1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Fair Queue CoDel discipline 4 * 5 * Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com> 6 */ 7 8 #include <linux/module.h> 9 #include <linux/types.h> 10 #include <linux/kernel.h> 11 #include <linux/jiffies.h> 12 #include <linux/string.h> 13 #include <linux/in.h> 14 #include <linux/errno.h> 15 #include <linux/init.h> 16 #include <linux/skbuff.h> 17 #include <linux/jhash.h> 18 #include <linux/slab.h> 19 #include <linux/vmalloc.h> 20 #include <net/netlink.h> 21 #include <net/pkt_sched.h> 22 #include <net/pkt_cls.h> 23 #include <net/codel.h> 24 #include <net/codel_impl.h> 25 #include <net/codel_qdisc.h> 26 27 /* Fair Queue CoDel. 28 * 29 * Principles : 30 * Packets are classified (internal classifier or external) on flows. 31 * This is a Stochastic model (as we use a hash, several flows 32 * might be hashed on same slot) 33 * Each flow has a CoDel managed queue. 34 * Flows are linked onto two (Round Robin) lists, 35 * so that new flows have priority on old ones. 36 * 37 * For a given flow, packets are not reordered (CoDel uses a FIFO) 38 * head drops only. 39 * ECN capability is on by default. 40 * Low memory footprint (64 bytes per flow) 41 */ 42 43 struct fq_codel_flow { 44 struct sk_buff *head; 45 struct sk_buff *tail; 46 struct list_head flowchain; 47 int deficit; 48 u32 dropped; /* number of drops (or ECN marks) on this flow */ 49 struct codel_vars cvars; 50 }; /* please try to keep this structure <= 64 bytes */ 51 52 struct fq_codel_sched_data { 53 struct tcf_proto __rcu *filter_list; /* optional external classifier */ 54 struct tcf_block *block; 55 struct fq_codel_flow *flows; /* Flows table [flows_cnt] */ 56 u32 *backlogs; /* backlog table [flows_cnt] */ 57 u32 flows_cnt; /* number of flows */ 58 u32 quantum; /* psched_mtu(qdisc_dev(sch)); */ 59 u32 drop_batch_size; 60 u32 memory_limit; 61 struct codel_params cparams; 62 struct codel_stats cstats; 63 u32 memory_usage; 64 u32 drop_overmemory; 65 u32 drop_overlimit; 66 u32 new_flow_count; 67 68 struct list_head new_flows; /* list of new flows */ 69 struct list_head old_flows; /* list of old flows */ 70 }; 71 72 static unsigned int fq_codel_hash(const struct fq_codel_sched_data *q, 73 struct sk_buff *skb) 74 { 75 return reciprocal_scale(skb_get_hash(skb), q->flows_cnt); 76 } 77 78 static unsigned int fq_codel_classify(struct sk_buff *skb, struct Qdisc *sch, 79 int *qerr) 80 { 81 struct fq_codel_sched_data *q = qdisc_priv(sch); 82 struct tcf_proto *filter; 83 struct tcf_result res; 84 int result; 85 86 if (TC_H_MAJ(skb->priority) == sch->handle && 87 TC_H_MIN(skb->priority) > 0 && 88 TC_H_MIN(skb->priority) <= q->flows_cnt) 89 return TC_H_MIN(skb->priority); 90 91 filter = rcu_dereference_bh(q->filter_list); 92 if (!filter) 93 return fq_codel_hash(q, skb) + 1; 94 95 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 96 result = tcf_classify(skb, filter, &res, false); 97 if (result >= 0) { 98 #ifdef CONFIG_NET_CLS_ACT 99 switch (result) { 100 case TC_ACT_STOLEN: 101 case TC_ACT_QUEUED: 102 case TC_ACT_TRAP: 103 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 104 /* fall through */ 105 case TC_ACT_SHOT: 106 return 0; 107 } 108 #endif 109 if (TC_H_MIN(res.classid) <= q->flows_cnt) 110 return TC_H_MIN(res.classid); 111 } 112 return 0; 113 } 114 115 /* helper functions : might be changed when/if skb use a standard list_head */ 116 117 /* remove one skb from head of slot queue */ 118 static inline struct sk_buff *dequeue_head(struct fq_codel_flow *flow) 119 { 120 struct sk_buff *skb = flow->head; 121 122 flow->head = skb->next; 123 skb_mark_not_on_list(skb); 124 return skb; 125 } 126 127 /* add skb to flow queue (tail add) */ 128 static inline void flow_queue_add(struct fq_codel_flow *flow, 129 struct sk_buff *skb) 130 { 131 if (flow->head == NULL) 132 flow->head = skb; 133 else 134 flow->tail->next = skb; 135 flow->tail = skb; 136 skb->next = NULL; 137 } 138 139 static unsigned int fq_codel_drop(struct Qdisc *sch, unsigned int max_packets, 140 struct sk_buff **to_free) 141 { 142 struct fq_codel_sched_data *q = qdisc_priv(sch); 143 struct sk_buff *skb; 144 unsigned int maxbacklog = 0, idx = 0, i, len; 145 struct fq_codel_flow *flow; 146 unsigned int threshold; 147 unsigned int mem = 0; 148 149 /* Queue is full! Find the fat flow and drop packet(s) from it. 150 * This might sound expensive, but with 1024 flows, we scan 151 * 4KB of memory, and we dont need to handle a complex tree 152 * in fast path (packet queue/enqueue) with many cache misses. 153 * In stress mode, we'll try to drop 64 packets from the flow, 154 * amortizing this linear lookup to one cache line per drop. 155 */ 156 for (i = 0; i < q->flows_cnt; i++) { 157 if (q->backlogs[i] > maxbacklog) { 158 maxbacklog = q->backlogs[i]; 159 idx = i; 160 } 161 } 162 163 /* Our goal is to drop half of this fat flow backlog */ 164 threshold = maxbacklog >> 1; 165 166 flow = &q->flows[idx]; 167 len = 0; 168 i = 0; 169 do { 170 skb = dequeue_head(flow); 171 len += qdisc_pkt_len(skb); 172 mem += get_codel_cb(skb)->mem_usage; 173 __qdisc_drop(skb, to_free); 174 } while (++i < max_packets && len < threshold); 175 176 flow->dropped += i; 177 q->backlogs[idx] -= len; 178 q->memory_usage -= mem; 179 sch->qstats.drops += i; 180 sch->qstats.backlog -= len; 181 sch->q.qlen -= i; 182 return idx; 183 } 184 185 static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch, 186 struct sk_buff **to_free) 187 { 188 struct fq_codel_sched_data *q = qdisc_priv(sch); 189 unsigned int idx, prev_backlog, prev_qlen; 190 struct fq_codel_flow *flow; 191 int uninitialized_var(ret); 192 unsigned int pkt_len; 193 bool memory_limited; 194 195 idx = fq_codel_classify(skb, sch, &ret); 196 if (idx == 0) { 197 if (ret & __NET_XMIT_BYPASS) 198 qdisc_qstats_drop(sch); 199 __qdisc_drop(skb, to_free); 200 return ret; 201 } 202 idx--; 203 204 codel_set_enqueue_time(skb); 205 flow = &q->flows[idx]; 206 flow_queue_add(flow, skb); 207 q->backlogs[idx] += qdisc_pkt_len(skb); 208 qdisc_qstats_backlog_inc(sch, skb); 209 210 if (list_empty(&flow->flowchain)) { 211 list_add_tail(&flow->flowchain, &q->new_flows); 212 q->new_flow_count++; 213 flow->deficit = q->quantum; 214 flow->dropped = 0; 215 } 216 get_codel_cb(skb)->mem_usage = skb->truesize; 217 q->memory_usage += get_codel_cb(skb)->mem_usage; 218 memory_limited = q->memory_usage > q->memory_limit; 219 if (++sch->q.qlen <= sch->limit && !memory_limited) 220 return NET_XMIT_SUCCESS; 221 222 prev_backlog = sch->qstats.backlog; 223 prev_qlen = sch->q.qlen; 224 225 /* save this packet length as it might be dropped by fq_codel_drop() */ 226 pkt_len = qdisc_pkt_len(skb); 227 /* fq_codel_drop() is quite expensive, as it performs a linear search 228 * in q->backlogs[] to find a fat flow. 229 * So instead of dropping a single packet, drop half of its backlog 230 * with a 64 packets limit to not add a too big cpu spike here. 231 */ 232 ret = fq_codel_drop(sch, q->drop_batch_size, to_free); 233 234 prev_qlen -= sch->q.qlen; 235 prev_backlog -= sch->qstats.backlog; 236 q->drop_overlimit += prev_qlen; 237 if (memory_limited) 238 q->drop_overmemory += prev_qlen; 239 240 /* As we dropped packet(s), better let upper stack know this. 241 * If we dropped a packet for this flow, return NET_XMIT_CN, 242 * but in this case, our parents wont increase their backlogs. 243 */ 244 if (ret == idx) { 245 qdisc_tree_reduce_backlog(sch, prev_qlen - 1, 246 prev_backlog - pkt_len); 247 return NET_XMIT_CN; 248 } 249 qdisc_tree_reduce_backlog(sch, prev_qlen, prev_backlog); 250 return NET_XMIT_SUCCESS; 251 } 252 253 /* This is the specific function called from codel_dequeue() 254 * to dequeue a packet from queue. Note: backlog is handled in 255 * codel, we dont need to reduce it here. 256 */ 257 static struct sk_buff *dequeue_func(struct codel_vars *vars, void *ctx) 258 { 259 struct Qdisc *sch = ctx; 260 struct fq_codel_sched_data *q = qdisc_priv(sch); 261 struct fq_codel_flow *flow; 262 struct sk_buff *skb = NULL; 263 264 flow = container_of(vars, struct fq_codel_flow, cvars); 265 if (flow->head) { 266 skb = dequeue_head(flow); 267 q->backlogs[flow - q->flows] -= qdisc_pkt_len(skb); 268 q->memory_usage -= get_codel_cb(skb)->mem_usage; 269 sch->q.qlen--; 270 sch->qstats.backlog -= qdisc_pkt_len(skb); 271 } 272 return skb; 273 } 274 275 static void drop_func(struct sk_buff *skb, void *ctx) 276 { 277 struct Qdisc *sch = ctx; 278 279 kfree_skb(skb); 280 qdisc_qstats_drop(sch); 281 } 282 283 static struct sk_buff *fq_codel_dequeue(struct Qdisc *sch) 284 { 285 struct fq_codel_sched_data *q = qdisc_priv(sch); 286 struct sk_buff *skb; 287 struct fq_codel_flow *flow; 288 struct list_head *head; 289 u32 prev_drop_count, prev_ecn_mark; 290 291 begin: 292 head = &q->new_flows; 293 if (list_empty(head)) { 294 head = &q->old_flows; 295 if (list_empty(head)) 296 return NULL; 297 } 298 flow = list_first_entry(head, struct fq_codel_flow, flowchain); 299 300 if (flow->deficit <= 0) { 301 flow->deficit += q->quantum; 302 list_move_tail(&flow->flowchain, &q->old_flows); 303 goto begin; 304 } 305 306 prev_drop_count = q->cstats.drop_count; 307 prev_ecn_mark = q->cstats.ecn_mark; 308 309 skb = codel_dequeue(sch, &sch->qstats.backlog, &q->cparams, 310 &flow->cvars, &q->cstats, qdisc_pkt_len, 311 codel_get_enqueue_time, drop_func, dequeue_func); 312 313 flow->dropped += q->cstats.drop_count - prev_drop_count; 314 flow->dropped += q->cstats.ecn_mark - prev_ecn_mark; 315 316 if (!skb) { 317 /* force a pass through old_flows to prevent starvation */ 318 if ((head == &q->new_flows) && !list_empty(&q->old_flows)) 319 list_move_tail(&flow->flowchain, &q->old_flows); 320 else 321 list_del_init(&flow->flowchain); 322 goto begin; 323 } 324 qdisc_bstats_update(sch, skb); 325 flow->deficit -= qdisc_pkt_len(skb); 326 /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0, 327 * or HTB crashes. Defer it for next round. 328 */ 329 if (q->cstats.drop_count && sch->q.qlen) { 330 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, 331 q->cstats.drop_len); 332 q->cstats.drop_count = 0; 333 q->cstats.drop_len = 0; 334 } 335 return skb; 336 } 337 338 static void fq_codel_flow_purge(struct fq_codel_flow *flow) 339 { 340 rtnl_kfree_skbs(flow->head, flow->tail); 341 flow->head = NULL; 342 } 343 344 static void fq_codel_reset(struct Qdisc *sch) 345 { 346 struct fq_codel_sched_data *q = qdisc_priv(sch); 347 int i; 348 349 INIT_LIST_HEAD(&q->new_flows); 350 INIT_LIST_HEAD(&q->old_flows); 351 for (i = 0; i < q->flows_cnt; i++) { 352 struct fq_codel_flow *flow = q->flows + i; 353 354 fq_codel_flow_purge(flow); 355 INIT_LIST_HEAD(&flow->flowchain); 356 codel_vars_init(&flow->cvars); 357 } 358 memset(q->backlogs, 0, q->flows_cnt * sizeof(u32)); 359 sch->q.qlen = 0; 360 sch->qstats.backlog = 0; 361 q->memory_usage = 0; 362 } 363 364 static const struct nla_policy fq_codel_policy[TCA_FQ_CODEL_MAX + 1] = { 365 [TCA_FQ_CODEL_TARGET] = { .type = NLA_U32 }, 366 [TCA_FQ_CODEL_LIMIT] = { .type = NLA_U32 }, 367 [TCA_FQ_CODEL_INTERVAL] = { .type = NLA_U32 }, 368 [TCA_FQ_CODEL_ECN] = { .type = NLA_U32 }, 369 [TCA_FQ_CODEL_FLOWS] = { .type = NLA_U32 }, 370 [TCA_FQ_CODEL_QUANTUM] = { .type = NLA_U32 }, 371 [TCA_FQ_CODEL_CE_THRESHOLD] = { .type = NLA_U32 }, 372 [TCA_FQ_CODEL_DROP_BATCH_SIZE] = { .type = NLA_U32 }, 373 [TCA_FQ_CODEL_MEMORY_LIMIT] = { .type = NLA_U32 }, 374 }; 375 376 static int fq_codel_change(struct Qdisc *sch, struct nlattr *opt, 377 struct netlink_ext_ack *extack) 378 { 379 struct fq_codel_sched_data *q = qdisc_priv(sch); 380 struct nlattr *tb[TCA_FQ_CODEL_MAX + 1]; 381 int err; 382 383 if (!opt) 384 return -EINVAL; 385 386 err = nla_parse_nested_deprecated(tb, TCA_FQ_CODEL_MAX, opt, 387 fq_codel_policy, NULL); 388 if (err < 0) 389 return err; 390 if (tb[TCA_FQ_CODEL_FLOWS]) { 391 if (q->flows) 392 return -EINVAL; 393 q->flows_cnt = nla_get_u32(tb[TCA_FQ_CODEL_FLOWS]); 394 if (!q->flows_cnt || 395 q->flows_cnt > 65536) 396 return -EINVAL; 397 } 398 sch_tree_lock(sch); 399 400 if (tb[TCA_FQ_CODEL_TARGET]) { 401 u64 target = nla_get_u32(tb[TCA_FQ_CODEL_TARGET]); 402 403 q->cparams.target = (target * NSEC_PER_USEC) >> CODEL_SHIFT; 404 } 405 406 if (tb[TCA_FQ_CODEL_CE_THRESHOLD]) { 407 u64 val = nla_get_u32(tb[TCA_FQ_CODEL_CE_THRESHOLD]); 408 409 q->cparams.ce_threshold = (val * NSEC_PER_USEC) >> CODEL_SHIFT; 410 } 411 412 if (tb[TCA_FQ_CODEL_INTERVAL]) { 413 u64 interval = nla_get_u32(tb[TCA_FQ_CODEL_INTERVAL]); 414 415 q->cparams.interval = (interval * NSEC_PER_USEC) >> CODEL_SHIFT; 416 } 417 418 if (tb[TCA_FQ_CODEL_LIMIT]) 419 sch->limit = nla_get_u32(tb[TCA_FQ_CODEL_LIMIT]); 420 421 if (tb[TCA_FQ_CODEL_ECN]) 422 q->cparams.ecn = !!nla_get_u32(tb[TCA_FQ_CODEL_ECN]); 423 424 if (tb[TCA_FQ_CODEL_QUANTUM]) 425 q->quantum = max(256U, nla_get_u32(tb[TCA_FQ_CODEL_QUANTUM])); 426 427 if (tb[TCA_FQ_CODEL_DROP_BATCH_SIZE]) 428 q->drop_batch_size = min(1U, nla_get_u32(tb[TCA_FQ_CODEL_DROP_BATCH_SIZE])); 429 430 if (tb[TCA_FQ_CODEL_MEMORY_LIMIT]) 431 q->memory_limit = min(1U << 31, nla_get_u32(tb[TCA_FQ_CODEL_MEMORY_LIMIT])); 432 433 while (sch->q.qlen > sch->limit || 434 q->memory_usage > q->memory_limit) { 435 struct sk_buff *skb = fq_codel_dequeue(sch); 436 437 q->cstats.drop_len += qdisc_pkt_len(skb); 438 rtnl_kfree_skbs(skb, skb); 439 q->cstats.drop_count++; 440 } 441 qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len); 442 q->cstats.drop_count = 0; 443 q->cstats.drop_len = 0; 444 445 sch_tree_unlock(sch); 446 return 0; 447 } 448 449 static void fq_codel_destroy(struct Qdisc *sch) 450 { 451 struct fq_codel_sched_data *q = qdisc_priv(sch); 452 453 tcf_block_put(q->block); 454 kvfree(q->backlogs); 455 kvfree(q->flows); 456 } 457 458 static int fq_codel_init(struct Qdisc *sch, struct nlattr *opt, 459 struct netlink_ext_ack *extack) 460 { 461 struct fq_codel_sched_data *q = qdisc_priv(sch); 462 int i; 463 int err; 464 465 sch->limit = 10*1024; 466 q->flows_cnt = 1024; 467 q->memory_limit = 32 << 20; /* 32 MBytes */ 468 q->drop_batch_size = 64; 469 q->quantum = psched_mtu(qdisc_dev(sch)); 470 INIT_LIST_HEAD(&q->new_flows); 471 INIT_LIST_HEAD(&q->old_flows); 472 codel_params_init(&q->cparams); 473 codel_stats_init(&q->cstats); 474 q->cparams.ecn = true; 475 q->cparams.mtu = psched_mtu(qdisc_dev(sch)); 476 477 if (opt) { 478 err = fq_codel_change(sch, opt, extack); 479 if (err) 480 goto init_failure; 481 } 482 483 err = tcf_block_get(&q->block, &q->filter_list, sch, extack); 484 if (err) 485 goto init_failure; 486 487 if (!q->flows) { 488 q->flows = kvcalloc(q->flows_cnt, 489 sizeof(struct fq_codel_flow), 490 GFP_KERNEL); 491 if (!q->flows) { 492 err = -ENOMEM; 493 goto init_failure; 494 } 495 q->backlogs = kvcalloc(q->flows_cnt, sizeof(u32), GFP_KERNEL); 496 if (!q->backlogs) { 497 err = -ENOMEM; 498 goto alloc_failure; 499 } 500 for (i = 0; i < q->flows_cnt; i++) { 501 struct fq_codel_flow *flow = q->flows + i; 502 503 INIT_LIST_HEAD(&flow->flowchain); 504 codel_vars_init(&flow->cvars); 505 } 506 } 507 if (sch->limit >= 1) 508 sch->flags |= TCQ_F_CAN_BYPASS; 509 else 510 sch->flags &= ~TCQ_F_CAN_BYPASS; 511 return 0; 512 513 alloc_failure: 514 kvfree(q->flows); 515 q->flows = NULL; 516 init_failure: 517 q->flows_cnt = 0; 518 return err; 519 } 520 521 static int fq_codel_dump(struct Qdisc *sch, struct sk_buff *skb) 522 { 523 struct fq_codel_sched_data *q = qdisc_priv(sch); 524 struct nlattr *opts; 525 526 opts = nla_nest_start_noflag(skb, TCA_OPTIONS); 527 if (opts == NULL) 528 goto nla_put_failure; 529 530 if (nla_put_u32(skb, TCA_FQ_CODEL_TARGET, 531 codel_time_to_us(q->cparams.target)) || 532 nla_put_u32(skb, TCA_FQ_CODEL_LIMIT, 533 sch->limit) || 534 nla_put_u32(skb, TCA_FQ_CODEL_INTERVAL, 535 codel_time_to_us(q->cparams.interval)) || 536 nla_put_u32(skb, TCA_FQ_CODEL_ECN, 537 q->cparams.ecn) || 538 nla_put_u32(skb, TCA_FQ_CODEL_QUANTUM, 539 q->quantum) || 540 nla_put_u32(skb, TCA_FQ_CODEL_DROP_BATCH_SIZE, 541 q->drop_batch_size) || 542 nla_put_u32(skb, TCA_FQ_CODEL_MEMORY_LIMIT, 543 q->memory_limit) || 544 nla_put_u32(skb, TCA_FQ_CODEL_FLOWS, 545 q->flows_cnt)) 546 goto nla_put_failure; 547 548 if (q->cparams.ce_threshold != CODEL_DISABLED_THRESHOLD && 549 nla_put_u32(skb, TCA_FQ_CODEL_CE_THRESHOLD, 550 codel_time_to_us(q->cparams.ce_threshold))) 551 goto nla_put_failure; 552 553 return nla_nest_end(skb, opts); 554 555 nla_put_failure: 556 return -1; 557 } 558 559 static int fq_codel_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 560 { 561 struct fq_codel_sched_data *q = qdisc_priv(sch); 562 struct tc_fq_codel_xstats st = { 563 .type = TCA_FQ_CODEL_XSTATS_QDISC, 564 }; 565 struct list_head *pos; 566 567 st.qdisc_stats.maxpacket = q->cstats.maxpacket; 568 st.qdisc_stats.drop_overlimit = q->drop_overlimit; 569 st.qdisc_stats.ecn_mark = q->cstats.ecn_mark; 570 st.qdisc_stats.new_flow_count = q->new_flow_count; 571 st.qdisc_stats.ce_mark = q->cstats.ce_mark; 572 st.qdisc_stats.memory_usage = q->memory_usage; 573 st.qdisc_stats.drop_overmemory = q->drop_overmemory; 574 575 sch_tree_lock(sch); 576 list_for_each(pos, &q->new_flows) 577 st.qdisc_stats.new_flows_len++; 578 579 list_for_each(pos, &q->old_flows) 580 st.qdisc_stats.old_flows_len++; 581 sch_tree_unlock(sch); 582 583 return gnet_stats_copy_app(d, &st, sizeof(st)); 584 } 585 586 static struct Qdisc *fq_codel_leaf(struct Qdisc *sch, unsigned long arg) 587 { 588 return NULL; 589 } 590 591 static unsigned long fq_codel_find(struct Qdisc *sch, u32 classid) 592 { 593 return 0; 594 } 595 596 static unsigned long fq_codel_bind(struct Qdisc *sch, unsigned long parent, 597 u32 classid) 598 { 599 /* we cannot bypass queue discipline anymore */ 600 sch->flags &= ~TCQ_F_CAN_BYPASS; 601 return 0; 602 } 603 604 static void fq_codel_unbind(struct Qdisc *q, unsigned long cl) 605 { 606 } 607 608 static struct tcf_block *fq_codel_tcf_block(struct Qdisc *sch, unsigned long cl, 609 struct netlink_ext_ack *extack) 610 { 611 struct fq_codel_sched_data *q = qdisc_priv(sch); 612 613 if (cl) 614 return NULL; 615 return q->block; 616 } 617 618 static int fq_codel_dump_class(struct Qdisc *sch, unsigned long cl, 619 struct sk_buff *skb, struct tcmsg *tcm) 620 { 621 tcm->tcm_handle |= TC_H_MIN(cl); 622 return 0; 623 } 624 625 static int fq_codel_dump_class_stats(struct Qdisc *sch, unsigned long cl, 626 struct gnet_dump *d) 627 { 628 struct fq_codel_sched_data *q = qdisc_priv(sch); 629 u32 idx = cl - 1; 630 struct gnet_stats_queue qs = { 0 }; 631 struct tc_fq_codel_xstats xstats; 632 633 if (idx < q->flows_cnt) { 634 const struct fq_codel_flow *flow = &q->flows[idx]; 635 const struct sk_buff *skb; 636 637 memset(&xstats, 0, sizeof(xstats)); 638 xstats.type = TCA_FQ_CODEL_XSTATS_CLASS; 639 xstats.class_stats.deficit = flow->deficit; 640 xstats.class_stats.ldelay = 641 codel_time_to_us(flow->cvars.ldelay); 642 xstats.class_stats.count = flow->cvars.count; 643 xstats.class_stats.lastcount = flow->cvars.lastcount; 644 xstats.class_stats.dropping = flow->cvars.dropping; 645 if (flow->cvars.dropping) { 646 codel_tdiff_t delta = flow->cvars.drop_next - 647 codel_get_time(); 648 649 xstats.class_stats.drop_next = (delta >= 0) ? 650 codel_time_to_us(delta) : 651 -codel_time_to_us(-delta); 652 } 653 if (flow->head) { 654 sch_tree_lock(sch); 655 skb = flow->head; 656 while (skb) { 657 qs.qlen++; 658 skb = skb->next; 659 } 660 sch_tree_unlock(sch); 661 } 662 qs.backlog = q->backlogs[idx]; 663 qs.drops = flow->dropped; 664 } 665 if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0) 666 return -1; 667 if (idx < q->flows_cnt) 668 return gnet_stats_copy_app(d, &xstats, sizeof(xstats)); 669 return 0; 670 } 671 672 static void fq_codel_walk(struct Qdisc *sch, struct qdisc_walker *arg) 673 { 674 struct fq_codel_sched_data *q = qdisc_priv(sch); 675 unsigned int i; 676 677 if (arg->stop) 678 return; 679 680 for (i = 0; i < q->flows_cnt; i++) { 681 if (list_empty(&q->flows[i].flowchain) || 682 arg->count < arg->skip) { 683 arg->count++; 684 continue; 685 } 686 if (arg->fn(sch, i + 1, arg) < 0) { 687 arg->stop = 1; 688 break; 689 } 690 arg->count++; 691 } 692 } 693 694 static const struct Qdisc_class_ops fq_codel_class_ops = { 695 .leaf = fq_codel_leaf, 696 .find = fq_codel_find, 697 .tcf_block = fq_codel_tcf_block, 698 .bind_tcf = fq_codel_bind, 699 .unbind_tcf = fq_codel_unbind, 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