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 unsigned int pkt_len; 203 bool memory_limited; 204 205 idx = fq_codel_classify(skb, sch, &ret); 206 if (idx == 0) { 207 if (ret & __NET_XMIT_BYPASS) 208 qdisc_qstats_drop(sch); 209 kfree_skb(skb); 210 return ret; 211 } 212 idx--; 213 214 codel_set_enqueue_time(skb); 215 flow = &q->flows[idx]; 216 flow_queue_add(flow, skb); 217 q->backlogs[idx] += qdisc_pkt_len(skb); 218 qdisc_qstats_backlog_inc(sch, skb); 219 220 if (list_empty(&flow->flowchain)) { 221 list_add_tail(&flow->flowchain, &q->new_flows); 222 q->new_flow_count++; 223 flow->deficit = q->quantum; 224 flow->dropped = 0; 225 } 226 q->memory_usage += skb->truesize; 227 memory_limited = q->memory_usage > q->memory_limit; 228 if (++sch->q.qlen <= sch->limit && !memory_limited) 229 return NET_XMIT_SUCCESS; 230 231 prev_backlog = sch->qstats.backlog; 232 prev_qlen = sch->q.qlen; 233 234 /* save this packet length as it might be dropped by fq_codel_drop() */ 235 pkt_len = qdisc_pkt_len(skb); 236 /* fq_codel_drop() is quite expensive, as it performs a linear search 237 * in q->backlogs[] to find a fat flow. 238 * So instead of dropping a single packet, drop half of its backlog 239 * with a 64 packets limit to not add a too big cpu spike here. 240 */ 241 ret = fq_codel_drop(sch, q->drop_batch_size); 242 243 prev_qlen -= sch->q.qlen; 244 prev_backlog -= sch->qstats.backlog; 245 q->drop_overlimit += prev_qlen; 246 if (memory_limited) 247 q->drop_overmemory += prev_qlen; 248 249 /* As we dropped packet(s), better let upper stack know this. 250 * If we dropped a packet for this flow, return NET_XMIT_CN, 251 * but in this case, our parents wont increase their backlogs. 252 */ 253 if (ret == idx) { 254 qdisc_tree_reduce_backlog(sch, prev_qlen - 1, 255 prev_backlog - pkt_len); 256 return NET_XMIT_CN; 257 } 258 qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); 259 return NET_XMIT_SUCCESS; 260 } 261 262 /* This is the specific function called from codel_dequeue() 263 * to dequeue a packet from queue. Note: backlog is handled in 264 * codel, we dont need to reduce it here. 265 */ 266 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 267 { 268 struct Qdisc *sch = ctx; 269 struct fq_codel_sched_data *q = qdisc_priv(sch); 270 struct fq_codel_flow *flow; 271 struct sk_buff *skb = NULL; 272 273 flow = container_of(vars, struct fq_codel_flow, cvars); 274 if (flow->head) { 275 skb = dequeue_head(flow); 276 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 277 q->memory_usage -= skb->truesize; 278 sch->q.qlen--; 279 sch->qstats.backlog -= qdisc_pkt_len(skb); 280 } 281 return skb; 282 } 283 284 static void drop_func(struct sk_buff *skb, void *ctx) 285 { 286 struct Qdisc *sch = ctx; 287 288 qdisc_drop(skb, sch); 289 } 290 291 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 292 { 293 struct fq_codel_sched_data *q = qdisc_priv(sch); 294 struct sk_buff *skb; 295 struct fq_codel_flow *flow; 296 struct list_head *head; 297 u32 prev_drop_count, prev_ecn_mark; 298 unsigned int prev_backlog; 299 300 begin: 301 head = &q->new_flows; 302 if (list_empty(head)) { 303 head = &q->old_flows; 304 if (list_empty(head)) 305 return NULL; 306 } 307 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 308 309 if (flow->deficit <= 0) { 310 flow->deficit += q->quantum; 311 list_move_tail(&flow->flowchain, &q->old_flows); 312 goto begin; 313 } 314 315 prev_drop_count = q->cstats.drop_count; 316 prev_ecn_mark = q->cstats.ecn_mark; 317 prev_backlog = sch->qstats.backlog; 318 319 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 320 &flow->cvars, &q->cstats, qdisc_pkt_len, 321 codel_get_enqueue_time, drop_func, dequeue_func); 322 323 flow->dropped += q->cstats.drop_count - prev_drop_count; 324 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; 325 326 if (!skb) { 327 /* force a pass through old_flows to prevent starvation */ 328 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 329 list_move_tail(&flow->flowchain, &q->old_flows); 330 else 331 list_del_init(&flow->flowchain); 332 goto begin; 333 } 334 qdisc_bstats_update(sch, skb); 335 flow->deficit -= qdisc_pkt_len(skb); 336 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 337 * or HTB crashes. Defer it for next round. 338 */ 339 if (q->cstats.drop_count && sch->q.qlen) { 340 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 341 q->cstats.drop_len); 342 q->cstats.drop_count = 0; 343 q->cstats.drop_len = 0; 344 } 345 return skb; 346 } 347 348 static void fq_codel_reset(struct Qdisc *sch) 349 { 350 struct fq_codel_sched_data *q = qdisc_priv(sch); 351 int i; 352 353 INIT_LIST_HEAD(&q->new_flows); 354 INIT_LIST_HEAD(&q->old_flows); 355 for (i = 0; i < q->flows_cnt; i++) { 356 struct fq_codel_flow *flow = q->flows + i; 357 358 while (flow->head) { 359 struct sk_buff *skb = dequeue_head(flow); 360 361 qdisc_qstats_backlog_dec(sch, skb); 362 kfree_skb(skb); 363 } 364 365 INIT_LIST_HEAD(&flow->flowchain); 366 codel_vars_init(&flow->cvars); 367 } 368 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 369 sch->q.qlen = 0; 370 q->memory_usage = 0; 371 } 372 373 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 374 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 375 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 376 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 377 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 378 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 379 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 380 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 381 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 382 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 383 }; 384 385 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt) 386 { 387 struct fq_codel_sched_data *q = qdisc_priv(sch); 388 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 389 int err; 390 391 if (!opt) 392 return -EINVAL; 393 394 err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy); 395 if (err < 0) 396 return err; 397 if (tb[TCA_FQ_CODEL_FLOWS]) { 398 if (q->flows) 399 return -EINVAL; 400 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 401 if (!q->flows_cnt || 402 q->flows_cnt > 65536) 403 return -EINVAL; 404 } 405 sch_tree_lock(sch); 406 407 if (tb[TCA_FQ_CODEL_TARGET]) { 408 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 409 410 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 411 } 412 413 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 414 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 415 416 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 417 } 418 419 if (tb[TCA_FQ_CODEL_INTERVAL]) { 420 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 421 422 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 423 } 424 425 if (tb[TCA_FQ_CODEL_LIMIT]) 426 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 427 428 if (tb[TCA_FQ_CODEL_ECN]) 429 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 430 431 if (tb[TCA_FQ_CODEL_QUANTUM]) 432 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 433 434 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 435 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 436 437 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 438 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 439 440 while (sch->q.qlen > sch->limit || 441 q->memory_usage > q->memory_limit) { 442 struct sk_buff *skb = fq_codel_dequeue(sch); 443 444 q->cstats.drop_len += qdisc_pkt_len(skb); 445 kfree_skb(skb); 446 q->cstats.drop_count++; 447 } 448 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 449 q->cstats.drop_count = 0; 450 q->cstats.drop_len = 0; 451 452 sch_tree_unlock(sch); 453 return 0; 454 } 455 456 static void *fq_codel_zalloc(size_t sz) 457 { 458 void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN); 459 460 if (!ptr) 461 ptr = vzalloc(sz); 462 return ptr; 463 } 464 465 static void fq_codel_free(void *addr) 466 { 467 kvfree(addr); 468 } 469 470 static void fq_codel_destroy(struct Qdisc *sch) 471 { 472 struct fq_codel_sched_data *q = qdisc_priv(sch); 473 474 tcf_destroy_chain(&q->filter_list); 475 fq_codel_free(q->backlogs); 476 fq_codel_free(q->flows); 477 } 478 479 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) 480 { 481 struct fq_codel_sched_data *q = qdisc_priv(sch); 482 int i; 483 484 sch->limit = 10*1024; 485 q->flows_cnt = 1024; 486 q->memory_limit = 32 << 20; /* 32 MBytes */ 487 q->drop_batch_size = 64; 488 q->quantum = psched_mtu(qdisc_dev(sch)); 489 q->perturbation = prandom_u32(); 490 INIT_LIST_HEAD(&q->new_flows); 491 INIT_LIST_HEAD(&q->old_flows); 492 codel_params_init(&q->cparams); 493 codel_stats_init(&q->cstats); 494 q->cparams.ecn = true; 495 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 496 497 if (opt) { 498 int err = fq_codel_change(sch, opt); 499 if (err) 500 return err; 501 } 502 503 if (!q->flows) { 504 q->flows = fq_codel_zalloc(q->flows_cnt * 505 sizeof(struct fq_codel_flow)); 506 if (!q->flows) 507 return -ENOMEM; 508 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32)); 509 if (!q->backlogs) { 510 fq_codel_free(q->flows); 511 return -ENOMEM; 512 } 513 for (i = 0; i < q->flows_cnt; i++) { 514 struct fq_codel_flow *flow = q->flows + i; 515 516 INIT_LIST_HEAD(&flow->flowchain); 517 codel_vars_init(&flow->cvars); 518 } 519 } 520 if (sch->limit >= 1) 521 sch->flags |= TCQ_F_CAN_BYPASS; 522 else 523 sch->flags &= ~TCQ_F_CAN_BYPASS; 524 return 0; 525 } 526 527 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 528 { 529 struct fq_codel_sched_data *q = qdisc_priv(sch); 530 struct nlattr *opts; 531 532 opts = nla_nest_start(skb, TCA_OPTIONS); 533 if (opts == NULL) 534 goto nla_put_failure; 535 536 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 537 codel_time_to_us(q->cparams.target)) || 538 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 539 sch->limit) || 540 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 541 codel_time_to_us(q->cparams.interval)) || 542 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 543 q->cparams.ecn) || 544 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 545 q->quantum) || 546 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 547 q->drop_batch_size) || 548 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 549 q->memory_limit) || 550 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 551 q->flows_cnt)) 552 goto nla_put_failure; 553 554 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 555 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 556 codel_time_to_us(q->cparams.ce_threshold))) 557 goto nla_put_failure; 558 559 return nla_nest_end(skb, opts); 560 561 nla_put_failure: 562 return -1; 563 } 564 565 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 566 { 567 struct fq_codel_sched_data *q = qdisc_priv(sch); 568 struct tc_fq_codel_xstats st = { 569 .type = TCA_FQ_CODEL_XSTATS_QDISC, 570 }; 571 struct list_head *pos; 572 573 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 574 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 575 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 576 st.qdisc_stats.new_flow_count = q->new_flow_count; 577 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 578 st.qdisc_stats.memory_usage = q->memory_usage; 579 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 580 581 list_for_each(pos, &q->new_flows) 582 st.qdisc_stats.new_flows_len++; 583 584 list_for_each(pos, &q->old_flows) 585 st.qdisc_stats.old_flows_len++; 586 587 return gnet_stats_copy_app(d, &st, sizeof(st)); 588 } 589 590 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 591 { 592 return NULL; 593 } 594 595 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid) 596 { 597 return 0; 598 } 599 600 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 601 u32 classid) 602 { 603 /* we cannot bypass queue discipline anymore */ 604 sch->flags &= ~TCQ_F_CAN_BYPASS; 605 return 0; 606 } 607 608 static void fq_codel_put(struct Qdisc *q, unsigned long cl) 609 { 610 } 611 612 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch, 613 unsigned long cl) 614 { 615 struct fq_codel_sched_data *q = qdisc_priv(sch); 616 617 if (cl) 618 return NULL; 619 return &q->filter_list; 620 } 621 622 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 623 struct sk_buff *skb, struct tcmsg *tcm) 624 { 625 tcm->tcm_handle |= TC_H_MIN(cl); 626 return 0; 627 } 628 629 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 630 struct gnet_dump *d) 631 { 632 struct fq_codel_sched_data *q = qdisc_priv(sch); 633 u32 idx = cl - 1; 634 struct gnet_stats_queue qs = { 0 }; 635 struct tc_fq_codel_xstats xstats; 636 637 if (idx < q->flows_cnt) { 638 const struct fq_codel_flow *flow = &q->flows[idx]; 639 const struct sk_buff *skb = flow->head; 640 641 memset(&xstats, 0, sizeof(xstats)); 642 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 643 xstats.class_stats.deficit = flow->deficit; 644 xstats.class_stats.ldelay = 645 codel_time_to_us(flow->cvars.ldelay); 646 xstats.class_stats.count = flow->cvars.count; 647 xstats.class_stats.lastcount = flow->cvars.lastcount; 648 xstats.class_stats.dropping = flow->cvars.dropping; 649 if (flow->cvars.dropping) { 650 codel_tdiff_t delta = flow->cvars.drop_next - 651 codel_get_time(); 652 653 xstats.class_stats.drop_next = (delta >= 0) ? 654 codel_time_to_us(delta) : 655 -codel_time_to_us(-delta); 656 } 657 while (skb) { 658 qs.qlen++; 659 skb = skb->next; 660 } 661 qs.backlog = q->backlogs[idx]; 662 qs.drops = flow->dropped; 663 } 664 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) 665 return -1; 666 if (idx < q->flows_cnt) 667 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 668 return 0; 669 } 670 671 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 672 { 673 struct fq_codel_sched_data *q = qdisc_priv(sch); 674 unsigned int i; 675 676 if (arg->stop) 677 return; 678 679 for (i = 0; i < q->flows_cnt; i++) { 680 if (list_empty(&q->flows[i].flowchain) || 681 arg->count < arg->skip) { 682 arg->count++; 683 continue; 684 } 685 if (arg->fn(sch, i + 1, arg) < 0) { 686 arg->stop = 1; 687 break; 688 } 689 arg->count++; 690 } 691 } 692 693 static const struct Qdisc_class_ops fq_codel_class_ops = { 694 .leaf = fq_codel_leaf, 695 .get = fq_codel_get, 696 .put = fq_codel_put, 697 .tcf_chain = fq_codel_find_tcf, 698 .bind_tcf = fq_codel_bind, 699 .unbind_tcf = fq_codel_put, 700 .dump = fq_codel_dump_class, 701 .dump_stats = fq_codel_dump_class_stats, 702 .walk = fq_codel_walk, 703 }; 704 705 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = { 706 .cl_ops = &fq_codel_class_ops, 707 .id = "fq_codel", 708 .priv_size = sizeof(struct fq_codel_sched_data), 709 .enqueue = fq_codel_enqueue, 710 .dequeue = fq_codel_dequeue, 711 .peek = qdisc_peek_dequeued, 712 .drop = fq_codel_qdisc_drop, 713 .init = fq_codel_init, 714 .reset = fq_codel_reset, 715 .destroy = fq_codel_destroy, 716 .change = fq_codel_change, 717 .dump = fq_codel_dump, 718 .dump_stats = fq_codel_dump_stats, 719 .owner = THIS_MODULE, 720 }; 721 722 static int __init fq_codel_module_init(void) 723 { 724 return register_qdisc(&fq_codel_qdisc_ops); 725 } 726 727 static void __exit fq_codel_module_exit(void) 728 { 729 unregister_qdisc(&fq_codel_qdisc_ops); 730 } 731 732 module_init(fq_codel_module_init) 733 module_exit(fq_codel_module_exit) 734 MODULE_AUTHOR("Eric Dumazet"); 735 MODULE_LICENSE("GPL"); 736