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 struct sk_buff **to_free) 144 { 145 struct fq_codel_sched_data *q = qdisc_priv(sch); 146 struct sk_buff *skb; 147 unsigned int maxbacklog = 0, idx = 0, i, len; 148 struct fq_codel_flow *flow; 149 unsigned int threshold; 150 unsigned int mem = 0; 151 152 /* Queue is full! Find the fat flow and drop packet(s) from it. 153 * This might sound expensive, but with 1024 flows, we scan 154 * 4KB of memory, and we dont need to handle a complex tree 155 * in fast path (packet queue/enqueue) with many cache misses. 156 * In stress mode, we'll try to drop 64 packets from the flow, 157 * amortizing this linear lookup to one cache line per drop. 158 */ 159 for (i = 0; i < q->flows_cnt; i++) { 160 if (q->backlogs[i] > maxbacklog) { 161 maxbacklog = q->backlogs[i]; 162 idx = i; 163 } 164 } 165 166 /* Our goal is to drop half of this fat flow backlog */ 167 threshold = maxbacklog >> 1; 168 169 flow = &q->flows[idx]; 170 len = 0; 171 i = 0; 172 do { 173 skb = dequeue_head(flow); 174 len += qdisc_pkt_len(skb); 175 mem += get_codel_cb(skb)->mem_usage; 176 __qdisc_drop(skb, to_free); 177 } while (++i < max_packets && len < threshold); 178 179 flow->dropped += i; 180 q->backlogs[idx] -= len; 181 q->memory_usage -= mem; 182 sch->qstats.drops += i; 183 sch->qstats.backlog -= len; 184 sch->q.qlen -= i; 185 return idx; 186 } 187 188 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, 189 struct sk_buff **to_free) 190 { 191 struct fq_codel_sched_data *q = qdisc_priv(sch); 192 unsigned int idx, prev_backlog, prev_qlen; 193 struct fq_codel_flow *flow; 194 int uninitialized_var(ret); 195 unsigned int pkt_len; 196 bool memory_limited; 197 198 idx = fq_codel_classify(skb, sch, &ret); 199 if (idx == 0) { 200 if (ret & __NET_XMIT_BYPASS) 201 qdisc_qstats_drop(sch); 202 __qdisc_drop(skb, to_free); 203 return ret; 204 } 205 idx--; 206 207 codel_set_enqueue_time(skb); 208 flow = &q->flows[idx]; 209 flow_queue_add(flow, skb); 210 q->backlogs[idx] += qdisc_pkt_len(skb); 211 qdisc_qstats_backlog_inc(sch, skb); 212 213 if (list_empty(&flow->flowchain)) { 214 list_add_tail(&flow->flowchain, &q->new_flows); 215 q->new_flow_count++; 216 flow->deficit = q->quantum; 217 flow->dropped = 0; 218 } 219 get_codel_cb(skb)->mem_usage = skb->truesize; 220 q->memory_usage += get_codel_cb(skb)->mem_usage; 221 memory_limited = q->memory_usage > q->memory_limit; 222 if (++sch->q.qlen <= sch->limit && !memory_limited) 223 return NET_XMIT_SUCCESS; 224 225 prev_backlog = sch->qstats.backlog; 226 prev_qlen = sch->q.qlen; 227 228 /* save this packet length as it might be dropped by fq_codel_drop() */ 229 pkt_len = qdisc_pkt_len(skb); 230 /* fq_codel_drop() is quite expensive, as it performs a linear search 231 * in q->backlogs[] to find a fat flow. 232 * So instead of dropping a single packet, drop half of its backlog 233 * with a 64 packets limit to not add a too big cpu spike here. 234 */ 235 ret = fq_codel_drop(sch, q->drop_batch_size, to_free); 236 237 prev_qlen -= sch->q.qlen; 238 prev_backlog -= sch->qstats.backlog; 239 q->drop_overlimit += prev_qlen; 240 if (memory_limited) 241 q->drop_overmemory += prev_qlen; 242 243 /* As we dropped packet(s), better let upper stack know this. 244 * If we dropped a packet for this flow, return NET_XMIT_CN, 245 * but in this case, our parents wont increase their backlogs. 246 */ 247 if (ret == idx) { 248 qdisc_tree_reduce_backlog(sch, prev_qlen - 1, 249 prev_backlog - pkt_len); 250 return NET_XMIT_CN; 251 } 252 qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); 253 return NET_XMIT_SUCCESS; 254 } 255 256 /* This is the specific function called from codel_dequeue() 257 * to dequeue a packet from queue. Note: backlog is handled in 258 * codel, we dont need to reduce it here. 259 */ 260 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 261 { 262 struct Qdisc *sch = ctx; 263 struct fq_codel_sched_data *q = qdisc_priv(sch); 264 struct fq_codel_flow *flow; 265 struct sk_buff *skb = NULL; 266 267 flow = container_of(vars, struct fq_codel_flow, cvars); 268 if (flow->head) { 269 skb = dequeue_head(flow); 270 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 271 q->memory_usage -= get_codel_cb(skb)->mem_usage; 272 sch->q.qlen--; 273 sch->qstats.backlog -= qdisc_pkt_len(skb); 274 } 275 return skb; 276 } 277 278 static void drop_func(struct sk_buff *skb, void *ctx) 279 { 280 struct Qdisc *sch = ctx; 281 282 kfree_skb(skb); 283 qdisc_qstats_drop(sch); 284 } 285 286 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 287 { 288 struct fq_codel_sched_data *q = qdisc_priv(sch); 289 struct sk_buff *skb; 290 struct fq_codel_flow *flow; 291 struct list_head *head; 292 u32 prev_drop_count, prev_ecn_mark; 293 unsigned int prev_backlog; 294 295 begin: 296 head = &q->new_flows; 297 if (list_empty(head)) { 298 head = &q->old_flows; 299 if (list_empty(head)) 300 return NULL; 301 } 302 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 303 304 if (flow->deficit <= 0) { 305 flow->deficit += q->quantum; 306 list_move_tail(&flow->flowchain, &q->old_flows); 307 goto begin; 308 } 309 310 prev_drop_count = q->cstats.drop_count; 311 prev_ecn_mark = q->cstats.ecn_mark; 312 prev_backlog = sch->qstats.backlog; 313 314 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 315 &flow->cvars, &q->cstats, qdisc_pkt_len, 316 codel_get_enqueue_time, drop_func, dequeue_func); 317 318 flow->dropped += q->cstats.drop_count - prev_drop_count; 319 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; 320 321 if (!skb) { 322 /* force a pass through old_flows to prevent starvation */ 323 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 324 list_move_tail(&flow->flowchain, &q->old_flows); 325 else 326 list_del_init(&flow->flowchain); 327 goto begin; 328 } 329 qdisc_bstats_update(sch, skb); 330 flow->deficit -= qdisc_pkt_len(skb); 331 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 332 * or HTB crashes. Defer it for next round. 333 */ 334 if (q->cstats.drop_count && sch->q.qlen) { 335 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 336 q->cstats.drop_len); 337 q->cstats.drop_count = 0; 338 q->cstats.drop_len = 0; 339 } 340 return skb; 341 } 342 343 static void fq_codel_flow_purge(struct fq_codel_flow *flow) 344 { 345 rtnl_kfree_skbs(flow->head, flow->tail); 346 flow->head = NULL; 347 } 348 349 static void fq_codel_reset(struct Qdisc *sch) 350 { 351 struct fq_codel_sched_data *q = qdisc_priv(sch); 352 int i; 353 354 INIT_LIST_HEAD(&q->new_flows); 355 INIT_LIST_HEAD(&q->old_flows); 356 for (i = 0; i < q->flows_cnt; i++) { 357 struct fq_codel_flow *flow = q->flows + i; 358 359 fq_codel_flow_purge(flow); 360 INIT_LIST_HEAD(&flow->flowchain); 361 codel_vars_init(&flow->cvars); 362 } 363 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 364 sch->q.qlen = 0; 365 sch->qstats.backlog = 0; 366 q->memory_usage = 0; 367 } 368 369 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 370 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 371 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 372 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 373 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 374 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 375 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 376 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 377 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 378 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 379 }; 380 381 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt) 382 { 383 struct fq_codel_sched_data *q = qdisc_priv(sch); 384 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 385 int err; 386 387 if (!opt) 388 return -EINVAL; 389 390 err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy); 391 if (err < 0) 392 return err; 393 if (tb[TCA_FQ_CODEL_FLOWS]) { 394 if (q->flows) 395 return -EINVAL; 396 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 397 if (!q->flows_cnt || 398 q->flows_cnt > 65536) 399 return -EINVAL; 400 } 401 sch_tree_lock(sch); 402 403 if (tb[TCA_FQ_CODEL_TARGET]) { 404 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 405 406 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 407 } 408 409 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 410 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 411 412 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 413 } 414 415 if (tb[TCA_FQ_CODEL_INTERVAL]) { 416 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 417 418 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 419 } 420 421 if (tb[TCA_FQ_CODEL_LIMIT]) 422 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 423 424 if (tb[TCA_FQ_CODEL_ECN]) 425 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 426 427 if (tb[TCA_FQ_CODEL_QUANTUM]) 428 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 429 430 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 431 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 432 433 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 434 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 435 436 while (sch->q.qlen > sch->limit || 437 q->memory_usage > q->memory_limit) { 438 struct sk_buff *skb = fq_codel_dequeue(sch); 439 440 q->cstats.drop_len += qdisc_pkt_len(skb); 441 rtnl_kfree_skbs(skb, skb); 442 q->cstats.drop_count++; 443 } 444 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 445 q->cstats.drop_count = 0; 446 q->cstats.drop_len = 0; 447 448 sch_tree_unlock(sch); 449 return 0; 450 } 451 452 static void *fq_codel_zalloc(size_t sz) 453 { 454 void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN); 455 456 if (!ptr) 457 ptr = vzalloc(sz); 458 return ptr; 459 } 460 461 static void fq_codel_free(void *addr) 462 { 463 kvfree(addr); 464 } 465 466 static void fq_codel_destroy(struct Qdisc *sch) 467 { 468 struct fq_codel_sched_data *q = qdisc_priv(sch); 469 470 tcf_destroy_chain(&q->filter_list); 471 fq_codel_free(q->backlogs); 472 fq_codel_free(q->flows); 473 } 474 475 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) 476 { 477 struct fq_codel_sched_data *q = qdisc_priv(sch); 478 int i; 479 480 sch->limit = 10*1024; 481 q->flows_cnt = 1024; 482 q->memory_limit = 32 << 20; /* 32 MBytes */ 483 q->drop_batch_size = 64; 484 q->quantum = psched_mtu(qdisc_dev(sch)); 485 q->perturbation = prandom_u32(); 486 INIT_LIST_HEAD(&q->new_flows); 487 INIT_LIST_HEAD(&q->old_flows); 488 codel_params_init(&q->cparams); 489 codel_stats_init(&q->cstats); 490 q->cparams.ecn = true; 491 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 492 493 if (opt) { 494 int err = fq_codel_change(sch, opt); 495 if (err) 496 return err; 497 } 498 499 if (!q->flows) { 500 q->flows = fq_codel_zalloc(q->flows_cnt * 501 sizeof(struct fq_codel_flow)); 502 if (!q->flows) 503 return -ENOMEM; 504 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32)); 505 if (!q->backlogs) { 506 fq_codel_free(q->flows); 507 return -ENOMEM; 508 } 509 for (i = 0; i < q->flows_cnt; i++) { 510 struct fq_codel_flow *flow = q->flows + i; 511 512 INIT_LIST_HEAD(&flow->flowchain); 513 codel_vars_init(&flow->cvars); 514 } 515 } 516 if (sch->limit >= 1) 517 sch->flags |= TCQ_F_CAN_BYPASS; 518 else 519 sch->flags &= ~TCQ_F_CAN_BYPASS; 520 return 0; 521 } 522 523 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 524 { 525 struct fq_codel_sched_data *q = qdisc_priv(sch); 526 struct nlattr *opts; 527 528 opts = nla_nest_start(skb, TCA_OPTIONS); 529 if (opts == NULL) 530 goto nla_put_failure; 531 532 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 533 codel_time_to_us(q->cparams.target)) || 534 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 535 sch->limit) || 536 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 537 codel_time_to_us(q->cparams.interval)) || 538 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 539 q->cparams.ecn) || 540 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 541 q->quantum) || 542 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 543 q->drop_batch_size) || 544 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 545 q->memory_limit) || 546 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 547 q->flows_cnt)) 548 goto nla_put_failure; 549 550 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 551 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 552 codel_time_to_us(q->cparams.ce_threshold))) 553 goto nla_put_failure; 554 555 return nla_nest_end(skb, opts); 556 557 nla_put_failure: 558 return -1; 559 } 560 561 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 562 { 563 struct fq_codel_sched_data *q = qdisc_priv(sch); 564 struct tc_fq_codel_xstats st = { 565 .type = TCA_FQ_CODEL_XSTATS_QDISC, 566 }; 567 struct list_head *pos; 568 569 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 570 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 571 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 572 st.qdisc_stats.new_flow_count = q->new_flow_count; 573 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 574 st.qdisc_stats.memory_usage = q->memory_usage; 575 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 576 577 sch_tree_lock(sch); 578 list_for_each(pos, &q->new_flows) 579 st.qdisc_stats.new_flows_len++; 580 581 list_for_each(pos, &q->old_flows) 582 st.qdisc_stats.old_flows_len++; 583 sch_tree_unlock(sch); 584 585 return gnet_stats_copy_app(d, &st, sizeof(st)); 586 } 587 588 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 589 { 590 return NULL; 591 } 592 593 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid) 594 { 595 return 0; 596 } 597 598 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 599 u32 classid) 600 { 601 /* we cannot bypass queue discipline anymore */ 602 sch->flags &= ~TCQ_F_CAN_BYPASS; 603 return 0; 604 } 605 606 static void fq_codel_put(struct Qdisc *q, unsigned long cl) 607 { 608 } 609 610 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch, 611 unsigned long cl) 612 { 613 struct fq_codel_sched_data *q = qdisc_priv(sch); 614 615 if (cl) 616 return NULL; 617 return &q->filter_list; 618 } 619 620 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 621 struct sk_buff *skb, struct tcmsg *tcm) 622 { 623 tcm->tcm_handle |= TC_H_MIN(cl); 624 return 0; 625 } 626 627 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 628 struct gnet_dump *d) 629 { 630 struct fq_codel_sched_data *q = qdisc_priv(sch); 631 u32 idx = cl - 1; 632 struct gnet_stats_queue qs = { 0 }; 633 struct tc_fq_codel_xstats xstats; 634 635 if (idx < q->flows_cnt) { 636 const struct fq_codel_flow *flow = &q->flows[idx]; 637 const struct sk_buff *skb; 638 639 memset(&xstats, 0, sizeof(xstats)); 640 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 641 xstats.class_stats.deficit = flow->deficit; 642 xstats.class_stats.ldelay = 643 codel_time_to_us(flow->cvars.ldelay); 644 xstats.class_stats.count = flow->cvars.count; 645 xstats.class_stats.lastcount = flow->cvars.lastcount; 646 xstats.class_stats.dropping = flow->cvars.dropping; 647 if (flow->cvars.dropping) { 648 codel_tdiff_t delta = flow->cvars.drop_next - 649 codel_get_time(); 650 651 xstats.class_stats.drop_next = (delta >= 0) ? 652 codel_time_to_us(delta) : 653 -codel_time_to_us(-delta); 654 } 655 if (flow->head) { 656 sch_tree_lock(sch); 657 skb = flow->head; 658 while (skb) { 659 qs.qlen++; 660 skb = skb->next; 661 } 662 sch_tree_unlock(sch); 663 } 664 qs.backlog = q->backlogs[idx]; 665 qs.drops = flow->dropped; 666 } 667 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) 668 return -1; 669 if (idx < q->flows_cnt) 670 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 671 return 0; 672 } 673 674 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 675 { 676 struct fq_codel_sched_data *q = qdisc_priv(sch); 677 unsigned int i; 678 679 if (arg->stop) 680 return; 681 682 for (i = 0; i < q->flows_cnt; i++) { 683 if (list_empty(&q->flows[i].flowchain) || 684 arg->count < arg->skip) { 685 arg->count++; 686 continue; 687 } 688 if (arg->fn(sch, i + 1, arg) < 0) { 689 arg->stop = 1; 690 break; 691 } 692 arg->count++; 693 } 694 } 695 696 static const struct Qdisc_class_ops fq_codel_class_ops = { 697 .leaf = fq_codel_leaf, 698 .get = fq_codel_get, 699 .put = fq_codel_put, 700 .tcf_chain = fq_codel_find_tcf, 701 .bind_tcf = fq_codel_bind, 702 .unbind_tcf = fq_codel_put, 703 .dump = fq_codel_dump_class, 704 .dump_stats = fq_codel_dump_class_stats, 705 .walk = fq_codel_walk, 706 }; 707 708 static struct Qdisc_ops fq_codel_qdisc_ops __read_mostly = { 709 .cl_ops = &fq_codel_class_ops, 710 .id = "fq_codel", 711 .priv_size = sizeof(struct fq_codel_sched_data), 712 .enqueue = fq_codel_enqueue, 713 .dequeue = fq_codel_dequeue, 714 .peek = qdisc_peek_dequeued, 715 .init = fq_codel_init, 716 .reset = fq_codel_reset, 717 .destroy = fq_codel_destroy, 718 .change = fq_codel_change, 719 .dump = fq_codel_dump, 720 .dump_stats = fq_codel_dump_stats, 721 .owner = THIS_MODULE, 722 }; 723 724 static int __init fq_codel_module_init(void) 725 { 726 return register_qdisc(&fq_codel_qdisc_ops); 727 } 728 729 static void __exit fq_codel_module_exit(void) 730 { 731 unregister_qdisc(&fq_codel_qdisc_ops); 732 } 733 734 module_init(fq_codel_module_init) 735 module_exit(fq_codel_module_exit) 736 MODULE_AUTHOR("Eric Dumazet"); 737 MODULE_LICENSE("GPL"); 738