target/linux/generic/hack-4.14/662-remove_pfifo_fast.patch

   1 From b531d492d5ef1cf9dba0f4888eb5fd8624a6d762 Mon Sep 17 00:00:00 2001
   2 From: Felix Fietkau <nbd@nbd.name>
   3 Date: Fri, 7 Jul 2017 17:23:42 +0200
   4 Subject: net: sched: switch default qdisc from pfifo_fast to fq_codel and remove pfifo_fast
   5
   6 Signed-off-by: Felix Fietkau <nbd@nbd.name>
   7 ---
   8  net/sched/sch_generic.c | 140 ------------------------------------------------
   9  1 file changed, 140 deletions(-)
  10
  11 --- a/net/sched/sch_generic.c
  12 +++ b/net/sched/sch_generic.c
  13 @@ -453,146 +453,6 @@ struct Qdisc_ops noqueue_qdisc_ops __rea
  14         .owner          =       THIS_MODULE,
  15  };
  16
  17 -static const u8 prio2band[TC_PRIO_MAX + 1] = {
  18 -       1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
  19 -};
  20 -
  21 -/* 3-band FIFO queue: old style, but should be a bit faster than
  22 -   generic prio+fifo combination.
  23 - */
  24 -
  25 -#define PFIFO_FAST_BANDS 3
  26 -
  27 -/*
  28 - * Private data for a pfifo_fast scheduler containing:
  29 - *     - queues for the three band
  30 - *     - bitmap indicating which of the bands contain skbs
  31 - */
  32 -struct pfifo_fast_priv {
  33 -       u32 bitmap;
  34 -       struct qdisc_skb_head q[PFIFO_FAST_BANDS];
  35 -};
  36 -
  37 -/*
  38 - * Convert a bitmap to the first band number where an skb is queued, where:
  39 - *     bitmap=0 means there are no skbs on any band.
  40 - *     bitmap=1 means there is an skb on band 0.
  41 - *     bitmap=7 means there are skbs on all 3 bands, etc.
  42 - */
  43 -static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
  44 -
  45 -static inline struct qdisc_skb_head *band2list(struct pfifo_fast_priv *priv,
  46 -                                            int band)
  47 -{
  48 -       return priv->q + band;
  49 -}
  50 -
  51 -static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
  52 -                             struct sk_buff **to_free)
  53 -{
  54 -       if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) {
  55 -               int band = prio2band[skb->priority & TC_PRIO_MAX];
  56 -               struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  57 -               struct qdisc_skb_head *list = band2list(priv, band);
  58 -
  59 -               priv->bitmap |= (1 << band);
  60 -               qdisc->q.qlen++;
  61 -               return __qdisc_enqueue_tail(skb, qdisc, list);
  62 -       }
  63 -
  64 -       return qdisc_drop(skb, qdisc, to_free);
  65 -}
  66 -
  67 -static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
  68 -{
  69 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  70 -       int band = bitmap2band[priv->bitmap];
  71 -
  72 -       if (likely(band >= 0)) {
  73 -               struct qdisc_skb_head *qh = band2list(priv, band);
  74 -               struct sk_buff *skb = __qdisc_dequeue_head(qh);
  75 -
  76 -               if (likely(skb != NULL)) {
  77 -                       qdisc_qstats_backlog_dec(qdisc, skb);
  78 -                       qdisc_bstats_update(qdisc, skb);
  79 -               }
  80 -
  81 -               qdisc->q.qlen--;
  82 -               if (qh->qlen == 0)
  83 -                       priv->bitmap &= ~(1 << band);
  84 -
  85 -               return skb;
  86 -       }
  87 -
  88 -       return NULL;
  89 -}
  90 -
  91 -static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
  92 -{
  93 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  94 -       int band = bitmap2band[priv->bitmap];
  95 -
  96 -       if (band >= 0) {
  97 -               struct qdisc_skb_head *qh = band2list(priv, band);
  98 -
  99 -               return qh->head;
 100 -       }
 101 -
 102 -       return NULL;
 103 -}
 104 -
 105 -static void pfifo_fast_reset(struct Qdisc *qdisc)
 106 -{
 107 -       int prio;
 108 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 109 -
 110 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
 111 -               __qdisc_reset_queue(band2list(priv, prio));
 112 -
 113 -       priv->bitmap = 0;
 114 -       qdisc->qstats.backlog = 0;
 115 -       qdisc->q.qlen = 0;
 116 -}
 117 -
 118 -static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 119 -{
 120 -       struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 121 -
 122 -       memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
 123 -       if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 124 -               goto nla_put_failure;
 125 -       return skb->len;
 126 -
 127 -nla_put_failure:
 128 -       return -1;
 129 -}
 130 -
 131 -static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
 132 -{
 133 -       int prio;
 134 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 135 -
 136 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
 137 -               qdisc_skb_head_init(band2list(priv, prio));
 138 -
 139 -       /* Can by-pass the queue discipline */
 140 -       qdisc->flags |= TCQ_F_CAN_BYPASS;
 141 -       return 0;
 142 -}
 143 -
 144 -struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 145 -       .id             =       "pfifo_fast",
 146 -       .priv_size      =       sizeof(struct pfifo_fast_priv),
 147 -       .enqueue        =       pfifo_fast_enqueue,
 148 -       .dequeue        =       pfifo_fast_dequeue,
 149 -       .peek           =       pfifo_fast_peek,
 150 -       .init           =       pfifo_fast_init,
 151 -       .reset          =       pfifo_fast_reset,
 152 -       .dump           =       pfifo_fast_dump,
 153 -       .owner          =       THIS_MODULE,
 154 -};
 155 -EXPORT_SYMBOL(pfifo_fast_ops);
 156 -
 157  static struct lock_class_key qdisc_tx_busylock;
 158  static struct lock_class_key qdisc_running_key;
 159