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Version: 2.6.32 2.6.33 2.6.34 2.6.35 2.6.36 2.6.37 2.6.38 2.6.39 3.0 3.1 3.2 3.3 3.4 3.5 3.6 3.7 3.8 3.9
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1 /* 2 * net/sched/sch_cbq.c Class-Based Queueing 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 * Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru> 10 * 11 */ 12 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/types.h> 16 #include <linux/kernel.h> 17 #include <linux/string.h> 18 #include <linux/errno.h> 19 #include <linux/skbuff.h> 20 #include <net/netlink.h> 21 #include <net/pkt_sched.h> 22 23 24 /* Class-Based Queueing (CBQ) algorithm. 25 ======================================= 26 27 Sources: [1] Sally Floyd and Van Jacobson, "Link-sharing and Resource 28 Management Models for Packet Networks", 29 IEEE/ACM Transactions on Networking, Vol.3, No.4, 1995 30 31 [2] Sally Floyd, "Notes on CBQ and Guaranteed Service", 1995 32 33 [3] Sally Floyd, "Notes on Class-Based Queueing: Setting 34 Parameters", 1996 35 36 [4] Sally Floyd and Michael Speer, "Experimental Results 37 for Class-Based Queueing", 1998, not published. 38 39 ----------------------------------------------------------------------- 40 41 Algorithm skeleton was taken from NS simulator cbq.cc. 42 If someone wants to check this code against the LBL version, 43 he should take into account that ONLY the skeleton was borrowed, 44 the implementation is different. Particularly: 45 46 --- The WRR algorithm is different. Our version looks more 47 reasonable (I hope) and works when quanta are allowed to be 48 less than MTU, which is always the case when real time classes 49 have small rates. Note, that the statement of [3] is 50 incomplete, delay may actually be estimated even if class 51 per-round allotment is less than MTU. Namely, if per-round 52 allotment is W*r_i, and r_1+...+r_k = r < 1 53 54 delay_i <= ([MTU/(W*r_i)]*W*r + W*r + k*MTU)/B 55 56 In the worst case we have IntServ estimate with D = W*r+k*MTU 57 and C = MTU*r. The proof (if correct at all) is trivial. 58 59 60 --- It seems that cbq-2.0 is not very accurate. At least, I cannot 61 interpret some places, which look like wrong translations 62 from NS. Anyone is advised to find these differences 63 and explain to me, why I am wrong 8). 64 65 --- Linux has no EOI event, so that we cannot estimate true class 66 idle time. Workaround is to consider the next dequeue event 67 as sign that previous packet is finished. This is wrong because of 68 internal device queueing, but on a permanently loaded link it is true. 69 Moreover, combined with clock integrator, this scheme looks 70 very close to an ideal solution. */ 71 72 struct cbq_sched_data; 73 74 75 struct cbq_class { 76 struct Qdisc_class_common common; 77 struct cbq_class *next_alive; /* next class with backlog in this priority band */ 78 79 /* Parameters */ 80 unsigned char priority; /* class priority */ 81 unsigned char priority2; /* priority to be used after overlimit */ 82 unsigned char ewma_log; /* time constant for idle time calculation */ 83 unsigned char ovl_strategy; 84 #ifdef CONFIG_NET_CLS_ACT 85 unsigned char police; 86 #endif 87 88 u32 defmap; 89 90 /* Link-sharing scheduler parameters */ 91 long maxidle; /* Class parameters: see below. */ 92 long offtime; 93 long minidle; 94 u32 avpkt; 95 struct qdisc_rate_table *R_tab; 96 97 /* Overlimit strategy parameters */ 98 void (*overlimit)(struct cbq_class *cl); 99 psched_tdiff_t penalty; 100 101 /* General scheduler (WRR) parameters */ 102 long allot; 103 long quantum; /* Allotment per WRR round */ 104 long weight; /* Relative allotment: see below */ 105 106 struct Qdisc *qdisc; /* Ptr to CBQ discipline */ 107 struct cbq_class *split; /* Ptr to split node */ 108 struct cbq_class *share; /* Ptr to LS parent in the class tree */ 109 struct cbq_class *tparent; /* Ptr to tree parent in the class tree */ 110 struct cbq_class *borrow; /* NULL if class is bandwidth limited; 111 parent otherwise */ 112 struct cbq_class *sibling; /* Sibling chain */ 113 struct cbq_class *children; /* Pointer to children chain */ 114 115 struct Qdisc *q; /* Elementary queueing discipline */ 116 117 118 /* Variables */ 119 unsigned char cpriority; /* Effective priority */ 120 unsigned char delayed; 121 unsigned char level; /* level of the class in hierarchy: 122 0 for leaf classes, and maximal 123 level of children + 1 for nodes. 124 */ 125 126 psched_time_t last; /* Last end of service */ 127 psched_time_t undertime; 128 long avgidle; 129 long deficit; /* Saved deficit for WRR */ 130 psched_time_t penalized; 131 struct gnet_stats_basic_packed bstats; 132 struct gnet_stats_queue qstats; 133 struct gnet_stats_rate_est rate_est; 134 struct tc_cbq_xstats xstats; 135 136 struct tcf_proto *filter_list; 137 138 int refcnt; 139 int filters; 140 141 struct cbq_class *defaults[TC_PRIO_MAX + 1]; 142 }; 143 144 struct cbq_sched_data { 145 struct Qdisc_class_hash clhash; /* Hash table of all classes */ 146 int nclasses[TC_CBQ_MAXPRIO + 1]; 147 unsigned int quanta[TC_CBQ_MAXPRIO + 1]; 148 149 struct cbq_class link; 150 151 unsigned int activemask; 152 struct cbq_class *active[TC_CBQ_MAXPRIO + 1]; /* List of all classes 153 with backlog */ 154 155 #ifdef CONFIG_NET_CLS_ACT 156 struct cbq_class *rx_class; 157 #endif 158 struct cbq_class *tx_class; 159 struct cbq_class *tx_borrowed; 160 int tx_len; 161 psched_time_t now; /* Cached timestamp */ 162 psched_time_t now_rt; /* Cached real time */ 163 unsigned int pmask; 164 165 struct hrtimer delay_timer; 166 struct qdisc_watchdog watchdog; /* Watchdog timer, 167 started when CBQ has 168 backlog, but cannot 169 transmit just now */ 170 psched_tdiff_t wd_expires; 171 int toplevel; 172 u32 hgenerator; 173 }; 174 175 176 #define L2T(cl, len) qdisc_l2t((cl)->R_tab, len) 177 178 static inline struct cbq_class * 179 cbq_class_lookup(struct cbq_sched_data *q, u32 classid) 180 { 181 struct Qdisc_class_common *clc; 182 183 clc = qdisc_class_find(&q->clhash, classid); 184 if (clc == NULL) 185 return NULL; 186 return container_of(clc, struct cbq_class, common); 187 } 188 189 #ifdef CONFIG_NET_CLS_ACT 190 191 static struct cbq_class * 192 cbq_reclassify(struct sk_buff *skb, struct cbq_class *this) 193 { 194 struct cbq_class *cl; 195 196 for (cl = this->tparent; cl; cl = cl->tparent) { 197 struct cbq_class *new = cl->defaults[TC_PRIO_BESTEFFORT]; 198 199 if (new != NULL && new != this) 200 return new; 201 } 202 return NULL; 203 } 204 205 #endif 206 207 /* Classify packet. The procedure is pretty complicated, but 208 * it allows us to combine link sharing and priority scheduling 209 * transparently. 210 * 211 * Namely, you can put link sharing rules (f.e. route based) at root of CBQ, 212 * so that it resolves to split nodes. Then packets are classified 213 * by logical priority, or a more specific classifier may be attached 214 * to the split node. 215 */ 216 217 static struct cbq_class * 218 cbq_classify(struct sk_buff *skb, struct Qdisc *sch, int *qerr) 219 { 220 struct cbq_sched_data *q = qdisc_priv(sch); 221 struct cbq_class *head = &q->link; 222 struct cbq_class **defmap; 223 struct cbq_class *cl = NULL; 224 u32 prio = skb->priority; 225 struct tcf_result res; 226 227 /* 228 * Step 1. If skb->priority points to one of our classes, use it. 229 */ 230 if (TC_H_MAJ(prio ^ sch->handle) == 0 && 231 (cl = cbq_class_lookup(q, prio)) != NULL) 232 return cl; 233 234 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_BYPASS; 235 for (;;) { 236 int result = 0; 237 defmap = head->defaults; 238 239 /* 240 * Step 2+n. Apply classifier. 241 */ 242 if (!head->filter_list || 243 (result = tc_classify_compat(skb, head->filter_list, &res)) < 0) 244 goto fallback; 245 246 cl = (void *)res.class; 247 if (!cl) { 248 if (TC_H_MAJ(res.classid)) 249 cl = cbq_class_lookup(q, res.classid); 250 else if ((cl = defmap[res.classid & TC_PRIO_MAX]) == NULL) 251 cl = defmap[TC_PRIO_BESTEFFORT]; 252 253 if (cl == NULL) 254 goto fallback; 255 } 256 if (cl->level >= head->level) 257 goto fallback; 258 #ifdef CONFIG_NET_CLS_ACT 259 switch (result) { 260 case TC_ACT_QUEUED: 261 case TC_ACT_STOLEN: 262 *qerr = NET_XMIT_SUCCESS | __NET_XMIT_STOLEN; 263 case TC_ACT_SHOT: 264 return NULL; 265 case TC_ACT_RECLASSIFY: 266 return cbq_reclassify(skb, cl); 267 } 268 #endif 269 if (cl->level == 0) 270 return cl; 271 272 /* 273 * Step 3+n. If classifier selected a link sharing class, 274 * apply agency specific classifier. 275 * Repeat this procdure until we hit a leaf node. 276 */ 277 head = cl; 278 } 279 280 fallback: 281 cl = head; 282 283 /* 284 * Step 4. No success... 285 */ 286 if (TC_H_MAJ(prio) == 0 && 287 !(cl = head->defaults[prio & TC_PRIO_MAX]) && 288 !(cl = head->defaults[TC_PRIO_BESTEFFORT])) 289 return head; 290 291 return cl; 292 } 293 294 /* 295 * A packet has just been enqueued on the empty class. 296 * cbq_activate_class adds it to the tail of active class list 297 * of its priority band. 298 */ 299 300 static inline void cbq_activate_class(struct cbq_class *cl) 301 { 302 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 303 int prio = cl->cpriority; 304 struct cbq_class *cl_tail; 305 306 cl_tail = q->active[prio]; 307 q->active[prio] = cl; 308 309 if (cl_tail != NULL) { 310 cl->next_alive = cl_tail->next_alive; 311 cl_tail->next_alive = cl; 312 } else { 313 cl->next_alive = cl; 314 q->activemask |= (1<<prio); 315 } 316 } 317 318 /* 319 * Unlink class from active chain. 320 * Note that this same procedure is done directly in cbq_dequeue* 321 * during round-robin procedure. 322 */ 323 324 static void cbq_deactivate_class(struct cbq_class *this) 325 { 326 struct cbq_sched_data *q = qdisc_priv(this->qdisc); 327 int prio = this->cpriority; 328 struct cbq_class *cl; 329 struct cbq_class *cl_prev = q->active[prio]; 330 331 do { 332 cl = cl_prev->next_alive; 333 if (cl == this) { 334 cl_prev->next_alive = cl->next_alive; 335 cl->next_alive = NULL; 336 337 if (cl == q->active[prio]) { 338 q->active[prio] = cl_prev; 339 if (cl == q->active[prio]) { 340 q->active[prio] = NULL; 341 q->activemask &= ~(1<<prio); 342 return; 343 } 344 } 345 return; 346 } 347 } while ((cl_prev = cl) != q->active[prio]); 348 } 349 350 static void 351 cbq_mark_toplevel(struct cbq_sched_data *q, struct cbq_class *cl) 352 { 353 int toplevel = q->toplevel; 354 355 if (toplevel > cl->level && !(qdisc_is_throttled(cl->q))) { 356 psched_time_t now; 357 psched_tdiff_t incr; 358 359 now = psched_get_time(); 360 incr = now - q->now_rt; 361 now = q->now + incr; 362 363 do { 364 if (cl->undertime < now) { 365 q->toplevel = cl->level; 366 return; 367 } 368 } while ((cl = cl->borrow) != NULL && toplevel > cl->level); 369 } 370 } 371 372 static int 373 cbq_enqueue(struct sk_buff *skb, struct Qdisc *sch) 374 { 375 struct cbq_sched_data *q = qdisc_priv(sch); 376 int uninitialized_var(ret); 377 struct cbq_class *cl = cbq_classify(skb, sch, &ret); 378 379 #ifdef CONFIG_NET_CLS_ACT 380 q->rx_class = cl; 381 #endif 382 if (cl == NULL) { 383 if (ret & __NET_XMIT_BYPASS) 384 sch->qstats.drops++; 385 kfree_skb(skb); 386 return ret; 387 } 388 389 #ifdef CONFIG_NET_CLS_ACT 390 cl->q->__parent = sch; 391 #endif 392 ret = qdisc_enqueue(skb, cl->q); 393 if (ret == NET_XMIT_SUCCESS) { 394 sch->q.qlen++; 395 cbq_mark_toplevel(q, cl); 396 if (!cl->next_alive) 397 cbq_activate_class(cl); 398 return ret; 399 } 400 401 if (net_xmit_drop_count(ret)) { 402 sch->qstats.drops++; 403 cbq_mark_toplevel(q, cl); 404 cl->qstats.drops++; 405 } 406 return ret; 407 } 408 409 /* Overlimit actions */ 410 411 /* TC_CBQ_OVL_CLASSIC: (default) penalize leaf class by adding offtime */ 412 413 static void cbq_ovl_classic(struct cbq_class *cl) 414 { 415 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 416 psched_tdiff_t delay = cl->undertime - q->now; 417 418 if (!cl->delayed) { 419 delay += cl->offtime; 420 421 /* 422 * Class goes to sleep, so that it will have no 423 * chance to work avgidle. Let's forgive it 8) 424 * 425 * BTW cbq-2.0 has a crap in this 426 * place, apparently they forgot to shift it by cl->ewma_log. 427 */ 428 if (cl->avgidle < 0) 429 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log); 430 if (cl->avgidle < cl->minidle) 431 cl->avgidle = cl->minidle; 432 if (delay <= 0) 433 delay = 1; 434 cl->undertime = q->now + delay; 435 436 cl->xstats.overactions++; 437 cl->delayed = 1; 438 } 439 if (q->wd_expires == 0 || q->wd_expires > delay) 440 q->wd_expires = delay; 441 442 /* Dirty work! We must schedule wakeups based on 443 * real available rate, rather than leaf rate, 444 * which may be tiny (even zero). 445 */ 446 if (q->toplevel == TC_CBQ_MAXLEVEL) { 447 struct cbq_class *b; 448 psched_tdiff_t base_delay = q->wd_expires; 449 450 for (b = cl->borrow; b; b = b->borrow) { 451 delay = b->undertime - q->now; 452 if (delay < base_delay) { 453 if (delay <= 0) 454 delay = 1; 455 base_delay = delay; 456 } 457 } 458 459 q->wd_expires = base_delay; 460 } 461 } 462 463 /* TC_CBQ_OVL_RCLASSIC: penalize by offtime classes in hierarchy, when 464 * they go overlimit 465 */ 466 467 static void cbq_ovl_rclassic(struct cbq_class *cl) 468 { 469 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 470 struct cbq_class *this = cl; 471 472 do { 473 if (cl->level > q->toplevel) { 474 cl = NULL; 475 break; 476 } 477 } while ((cl = cl->borrow) != NULL); 478 479 if (cl == NULL) 480 cl = this; 481 cbq_ovl_classic(cl); 482 } 483 484 /* TC_CBQ_OVL_DELAY: delay until it will go to underlimit */ 485 486 static void cbq_ovl_delay(struct cbq_class *cl) 487 { 488 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 489 psched_tdiff_t delay = cl->undertime - q->now; 490 491 if (test_bit(__QDISC_STATE_DEACTIVATED, 492 &qdisc_root_sleeping(cl->qdisc)->state)) 493 return; 494 495 if (!cl->delayed) { 496 psched_time_t sched = q->now; 497 ktime_t expires; 498 499 delay += cl->offtime; 500 if (cl->avgidle < 0) 501 delay -= (-cl->avgidle) - ((-cl->avgidle) >> cl->ewma_log); 502 if (cl->avgidle < cl->minidle) 503 cl->avgidle = cl->minidle; 504 cl->undertime = q->now + delay; 505 506 if (delay > 0) { 507 sched += delay + cl->penalty; 508 cl->penalized = sched; 509 cl->cpriority = TC_CBQ_MAXPRIO; 510 q->pmask |= (1<<TC_CBQ_MAXPRIO); 511 512 expires = ns_to_ktime(PSCHED_TICKS2NS(sched)); 513 if (hrtimer_try_to_cancel(&q->delay_timer) && 514 ktime_to_ns(ktime_sub( 515 hrtimer_get_expires(&q->delay_timer), 516 expires)) > 0) 517 hrtimer_set_expires(&q->delay_timer, expires); 518 hrtimer_restart(&q->delay_timer); 519 cl->delayed = 1; 520 cl->xstats.overactions++; 521 return; 522 } 523 delay = 1; 524 } 525 if (q->wd_expires == 0 || q->wd_expires > delay) 526 q->wd_expires = delay; 527 } 528 529 /* TC_CBQ_OVL_LOWPRIO: penalize class by lowering its priority band */ 530 531 static void cbq_ovl_lowprio(struct cbq_class *cl) 532 { 533 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 534 535 cl->penalized = q->now + cl->penalty; 536 537 if (cl->cpriority != cl->priority2) { 538 cl->cpriority = cl->priority2; 539 q->pmask |= (1<<cl->cpriority); 540 cl->xstats.overactions++; 541 } 542 cbq_ovl_classic(cl); 543 } 544 545 /* TC_CBQ_OVL_DROP: penalize class by dropping */ 546 547 static void cbq_ovl_drop(struct cbq_class *cl) 548 { 549 if (cl->q->ops->drop) 550 if (cl->q->ops->drop(cl->q)) 551 cl->qdisc->q.qlen--; 552 cl->xstats.overactions++; 553 cbq_ovl_classic(cl); 554 } 555 556 static psched_tdiff_t cbq_undelay_prio(struct cbq_sched_data *q, int prio, 557 psched_time_t now) 558 { 559 struct cbq_class *cl; 560 struct cbq_class *cl_prev = q->active[prio]; 561 psched_time_t sched = now; 562 563 if (cl_prev == NULL) 564 return 0; 565 566 do { 567 cl = cl_prev->next_alive; 568 if (now - cl->penalized > 0) { 569 cl_prev->next_alive = cl->next_alive; 570 cl->next_alive = NULL; 571 cl->cpriority = cl->priority; 572 cl->delayed = 0; 573 cbq_activate_class(cl); 574 575 if (cl == q->active[prio]) { 576 q->active[prio] = cl_prev; 577 if (cl == q->active[prio]) { 578 q->active[prio] = NULL; 579 return 0; 580 } 581 } 582 583 cl = cl_prev->next_alive; 584 } else if (sched - cl->penalized > 0) 585 sched = cl->penalized; 586 } while ((cl_prev = cl) != q->active[prio]); 587 588 return sched - now; 589 } 590 591 static enum hrtimer_restart cbq_undelay(struct hrtimer *timer) 592 { 593 struct cbq_sched_data *q = container_of(timer, struct cbq_sched_data, 594 delay_timer); 595 struct Qdisc *sch = q->watchdog.qdisc; 596 psched_time_t now; 597 psched_tdiff_t delay = 0; 598 unsigned int pmask; 599 600 now = psched_get_time(); 601 602 pmask = q->pmask; 603 q->pmask = 0; 604 605 while (pmask) { 606 int prio = ffz(~pmask); 607 psched_tdiff_t tmp; 608 609 pmask &= ~(1<<prio); 610 611 tmp = cbq_undelay_prio(q, prio, now); 612 if (tmp > 0) { 613 q->pmask |= 1<<prio; 614 if (tmp < delay || delay == 0) 615 delay = tmp; 616 } 617 } 618 619 if (delay) { 620 ktime_t time; 621 622 time = ktime_set(0, 0); 623 time = ktime_add_ns(time, PSCHED_TICKS2NS(now + delay)); 624 hrtimer_start(&q->delay_timer, time, HRTIMER_MODE_ABS); 625 } 626 627 qdisc_unthrottled(sch); 628 __netif_schedule(qdisc_root(sch)); 629 return HRTIMER_NORESTART; 630 } 631 632 #ifdef CONFIG_NET_CLS_ACT 633 static int cbq_reshape_fail(struct sk_buff *skb, struct Qdisc *child) 634 { 635 struct Qdisc *sch = child->__parent; 636 struct cbq_sched_data *q = qdisc_priv(sch); 637 struct cbq_class *cl = q->rx_class; 638 639 q->rx_class = NULL; 640 641 if (cl && (cl = cbq_reclassify(skb, cl)) != NULL) { 642 int ret; 643 644 cbq_mark_toplevel(q, cl); 645 646 q->rx_class = cl; 647 cl->q->__parent = sch; 648 649 ret = qdisc_enqueue(skb, cl->q); 650 if (ret == NET_XMIT_SUCCESS) { 651 sch->q.qlen++; 652 if (!cl->next_alive) 653 cbq_activate_class(cl); 654 return 0; 655 } 656 if (net_xmit_drop_count(ret)) 657 sch->qstats.drops++; 658 return 0; 659 } 660 661 sch->qstats.drops++; 662 return -1; 663 } 664 #endif 665 666 /* 667 * It is mission critical procedure. 668 * 669 * We "regenerate" toplevel cutoff, if transmitting class 670 * has backlog and it is not regulated. It is not part of 671 * original CBQ description, but looks more reasonable. 672 * Probably, it is wrong. This question needs further investigation. 673 */ 674 675 static inline void 676 cbq_update_toplevel(struct cbq_sched_data *q, struct cbq_class *cl, 677 struct cbq_class *borrowed) 678 { 679 if (cl && q->toplevel >= borrowed->level) { 680 if (cl->q->q.qlen > 1) { 681 do { 682 if (borrowed->undertime == PSCHED_PASTPERFECT) { 683 q->toplevel = borrowed->level; 684 return; 685 } 686 } while ((borrowed = borrowed->borrow) != NULL); 687 } 688 #if 0 689 /* It is not necessary now. Uncommenting it 690 will save CPU cycles, but decrease fairness. 691 */ 692 q->toplevel = TC_CBQ_MAXLEVEL; 693 #endif 694 } 695 } 696 697 static void 698 cbq_update(struct cbq_sched_data *q) 699 { 700 struct cbq_class *this = q->tx_class; 701 struct cbq_class *cl = this; 702 int len = q->tx_len; 703 704 q->tx_class = NULL; 705 706 for ( ; cl; cl = cl->share) { 707 long avgidle = cl->avgidle; 708 long idle; 709 710 cl->bstats.packets++; 711 cl->bstats.bytes += len; 712 713 /* 714 * (now - last) is total time between packet right edges. 715 * (last_pktlen/rate) is "virtual" busy time, so that 716 * 717 * idle = (now - last) - last_pktlen/rate 718 */ 719 720 idle = q->now - cl->last; 721 if ((unsigned long)idle > 128*1024*1024) { 722 avgidle = cl->maxidle; 723 } else { 724 idle -= L2T(cl, len); 725 726 /* true_avgidle := (1-W)*true_avgidle + W*idle, 727 * where W=2^{-ewma_log}. But cl->avgidle is scaled: 728 * cl->avgidle == true_avgidle/W, 729 * hence: 730 */ 731 avgidle += idle - (avgidle>>cl->ewma_log); 732 } 733 734 if (avgidle <= 0) { 735 /* Overlimit or at-limit */ 736 737 if (avgidle < cl->minidle) 738 avgidle = cl->minidle; 739 740 cl->avgidle = avgidle; 741 742 /* Calculate expected time, when this class 743 * will be allowed to send. 744 * It will occur, when: 745 * (1-W)*true_avgidle + W*delay = 0, i.e. 746 * idle = (1/W - 1)*(-true_avgidle) 747 * or 748 * idle = (1 - W)*(-cl->avgidle); 749 */ 750 idle = (-avgidle) - ((-avgidle) >> cl->ewma_log); 751 752 /* 753 * That is not all. 754 * To maintain the rate allocated to the class, 755 * we add to undertime virtual clock, 756 * necessary to complete transmitted packet. 757 * (len/phys_bandwidth has been already passed 758 * to the moment of cbq_update) 759 */ 760 761 idle -= L2T(&q->link, len); 762 idle += L2T(cl, len); 763 764 cl->undertime = q->now + idle; 765 } else { 766 /* Underlimit */ 767 768 cl->undertime = PSCHED_PASTPERFECT; 769 if (avgidle > cl->maxidle) 770 cl->avgidle = cl->maxidle; 771 else 772 cl->avgidle = avgidle; 773 } 774 cl->last = q->now; 775 } 776 777 cbq_update_toplevel(q, this, q->tx_borrowed); 778 } 779 780 static inline struct cbq_class * 781 cbq_under_limit(struct cbq_class *cl) 782 { 783 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 784 struct cbq_class *this_cl = cl; 785 786 if (cl->tparent == NULL) 787 return cl; 788 789 if (cl->undertime == PSCHED_PASTPERFECT || q->now >= cl->undertime) { 790 cl->delayed = 0; 791 return cl; 792 } 793 794 do { 795 /* It is very suspicious place. Now overlimit 796 * action is generated for not bounded classes 797 * only if link is completely congested. 798 * Though it is in agree with ancestor-only paradigm, 799 * it looks very stupid. Particularly, 800 * it means that this chunk of code will either 801 * never be called or result in strong amplification 802 * of burstiness. Dangerous, silly, and, however, 803 * no another solution exists. 804 */ 805 cl = cl->borrow; 806 if (!cl) { 807 this_cl->qstats.overlimits++; 808 this_cl->overlimit(this_cl); 809 return NULL; 810 } 811 if (cl->level > q->toplevel) 812 return NULL; 813 } while (cl->undertime != PSCHED_PASTPERFECT && q->now < cl->undertime); 814 815 cl->delayed = 0; 816 return cl; 817 } 818 819 static inline struct sk_buff * 820 cbq_dequeue_prio(struct Qdisc *sch, int prio) 821 { 822 struct cbq_sched_data *q = qdisc_priv(sch); 823 struct cbq_class *cl_tail, *cl_prev, *cl; 824 struct sk_buff *skb; 825 int deficit; 826 827 cl_tail = cl_prev = q->active[prio]; 828 cl = cl_prev->next_alive; 829 830 do { 831 deficit = 0; 832 833 /* Start round */ 834 do { 835 struct cbq_class *borrow = cl; 836 837 if (cl->q->q.qlen && 838 (borrow = cbq_under_limit(cl)) == NULL) 839 goto skip_class; 840 841 if (cl->deficit <= 0) { 842 /* Class exhausted its allotment per 843 * this round. Switch to the next one. 844 */ 845 deficit = 1; 846 cl->deficit += cl->quantum; 847 goto next_class; 848 } 849 850 skb = cl->q->dequeue(cl->q); 851 852 /* Class did not give us any skb :-( 853 * It could occur even if cl->q->q.qlen != 0 854 * f.e. if cl->q == "tbf" 855 */ 856 if (skb == NULL) 857 goto skip_class; 858 859 cl->deficit -= qdisc_pkt_len(skb); 860 q->tx_class = cl; 861 q->tx_borrowed = borrow; 862 if (borrow != cl) { 863 #ifndef CBQ_XSTATS_BORROWS_BYTES 864 borrow->xstats.borrows++; 865 cl->xstats.borrows++; 866 #else 867 borrow->xstats.borrows += qdisc_pkt_len(skb); 868 cl->xstats.borrows += qdisc_pkt_len(skb); 869 #endif 870 } 871 q->tx_len = qdisc_pkt_len(skb); 872 873 if (cl->deficit <= 0) { 874 q->active[prio] = cl; 875 cl = cl->next_alive; 876 cl->deficit += cl->quantum; 877 } 878 return skb; 879 880 skip_class: 881 if (cl->q->q.qlen == 0 || prio != cl->cpriority) { 882 /* Class is empty or penalized. 883 * Unlink it from active chain. 884 */ 885 cl_prev->next_alive = cl->next_alive; 886 cl->next_alive = NULL; 887 888 /* Did cl_tail point to it? */ 889 if (cl == cl_tail) { 890 /* Repair it! */ 891 cl_tail = cl_prev; 892 893 /* Was it the last class in this band? */ 894 if (cl == cl_tail) { 895 /* Kill the band! */ 896 q->active[prio] = NULL; 897 q->activemask &= ~(1<<prio); 898 if (cl->q->q.qlen) 899 cbq_activate_class(cl); 900 return NULL; 901 } 902 903 q->active[prio] = cl_tail; 904 } 905 if (cl->q->q.qlen) 906 cbq_activate_class(cl); 907 908 cl = cl_prev; 909 } 910 911 next_class: 912 cl_prev = cl; 913 cl = cl->next_alive; 914 } while (cl_prev != cl_tail); 915 } while (deficit); 916 917 q->active[prio] = cl_prev; 918 919 return NULL; 920 } 921 922 static inline struct sk_buff * 923 cbq_dequeue_1(struct Qdisc *sch) 924 { 925 struct cbq_sched_data *q = qdisc_priv(sch); 926 struct sk_buff *skb; 927 unsigned int activemask; 928 929 activemask = q->activemask & 0xFF; 930 while (activemask) { 931 int prio = ffz(~activemask); 932 activemask &= ~(1<<prio); 933 skb = cbq_dequeue_prio(sch, prio); 934 if (skb) 935 return skb; 936 } 937 return NULL; 938 } 939 940 static struct sk_buff * 941 cbq_dequeue(struct Qdisc *sch) 942 { 943 struct sk_buff *skb; 944 struct cbq_sched_data *q = qdisc_priv(sch); 945 psched_time_t now; 946 psched_tdiff_t incr; 947 948 now = psched_get_time(); 949 incr = now - q->now_rt; 950 951 if (q->tx_class) { 952 psched_tdiff_t incr2; 953 /* Time integrator. We calculate EOS time 954 * by adding expected packet transmission time. 955 * If real time is greater, we warp artificial clock, 956 * so that: 957 * 958 * cbq_time = max(real_time, work); 959 */ 960 incr2 = L2T(&q->link, q->tx_len); 961 q->now += incr2; 962 cbq_update(q); 963 if ((incr -= incr2) < 0) 964 incr = 0; 965 q->now += incr; 966 } else { 967 if (now > q->now) 968 q->now = now; 969 } 970 q->now_rt = now; 971 972 for (;;) { 973 q->wd_expires = 0; 974 975 skb = cbq_dequeue_1(sch); 976 if (skb) { 977 qdisc_bstats_update(sch, skb); 978 sch->q.qlen--; 979 qdisc_unthrottled(sch); 980 return skb; 981 } 982 983 /* All the classes are overlimit. 984 * 985 * It is possible, if: 986 * 987 * 1. Scheduler is empty. 988 * 2. Toplevel cutoff inhibited borrowing. 989 * 3. Root class is overlimit. 990 * 991 * Reset 2d and 3d conditions and retry. 992 * 993 * Note, that NS and cbq-2.0 are buggy, peeking 994 * an arbitrary class is appropriate for ancestor-only 995 * sharing, but not for toplevel algorithm. 996 * 997 * Our version is better, but slower, because it requires 998 * two passes, but it is unavoidable with top-level sharing. 999 */ 1000 1001 if (q->toplevel == TC_CBQ_MAXLEVEL && 1002 q->link.undertime == PSCHED_PASTPERFECT) 1003 break; 1004 1005 q->toplevel = TC_CBQ_MAXLEVEL; 1006 q->link.undertime = PSCHED_PASTPERFECT; 1007 } 1008 1009 /* No packets in scheduler or nobody wants to give them to us :-( 1010 * Sigh... start watchdog timer in the last case. 1011 */ 1012 1013 if (sch->q.qlen) { 1014 sch->qstats.overlimits++; 1015 if (q->wd_expires) 1016 qdisc_watchdog_schedule(&q->watchdog, 1017 now + q->wd_expires); 1018 } 1019 return NULL; 1020 } 1021 1022 /* CBQ class maintanance routines */ 1023 1024 static void cbq_adjust_levels(struct cbq_class *this) 1025 { 1026 if (this == NULL) 1027 return; 1028 1029 do { 1030 int level = 0; 1031 struct cbq_class *cl; 1032 1033 cl = this->children; 1034 if (cl) { 1035 do { 1036 if (cl->level > level) 1037 level = cl->level; 1038 } while ((cl = cl->sibling) != this->children); 1039 } 1040 this->level = level + 1; 1041 } while ((this = this->tparent) != NULL); 1042 } 1043 1044 static void cbq_normalize_quanta(struct cbq_sched_data *q, int prio) 1045 { 1046 struct cbq_class *cl; 1047 unsigned int h; 1048 1049 if (q->quanta[prio] == 0) 1050 return; 1051 1052 for (h = 0; h < q->clhash.hashsize; h++) { 1053 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) { 1054 /* BUGGGG... Beware! This expression suffer of 1055 * arithmetic overflows! 1056 */ 1057 if (cl->priority == prio) { 1058 cl->quantum = (cl->weight*cl->allot*q->nclasses[prio])/ 1059 q->quanta[prio]; 1060 } 1061 if (cl->quantum <= 0 || cl->quantum>32*qdisc_dev(cl->qdisc)->mtu) { 1062 pr_warning("CBQ: class %08x has bad quantum==%ld, repaired.\n", 1063 cl->common.classid, cl->quantum); 1064 cl->quantum = qdisc_dev(cl->qdisc)->mtu/2 + 1; 1065 } 1066 } 1067 } 1068 } 1069 1070 static void cbq_sync_defmap(struct cbq_class *cl) 1071 { 1072 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 1073 struct cbq_class *split = cl->split; 1074 unsigned int h; 1075 int i; 1076 1077 if (split == NULL) 1078 return; 1079 1080 for (i = 0; i <= TC_PRIO_MAX; i++) { 1081 if (split->defaults[i] == cl && !(cl->defmap & (1<<i))) 1082 split->defaults[i] = NULL; 1083 } 1084 1085 for (i = 0; i <= TC_PRIO_MAX; i++) { 1086 int level = split->level; 1087 1088 if (split->defaults[i]) 1089 continue; 1090 1091 for (h = 0; h < q->clhash.hashsize; h++) { 1092 struct cbq_class *c; 1093 1094 hlist_for_each_entry(c, &q->clhash.hash[h], 1095 common.hnode) { 1096 if (c->split == split && c->level < level && 1097 c->defmap & (1<<i)) { 1098 split->defaults[i] = c; 1099 level = c->level; 1100 } 1101 } 1102 } 1103 } 1104 } 1105 1106 static void cbq_change_defmap(struct cbq_class *cl, u32 splitid, u32 def, u32 mask) 1107 { 1108 struct cbq_class *split = NULL; 1109 1110 if (splitid == 0) { 1111 split = cl->split; 1112 if (!split) 1113 return; 1114 splitid = split->common.classid; 1115 } 1116 1117 if (split == NULL || split->common.classid != splitid) { 1118 for (split = cl->tparent; split; split = split->tparent) 1119 if (split->common.classid == splitid) 1120 break; 1121 } 1122 1123 if (split == NULL) 1124 return; 1125 1126 if (cl->split != split) { 1127 cl->defmap = 0; 1128 cbq_sync_defmap(cl); 1129 cl->split = split; 1130 cl->defmap = def & mask; 1131 } else 1132 cl->defmap = (cl->defmap & ~mask) | (def & mask); 1133 1134 cbq_sync_defmap(cl); 1135 } 1136 1137 static void cbq_unlink_class(struct cbq_class *this) 1138 { 1139 struct cbq_class *cl, **clp; 1140 struct cbq_sched_data *q = qdisc_priv(this->qdisc); 1141 1142 qdisc_class_hash_remove(&q->clhash, &this->common); 1143 1144 if (this->tparent) { 1145 clp = &this->sibling; 1146 cl = *clp; 1147 do { 1148 if (cl == this) { 1149 *clp = cl->sibling; 1150 break; 1151 } 1152 clp = &cl->sibling; 1153 } while ((cl = *clp) != this->sibling); 1154 1155 if (this->tparent->children == this) { 1156 this->tparent->children = this->sibling; 1157 if (this->sibling == this) 1158 this->tparent->children = NULL; 1159 } 1160 } else { 1161 WARN_ON(this->sibling != this); 1162 } 1163 } 1164 1165 static void cbq_link_class(struct cbq_class *this) 1166 { 1167 struct cbq_sched_data *q = qdisc_priv(this->qdisc); 1168 struct cbq_class *parent = this->tparent; 1169 1170 this->sibling = this; 1171 qdisc_class_hash_insert(&q->clhash, &this->common); 1172 1173 if (parent == NULL) 1174 return; 1175 1176 if (parent->children == NULL) { 1177 parent->children = this; 1178 } else { 1179 this->sibling = parent->children->sibling; 1180 parent->children->sibling = this; 1181 } 1182 } 1183 1184 static unsigned int cbq_drop(struct Qdisc *sch) 1185 { 1186 struct cbq_sched_data *q = qdisc_priv(sch); 1187 struct cbq_class *cl, *cl_head; 1188 int prio; 1189 unsigned int len; 1190 1191 for (prio = TC_CBQ_MAXPRIO; prio >= 0; prio--) { 1192 cl_head = q->active[prio]; 1193 if (!cl_head) 1194 continue; 1195 1196 cl = cl_head; 1197 do { 1198 if (cl->q->ops->drop && (len = cl->q->ops->drop(cl->q))) { 1199 sch->q.qlen--; 1200 if (!cl->q->q.qlen) 1201 cbq_deactivate_class(cl); 1202 return len; 1203 } 1204 } while ((cl = cl->next_alive) != cl_head); 1205 } 1206 return 0; 1207 } 1208 1209 static void 1210 cbq_reset(struct Qdisc *sch) 1211 { 1212 struct cbq_sched_data *q = qdisc_priv(sch); 1213 struct cbq_class *cl; 1214 int prio; 1215 unsigned int h; 1216 1217 q->activemask = 0; 1218 q->pmask = 0; 1219 q->tx_class = NULL; 1220 q->tx_borrowed = NULL; 1221 qdisc_watchdog_cancel(&q->watchdog); 1222 hrtimer_cancel(&q->delay_timer); 1223 q->toplevel = TC_CBQ_MAXLEVEL; 1224 q->now = psched_get_time(); 1225 q->now_rt = q->now; 1226 1227 for (prio = 0; prio <= TC_CBQ_MAXPRIO; prio++) 1228 q->active[prio] = NULL; 1229 1230 for (h = 0; h < q->clhash.hashsize; h++) { 1231 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) { 1232 qdisc_reset(cl->q); 1233 1234 cl->next_alive = NULL; 1235 cl->undertime = PSCHED_PASTPERFECT; 1236 cl->avgidle = cl->maxidle; 1237 cl->deficit = cl->quantum; 1238 cl->cpriority = cl->priority; 1239 } 1240 } 1241 sch->q.qlen = 0; 1242 } 1243 1244 1245 static int cbq_set_lss(struct cbq_class *cl, struct tc_cbq_lssopt *lss) 1246 { 1247 if (lss->change & TCF_CBQ_LSS_FLAGS) { 1248 cl->share = (lss->flags & TCF_CBQ_LSS_ISOLATED) ? NULL : cl->tparent; 1249 cl->borrow = (lss->flags & TCF_CBQ_LSS_BOUNDED) ? NULL : cl->tparent; 1250 } 1251 if (lss->change & TCF_CBQ_LSS_EWMA) 1252 cl->ewma_log = lss->ewma_log; 1253 if (lss->change & TCF_CBQ_LSS_AVPKT) 1254 cl->avpkt = lss->avpkt; 1255 if (lss->change & TCF_CBQ_LSS_MINIDLE) 1256 cl->minidle = -(long)lss->minidle; 1257 if (lss->change & TCF_CBQ_LSS_MAXIDLE) { 1258 cl->maxidle = lss->maxidle; 1259 cl->avgidle = lss->maxidle; 1260 } 1261 if (lss->change & TCF_CBQ_LSS_OFFTIME) 1262 cl->offtime = lss->offtime; 1263 return 0; 1264 } 1265 1266 static void cbq_rmprio(struct cbq_sched_data *q, struct cbq_class *cl) 1267 { 1268 q->nclasses[cl->priority]--; 1269 q->quanta[cl->priority] -= cl->weight; 1270 cbq_normalize_quanta(q, cl->priority); 1271 } 1272 1273 static void cbq_addprio(struct cbq_sched_data *q, struct cbq_class *cl) 1274 { 1275 q->nclasses[cl->priority]++; 1276 q->quanta[cl->priority] += cl->weight; 1277 cbq_normalize_quanta(q, cl->priority); 1278 } 1279 1280 static int cbq_set_wrr(struct cbq_class *cl, struct tc_cbq_wrropt *wrr) 1281 { 1282 struct cbq_sched_data *q = qdisc_priv(cl->qdisc); 1283 1284 if (wrr->allot) 1285 cl->allot = wrr->allot; 1286 if (wrr->weight) 1287 cl->weight = wrr->weight; 1288 if (wrr->priority) { 1289 cl->priority = wrr->priority - 1; 1290 cl->cpriority = cl->priority; 1291 if (cl->priority >= cl->priority2) 1292 cl->priority2 = TC_CBQ_MAXPRIO - 1; 1293 } 1294 1295 cbq_addprio(q, cl); 1296 return 0; 1297 } 1298 1299 static int cbq_set_overlimit(struct cbq_class *cl, struct tc_cbq_ovl *ovl) 1300 { 1301 switch (ovl->strategy) { 1302 case TC_CBQ_OVL_CLASSIC: 1303 cl->overlimit = cbq_ovl_classic; 1304 break; 1305 case TC_CBQ_OVL_DELAY: 1306 cl->overlimit = cbq_ovl_delay; 1307 break; 1308 case TC_CBQ_OVL_LOWPRIO: 1309 if (ovl->priority2 - 1 >= TC_CBQ_MAXPRIO || 1310 ovl->priority2 - 1 <= cl->priority) 1311 return -EINVAL; 1312 cl->priority2 = ovl->priority2 - 1; 1313 cl->overlimit = cbq_ovl_lowprio; 1314 break; 1315 case TC_CBQ_OVL_DROP: 1316 cl->overlimit = cbq_ovl_drop; 1317 break; 1318 case TC_CBQ_OVL_RCLASSIC: 1319 cl->overlimit = cbq_ovl_rclassic; 1320 break; 1321 default: 1322 return -EINVAL; 1323 } 1324 cl->penalty = ovl->penalty; 1325 return 0; 1326 } 1327 1328 #ifdef CONFIG_NET_CLS_ACT 1329 static int cbq_set_police(struct cbq_class *cl, struct tc_cbq_police *p) 1330 { 1331 cl->police = p->police; 1332 1333 if (cl->q->handle) { 1334 if (p->police == TC_POLICE_RECLASSIFY) 1335 cl->q->reshape_fail = cbq_reshape_fail; 1336 else 1337 cl->q->reshape_fail = NULL; 1338 } 1339 return 0; 1340 } 1341 #endif 1342 1343 static int cbq_set_fopt(struct cbq_class *cl, struct tc_cbq_fopt *fopt) 1344 { 1345 cbq_change_defmap(cl, fopt->split, fopt->defmap, fopt->defchange); 1346 return 0; 1347 } 1348 1349 static const struct nla_policy cbq_policy[TCA_CBQ_MAX + 1] = { 1350 [TCA_CBQ_LSSOPT] = { .len = sizeof(struct tc_cbq_lssopt) }, 1351 [TCA_CBQ_WRROPT] = { .len = sizeof(struct tc_cbq_wrropt) }, 1352 [TCA_CBQ_FOPT] = { .len = sizeof(struct tc_cbq_fopt) }, 1353 [TCA_CBQ_OVL_STRATEGY] = { .len = sizeof(struct tc_cbq_ovl) }, 1354 [TCA_CBQ_RATE] = { .len = sizeof(struct tc_ratespec) }, 1355 [TCA_CBQ_RTAB] = { .type = NLA_BINARY, .len = TC_RTAB_SIZE }, 1356 [TCA_CBQ_POLICE] = { .len = sizeof(struct tc_cbq_police) }, 1357 }; 1358 1359 static int cbq_init(struct Qdisc *sch, struct nlattr *opt) 1360 { 1361 struct cbq_sched_data *q = qdisc_priv(sch); 1362 struct nlattr *tb[TCA_CBQ_MAX + 1]; 1363 struct tc_ratespec *r; 1364 int err; 1365 1366 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy); 1367 if (err < 0) 1368 return err; 1369 1370 if (tb[TCA_CBQ_RTAB] == NULL || tb[TCA_CBQ_RATE] == NULL) 1371 return -EINVAL; 1372 1373 r = nla_data(tb[TCA_CBQ_RATE]); 1374 1375 if ((q->link.R_tab = qdisc_get_rtab(r, tb[TCA_CBQ_RTAB])) == NULL) 1376 return -EINVAL; 1377 1378 err = qdisc_class_hash_init(&q->clhash); 1379 if (err < 0) 1380 goto put_rtab; 1381 1382 q->link.refcnt = 1; 1383 q->link.sibling = &q->link; 1384 q->link.common.classid = sch->handle; 1385 q->link.qdisc = sch; 1386 q->link.q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, 1387 sch->handle); 1388 if (!q->link.q) 1389 q->link.q = &noop_qdisc; 1390 1391 q->link.priority = TC_CBQ_MAXPRIO - 1; 1392 q->link.priority2 = TC_CBQ_MAXPRIO - 1; 1393 q->link.cpriority = TC_CBQ_MAXPRIO - 1; 1394 q->link.ovl_strategy = TC_CBQ_OVL_CLASSIC; 1395 q->link.overlimit = cbq_ovl_classic; 1396 q->link.allot = psched_mtu(qdisc_dev(sch)); 1397 q->link.quantum = q->link.allot; 1398 q->link.weight = q->link.R_tab->rate.rate; 1399 1400 q->link.ewma_log = TC_CBQ_DEF_EWMA; 1401 q->link.avpkt = q->link.allot/2; 1402 q->link.minidle = -0x7FFFFFFF; 1403 1404 qdisc_watchdog_init(&q->watchdog, sch); 1405 hrtimer_init(&q->delay_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS); 1406 q->delay_timer.function = cbq_undelay; 1407 q->toplevel = TC_CBQ_MAXLEVEL; 1408 q->now = psched_get_time(); 1409 q->now_rt = q->now; 1410 1411 cbq_link_class(&q->link); 1412 1413 if (tb[TCA_CBQ_LSSOPT]) 1414 cbq_set_lss(&q->link, nla_data(tb[TCA_CBQ_LSSOPT])); 1415 1416 cbq_addprio(q, &q->link); 1417 return 0; 1418 1419 put_rtab: 1420 qdisc_put_rtab(q->link.R_tab); 1421 return err; 1422 } 1423 1424 static int cbq_dump_rate(struct sk_buff *skb, struct cbq_class *cl) 1425 { 1426 unsigned char *b = skb_tail_pointer(skb); 1427 1428 if (nla_put(skb, TCA_CBQ_RATE, sizeof(cl->R_tab->rate), &cl->R_tab->rate)) 1429 goto nla_put_failure; 1430 return skb->len; 1431 1432 nla_put_failure: 1433 nlmsg_trim(skb, b); 1434 return -1; 1435 } 1436 1437 static int cbq_dump_lss(struct sk_buff *skb, struct cbq_class *cl) 1438 { 1439 unsigned char *b = skb_tail_pointer(skb); 1440 struct tc_cbq_lssopt opt; 1441 1442 opt.flags = 0; 1443 if (cl->borrow == NULL) 1444 opt.flags |= TCF_CBQ_LSS_BOUNDED; 1445 if (cl->share == NULL) 1446 opt.flags |= TCF_CBQ_LSS_ISOLATED; 1447 opt.ewma_log = cl->ewma_log; 1448 opt.level = cl->level; 1449 opt.avpkt = cl->avpkt; 1450 opt.maxidle = cl->maxidle; 1451 opt.minidle = (u32)(-cl->minidle); 1452 opt.offtime = cl->offtime; 1453 opt.change = ~0; 1454 if (nla_put(skb, TCA_CBQ_LSSOPT, sizeof(opt), &opt)) 1455 goto nla_put_failure; 1456 return skb->len; 1457 1458 nla_put_failure: 1459 nlmsg_trim(skb, b); 1460 return -1; 1461 } 1462 1463 static int cbq_dump_wrr(struct sk_buff *skb, struct cbq_class *cl) 1464 { 1465 unsigned char *b = skb_tail_pointer(skb); 1466 struct tc_cbq_wrropt opt; 1467 1468 opt.flags = 0; 1469 opt.allot = cl->allot; 1470 opt.priority = cl->priority + 1; 1471 opt.cpriority = cl->cpriority + 1; 1472 opt.weight = cl->weight; 1473 if (nla_put(skb, TCA_CBQ_WRROPT, sizeof(opt), &opt)) 1474 goto nla_put_failure; 1475 return skb->len; 1476 1477 nla_put_failure: 1478 nlmsg_trim(skb, b); 1479 return -1; 1480 } 1481 1482 static int cbq_dump_ovl(struct sk_buff *skb, struct cbq_class *cl) 1483 { 1484 unsigned char *b = skb_tail_pointer(skb); 1485 struct tc_cbq_ovl opt; 1486 1487 opt.strategy = cl->ovl_strategy; 1488 opt.priority2 = cl->priority2 + 1; 1489 opt.pad = 0; 1490 opt.penalty = cl->penalty; 1491 if (nla_put(skb, TCA_CBQ_OVL_STRATEGY, sizeof(opt), &opt)) 1492 goto nla_put_failure; 1493 return skb->len; 1494 1495 nla_put_failure: 1496 nlmsg_trim(skb, b); 1497 return -1; 1498 } 1499 1500 static int cbq_dump_fopt(struct sk_buff *skb, struct cbq_class *cl) 1501 { 1502 unsigned char *b = skb_tail_pointer(skb); 1503 struct tc_cbq_fopt opt; 1504 1505 if (cl->split || cl->defmap) { 1506 opt.split = cl->split ? cl->split->common.classid : 0; 1507 opt.defmap = cl->defmap; 1508 opt.defchange = ~0; 1509 if (nla_put(skb, TCA_CBQ_FOPT, sizeof(opt), &opt)) 1510 goto nla_put_failure; 1511 } 1512 return skb->len; 1513 1514 nla_put_failure: 1515 nlmsg_trim(skb, b); 1516 return -1; 1517 } 1518 1519 #ifdef CONFIG_NET_CLS_ACT 1520 static int cbq_dump_police(struct sk_buff *skb, struct cbq_class *cl) 1521 { 1522 unsigned char *b = skb_tail_pointer(skb); 1523 struct tc_cbq_police opt; 1524 1525 if (cl->police) { 1526 opt.police = cl->police; 1527 opt.__res1 = 0; 1528 opt.__res2 = 0; 1529 if (nla_put(skb, TCA_CBQ_POLICE, sizeof(opt), &opt)) 1530 goto nla_put_failure; 1531 } 1532 return skb->len; 1533 1534 nla_put_failure: 1535 nlmsg_trim(skb, b); 1536 return -1; 1537 } 1538 #endif 1539 1540 static int cbq_dump_attr(struct sk_buff *skb, struct cbq_class *cl) 1541 { 1542 if (cbq_dump_lss(skb, cl) < 0 || 1543 cbq_dump_rate(skb, cl) < 0 || 1544 cbq_dump_wrr(skb, cl) < 0 || 1545 cbq_dump_ovl(skb, cl) < 0 || 1546 #ifdef CONFIG_NET_CLS_ACT 1547 cbq_dump_police(skb, cl) < 0 || 1548 #endif 1549 cbq_dump_fopt(skb, cl) < 0) 1550 return -1; 1551 return 0; 1552 } 1553 1554 static int cbq_dump(struct Qdisc *sch, struct sk_buff *skb) 1555 { 1556 struct cbq_sched_data *q = qdisc_priv(sch); 1557 struct nlattr *nest; 1558 1559 nest = nla_nest_start(skb, TCA_OPTIONS); 1560 if (nest == NULL) 1561 goto nla_put_failure; 1562 if (cbq_dump_attr(skb, &q->link) < 0) 1563 goto nla_put_failure; 1564 nla_nest_end(skb, nest); 1565 return skb->len; 1566 1567 nla_put_failure: 1568 nla_nest_cancel(skb, nest); 1569 return -1; 1570 } 1571 1572 static int 1573 cbq_dump_stats(struct Qdisc *sch, struct gnet_dump *d) 1574 { 1575 struct cbq_sched_data *q = qdisc_priv(sch); 1576 1577 q->link.xstats.avgidle = q->link.avgidle; 1578 return gnet_stats_copy_app(d, &q->link.xstats, sizeof(q->link.xstats)); 1579 } 1580 1581 static int 1582 cbq_dump_class(struct Qdisc *sch, unsigned long arg, 1583 struct sk_buff *skb, struct tcmsg *tcm) 1584 { 1585 struct cbq_class *cl = (struct cbq_class *)arg; 1586 struct nlattr *nest; 1587 1588 if (cl->tparent) 1589 tcm->tcm_parent = cl->tparent->common.classid; 1590 else 1591 tcm->tcm_parent = TC_H_ROOT; 1592 tcm->tcm_handle = cl->common.classid; 1593 tcm->tcm_info = cl->q->handle; 1594 1595 nest = nla_nest_start(skb, TCA_OPTIONS); 1596 if (nest == NULL) 1597 goto nla_put_failure; 1598 if (cbq_dump_attr(skb, cl) < 0) 1599 goto nla_put_failure; 1600 nla_nest_end(skb, nest); 1601 return skb->len; 1602 1603 nla_put_failure: 1604 nla_nest_cancel(skb, nest); 1605 return -1; 1606 } 1607 1608 static int 1609 cbq_dump_class_stats(struct Qdisc *sch, unsigned long arg, 1610 struct gnet_dump *d) 1611 { 1612 struct cbq_sched_data *q = qdisc_priv(sch); 1613 struct cbq_class *cl = (struct cbq_class *)arg; 1614 1615 cl->qstats.qlen = cl->q->q.qlen; 1616 cl->xstats.avgidle = cl->avgidle; 1617 cl->xstats.undertime = 0; 1618 1619 if (cl->undertime != PSCHED_PASTPERFECT) 1620 cl->xstats.undertime = cl->undertime - q->now; 1621 1622 if (gnet_stats_copy_basic(d, &cl->bstats) < 0 || 1623 gnet_stats_copy_rate_est(d, &cl->bstats, &cl->rate_est) < 0 || 1624 gnet_stats_copy_queue(d, &cl->qstats) < 0) 1625 return -1; 1626 1627 return gnet_stats_copy_app(d, &cl->xstats, sizeof(cl->xstats)); 1628 } 1629 1630 static int cbq_graft(struct Qdisc *sch, unsigned long arg, struct Qdisc *new, 1631 struct Qdisc **old) 1632 { 1633 struct cbq_class *cl = (struct cbq_class *)arg; 1634 1635 if (new == NULL) { 1636 new = qdisc_create_dflt(sch->dev_queue, 1637 &pfifo_qdisc_ops, cl->common.classid); 1638 if (new == NULL) 1639 return -ENOBUFS; 1640 } else { 1641 #ifdef CONFIG_NET_CLS_ACT 1642 if (cl->police == TC_POLICE_RECLASSIFY) 1643 new->reshape_fail = cbq_reshape_fail; 1644 #endif 1645 } 1646 sch_tree_lock(sch); 1647 *old = cl->q; 1648 cl->q = new; 1649 qdisc_tree_decrease_qlen(*old, (*old)->q.qlen); 1650 qdisc_reset(*old); 1651 sch_tree_unlock(sch); 1652 1653 return 0; 1654 } 1655 1656 static struct Qdisc *cbq_leaf(struct Qdisc *sch, unsigned long arg) 1657 { 1658 struct cbq_class *cl = (struct cbq_class *)arg; 1659 1660 return cl->q; 1661 } 1662 1663 static void cbq_qlen_notify(struct Qdisc *sch, unsigned long arg) 1664 { 1665 struct cbq_class *cl = (struct cbq_class *)arg; 1666 1667 if (cl->q->q.qlen == 0) 1668 cbq_deactivate_class(cl); 1669 } 1670 1671 static unsigned long cbq_get(struct Qdisc *sch, u32 classid) 1672 { 1673 struct cbq_sched_data *q = qdisc_priv(sch); 1674 struct cbq_class *cl = cbq_class_lookup(q, classid); 1675 1676 if (cl) { 1677 cl->refcnt++; 1678 return (unsigned long)cl; 1679 } 1680 return 0; 1681 } 1682 1683 static void cbq_destroy_class(struct Qdisc *sch, struct cbq_class *cl) 1684 { 1685 struct cbq_sched_data *q = qdisc_priv(sch); 1686 1687 WARN_ON(cl->filters); 1688 1689 tcf_destroy_chain(&cl->filter_list); 1690 qdisc_destroy(cl->q); 1691 qdisc_put_rtab(cl->R_tab); 1692 gen_kill_estimator(&cl->bstats, &cl->rate_est); 1693 if (cl != &q->link) 1694 kfree(cl); 1695 } 1696 1697 static void cbq_destroy(struct Qdisc *sch) 1698 { 1699 struct cbq_sched_data *q = qdisc_priv(sch); 1700 struct hlist_node *next; 1701 struct cbq_class *cl; 1702 unsigned int h; 1703 1704 #ifdef CONFIG_NET_CLS_ACT 1705 q->rx_class = NULL; 1706 #endif 1707 /* 1708 * Filters must be destroyed first because we don't destroy the 1709 * classes from root to leafs which means that filters can still 1710 * be bound to classes which have been destroyed already. --TGR '04 1711 */ 1712 for (h = 0; h < q->clhash.hashsize; h++) { 1713 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) 1714 tcf_destroy_chain(&cl->filter_list); 1715 } 1716 for (h = 0; h < q->clhash.hashsize; h++) { 1717 hlist_for_each_entry_safe(cl, next, &q->clhash.hash[h], 1718 common.hnode) 1719 cbq_destroy_class(sch, cl); 1720 } 1721 qdisc_class_hash_destroy(&q->clhash); 1722 } 1723 1724 static void cbq_put(struct Qdisc *sch, unsigned long arg) 1725 { 1726 struct cbq_class *cl = (struct cbq_class *)arg; 1727 1728 if (--cl->refcnt == 0) { 1729 #ifdef CONFIG_NET_CLS_ACT 1730 spinlock_t *root_lock = qdisc_root_sleeping_lock(sch); 1731 struct cbq_sched_data *q = qdisc_priv(sch); 1732 1733 spin_lock_bh(root_lock); 1734 if (q->rx_class == cl) 1735 q->rx_class = NULL; 1736 spin_unlock_bh(root_lock); 1737 #endif 1738 1739 cbq_destroy_class(sch, cl); 1740 } 1741 } 1742 1743 static int 1744 cbq_change_class(struct Qdisc *sch, u32 classid, u32 parentid, struct nlattr **tca, 1745 unsigned long *arg) 1746 { 1747 int err; 1748 struct cbq_sched_data *q = qdisc_priv(sch); 1749 struct cbq_class *cl = (struct cbq_class *)*arg; 1750 struct nlattr *opt = tca[TCA_OPTIONS]; 1751 struct nlattr *tb[TCA_CBQ_MAX + 1]; 1752 struct cbq_class *parent; 1753 struct qdisc_rate_table *rtab = NULL; 1754 1755 if (opt == NULL) 1756 return -EINVAL; 1757 1758 err = nla_parse_nested(tb, TCA_CBQ_MAX, opt, cbq_policy); 1759 if (err < 0) 1760 return err; 1761 1762 if (cl) { 1763 /* Check parent */ 1764 if (parentid) { 1765 if (cl->tparent && 1766 cl->tparent->common.classid != parentid) 1767 return -EINVAL; 1768 if (!cl->tparent && parentid != TC_H_ROOT) 1769 return -EINVAL; 1770 } 1771 1772 if (tb[TCA_CBQ_RATE]) { 1773 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), 1774 tb[TCA_CBQ_RTAB]); 1775 if (rtab == NULL) 1776 return -EINVAL; 1777 } 1778 1779 if (tca[TCA_RATE]) { 1780 err = gen_replace_estimator(&cl->bstats, &cl->rate_est, 1781 qdisc_root_sleeping_lock(sch), 1782 tca[TCA_RATE]); 1783 if (err) { 1784 if (rtab) 1785 qdisc_put_rtab(rtab); 1786 return err; 1787 } 1788 } 1789 1790 /* Change class parameters */ 1791 sch_tree_lock(sch); 1792 1793 if (cl->next_alive != NULL) 1794 cbq_deactivate_class(cl); 1795 1796 if (rtab) { 1797 qdisc_put_rtab(cl->R_tab); 1798 cl->R_tab = rtab; 1799 } 1800 1801 if (tb[TCA_CBQ_LSSOPT]) 1802 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT])); 1803 1804 if (tb[TCA_CBQ_WRROPT]) { 1805 cbq_rmprio(q, cl); 1806 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT])); 1807 } 1808 1809 if (tb[TCA_CBQ_OVL_STRATEGY]) 1810 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY])); 1811 1812 #ifdef CONFIG_NET_CLS_ACT 1813 if (tb[TCA_CBQ_POLICE]) 1814 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE])); 1815 #endif 1816 1817 if (tb[TCA_CBQ_FOPT]) 1818 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT])); 1819 1820 if (cl->q->q.qlen) 1821 cbq_activate_class(cl); 1822 1823 sch_tree_unlock(sch); 1824 1825 return 0; 1826 } 1827 1828 if (parentid == TC_H_ROOT) 1829 return -EINVAL; 1830 1831 if (tb[TCA_CBQ_WRROPT] == NULL || tb[TCA_CBQ_RATE] == NULL || 1832 tb[TCA_CBQ_LSSOPT] == NULL) 1833 return -EINVAL; 1834 1835 rtab = qdisc_get_rtab(nla_data(tb[TCA_CBQ_RATE]), tb[TCA_CBQ_RTAB]); 1836 if (rtab == NULL) 1837 return -EINVAL; 1838 1839 if (classid) { 1840 err = -EINVAL; 1841 if (TC_H_MAJ(classid ^ sch->handle) || 1842 cbq_class_lookup(q, classid)) 1843 goto failure; 1844 } else { 1845 int i; 1846 classid = TC_H_MAKE(sch->handle, 0x8000); 1847 1848 for (i = 0; i < 0x8000; i++) { 1849 if (++q->hgenerator >= 0x8000) 1850 q->hgenerator = 1; 1851 if (cbq_class_lookup(q, classid|q->hgenerator) == NULL) 1852 break; 1853 } 1854 err = -ENOSR; 1855 if (i >= 0x8000) 1856 goto failure; 1857 classid = classid|q->hgenerator; 1858 } 1859 1860 parent = &q->link; 1861 if (parentid) { 1862 parent = cbq_class_lookup(q, parentid); 1863 err = -EINVAL; 1864 if (parent == NULL) 1865 goto failure; 1866 } 1867 1868 err = -ENOBUFS; 1869 cl = kzalloc(sizeof(*cl), GFP_KERNEL); 1870 if (cl == NULL) 1871 goto failure; 1872 1873 if (tca[TCA_RATE]) { 1874 err = gen_new_estimator(&cl->bstats, &cl->rate_est, 1875 qdisc_root_sleeping_lock(sch), 1876 tca[TCA_RATE]); 1877 if (err) { 1878 kfree(cl); 1879 goto failure; 1880 } 1881 } 1882 1883 cl->R_tab = rtab; 1884 rtab = NULL; 1885 cl->refcnt = 1; 1886 cl->q = qdisc_create_dflt(sch->dev_queue, &pfifo_qdisc_ops, classid); 1887 if (!cl->q) 1888 cl->q = &noop_qdisc; 1889 cl->common.classid = classid; 1890 cl->tparent = parent; 1891 cl->qdisc = sch; 1892 cl->allot = parent->allot; 1893 cl->quantum = cl->allot; 1894 cl->weight = cl->R_tab->rate.rate; 1895 1896 sch_tree_lock(sch); 1897 cbq_link_class(cl); 1898 cl->borrow = cl->tparent; 1899 if (cl->tparent != &q->link) 1900 cl->share = cl->tparent; 1901 cbq_adjust_levels(parent); 1902 cl->minidle = -0x7FFFFFFF; 1903 cbq_set_lss(cl, nla_data(tb[TCA_CBQ_LSSOPT])); 1904 cbq_set_wrr(cl, nla_data(tb[TCA_CBQ_WRROPT])); 1905 if (cl->ewma_log == 0) 1906 cl->ewma_log = q->link.ewma_log; 1907 if (cl->maxidle == 0) 1908 cl->maxidle = q->link.maxidle; 1909 if (cl->avpkt == 0) 1910 cl->avpkt = q->link.avpkt; 1911 cl->overlimit = cbq_ovl_classic; 1912 if (tb[TCA_CBQ_OVL_STRATEGY]) 1913 cbq_set_overlimit(cl, nla_data(tb[TCA_CBQ_OVL_STRATEGY])); 1914 #ifdef CONFIG_NET_CLS_ACT 1915 if (tb[TCA_CBQ_POLICE]) 1916 cbq_set_police(cl, nla_data(tb[TCA_CBQ_POLICE])); 1917 #endif 1918 if (tb[TCA_CBQ_FOPT]) 1919 cbq_set_fopt(cl, nla_data(tb[TCA_CBQ_FOPT])); 1920 sch_tree_unlock(sch); 1921 1922 qdisc_class_hash_grow(sch, &q->clhash); 1923 1924 *arg = (unsigned long)cl; 1925 return 0; 1926 1927 failure: 1928 qdisc_put_rtab(rtab); 1929 return err; 1930 } 1931 1932 static int cbq_delete(struct Qdisc *sch, unsigned long arg) 1933 { 1934 struct cbq_sched_data *q = qdisc_priv(sch); 1935 struct cbq_class *cl = (struct cbq_class *)arg; 1936 unsigned int qlen; 1937 1938 if (cl->filters || cl->children || cl == &q->link) 1939 return -EBUSY; 1940 1941 sch_tree_lock(sch); 1942 1943 qlen = cl->q->q.qlen; 1944 qdisc_reset(cl->q); 1945 qdisc_tree_decrease_qlen(cl->q, qlen); 1946 1947 if (cl->next_alive) 1948 cbq_deactivate_class(cl); 1949 1950 if (q->tx_borrowed == cl) 1951 q->tx_borrowed = q->tx_class; 1952 if (q->tx_class == cl) { 1953 q->tx_class = NULL; 1954 q->tx_borrowed = NULL; 1955 } 1956 #ifdef CONFIG_NET_CLS_ACT 1957 if (q->rx_class == cl) 1958 q->rx_class = NULL; 1959 #endif 1960 1961 cbq_unlink_class(cl); 1962 cbq_adjust_levels(cl->tparent); 1963 cl->defmap = 0; 1964 cbq_sync_defmap(cl); 1965 1966 cbq_rmprio(q, cl); 1967 sch_tree_unlock(sch); 1968 1969 BUG_ON(--cl->refcnt == 0); 1970 /* 1971 * This shouldn't happen: we "hold" one cops->get() when called 1972 * from tc_ctl_tclass; the destroy method is done from cops->put(). 1973 */ 1974 1975 return 0; 1976 } 1977 1978 static struct tcf_proto **cbq_find_tcf(struct Qdisc *sch, unsigned long arg) 1979 { 1980 struct cbq_sched_data *q = qdisc_priv(sch); 1981 struct cbq_class *cl = (struct cbq_class *)arg; 1982 1983 if (cl == NULL) 1984 cl = &q->link; 1985 1986 return &cl->filter_list; 1987 } 1988 1989 static unsigned long cbq_bind_filter(struct Qdisc *sch, unsigned long parent, 1990 u32 classid) 1991 { 1992 struct cbq_sched_data *q = qdisc_priv(sch); 1993 struct cbq_class *p = (struct cbq_class *)parent; 1994 struct cbq_class *cl = cbq_class_lookup(q, classid); 1995 1996 if (cl) { 1997 if (p && p->level <= cl->level) 1998 return 0; 1999 cl->filters++; 2000 return (unsigned long)cl; 2001 } 2002 return 0; 2003 } 2004 2005 static void cbq_unbind_filter(struct Qdisc *sch, unsigned long arg) 2006 { 2007 struct cbq_class *cl = (struct cbq_class *)arg; 2008 2009 cl->filters--; 2010 } 2011 2012 static void cbq_walk(struct Qdisc *sch, struct qdisc_walker *arg) 2013 { 2014 struct cbq_sched_data *q = qdisc_priv(sch); 2015 struct cbq_class *cl; 2016 unsigned int h; 2017 2018 if (arg->stop) 2019 return; 2020 2021 for (h = 0; h < q->clhash.hashsize; h++) { 2022 hlist_for_each_entry(cl, &q->clhash.hash[h], common.hnode) { 2023 if (arg->count < arg->skip) { 2024 arg->count++; 2025 continue; 2026 } 2027 if (arg->fn(sch, (unsigned long)cl, arg) < 0) { 2028 arg->stop = 1; 2029 return; 2030 } 2031 arg->count++; 2032 } 2033 } 2034 } 2035 2036 static const struct Qdisc_class_ops cbq_class_ops = { 2037 .graft = cbq_graft, 2038 .leaf = cbq_leaf, 2039 .qlen_notify = cbq_qlen_notify, 2040 .get = cbq_get, 2041 .put = cbq_put, 2042 .change = cbq_change_class, 2043 .delete = cbq_delete, 2044 .walk = cbq_walk, 2045 .tcf_chain = cbq_find_tcf, 2046 .bind_tcf = cbq_bind_filter, 2047 .unbind_tcf = cbq_unbind_filter, 2048 .dump = cbq_dump_class, 2049 .dump_stats = cbq_dump_class_stats, 2050 }; 2051 2052 static struct Qdisc_ops cbq_qdisc_ops __read_mostly = { 2053 .next = NULL, 2054 .cl_ops = &cbq_class_ops, 2055 .id = "cbq", 2056 .priv_size = sizeof(struct cbq_sched_data), 2057 .enqueue = cbq_enqueue, 2058 .dequeue = cbq_dequeue, 2059 .peek = qdisc_peek_dequeued, 2060 .drop = cbq_drop, 2061 .init = cbq_init, 2062 .reset = cbq_reset, 2063 .destroy = cbq_destroy, 2064 .change = NULL, 2065 .dump = cbq_dump, 2066 .dump_stats = cbq_dump_stats, 2067 .owner = THIS_MODULE, 2068 }; 2069 2070 static int __init cbq_module_init(void) 2071 { 2072 return register_qdisc(&cbq_qdisc_ops); 2073 } 2074 static void __exit cbq_module_exit(void) 2075 { 2076 unregister_qdisc(&cbq_qdisc_ops); 2077 } 2078 module_init(cbq_module_init) 2079 module_exit(cbq_module_exit) 2080 MODULE_LICENSE("GPL"); 2081
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