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 fq_codel_flow *flows; /* Flows table [flows_cnt] */ 59 u32 *backlogs; /* backlog table [flows_cnt] */ 60 u32 flows_cnt; /* number of flows */ 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 return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); 79 } 80 81 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, 82 int *qerr) 83 { 84 struct fq_codel_sched_data *q = qdisc_priv(sch); 85 struct tcf_proto *filter; 86 struct tcf_result res; 87 int result; 88 89 if (TC_H_MAJ(skb->priority) == sch->handle && 90 TC_H_MIN(skb->priority) > 0 && 91 TC_H_MIN(skb->priority) <= q->flows_cnt) 92 return TC_H_MIN(skb->priority); 93 94 filter = rcu_dereference_bh(q->filter_list); 95 if (!filter) 96 return fq_codel_hash(q, skb) + 1; 97 98 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 99 result = tc_classify(skb, filter, &res, false); 100 if (result >= 0) { 101 #ifdef CONFIG_NET_CLS_ACT 102 switch (result) { 103 case TC_ACT_STOLEN: 104 case TC_ACT_QUEUED: 105 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 106 case TC_ACT_SHOT: 107 return 0; 108 } 109 #endif 110 if (TC_H_MIN(res.classid) <= q->flows_cnt) 111 return TC_H_MIN(res.classid); 112 } 113 return 0; 114 } 115 116 /* helper functions : might be changed when/if skb use a standard list_head */ 117 118 /* remove one skb from head of slot queue */ 119 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow) 120 { 121 struct sk_buff *skb = flow->head; 122 123 flow->head = skb->next; 124 skb->next = NULL; 125 return skb; 126 } 127 128 /* add skb to flow queue (tail add) */ 129 static inline void flow_queue_add(struct fq_codel_flow *flow, 130 struct sk_buff *skb) 131 { 132 if (flow->head == NULL) 133 flow->head = skb; 134 else 135 flow->tail->next = skb; 136 flow->tail = skb; 137 skb->next = NULL; 138 } 139 140 static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets, 141 struct sk_buff **to_free) 142 { 143 struct fq_codel_sched_data *q = qdisc_priv(sch); 144 struct sk_buff *skb; 145 unsigned int maxbacklog = 0, idx = 0, i, len; 146 struct fq_codel_flow *flow; 147 unsigned int threshold; 148 unsigned int mem = 0; 149 150 /* Queue is full! Find the fat flow and drop packet(s) from it. 151 * This might sound expensive, but with 1024 flows, we scan 152 * 4KB of memory, and we dont need to handle a complex tree 153 * in fast path (packet queue/enqueue) with many cache misses. 154 * In stress mode, we'll try to drop 64 packets from the flow, 155 * amortizing this linear lookup to one cache line per drop. 156 */ 157 for (i = 0; i < q->flows_cnt; i++) { 158 if (q->backlogs[i] > maxbacklog) { 159 maxbacklog = q->backlogs[i]; 160 idx = i; 161 } 162 } 163 164 /* Our goal is to drop half of this fat flow backlog */ 165 threshold = maxbacklog >> 1; 166 167 flow = &q->flows[idx]; 168 len = 0; 169 i = 0; 170 do { 171 skb = dequeue_head(flow); 172 len += qdisc_pkt_len(skb); 173 mem += get_codel_cb(skb)->mem_usage; 174 __qdisc_drop(skb, to_free); 175 } while (++i < max_packets && len < threshold); 176 177 flow->dropped += i; 178 q->backlogs[idx] -= len; 179 q->memory_usage -= mem; 180 sch->qstats.drops += i; 181 sch->qstats.backlog -= len; 182 sch->q.qlen -= i; 183 return idx; 184 } 185 186 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, 187 struct sk_buff **to_free) 188 { 189 struct fq_codel_sched_data *q = qdisc_priv(sch); 190 unsigned int idx, prev_backlog, prev_qlen; 191 struct fq_codel_flow *flow; 192 int uninitialized_var(ret); 193 unsigned int pkt_len; 194 bool memory_limited; 195 196 idx = fq_codel_classify(skb, sch, &ret); 197 if (idx == 0) { 198 if (ret & __NET_XMIT_BYPASS) 199 qdisc_qstats_drop(sch); 200 __qdisc_drop(skb, to_free); 201 return ret; 202 } 203 idx--; 204 205 codel_set_enqueue_time(skb); 206 flow = &q->flows[idx]; 207 flow_queue_add(flow, skb); 208 q->backlogs[idx] += qdisc_pkt_len(skb); 209 qdisc_qstats_backlog_inc(sch, skb); 210 211 if (list_empty(&flow->flowchain)) { 212 list_add_tail(&flow->flowchain, &q->new_flows); 213 q->new_flow_count++; 214 flow->deficit = q->quantum; 215 flow->dropped = 0; 216 } 217 get_codel_cb(skb)->mem_usage = skb->truesize; 218 q->memory_usage += get_codel_cb(skb)->mem_usage; 219 memory_limited = q->memory_usage > q->memory_limit; 220 if (++sch->q.qlen <= sch->limit && !memory_limited) 221 return NET_XMIT_SUCCESS; 222 223 prev_backlog = sch->qstats.backlog; 224 prev_qlen = sch->q.qlen; 225 226 /* save this packet length as it might be dropped by fq_codel_drop() */ 227 pkt_len = qdisc_pkt_len(skb); 228 /* fq_codel_drop() is quite expensive, as it performs a linear search 229 * in q->backlogs[] to find a fat flow. 230 * So instead of dropping a single packet, drop half of its backlog 231 * with a 64 packets limit to not add a too big cpu spike here. 232 */ 233 ret = fq_codel_drop(sch, q->drop_batch_size, to_free); 234 235 prev_qlen -= sch->q.qlen; 236 prev_backlog -= sch->qstats.backlog; 237 q->drop_overlimit += prev_qlen; 238 if (memory_limited) 239 q->drop_overmemory += prev_qlen; 240 241 /* As we dropped packet(s), better let upper stack know this. 242 * If we dropped a packet for this flow, return NET_XMIT_CN, 243 * but in this case, our parents wont increase their backlogs. 244 */ 245 if (ret == idx) { 246 qdisc_tree_reduce_backlog(sch, prev_qlen - 1, 247 prev_backlog - pkt_len); 248 return NET_XMIT_CN; 249 } 250 qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); 251 return NET_XMIT_SUCCESS; 252 } 253 254 /* This is the specific function called from codel_dequeue() 255 * to dequeue a packet from queue. Note: backlog is handled in 256 * codel, we dont need to reduce it here. 257 */ 258 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 259 { 260 struct Qdisc *sch = ctx; 261 struct fq_codel_sched_data *q = qdisc_priv(sch); 262 struct fq_codel_flow *flow; 263 struct sk_buff *skb = NULL; 264 265 flow = container_of(vars, struct fq_codel_flow, cvars); 266 if (flow->head) { 267 skb = dequeue_head(flow); 268 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 269 q->memory_usage -= get_codel_cb(skb)->mem_usage; 270 sch->q.qlen--; 271 sch->qstats.backlog -= qdisc_pkt_len(skb); 272 } 273 return skb; 274 } 275 276 static void drop_func(struct sk_buff *skb, void *ctx) 277 { 278 struct Qdisc *sch = ctx; 279 280 kfree_skb(skb); 281 qdisc_qstats_drop(sch); 282 } 283 284 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 285 { 286 struct fq_codel_sched_data *q = qdisc_priv(sch); 287 struct sk_buff *skb; 288 struct fq_codel_flow *flow; 289 struct list_head *head; 290 u32 prev_drop_count, prev_ecn_mark; 291 unsigned int prev_backlog; 292 293 begin: 294 head = &q->new_flows; 295 if (list_empty(head)) { 296 head = &q->old_flows; 297 if (list_empty(head)) 298 return NULL; 299 } 300 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 301 302 if (flow->deficit <= 0) { 303 flow->deficit += q->quantum; 304 list_move_tail(&flow->flowchain, &q->old_flows); 305 goto begin; 306 } 307 308 prev_drop_count = q->cstats.drop_count; 309 prev_ecn_mark = q->cstats.ecn_mark; 310 prev_backlog = sch->qstats.backlog; 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 if (err < 0) 390 return err; 391 if (tb[TCA_FQ_CODEL_FLOWS]) { 392 if (q->flows) 393 return -EINVAL; 394 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 395 if (!q->flows_cnt || 396 q->flows_cnt > 65536) 397 return -EINVAL; 398 } 399 sch_tree_lock(sch); 400 401 if (tb[TCA_FQ_CODEL_TARGET]) { 402 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 403 404 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 405 } 406 407 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 408 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 409 410 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 411 } 412 413 if (tb[TCA_FQ_CODEL_INTERVAL]) { 414 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 415 416 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 417 } 418 419 if (tb[TCA_FQ_CODEL_LIMIT]) 420 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 421 422 if (tb[TCA_FQ_CODEL_ECN]) 423 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 424 425 if (tb[TCA_FQ_CODEL_QUANTUM]) 426 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 427 428 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 429 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 430 431 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 432 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 433 434 while (sch->q.qlen > sch->limit || 435 q->memory_usage > q->memory_limit) { 436 struct sk_buff *skb = fq_codel_dequeue(sch); 437 438 q->cstats.drop_len += qdisc_pkt_len(skb); 439 rtnl_kfree_skbs(skb, skb); 440 q->cstats.drop_count++; 441 } 442 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 443 q->cstats.drop_count = 0; 444 q->cstats.drop_len = 0; 445 446 sch_tree_unlock(sch); 447 return 0; 448 } 449 450 static void *fq_codel_zalloc(size_t sz) 451 { 452 void *ptr = kzalloc(sz, GFP_KERNEL | __GFP_NOWARN); 453 454 if (!ptr) 455 ptr = vzalloc(sz); 456 return ptr; 457 } 458 459 static void fq_codel_free(void *addr) 460 { 461 kvfree(addr); 462 } 463 464 static void fq_codel_destroy(struct Qdisc *sch) 465 { 466 struct fq_codel_sched_data *q = qdisc_priv(sch); 467 468 tcf_destroy_chain(&q->filter_list); 469 fq_codel_free(q->backlogs); 470 fq_codel_free(q->flows); 471 } 472 473 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt) 474 { 475 struct fq_codel_sched_data *q = qdisc_priv(sch); 476 int i; 477 478 sch->limit = 10*1024; 479 q->flows_cnt = 1024; 480 q->memory_limit = 32 << 20; /* 32 MBytes */ 481 q->drop_batch_size = 64; 482 q->quantum = psched_mtu(qdisc_dev(sch)); 483 INIT_LIST_HEAD(&q->new_flows); 484 INIT_LIST_HEAD(&q->old_flows); 485 codel_params_init(&q->cparams); 486 codel_stats_init(&q->cstats); 487 q->cparams.ecn = true; 488 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 489 490 if (opt) { 491 int err = fq_codel_change(sch, opt); 492 if (err) 493 return err; 494 } 495 496 if (!q->flows) { 497 q->flows = fq_codel_zalloc(q->flows_cnt * 498 sizeof(struct fq_codel_flow)); 499 if (!q->flows) 500 return -ENOMEM; 501 q->backlogs = fq_codel_zalloc(q->flows_cnt * sizeof(u32)); 502 if (!q->backlogs) { 503 fq_codel_free(q->flows); 504 return -ENOMEM; 505 } 506 for (i = 0; i < q->flows_cnt; i++) { 507 struct fq_codel_flow *flow = q->flows + i; 508 509 INIT_LIST_HEAD(&flow->flowchain); 510 codel_vars_init(&flow->cvars); 511 } 512 } 513 if (sch->limit >= 1) 514 sch->flags |= TCQ_F_CAN_BYPASS; 515 else 516 sch->flags &= ~TCQ_F_CAN_BYPASS; 517 return 0; 518 } 519 520 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 521 { 522 struct fq_codel_sched_data *q = qdisc_priv(sch); 523 struct nlattr *opts; 524 525 opts = nla_nest_start(skb, TCA_OPTIONS); 526 if (opts == NULL) 527 goto nla_put_failure; 528 529 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 530 codel_time_to_us(q->cparams.target)) || 531 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 532 sch->limit) || 533 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 534 codel_time_to_us(q->cparams.interval)) || 535 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 536 q->cparams.ecn) || 537 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 538 q->quantum) || 539 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 540 q->drop_batch_size) || 541 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 542 q->memory_limit) || 543 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 544 q->flows_cnt)) 545 goto nla_put_failure; 546 547 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 548 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 549 codel_time_to_us(q->cparams.ce_threshold))) 550 goto nla_put_failure; 551 552 return nla_nest_end(skb, opts); 553 554 nla_put_failure: 555 return -1; 556 } 557 558 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 559 { 560 struct fq_codel_sched_data *q = qdisc_priv(sch); 561 struct tc_fq_codel_xstats st = { 562 .type = TCA_FQ_CODEL_XSTATS_QDISC, 563 }; 564 struct list_head *pos; 565 566 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 567 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 568 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 569 st.qdisc_stats.new_flow_count = q->new_flow_count; 570 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 571 st.qdisc_stats.memory_usage = q->memory_usage; 572 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 573 574 sch_tree_lock(sch); 575 list_for_each(pos, &q->new_flows) 576 st.qdisc_stats.new_flows_len++; 577 578 list_for_each(pos, &q->old_flows) 579 st.qdisc_stats.old_flows_len++; 580 sch_tree_unlock(sch); 581 582 return gnet_stats_copy_app(d, &st, sizeof(st)); 583 } 584 585 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 586 { 587 return NULL; 588 } 589 590 static unsigned long fq_codel_get(struct Qdisc *sch, u32 classid) 591 { 592 return 0; 593 } 594 595 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 596 u32 classid) 597 { 598 /* we cannot bypass queue discipline anymore */ 599 sch->flags &= ~TCQ_F_CAN_BYPASS; 600 return 0; 601 } 602 603 static void fq_codel_put(struct Qdisc *q, unsigned long cl) 604 { 605 } 606 607 static struct tcf_proto __rcu **fq_codel_find_tcf(struct Qdisc *sch, 608 unsigned long cl) 609 { 610 struct fq_codel_sched_data *q = qdisc_priv(sch); 611 612 if (cl) 613 return NULL; 614 return &q->filter_list; 615 } 616 617 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 618 struct sk_buff *skb, struct tcmsg *tcm) 619 { 620 tcm->tcm_handle |= TC_H_MIN(cl); 621 return 0; 622 } 623 624 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 625 struct gnet_dump *d) 626 { 627 struct fq_codel_sched_data *q = qdisc_priv(sch); 628 u32 idx = cl - 1; 629 struct gnet_stats_queue qs = { 0 }; 630 struct tc_fq_codel_xstats xstats; 631 632 if (idx < q->flows_cnt) { 633 const struct fq_codel_flow *flow = &q->flows[idx]; 634 const struct sk_buff *skb; 635 636 memset(&xstats, 0, sizeof(xstats)); 637 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 638 xstats.class_stats.deficit = flow->deficit; 639 xstats.class_stats.ldelay = 640 codel_time_to_us(flow->cvars.ldelay); 641 xstats.class_stats.count = flow->cvars.count; 642 xstats.class_stats.lastcount = flow->cvars.lastcount; 643 xstats.class_stats.dropping = flow->cvars.dropping; 644 if (flow->cvars.dropping) { 645 codel_tdiff_t delta = flow->cvars.drop_next - 646 codel_get_time(); 647 648 xstats.class_stats.drop_next = (delta >= 0) ? 649 codel_time_to_us(delta) : 650 -codel_time_to_us(-delta); 651 } 652 if (flow->head) { 653 sch_tree_lock(sch); 654 skb = flow->head; 655 while (skb) { 656 qs.qlen++; 657 skb = skb->next; 658 } 659 sch_tree_unlock(sch); 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 .init = fq_codel_init, 713 .reset = fq_codel_reset, 714 .destroy = fq_codel_destroy, 715 .change = fq_codel_change, 716 .dump = fq_codel_dump, 717 .dump_stats = fq_codel_dump_stats, 718 .owner = THIS_MODULE, 719 }; 720 721 static int __init fq_codel_module_init(void) 722 { 723 return register_qdisc(&fq_codel_qdisc_ops); 724 } 725 726 static void __exit fq_codel_module_exit(void) 727 { 728 unregister_qdisc(&fq_codel_qdisc_ops); 729 } 730 731 module_init(fq_codel_module_init) 732 module_exit(fq_codel_module_exit) 733 MODULE_AUTHOR("Eric Dumazet"); 734 MODULE_LICENSE("GPL"); 735