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/pkt_cls.h> 27 #include <net/codel.h> 28 #include <net/codel_impl.h> 29 #include <net/codel_qdisc.h> 30 31 /* Fair Queue CoDel. 32 * 33 * Principles : 34 * Packets are classified (internal classifier or external) on flows. 35 * This is a Stochastic model (as we use a hash, several flows 36 * might be hashed on same slot) 37 * Each flow has a CoDel managed queue. 38 * Flows are linked onto two (Round Robin) lists, 39 * so that new flows have priority on old ones. 40 * 41 * For a given flow, packets are not reordered (CoDel uses a FIFO) 42 * head drops only. 43 * ECN capability is on by default. 44 * Low memory footprint (64 bytes per flow) 45 */ 46 47 struct fq_codel_flow { 48 struct sk_buff *head; 49 struct sk_buff *tail; 50 struct list_head flowchain; 51 int deficit; 52 u32 dropped; /* number of drops (or ECN marks) on this flow */ 53 struct codel_vars cvars; 54 }; /* please try to keep this structure <= 64 bytes */ 55 56 struct fq_codel_sched_data { 57 struct tcf_proto __rcu *filter_list; /* optional external classifier */ 58 struct tcf_block *block; 59 struct fq_codel_flow *flows; /* Flows table [flows_cnt] */ 60 u32 *backlogs; /* backlog table [flows_cnt] */ 61 u32 flows_cnt; /* number of flows */ 62 u32 quantum; /* psched_mtu(qdisc_dev(sch)); */ 63 u32 drop_batch_size; 64 u32 memory_limit; 65 struct codel_params cparams; 66 struct codel_stats cstats; 67 u32 memory_usage; 68 u32 drop_overmemory; 69 u32 drop_overlimit; 70 u32 new_flow_count; 71 72 struct list_head new_flows; /* list of new flows */ 73 struct list_head old_flows; /* list of old flows */ 74 }; 75 76 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q, 77 struct sk_buff *skb) 78 { 79 return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); 80 } 81 82 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, 83 int *qerr) 84 { 85 struct fq_codel_sched_data *q = qdisc_priv(sch); 86 struct tcf_proto *filter; 87 struct tcf_result res; 88 int result; 89 90 if (TC_H_MAJ(skb->priority) == sch->handle && 91 TC_H_MIN(skb->priority) > 0 && 92 TC_H_MIN(skb->priority) <= q->flows_cnt) 93 return TC_H_MIN(skb->priority); 94 95 filter = rcu_dereference_bh(q->filter_list); 96 if (!filter) 97 return fq_codel_hash(q, skb) + 1; 98 99 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 100 result = tcf_classify(skb, filter, &res, false); 101 if (result >= 0) { 102 #ifdef CONFIG_NET_CLS_ACT 103 switch (result) { 104 case TC_ACT_STOLEN: 105 case TC_ACT_QUEUED: 106 case TC_ACT_TRAP: 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; 293 294 begin: 295 head = &q->new_flows; 296 if (list_empty(head)) { 297 head = &q->old_flows; 298 if (list_empty(head)) 299 return NULL; 300 } 301 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 302 303 if (flow->deficit <= 0) { 304 flow->deficit += q->quantum; 305 list_move_tail(&flow->flowchain, &q->old_flows); 306 goto begin; 307 } 308 309 prev_drop_count = q->cstats.drop_count; 310 prev_ecn_mark = q->cstats.ecn_mark; 311 312 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 313 &flow->cvars, &q->cstats, qdisc_pkt_len, 314 codel_get_enqueue_time, drop_func, dequeue_func); 315 316 flow->dropped += q->cstats.drop_count - prev_drop_count; 317 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; 318 319 if (!skb) { 320 /* force a pass through old_flows to prevent starvation */ 321 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 322 list_move_tail(&flow->flowchain, &q->old_flows); 323 else 324 list_del_init(&flow->flowchain); 325 goto begin; 326 } 327 qdisc_bstats_update(sch, skb); 328 flow->deficit -= qdisc_pkt_len(skb); 329 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 330 * or HTB crashes. Defer it for next round. 331 */ 332 if (q->cstats.drop_count && sch->q.qlen) { 333 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 334 q->cstats.drop_len); 335 q->cstats.drop_count = 0; 336 q->cstats.drop_len = 0; 337 } 338 return skb; 339 } 340 341 static void fq_codel_flow_purge(struct fq_codel_flow *flow) 342 { 343 rtnl_kfree_skbs(flow->head, flow->tail); 344 flow->head = NULL; 345 } 346 347 static void fq_codel_reset(struct Qdisc *sch) 348 { 349 struct fq_codel_sched_data *q = qdisc_priv(sch); 350 int i; 351 352 INIT_LIST_HEAD(&q->new_flows); 353 INIT_LIST_HEAD(&q->old_flows); 354 for (i = 0; i < q->flows_cnt; i++) { 355 struct fq_codel_flow *flow = q->flows + i; 356 357 fq_codel_flow_purge(flow); 358 INIT_LIST_HEAD(&flow->flowchain); 359 codel_vars_init(&flow->cvars); 360 } 361 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 362 sch->q.qlen = 0; 363 sch->qstats.backlog = 0; 364 q->memory_usage = 0; 365 } 366 367 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 368 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 369 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 370 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 371 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 372 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 373 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 374 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 375 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 376 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 377 }; 378 379 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt) 380 { 381 struct fq_codel_sched_data *q = qdisc_priv(sch); 382 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 383 int err; 384 385 if (!opt) 386 return -EINVAL; 387 388 err = nla_parse_nested(tb, TCA_FQ_CODEL_MAX, opt, fq_codel_policy, 389 NULL); 390 if (err < 0) 391 return err; 392 if (tb[TCA_FQ_CODEL_FLOWS]) { 393 if (q->flows) 394 return -EINVAL; 395 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 396 if (!q->flows_cnt || 397 q->flows_cnt > 65536) 398 return -EINVAL; 399 } 400 sch_tree_lock(sch); 401 402 if (tb[TCA_FQ_CODEL_TARGET]) { 403 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 404 405 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 406 } 407 408 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 409 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 410 411 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 412 } 413 414 if (tb[TCA_FQ_CODEL_INTERVAL]) { 415 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 416 417 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 418 } 419 420 if (tb[TCA_FQ_CODEL_LIMIT]) 421 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 422 423 if (tb[TCA_FQ_CODEL_ECN]) 424 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 425 426 if (tb[TCA_FQ_CODEL_QUANTUM]) 427 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 428 429 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 430 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 431 432 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 433 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 434 435 while (sch->q.qlen > sch->limit || 436 q->memory_usage > q->memory_limit) { 437 struct sk_buff *skb = fq_codel_dequeue(sch); 438 439 q->cstats.drop_len += qdisc_pkt_len(skb); 440 rtnl_kfree_skbs(skb, skb); 441 q->cstats.drop_count++; 442 } 443 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 444 q->cstats.drop_count = 0; 445 q->cstats.drop_len = 0; 446 447 sch_tree_unlock(sch); 448 return 0; 449 } 450 451 static void fq_codel_destroy(struct Qdisc *sch) 452 { 453 struct fq_codel_sched_data *q = qdisc_priv(sch); 454 455 tcf_block_put(q->block); 456 kvfree(q->backlogs); 457 kvfree(q->flows); 458 } 459 460 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) 461 { 462 struct fq_codel_sched_data *q = qdisc_priv(sch); 463 int i; 464 int err; 465 466 sch->limit = 10*1024; 467 q->flows_cnt = 1024; 468 q->memory_limit = 32 << 20; /* 32 MBytes */ 469 q->drop_batch_size = 64; 470 q->quantum = psched_mtu(qdisc_dev(sch)); 471 INIT_LIST_HEAD(&q->new_flows); 472 INIT_LIST_HEAD(&q->old_flows); 473 codel_params_init(&q->cparams); 474 codel_stats_init(&q->cstats); 475 q->cparams.ecn = true; 476 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 477 478 if (opt) { 479 int err = fq_codel_change(sch, opt); 480 if (err) 481 return err; 482 } 483 484 err = tcf_block_get(&q->block, &q->filter_list); 485 if (err) 486 return err; 487 488 if (!q->flows) { 489 q->flows = kvzalloc(q->flows_cnt * 490 sizeof(struct fq_codel_flow), GFP_KERNEL); 491 if (!q->flows) 492 return -ENOMEM; 493 q->backlogs = kvzalloc(q->flows_cnt * sizeof(u32), GFP_KERNEL); 494 if (!q->backlogs) 495 return -ENOMEM; 496 for (i = 0; i < q->flows_cnt; i++) { 497 struct fq_codel_flow *flow = q->flows + i; 498 499 INIT_LIST_HEAD(&flow->flowchain); 500 codel_vars_init(&flow->cvars); 501 } 502 } 503 if (sch->limit >= 1) 504 sch->flags |= TCQ_F_CAN_BYPASS; 505 else 506 sch->flags &= ~TCQ_F_CAN_BYPASS; 507 return 0; 508 } 509 510 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 511 { 512 struct fq_codel_sched_data *q = qdisc_priv(sch); 513 struct nlattr *opts; 514 515 opts = nla_nest_start(skb, TCA_OPTIONS); 516 if (opts == NULL) 517 goto nla_put_failure; 518 519 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 520 codel_time_to_us(q->cparams.target)) || 521 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 522 sch->limit) || 523 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 524 codel_time_to_us(q->cparams.interval)) || 525 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 526 q->cparams.ecn) || 527 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 528 q->quantum) || 529 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 530 q->drop_batch_size) || 531 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 532 q->memory_limit) || 533 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 534 q->flows_cnt)) 535 goto nla_put_failure; 536 537 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 538 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 539 codel_time_to_us(q->cparams.ce_threshold))) 540 goto nla_put_failure; 541 542 return nla_nest_end(skb, opts); 543 544 nla_put_failure: 545 return -1; 546 } 547 548 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 549 { 550 struct fq_codel_sched_data *q = qdisc_priv(sch); 551 struct tc_fq_codel_xstats st = { 552 .type = TCA_FQ_CODEL_XSTATS_QDISC, 553 }; 554 struct list_head *pos; 555 556 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 557 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 558 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 559 st.qdisc_stats.new_flow_count = q->new_flow_count; 560 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 561 st.qdisc_stats.memory_usage = q->memory_usage; 562 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 563 564 sch_tree_lock(sch); 565 list_for_each(pos, &q->new_flows) 566 st.qdisc_stats.new_flows_len++; 567 568 list_for_each(pos, &q->old_flows) 569 st.qdisc_stats.old_flows_len++; 570 sch_tree_unlock(sch); 571 572 return gnet_stats_copy_app(d, &st, sizeof(st)); 573 } 574 575 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 576 { 577 return NULL; 578 } 579 580 static unsigned long fq_codel_find(struct Qdisc *sch, u32 classid) 581 { 582 return 0; 583 } 584 585 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 586 u32 classid) 587 { 588 /* we cannot bypass queue discipline anymore */ 589 sch->flags &= ~TCQ_F_CAN_BYPASS; 590 return 0; 591 } 592 593 static void fq_codel_unbind(struct Qdisc *q, unsigned long cl) 594 { 595 } 596 597 static struct tcf_block *fq_codel_tcf_block(struct Qdisc *sch, unsigned long cl) 598 { 599 struct fq_codel_sched_data *q = qdisc_priv(sch); 600 601 if (cl) 602 return NULL; 603 return q->block; 604 } 605 606 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 607 struct sk_buff *skb, struct tcmsg *tcm) 608 { 609 tcm->tcm_handle |= TC_H_MIN(cl); 610 return 0; 611 } 612 613 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 614 struct gnet_dump *d) 615 { 616 struct fq_codel_sched_data *q = qdisc_priv(sch); 617 u32 idx = cl - 1; 618 struct gnet_stats_queue qs = { 0 }; 619 struct tc_fq_codel_xstats xstats; 620 621 if (idx < q->flows_cnt) { 622 const struct fq_codel_flow *flow = &q->flows[idx]; 623 const struct sk_buff *skb; 624 625 memset(&xstats, 0, sizeof(xstats)); 626 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 627 xstats.class_stats.deficit = flow->deficit; 628 xstats.class_stats.ldelay = 629 codel_time_to_us(flow->cvars.ldelay); 630 xstats.class_stats.count = flow->cvars.count; 631 xstats.class_stats.lastcount = flow->cvars.lastcount; 632 xstats.class_stats.dropping = flow->cvars.dropping; 633 if (flow->cvars.dropping) { 634 codel_tdiff_t delta = flow->cvars.drop_next - 635 codel_get_time(); 636 637 xstats.class_stats.drop_next = (delta >= 0) ? 638 codel_time_to_us(delta) : 639 -codel_time_to_us(-delta); 640 } 641 if (flow->head) { 642 sch_tree_lock(sch); 643 skb = flow->head; 644 while (skb) { 645 qs.qlen++; 646 skb = skb->next; 647 } 648 sch_tree_unlock(sch); 649 } 650 qs.backlog = q->backlogs[idx]; 651 qs.drops = flow->dropped; 652 } 653 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) 654 return -1; 655 if (idx < q->flows_cnt) 656 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 657 return 0; 658 } 659 660 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 661 { 662 struct fq_codel_sched_data *q = qdisc_priv(sch); 663 unsigned int i; 664 665 if (arg->stop) 666 return; 667 668 for (i = 0; i < q->flows_cnt; i++) { 669 if (list_empty(&q->flows[i].flowchain) || 670 arg->count < arg->skip) { 671 arg->count++; 672 continue; 673 } 674 if (arg->fn(sch, i + 1, arg) < 0) { 675 arg->stop = 1; 676 break; 677 } 678 arg->count++; 679 } 680 } 681 682 static const struct Qdisc_class_ops fq_codel_class_ops = { 683 .leaf = fq_codel_leaf, 684 .find = fq_codel_find, 685 .tcf_block = fq_codel_tcf_block, 686 .bind_tcf = fq_codel_bind, 687 .unbind_tcf = fq_codel_unbind, 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 .init = fq_codel_init, 701 .reset = fq_codel_reset, 702 .destroy = fq_codel_destroy, 703 .change = fq_codel_change, 704 .dump = fq_codel_dump, 705 .dump_stats = fq_codel_dump_stats, 706 .owner = THIS_MODULE, 707 }; 708 709 static int __init fq_codel_module_init(void) 710 { 711 return register_qdisc(&fq_codel_qdisc_ops); 712 } 713 714 static void __exit fq_codel_module_exit(void) 715 { 716 unregister_qdisc(&fq_codel_qdisc_ops); 717 } 718 719 module_init(fq_codel_module_init) 720 module_exit(fq_codel_module_exit) 721 MODULE_AUTHOR("Eric Dumazet"); 722 MODULE_LICENSE("GPL"); 723