target/linux/generic/patches-4.4/031-net_sched-update-hierarchical-backlog-too.patch

   1 From: WANG Cong <xiyou.wangcong@gmail.com>
   2 Date: Thu, 25 Feb 2016 14:55:01 -0800
   3 Subject: [PATCH] net_sched: update hierarchical backlog too
   4
   5 When the bottom qdisc decides to, for example, drop some packet,
   6 it calls qdisc_tree_decrease_qlen() to update the queue length
   7 for all its ancestors, we need to update the backlog too to
   8 keep the stats on root qdisc accurate.
   9
  10 Cc: Jamal Hadi Salim <jhs@mojatatu.com>
  11 Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
  12 Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
  13 Signed-off-by: David S. Miller <davem@davemloft.net>
  14 ---
  15
  16 --- a/include/net/codel.h
  17 +++ b/include/net/codel.h
  18 @@ -162,12 +162,14 @@ struct codel_vars {
  19   * struct codel_stats - contains codel shared variables and stats
  20   * @maxpacket: largest packet we've seen so far
  21   * @drop_count:        temp count of dropped packets in dequeue()
  22 + * @drop_len:  bytes of dropped packets in dequeue()
  23   * ecn_mark:   number of packets we ECN marked instead of dropping
  24   * ce_mark:    number of packets CE marked because sojourn time was above ce_threshold
  25   */
  26  struct codel_stats {
  27         u32             maxpacket;
  28         u32             drop_count;
  29 +       u32             drop_len;
  30         u32             ecn_mark;
  31         u32             ce_mark;
  32  };
  33 @@ -308,6 +310,7 @@ static struct sk_buff *codel_dequeue(str
  34                                                                   vars->rec_inv_sqrt);
  35                                         goto end;
  36                                 }
  37 +                               stats->drop_len += qdisc_pkt_len(skb);
  38                                 qdisc_drop(skb, sch);
  39                                 stats->drop_count++;
  40                                 skb = dequeue_func(vars, sch);
  41 @@ -330,6 +333,7 @@ static struct sk_buff *codel_dequeue(str
  42                 if (params->ecn && INET_ECN_set_ce(skb)) {
  43                         stats->ecn_mark++;
  44                 } else {
  45 +                       stats->drop_len += qdisc_pkt_len(skb);
  46                         qdisc_drop(skb, sch);
  47                         stats->drop_count++;
  48
  49 --- a/include/net/sch_generic.h
  50 +++ b/include/net/sch_generic.h
  51 @@ -396,7 +396,8 @@ struct Qdisc *dev_graft_qdisc(struct net
  52                               struct Qdisc *qdisc);
  53  void qdisc_reset(struct Qdisc *qdisc);
  54  void qdisc_destroy(struct Qdisc *qdisc);
  55 -void qdisc_tree_decrease_qlen(struct Qdisc *qdisc, unsigned int n);
  56 +void qdisc_tree_reduce_backlog(struct Qdisc *qdisc, unsigned int n,
  57 +                              unsigned int len);
  58  struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
  59                           const struct Qdisc_ops *ops);
  60  struct Qdisc *qdisc_create_dflt(struct netdev_queue *dev_queue,
  61 @@ -707,7 +708,7 @@ static inline struct Qdisc *qdisc_replac
  62         old = *pold;
  63         *pold = new;
  64         if (old != NULL) {
  65 -               qdisc_tree_decrease_qlen(old, old->q.qlen);
  66 +               qdisc_tree_reduce_backlog(old, old->q.qlen, old->qstats.backlog);
  67                 qdisc_reset(old);
  68         }
  69         sch_tree_unlock(sch);
  70 --- a/net/sched/sch_api.c
  71 +++ b/net/sched/sch_api.c
  72 @@ -744,14 +744,15 @@ static u32 qdisc_alloc_handle(struct net
  73         return 0;
  74  }
  75
  76 -void qdisc_tree_decrease_qlen(struct Qdisc *sch, unsigned int n)
  77 +void qdisc_tree_reduce_backlog(struct Qdisc *sch, unsigned int n,
  78 +                              unsigned int len)
  79  {
  80         const struct Qdisc_class_ops *cops;
  81         unsigned long cl;
  82         u32 parentid;
  83         int drops;
  84
  85 -       if (n == 0)
  86 +       if (n == 0 && len == 0)
  87                 return;
  88         drops = max_t(int, n, 0);
  89         rcu_read_lock();
  90 @@ -774,11 +775,12 @@ void qdisc_tree_decrease_qlen(struct Qdi
  91                         cops->put(sch, cl);
  92                 }
  93                 sch->q.qlen -= n;
  94 +               sch->qstats.backlog -= len;
  95                 __qdisc_qstats_drop(sch, drops);
  96         }
  97         rcu_read_unlock();
  98  }
  99 -EXPORT_SYMBOL(qdisc_tree_decrease_qlen);
 100 +EXPORT_SYMBOL(qdisc_tree_reduce_backlog);
 101
 102  static void notify_and_destroy(struct net *net, struct sk_buff *skb,
 103                                struct nlmsghdr *n, u32 clid,
 104 --- a/net/sched/sch_cbq.c
 105 +++ b/net/sched/sch_cbq.c
 106 @@ -1909,7 +1909,7 @@ static int cbq_delete(struct Qdisc *sch,
 107  {
 108         struct cbq_sched_data *q = qdisc_priv(sch);
 109         struct cbq_class *cl = (struct cbq_class *)arg;
 110 -       unsigned int qlen;
 111 +       unsigned int qlen, backlog;
 112
 113         if (cl->filters || cl->children || cl == &q->link)
 114                 return -EBUSY;
 115 @@ -1917,8 +1917,9 @@ static int cbq_delete(struct Qdisc *sch,
 116         sch_tree_lock(sch);
 117
 118         qlen = cl->q->q.qlen;
 119 +       backlog = cl->q->qstats.backlog;
 120         qdisc_reset(cl->q);
 121 -       qdisc_tree_decrease_qlen(cl->q, qlen);
 122 +       qdisc_tree_reduce_backlog(cl->q, qlen, backlog);
 123
 124         if (cl->next_alive)
 125                 cbq_deactivate_class(cl);
 126 --- a/net/sched/sch_choke.c
 127 +++ b/net/sched/sch_choke.c
 128 @@ -128,8 +128,8 @@ static void choke_drop_by_idx(struct Qdi
 129                 choke_zap_tail_holes(q);
 130
 131         qdisc_qstats_backlog_dec(sch, skb);
 132 +       qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
 133         qdisc_drop(skb, sch);
 134 -       qdisc_tree_decrease_qlen(sch, 1);
 135         --sch->q.qlen;
 136  }
 137
 138 @@ -456,6 +456,7 @@ static int choke_change(struct Qdisc *sc
 139                 old = q->tab;
 140                 if (old) {
 141                         unsigned int oqlen = sch->q.qlen, tail = 0;
 142 +                       unsigned dropped = 0;
 143
 144                         while (q->head != q->tail) {
 145                                 struct sk_buff *skb = q->tab[q->head];
 146 @@ -467,11 +468,12 @@ static int choke_change(struct Qdisc *sc
 147                                         ntab[tail++] = skb;
 148                                         continue;
 149                                 }
 150 +                               dropped += qdisc_pkt_len(skb);
 151                                 qdisc_qstats_backlog_dec(sch, skb);
 152                                 --sch->q.qlen;
 153                                 qdisc_drop(skb, sch);
 154                         }
 155 -                       qdisc_tree_decrease_qlen(sch, oqlen - sch->q.qlen);
 156 +                       qdisc_tree_reduce_backlog(sch, oqlen - sch->q.qlen, dropped);
 157                         q->head = 0;
 158                         q->tail = tail;
 159                 }
 160 --- a/net/sched/sch_codel.c
 161 +++ b/net/sched/sch_codel.c
 162 @@ -79,12 +79,13 @@ static struct sk_buff *codel_qdisc_deque
 163
 164         skb = codel_dequeue(sch, &q->params, &q->vars, &q->stats, dequeue);
 165
 166 -       /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
 167 +       /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
 168          * or HTB crashes. Defer it for next round.
 169          */
 170         if (q->stats.drop_count && sch->q.qlen) {
 171 -               qdisc_tree_decrease_qlen(sch, q->stats.drop_count);
 172 +               qdisc_tree_reduce_backlog(sch, q->stats.drop_count, q->stats.drop_len);
 173                 q->stats.drop_count = 0;
 174 +               q->stats.drop_len = 0;
 175         }
 176         if (skb)
 177                 qdisc_bstats_update(sch, skb);
 178 @@ -116,7 +117,7 @@ static int codel_change(struct Qdisc *sc
 179  {
 180         struct codel_sched_data *q = qdisc_priv(sch);
 181         struct nlattr *tb[TCA_CODEL_MAX + 1];
 182 -       unsigned int qlen;
 183 +       unsigned int qlen, dropped = 0;
 184         int err;
 185
 186         if (!opt)
 187 @@ -156,10 +157,11 @@ static int codel_change(struct Qdisc *sc
 188         while (sch->q.qlen > sch->limit) {
 189                 struct sk_buff *skb = __skb_dequeue(&sch->q);
 190
 191 +               dropped += qdisc_pkt_len(skb);
 192                 qdisc_qstats_backlog_dec(sch, skb);
 193                 qdisc_drop(skb, sch);
 194         }
 195 -       qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
 196 +       qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
 197
 198         sch_tree_unlock(sch);
 199         return 0;
 200 --- a/net/sched/sch_drr.c
 201 +++ b/net/sched/sch_drr.c
 202 @@ -53,9 +53,10 @@ static struct drr_class *drr_find_class(
 203  static void drr_purge_queue(struct drr_class *cl)
 204  {
 205         unsigned int len = cl->qdisc->q.qlen;
 206 +       unsigned int backlog = cl->qdisc->qstats.backlog;
 207
 208         qdisc_reset(cl->qdisc);
 209 -       qdisc_tree_decrease_qlen(cl->qdisc, len);
 210 +       qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
 211  }
 212
 213  static const struct nla_policy drr_policy[TCA_DRR_MAX + 1] = {
 214 --- a/net/sched/sch_fq.c
 215 +++ b/net/sched/sch_fq.c
 216 @@ -662,6 +662,7 @@ static int fq_change(struct Qdisc *sch,
 217         struct fq_sched_data *q = qdisc_priv(sch);
 218         struct nlattr *tb[TCA_FQ_MAX + 1];
 219         int err, drop_count = 0;
 220 +       unsigned drop_len = 0;
 221         u32 fq_log;
 222
 223         if (!opt)
 224 @@ -736,10 +737,11 @@ static int fq_change(struct Qdisc *sch,
 225
 226                 if (!skb)
 227                         break;
 228 +               drop_len += qdisc_pkt_len(skb);
 229                 kfree_skb(skb);
 230                 drop_count++;
 231         }
 232 -       qdisc_tree_decrease_qlen(sch, drop_count);
 233 +       qdisc_tree_reduce_backlog(sch, drop_count, drop_len);
 234
 235         sch_tree_unlock(sch);
 236         return err;
 237 --- a/net/sched/sch_fq_codel.c
 238 +++ b/net/sched/sch_fq_codel.c
 239 @@ -175,7 +175,7 @@ static unsigned int fq_codel_qdisc_drop(
 240  static int fq_codel_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 241  {
 242         struct fq_codel_sched_data *q = qdisc_priv(sch);
 243 -       unsigned int idx;
 244 +       unsigned int idx, prev_backlog;
 245         struct fq_codel_flow *flow;
 246         int uninitialized_var(ret);
 247
 248 @@ -203,6 +203,7 @@ static int fq_codel_enqueue(struct sk_bu
 249         if (++sch->q.qlen <= sch->limit)
 250                 return NET_XMIT_SUCCESS;
 251
 252 +       prev_backlog = sch->qstats.backlog;
 253         q->drop_overlimit++;
 254         /* Return Congestion Notification only if we dropped a packet
 255          * from this flow.
 256 @@ -211,7 +212,7 @@ static int fq_codel_enqueue(struct sk_bu
 257                 return NET_XMIT_CN;
 258
 259         /* As we dropped a packet, better let upper stack know this */
 260 -       qdisc_tree_decrease_qlen(sch, 1);
 261 +       qdisc_tree_reduce_backlog(sch, 1, prev_backlog - sch->qstats.backlog);
 262         return NET_XMIT_SUCCESS;
 263  }
 264
 265 @@ -241,6 +242,7 @@ static struct sk_buff *fq_codel_dequeue(
 266         struct fq_codel_flow *flow;
 267         struct list_head *head;
 268         u32 prev_drop_count, prev_ecn_mark;
 269 +       unsigned int prev_backlog;
 270
 271  begin:
 272         head = &q->new_flows;
 273 @@ -259,6 +261,7 @@ begin:
 274
 275         prev_drop_count = q->cstats.drop_count;
 276         prev_ecn_mark = q->cstats.ecn_mark;
 277 +       prev_backlog = sch->qstats.backlog;
 278
 279         skb = codel_dequeue(sch, &q->cparams, &flow->cvars, &q->cstats,
 280                             dequeue);
 281 @@ -276,12 +279,14 @@ begin:
 282         }
 283         qdisc_bstats_update(sch, skb);
 284         flow->deficit -= qdisc_pkt_len(skb);
 285 -       /* We cant call qdisc_tree_decrease_qlen() if our qlen is 0,
 286 +       /* We cant call qdisc_tree_reduce_backlog() if our qlen is 0,
 287          * or HTB crashes. Defer it for next round.
 288          */
 289         if (q->cstats.drop_count && sch->q.qlen) {
 290 -               qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 291 +               qdisc_tree_reduce_backlog(sch, q->cstats.drop_count,
 292 +                                         q->cstats.drop_len);
 293                 q->cstats.drop_count = 0;
 294 +               q->cstats.drop_len = 0;
 295         }
 296         return skb;
 297  }
 298 @@ -372,11 +377,13 @@ static int fq_codel_change(struct Qdisc
 299         while (sch->q.qlen > sch->limit) {
 300                 struct sk_buff *skb = fq_codel_dequeue(sch);
 301
 302 +               q->cstats.drop_len += qdisc_pkt_len(skb);
 303                 kfree_skb(skb);
 304                 q->cstats.drop_count++;
 305         }
 306 -       qdisc_tree_decrease_qlen(sch, q->cstats.drop_count);
 307 +       qdisc_tree_reduce_backlog(sch, q->cstats.drop_count, q->cstats.drop_len);
 308         q->cstats.drop_count = 0;
 309 +       q->cstats.drop_len = 0;
 310
 311         sch_tree_unlock(sch);
 312         return 0;
 313 --- a/net/sched/sch_hfsc.c
 314 +++ b/net/sched/sch_hfsc.c
 315 @@ -895,9 +895,10 @@ static void
 316  hfsc_purge_queue(struct Qdisc *sch, struct hfsc_class *cl)
 317  {
 318         unsigned int len = cl->qdisc->q.qlen;
 319 +       unsigned int backlog = cl->qdisc->qstats.backlog;
 320
 321         qdisc_reset(cl->qdisc);
 322 -       qdisc_tree_decrease_qlen(cl->qdisc, len);
 323 +       qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
 324  }
 325
 326  static void
 327 --- a/net/sched/sch_hhf.c
 328 +++ b/net/sched/sch_hhf.c
 329 @@ -382,6 +382,7 @@ static int hhf_enqueue(struct sk_buff *s
 330         struct hhf_sched_data *q = qdisc_priv(sch);
 331         enum wdrr_bucket_idx idx;
 332         struct wdrr_bucket *bucket;
 333 +       unsigned int prev_backlog;
 334
 335         idx = hhf_classify(skb, sch);
 336
 337 @@ -409,6 +410,7 @@ static int hhf_enqueue(struct sk_buff *s
 338         if (++sch->q.qlen <= sch->limit)
 339                 return NET_XMIT_SUCCESS;
 340
 341 +       prev_backlog = sch->qstats.backlog;
 342         q->drop_overlimit++;
 343         /* Return Congestion Notification only if we dropped a packet from this
 344          * bucket.
 345 @@ -417,7 +419,7 @@ static int hhf_enqueue(struct sk_buff *s
 346                 return NET_XMIT_CN;
 347
 348         /* As we dropped a packet, better let upper stack know this. */
 349 -       qdisc_tree_decrease_qlen(sch, 1);
 350 +       qdisc_tree_reduce_backlog(sch, 1, prev_backlog - sch->qstats.backlog);
 351         return NET_XMIT_SUCCESS;
 352  }
 353
 354 @@ -527,7 +529,7 @@ static int hhf_change(struct Qdisc *sch,
 355  {
 356         struct hhf_sched_data *q = qdisc_priv(sch);
 357         struct nlattr *tb[TCA_HHF_MAX + 1];
 358 -       unsigned int qlen;
 359 +       unsigned int qlen, prev_backlog;
 360         int err;
 361         u64 non_hh_quantum;
 362         u32 new_quantum = q->quantum;
 363 @@ -577,12 +579,14 @@ static int hhf_change(struct Qdisc *sch,
 364         }
 365
 366         qlen = sch->q.qlen;
 367 +       prev_backlog = sch->qstats.backlog;
 368         while (sch->q.qlen > sch->limit) {
 369                 struct sk_buff *skb = hhf_dequeue(sch);
 370
 371                 kfree_skb(skb);
 372         }
 373 -       qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
 374 +       qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen,
 375 +                                 prev_backlog - sch->qstats.backlog);
 376
 377         sch_tree_unlock(sch);
 378         return 0;
 379 --- a/net/sched/sch_htb.c
 380 +++ b/net/sched/sch_htb.c
 381 @@ -1265,7 +1265,6 @@ static int htb_delete(struct Qdisc *sch,
 382  {
 383         struct htb_sched *q = qdisc_priv(sch);
 384         struct htb_class *cl = (struct htb_class *)arg;
 385 -       unsigned int qlen;
 386         struct Qdisc *new_q = NULL;
 387         int last_child = 0;
 388
 389 @@ -1285,9 +1284,11 @@ static int htb_delete(struct Qdisc *sch,
 390         sch_tree_lock(sch);
 391
 392         if (!cl->level) {
 393 -               qlen = cl->un.leaf.q->q.qlen;
 394 +               unsigned int qlen = cl->un.leaf.q->q.qlen;
 395 +               unsigned int backlog = cl->un.leaf.q->qstats.backlog;
 396 +
 397                 qdisc_reset(cl->un.leaf.q);
 398 -               qdisc_tree_decrease_qlen(cl->un.leaf.q, qlen);
 399 +               qdisc_tree_reduce_backlog(cl->un.leaf.q, qlen, backlog);
 400         }
 401
 402         /* delete from hash and active; remainder in destroy_class */
 403 @@ -1421,10 +1422,11 @@ static int htb_change_class(struct Qdisc
 404                 sch_tree_lock(sch);
 405                 if (parent && !parent->level) {
 406                         unsigned int qlen = parent->un.leaf.q->q.qlen;
 407 +                       unsigned int backlog = parent->un.leaf.q->qstats.backlog;
 408
 409                         /* turn parent into inner node */
 410                         qdisc_reset(parent->un.leaf.q);
 411 -                       qdisc_tree_decrease_qlen(parent->un.leaf.q, qlen);
 412 +                       qdisc_tree_reduce_backlog(parent->un.leaf.q, qlen, backlog);
 413                         qdisc_destroy(parent->un.leaf.q);
 414                         if (parent->prio_activity)
 415                                 htb_deactivate(q, parent);
 416 --- a/net/sched/sch_multiq.c
 417 +++ b/net/sched/sch_multiq.c
 418 @@ -218,7 +218,8 @@ static int multiq_tune(struct Qdisc *sch
 419                 if (q->queues[i] != &noop_qdisc) {
 420                         struct Qdisc *child = q->queues[i];
 421                         q->queues[i] = &noop_qdisc;
 422 -                       qdisc_tree_decrease_qlen(child, child->q.qlen);
 423 +                       qdisc_tree_reduce_backlog(child, child->q.qlen,
 424 +                                                 child->qstats.backlog);
 425                         qdisc_destroy(child);
 426                 }
 427         }
 428 @@ -238,8 +239,9 @@ static int multiq_tune(struct Qdisc *sch
 429                                 q->queues[i] = child;
 430
 431                                 if (old != &noop_qdisc) {
 432 -                                       qdisc_tree_decrease_qlen(old,
 433 -                                                                old->q.qlen);
 434 +                                       qdisc_tree_reduce_backlog(old,
 435 +                                                                 old->q.qlen,
 436 +                                                                 old->qstats.backlog);
 437                                         qdisc_destroy(old);
 438                                 }
 439                                 sch_tree_unlock(sch);
 440 --- a/net/sched/sch_netem.c
 441 +++ b/net/sched/sch_netem.c
 442 @@ -598,7 +598,8 @@ deliver:
 443                                 if (unlikely(err != NET_XMIT_SUCCESS)) {
 444                                         if (net_xmit_drop_count(err)) {
 445                                                 qdisc_qstats_drop(sch);
 446 -                                               qdisc_tree_decrease_qlen(sch, 1);
 447 +                                               qdisc_tree_reduce_backlog(sch, 1,
 448 +                                                                         qdisc_pkt_len(skb));
 449                                         }
 450                                 }
 451                                 goto tfifo_dequeue;
 452 --- a/net/sched/sch_pie.c
 453 +++ b/net/sched/sch_pie.c
 454 @@ -183,7 +183,7 @@ static int pie_change(struct Qdisc *sch,
 455  {
 456         struct pie_sched_data *q = qdisc_priv(sch);
 457         struct nlattr *tb[TCA_PIE_MAX + 1];
 458 -       unsigned int qlen;
 459 +       unsigned int qlen, dropped = 0;
 460         int err;
 461
 462         if (!opt)
 463 @@ -232,10 +232,11 @@ static int pie_change(struct Qdisc *sch,
 464         while (sch->q.qlen > sch->limit) {
 465                 struct sk_buff *skb = __skb_dequeue(&sch->q);
 466
 467 +               dropped += qdisc_pkt_len(skb);
 468                 qdisc_qstats_backlog_dec(sch, skb);
 469                 qdisc_drop(skb, sch);
 470         }
 471 -       qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
 472 +       qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
 473
 474         sch_tree_unlock(sch);
 475         return 0;
 476 --- a/net/sched/sch_prio.c
 477 +++ b/net/sched/sch_prio.c
 478 @@ -191,7 +191,7 @@ static int prio_tune(struct Qdisc *sch,
 479                 struct Qdisc *child = q->queues[i];
 480                 q->queues[i] = &noop_qdisc;
 481                 if (child != &noop_qdisc) {
 482 -                       qdisc_tree_decrease_qlen(child, child->q.qlen);
 483 +                       qdisc_tree_reduce_backlog(child, child->q.qlen, child->qstats.backlog);
 484                         qdisc_destroy(child);
 485                 }
 486         }
 487 @@ -210,8 +210,9 @@ static int prio_tune(struct Qdisc *sch,
 488                                 q->queues[i] = child;
 489
 490                                 if (old != &noop_qdisc) {
 491 -                                       qdisc_tree_decrease_qlen(old,
 492 -                                                                old->q.qlen);
 493 +                                       qdisc_tree_reduce_backlog(old,
 494 +                                                                 old->q.qlen,
 495 +                                                                 old->qstats.backlog);
 496                                         qdisc_destroy(old);
 497                                 }
 498                                 sch_tree_unlock(sch);
 499 --- a/net/sched/sch_qfq.c
 500 +++ b/net/sched/sch_qfq.c
 501 @@ -220,9 +220,10 @@ static struct qfq_class *qfq_find_class(
 502  static void qfq_purge_queue(struct qfq_class *cl)
 503  {
 504         unsigned int len = cl->qdisc->q.qlen;
 505 +       unsigned int backlog = cl->qdisc->qstats.backlog;
 506
 507         qdisc_reset(cl->qdisc);
 508 -       qdisc_tree_decrease_qlen(cl->qdisc, len);
 509 +       qdisc_tree_reduce_backlog(cl->qdisc, len, backlog);
 510  }
 511
 512  static const struct nla_policy qfq_policy[TCA_QFQ_MAX + 1] = {
 513 --- a/net/sched/sch_red.c
 514 +++ b/net/sched/sch_red.c
 515 @@ -210,7 +210,8 @@ static int red_change(struct Qdisc *sch,
 516         q->flags = ctl->flags;
 517         q->limit = ctl->limit;
 518         if (child) {
 519 -               qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
 520 +               qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
 521 +                                         q->qdisc->qstats.backlog);
 522                 qdisc_destroy(q->qdisc);
 523                 q->qdisc = child;
 524         }
 525 --- a/net/sched/sch_sfb.c
 526 +++ b/net/sched/sch_sfb.c
 527 @@ -510,7 +510,8 @@ static int sfb_change(struct Qdisc *sch,
 528
 529         sch_tree_lock(sch);
 530
 531 -       qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
 532 +       qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
 533 +                                 q->qdisc->qstats.backlog);
 534         qdisc_destroy(q->qdisc);
 535         q->qdisc = child;
 536
 537 --- a/net/sched/sch_sfq.c
 538 +++ b/net/sched/sch_sfq.c
 539 @@ -346,7 +346,7 @@ static int
 540  sfq_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 541  {
 542         struct sfq_sched_data *q = qdisc_priv(sch);
 543 -       unsigned int hash;
 544 +       unsigned int hash, dropped;
 545         sfq_index x, qlen;
 546         struct sfq_slot *slot;
 547         int uninitialized_var(ret);
 548 @@ -461,7 +461,7 @@ enqueue:
 549                 return NET_XMIT_SUCCESS;
 550
 551         qlen = slot->qlen;
 552 -       sfq_drop(sch);
 553 +       dropped = sfq_drop(sch);
 554         /* Return Congestion Notification only if we dropped a packet
 555          * from this flow.
 556          */
 557 @@ -469,7 +469,7 @@ enqueue:
 558                 return NET_XMIT_CN;
 559
 560         /* As we dropped a packet, better let upper stack know this */
 561 -       qdisc_tree_decrease_qlen(sch, 1);
 562 +       qdisc_tree_reduce_backlog(sch, 1, dropped);
 563         return NET_XMIT_SUCCESS;
 564  }
 565
 566 @@ -537,6 +537,7 @@ static void sfq_rehash(struct Qdisc *sch
 567         struct sfq_slot *slot;
 568         struct sk_buff_head list;
 569         int dropped = 0;
 570 +       unsigned int drop_len = 0;
 571
 572         __skb_queue_head_init(&list);
 573
 574 @@ -565,6 +566,7 @@ static void sfq_rehash(struct Qdisc *sch
 575                         if (x >= SFQ_MAX_FLOWS) {
 576  drop:
 577                                 qdisc_qstats_backlog_dec(sch, skb);
 578 +                               drop_len += qdisc_pkt_len(skb);
 579                                 kfree_skb(skb);
 580                                 dropped++;
 581                                 continue;
 582 @@ -594,7 +596,7 @@ drop:
 583                 }
 584         }
 585         sch->q.qlen -= dropped;
 586 -       qdisc_tree_decrease_qlen(sch, dropped);
 587 +       qdisc_tree_reduce_backlog(sch, dropped, drop_len);
 588  }
 589
 590  static void sfq_perturbation(unsigned long arg)
 591 @@ -618,7 +620,7 @@ static int sfq_change(struct Qdisc *sch,
 592         struct sfq_sched_data *q = qdisc_priv(sch);
 593         struct tc_sfq_qopt *ctl = nla_data(opt);
 594         struct tc_sfq_qopt_v1 *ctl_v1 = NULL;
 595 -       unsigned int qlen;
 596 +       unsigned int qlen, dropped = 0;
 597         struct red_parms *p = NULL;
 598
 599         if (opt->nla_len < nla_attr_size(sizeof(*ctl)))
 600 @@ -667,8 +669,8 @@ static int sfq_change(struct Qdisc *sch,
 601
 602         qlen = sch->q.qlen;
 603         while (sch->q.qlen > q->limit)
 604 -               sfq_drop(sch);
 605 -       qdisc_tree_decrease_qlen(sch, qlen - sch->q.qlen);
 606 +               dropped += sfq_drop(sch);
 607 +       qdisc_tree_reduce_backlog(sch, qlen - sch->q.qlen, dropped);
 608
 609         del_timer(&q->perturb_timer);
 610         if (q->perturb_period) {
 611 --- a/net/sched/sch_tbf.c
 612 +++ b/net/sched/sch_tbf.c
 613 @@ -160,6 +160,7 @@ static int tbf_segment(struct sk_buff *s
 614         struct tbf_sched_data *q = qdisc_priv(sch);
 615         struct sk_buff *segs, *nskb;
 616         netdev_features_t features = netif_skb_features(skb);
 617 +       unsigned int len = 0, prev_len = qdisc_pkt_len(skb);
 618         int ret, nb;
 619
 620         segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
 621 @@ -172,6 +173,7 @@ static int tbf_segment(struct sk_buff *s
 622                 nskb = segs->next;
 623                 segs->next = NULL;
 624                 qdisc_skb_cb(segs)->pkt_len = segs->len;
 625 +               len += segs->len;
 626                 ret = qdisc_enqueue(segs, q->qdisc);
 627                 if (ret != NET_XMIT_SUCCESS) {
 628                         if (net_xmit_drop_count(ret))
 629 @@ -183,7 +185,7 @@ static int tbf_segment(struct sk_buff *s
 630         }
 631         sch->q.qlen += nb;
 632         if (nb > 1)
 633 -               qdisc_tree_decrease_qlen(sch, 1 - nb);
 634 +               qdisc_tree_reduce_backlog(sch, 1 - nb, prev_len - len);
 635         consume_skb(skb);
 636         return nb > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
 637  }
 638 @@ -399,7 +401,8 @@ static int tbf_change(struct Qdisc *sch,
 639
 640         sch_tree_lock(sch);
 641         if (child) {
 642 -               qdisc_tree_decrease_qlen(q->qdisc, q->qdisc->q.qlen);
 643 +               qdisc_tree_reduce_backlog(q->qdisc, q->qdisc->q.qlen,
 644 +                                         q->qdisc->qstats.backlog);
 645                 qdisc_destroy(q->qdisc);
 646                 q->qdisc = child;
 647         }