparams.target)) || 526 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 527 sch->limit) || 528 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 529 codel_time_to_us(q->cparams.interval)) || 530 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 531 q->cparams.ecn) || 532 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 533 q->quantum) || 534 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 535 q->drop_batch_size) || 536 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 537 q->memory_limit) || 538 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 539 q->flows_cnt)) 540 goto nla_put_failure; 541 542 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 543 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 544 codel_time_to_us(q->cparams.ce_threshold))) 545 goto nla_put_failure; 546 547 return nla_nest_end(skb, opts); 548 549 nla_put_failure: 550 return -1; 551 } 552 553 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 554 { 555 struct fq_codel_sched_data *q = qdisc_priv(sch); 556 struct tc_fq_codel_xstats st = { 557 .type = TCA_FQ_CODEL_XSTATS_QDISC, 558 }; 559 struct list_head *pos; 560 561 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 562 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 563 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 564 st.qdisc_stats.new_flow_count = q->new_flow_count; 565 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 566 st.qdisc_stats.memory_usage = q->memory_usage; 567 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 568 569 list_for_each(pos, &q->new_flows) 570 st.qdisc_stats.new_flows_len++; 571 572 list_for_each(pos, &q->old_flows) 573 st.qdisc_stats.old_flows_len++; 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_get(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 /* we cannot bypass queue discipline anymore */ 592 sch->flags &= ~TCQ_F_CAN_BYPASS; 593 return 0; 594 } 595 596 static void fq_codel_put(struct Qdisc *q, unsigned long cl) 597 { 598 } 599 600 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch, 601 unsigned long cl) 602 { 603 struct fq_codel_sched_data *q = qdisc_priv(sch); 604 605 if (cl) 606 return NULL; 607 return &q->filter_list; 608 } 609 610 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 611 struct sk_buff *skb, struct tcmsg *tcm) 612 { 613 tcm->tcm_handle |= TC_H_MIN(cl); 614 return 0; 615 } 616 617 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 618 struct gnet_dump *d) 619 { 620 struct fq_codel_sched_data *q = qdisc_priv(sch); 621 u32 idx = cl - 1; 622 struct gnet_stats_queue qs = { 0 }; 623 struct tc_fq_codel_xstats xstats; 624 625 if (idx < q->flows_cnt) { 626 const struct fq_codel_flow *flow = &q->flows[idx]; 627 const struct sk_buff *skb = flow->head; 628 629 memset(&xstats, 0, sizeof(xstats)); 630 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 631 xstats.class_stats.deficit = flow->deficit; 632 xstats.class_stats.ldelay = 633 codel_time_to_us(flow->cvars.ldelay); 634 xstats.class_stats.count = flow->cvars.count; 635 xstats.class_stats.lastcount = flow->cvars.lastcount; 636 xstats.class_stats.dropping = flow->cvars.dropping; 637 if (flow->cvars.dropping) { 638 codel_tdiff_t delta = flow->cvars.drop_next - 639 codel_get_time(); 640 641 xstats.class_stats.drop_next = (delta >= 0) ? 642 codel_time_to_us(delta) : 643 -codel_time_to_us(-delta); 644 } 645 while (skb) { 646 qs.qlen++; 647 skb = skb->next; 648 } 649 qs.backlog = q->backlogs[idx]; 650 qs.drops = flow->dropped; 651 } 652 if (gnet_stats_copy_queue(d, NULL, &qs, 0) < 0) 653 return -1; 654 if (idx < q->flows_cnt) 655 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 656 return 0; 657 } 658 659 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 660 { 661 struct fq_codel_sched_data *q = qdisc_priv(sch); 662 unsigned int i; 663 664 if (arg->stop) 665 return; 666 667 for (i = 0; i < q->flows_cnt; i++) { 668 if (list_empty(&q->flows[i].flowchain) || 669 arg->count < arg->skip) { 670 arg->count++; 671 continue; 672 } 673 if (arg->fn(sch, i + 1, arg) < 0) { 674 arg->stop = 1; 675 break; 676 } 677 arg->count++; 678 } 679 } 680 681 static const struct Qdisc_class_ops fq_codel_class_ops = { 682 .leaf = fq_codel_leaf, 683 .get = fq_codel_get, 684 .put = fq_codel_put, 685 .tcf_chain = fq_codel_find_tcf, 686 .bind_tcf = fq_codel_bind, 687 .unbind_tcf = fq_codel_put, 688 .dump = fq_codel_dump_class, 689 .dump_stats = fq_codel_dump_class_stats, 690 .walk = fq_codel_walk, 691 }; 692 693 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = { 694 .cl_ops = &fq_codel_class_ops, 695 .id = "fq_codel", 696 .priv_size = sizeof(struct fq_codel_sched_data), 697 .enqueue = fq_codel_enqueue, 698 .dequeue = fq_codel_dequeue, 699 .peek = qdisc_peek_dequeued, 700 .drop = fq_codel_qdisc_drop, 701 .init = fq_codel_init, 702 .reset = fq_codel_reset, 703 .destroy = fq_codel_destroy, 704 .change = fq_codel_change, 705 .dump = fq_codel_dump, 706 .dump_stats = fq_codel_dump_stats, 707 .owner = THIS_MODULE, 708 }; 709 710 static int __init fq_codel_module_init(void) 711 { 712 return register_qdisc(&fq_codel_qdisc_ops); 713 } 714 715 static void __exit fq_codel_module_exit(void) 716 { 717 unregister_qdisc(&fq_codel_qdisc_ops); 718 } 719 720 module_init(fq_codel_module_init) 721 module_exit(fq_codel_module_exit) 722 MODULE_AUTHOR("Eric Dumazet"); 723 MODULE_LICENSE("GPL"); 724