target/linux/generic/hack-4.9/662-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 diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
  12 index 97de97e3c5e2..a62de9e4e897 100644
  13 --- a/net/sched/sch_generic.c
  14 +++ b/net/sched/sch_generic.c
  15 @@ -449,146 +449,6 @@ struct Qdisc_ops noqueue_qdisc_ops __read_mostly = {
  16         .owner          =       THIS_MODULE,
  17  };
  18
  19 -static const u8 prio2band[TC_PRIO_MAX + 1] = {
  20 -       1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
  21 -};
  22 -
  23 -/* 3-band FIFO queue: old style, but should be a bit faster than
  24 -   generic prio+fifo combination.
  25 - */
  26 -
  27 -#define PFIFO_FAST_BANDS 3
  28 -
  29 -/*
  30 - * Private data for a pfifo_fast scheduler containing:
  31 - *     - queues for the three band
  32 - *     - bitmap indicating which of the bands contain skbs
  33 - */
  34 -struct pfifo_fast_priv {
  35 -       u32 bitmap;
  36 -       struct qdisc_skb_head q[PFIFO_FAST_BANDS];
  37 -};
  38 -
  39 -/*
  40 - * Convert a bitmap to the first band number where an skb is queued, where:
  41 - *     bitmap=0 means there are no skbs on any band.
  42 - *     bitmap=1 means there is an skb on band 0.
  43 - *     bitmap=7 means there are skbs on all 3 bands, etc.
  44 - */
  45 -static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
  46 -
  47 -static inline struct qdisc_skb_head *band2list(struct pfifo_fast_priv *priv,
  48 -                                            int band)
  49 -{
  50 -       return priv->q + band;
  51 -}
  52 -
  53 -static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
  54 -                             struct sk_buff **to_free)
  55 -{
  56 -       if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) {
  57 -               int band = prio2band[skb->priority & TC_PRIO_MAX];
  58 -               struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  59 -               struct qdisc_skb_head *list = band2list(priv, band);
  60 -
  61 -               priv->bitmap |= (1 << band);
  62 -               qdisc->q.qlen++;
  63 -               return __qdisc_enqueue_tail(skb, qdisc, list);
  64 -       }
  65 -
  66 -       return qdisc_drop(skb, qdisc, to_free);
  67 -}
  68 -
  69 -static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
  70 -{
  71 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  72 -       int band = bitmap2band[priv->bitmap];
  73 -
  74 -       if (likely(band >= 0)) {
  75 -               struct qdisc_skb_head *qh = band2list(priv, band);
  76 -               struct sk_buff *skb = __qdisc_dequeue_head(qh);
  77 -
  78 -               if (likely(skb != NULL)) {
  79 -                       qdisc_qstats_backlog_dec(qdisc, skb);
  80 -                       qdisc_bstats_update(qdisc, skb);
  81 -               }
  82 -
  83 -               qdisc->q.qlen--;
  84 -               if (qh->qlen == 0)
  85 -                       priv->bitmap &= ~(1 << band);
  86 -
  87 -               return skb;
  88 -       }
  89 -
  90 -       return NULL;
  91 -}
  92 -
  93 -static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
  94 -{
  95 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  96 -       int band = bitmap2band[priv->bitmap];
  97 -
  98 -       if (band >= 0) {
  99 -               struct qdisc_skb_head *qh = band2list(priv, band);
 100 -
 101 -               return qh->head;
 102 -       }
 103 -
 104 -       return NULL;
 105 -}
 106 -
 107 -static void pfifo_fast_reset(struct Qdisc *qdisc)
 108 -{
 109 -       int prio;
 110 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 111 -
 112 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
 113 -               __qdisc_reset_queue(band2list(priv, prio));
 114 -
 115 -       priv->bitmap = 0;
 116 -       qdisc->qstats.backlog = 0;
 117 -       qdisc->q.qlen = 0;
 118 -}
 119 -
 120 -static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 121 -{
 122 -       struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 123 -
 124 -       memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
 125 -       if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 126 -               goto nla_put_failure;
 127 -       return skb->len;
 128 -
 129 -nla_put_failure:
 130 -       return -1;
 131 -}
 132 -
 133 -static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
 134 -{
 135 -       int prio;
 136 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 137 -
 138 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
 139 -               qdisc_skb_head_init(band2list(priv, prio));
 140 -
 141 -       /* Can by-pass the queue discipline */
 142 -       qdisc->flags |= TCQ_F_CAN_BYPASS;
 143 -       return 0;
 144 -}
 145 -
 146 -struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 147 -       .id             =       "pfifo_fast",
 148 -       .priv_size      =       sizeof(struct pfifo_fast_priv),
 149 -       .enqueue        =       pfifo_fast_enqueue,
 150 -       .dequeue        =       pfifo_fast_dequeue,
 151 -       .peek           =       pfifo_fast_peek,
 152 -       .init           =       pfifo_fast_init,
 153 -       .reset          =       pfifo_fast_reset,
 154 -       .dump           =       pfifo_fast_dump,
 155 -       .owner          =       THIS_MODULE,
 156 -};
 157 -EXPORT_SYMBOL(pfifo_fast_ops);
 158 -
 159  static struct lock_class_key qdisc_tx_busylock;
 160  static struct lock_class_key qdisc_running_key;
 161
 162 --
 163 2.11.0
 164