target/linux/generic/hack-5.4/662-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 @@ -594,211 +594,6 @@ 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 - *     - rings for priority bands
  30 - */
  31 -struct pfifo_fast_priv {
  32 -       struct skb_array q[PFIFO_FAST_BANDS];
  33 -};
  34 -
  35 -static inline struct skb_array *band2list(struct pfifo_fast_priv *priv,
  36 -                                         int band)
  37 -{
  38 -       return &priv->q[band];
  39 -}
  40 -
  41 -static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
  42 -                             struct sk_buff **to_free)
  43 -{
  44 -       int band = prio2band[skb->priority & TC_PRIO_MAX];
  45 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  46 -       struct skb_array *q = band2list(priv, band);
  47 -       unsigned int pkt_len = qdisc_pkt_len(skb);
  48 -       int err;
  49 -
  50 -       err = skb_array_produce(q, skb);
  51 -
  52 -       if (unlikely(err)) {
  53 -               if (qdisc_is_percpu_stats(qdisc))
  54 -                       return qdisc_drop_cpu(skb, qdisc, to_free);
  55 -               else
  56 -                       return qdisc_drop(skb, qdisc, to_free);
  57 -       }
  58 -
  59 -       qdisc_update_stats_at_enqueue(qdisc, pkt_len);
  60 -       return NET_XMIT_SUCCESS;
  61 -}
  62 -
  63 -static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
  64 -{
  65 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  66 -       struct sk_buff *skb = NULL;
  67 -       int band;
  68 -
  69 -       for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
  70 -               struct skb_array *q = band2list(priv, band);
  71 -
  72 -               if (__skb_array_empty(q))
  73 -                       continue;
  74 -
  75 -               skb = __skb_array_consume(q);
  76 -       }
  77 -       if (likely(skb)) {
  78 -               qdisc_update_stats_at_dequeue(qdisc, skb);
  79 -       } else {
  80 -               WRITE_ONCE(qdisc->empty, true);
  81 -       }
  82 -
  83 -       return skb;
  84 -}
  85 -
  86 -static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
  87 -{
  88 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
  89 -       struct sk_buff *skb = NULL;
  90 -       int band;
  91 -
  92 -       for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
  93 -               struct skb_array *q = band2list(priv, band);
  94 -
  95 -               skb = __skb_array_peek(q);
  96 -       }
  97 -
  98 -       return skb;
  99 -}
 100 -
 101 -static void pfifo_fast_reset(struct Qdisc *qdisc)
 102 -{
 103 -       int i, band;
 104 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 105 -
 106 -       for (band = 0; band < PFIFO_FAST_BANDS; band++) {
 107 -               struct skb_array *q = band2list(priv, band);
 108 -               struct sk_buff *skb;
 109 -
 110 -               /* NULL ring is possible if destroy path is due to a failed
 111 -                * skb_array_init() in pfifo_fast_init() case.
 112 -                */
 113 -               if (!q->ring.queue)
 114 -                       continue;
 115 -
 116 -               while ((skb = __skb_array_consume(q)) != NULL)
 117 -                       kfree_skb(skb);
 118 -       }
 119 -
 120 -       if (qdisc_is_percpu_stats(qdisc)) {
 121 -               for_each_possible_cpu(i) {
 122 -                       struct gnet_stats_queue *q;
 123 -
 124 -                       q = per_cpu_ptr(qdisc->cpu_qstats, i);
 125 -                       q->backlog = 0;
 126 -                       q->qlen = 0;
 127 -               }
 128 -       }
 129 -}
 130 -
 131 -static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 132 -{
 133 -       struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 134 -
 135 -       memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
 136 -       if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 137 -               goto nla_put_failure;
 138 -       return skb->len;
 139 -
 140 -nla_put_failure:
 141 -       return -1;
 142 -}
 143 -
 144 -static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
 145 -                          struct netlink_ext_ack *extack)
 146 -{
 147 -       unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;
 148 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 149 -       int prio;
 150 -
 151 -       /* guard against zero length rings */
 152 -       if (!qlen)
 153 -               return -EINVAL;
 154 -
 155 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 156 -               struct skb_array *q = band2list(priv, prio);
 157 -               int err;
 158 -
 159 -               err = skb_array_init(q, qlen, GFP_KERNEL);
 160 -               if (err)
 161 -                       return -ENOMEM;
 162 -       }
 163 -
 164 -       /* Can by-pass the queue discipline */
 165 -       qdisc->flags |= TCQ_F_CAN_BYPASS;
 166 -       return 0;
 167 -}
 168 -
 169 -static void pfifo_fast_destroy(struct Qdisc *sch)
 170 -{
 171 -       struct pfifo_fast_priv *priv = qdisc_priv(sch);
 172 -       int prio;
 173 -
 174 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 175 -               struct skb_array *q = band2list(priv, prio);
 176 -
 177 -               /* NULL ring is possible if destroy path is due to a failed
 178 -                * skb_array_init() in pfifo_fast_init() case.
 179 -                */
 180 -               if (!q->ring.queue)
 181 -                       continue;
 182 -               /* Destroy ring but no need to kfree_skb because a call to
 183 -                * pfifo_fast_reset() has already done that work.
 184 -                */
 185 -               ptr_ring_cleanup(&q->ring, NULL);
 186 -       }
 187 -}
 188 -
 189 -static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
 190 -                                         unsigned int new_len)
 191 -{
 192 -       struct pfifo_fast_priv *priv = qdisc_priv(sch);
 193 -       struct skb_array *bands[PFIFO_FAST_BANDS];
 194 -       int prio;
 195 -
 196 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 197 -               struct skb_array *q = band2list(priv, prio);
 198 -
 199 -               bands[prio] = q;
 200 -       }
 201 -
 202 -       return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len,
 203 -                                        GFP_KERNEL);
 204 -}
 205 -
 206 -struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 207 -       .id             =       "pfifo_fast",
 208 -       .priv_size      =       sizeof(struct pfifo_fast_priv),
 209 -       .enqueue        =       pfifo_fast_enqueue,
 210 -       .dequeue        =       pfifo_fast_dequeue,
 211 -       .peek           =       pfifo_fast_peek,
 212 -       .init           =       pfifo_fast_init,
 213 -       .destroy        =       pfifo_fast_destroy,
 214 -       .reset          =       pfifo_fast_reset,
 215 -       .dump           =       pfifo_fast_dump,
 216 -       .change_tx_queue_len =  pfifo_fast_change_tx_queue_len,
 217 -       .owner          =       THIS_MODULE,
 218 -       .static_flags   =       TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
 219 -};
 220 -EXPORT_SYMBOL(pfifo_fast_ops);
 221 -
 222  struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
 223                           const struct Qdisc_ops *ops,
 224                           struct netlink_ext_ack *extack)