target/linux/generic/hack-4.19/662-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 @@ -595,208 +595,6 @@ 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 -               return qdisc_drop_cpu(skb, qdisc, to_free);
  54 -
  55 -       qdisc_qstats_cpu_qlen_inc(qdisc);
  56 -       /* Note: skb can not be used after skb_array_produce(),
  57 -        * so we better not use qdisc_qstats_cpu_backlog_inc()
  58 -        */
  59 -       this_cpu_add(qdisc->cpu_qstats->backlog, 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_qstats_cpu_backlog_dec(qdisc, skb);
  79 -               qdisc_bstats_cpu_update(qdisc, skb);
  80 -               qdisc_qstats_cpu_qlen_dec(qdisc);
  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 -       for_each_possible_cpu(i) {
 121 -               struct gnet_stats_queue *q = per_cpu_ptr(qdisc->cpu_qstats, i);
 122 -
 123 -               q->backlog = 0;
 124 -               q->qlen = 0;
 125 -       }
 126 -}
 127 -
 128 -static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
 129 -{
 130 -       struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
 131 -
 132 -       memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
 133 -       if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
 134 -               goto nla_put_failure;
 135 -       return skb->len;
 136 -
 137 -nla_put_failure:
 138 -       return -1;
 139 -}
 140 -
 141 -static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
 142 -                          struct netlink_ext_ack *extack)
 143 -{
 144 -       unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;
 145 -       struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
 146 -       int prio;
 147 -
 148 -       /* guard against zero length rings */
 149 -       if (!qlen)
 150 -               return -EINVAL;
 151 -
 152 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 153 -               struct skb_array *q = band2list(priv, prio);
 154 -               int err;
 155 -
 156 -               err = skb_array_init(q, qlen, GFP_KERNEL);
 157 -               if (err)
 158 -                       return -ENOMEM;
 159 -       }
 160 -
 161 -       /* Can by-pass the queue discipline */
 162 -       qdisc->flags |= TCQ_F_CAN_BYPASS;
 163 -       return 0;
 164 -}
 165 -
 166 -static void pfifo_fast_destroy(struct Qdisc *sch)
 167 -{
 168 -       struct pfifo_fast_priv *priv = qdisc_priv(sch);
 169 -       int prio;
 170 -
 171 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 172 -               struct skb_array *q = band2list(priv, prio);
 173 -
 174 -               /* NULL ring is possible if destroy path is due to a failed
 175 -                * skb_array_init() in pfifo_fast_init() case.
 176 -                */
 177 -               if (!q->ring.queue)
 178 -                       continue;
 179 -               /* Destroy ring but no need to kfree_skb because a call to
 180 -                * pfifo_fast_reset() has already done that work.
 181 -                */
 182 -               ptr_ring_cleanup(&q->ring, NULL);
 183 -       }
 184 -}
 185 -
 186 -static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
 187 -                                         unsigned int new_len)
 188 -{
 189 -       struct pfifo_fast_priv *priv = qdisc_priv(sch);
 190 -       struct skb_array *bands[PFIFO_FAST_BANDS];
 191 -       int prio;
 192 -
 193 -       for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
 194 -               struct skb_array *q = band2list(priv, prio);
 195 -
 196 -               bands[prio] = q;
 197 -       }
 198 -
 199 -       return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len,
 200 -                                        GFP_KERNEL);
 201 -}
 202 -
 203 -struct Qdisc_ops pfifo_fast_ops __read_mostly = {
 204 -       .id             =       "pfifo_fast",
 205 -       .priv_size      =       sizeof(struct pfifo_fast_priv),
 206 -       .enqueue        =       pfifo_fast_enqueue,
 207 -       .dequeue        =       pfifo_fast_dequeue,
 208 -       .peek           =       pfifo_fast_peek,
 209 -       .init           =       pfifo_fast_init,
 210 -       .destroy        =       pfifo_fast_destroy,
 211 -       .reset          =       pfifo_fast_reset,
 212 -       .dump           =       pfifo_fast_dump,
 213 -       .change_tx_queue_len =  pfifo_fast_change_tx_queue_len,
 214 -       .owner          =       THIS_MODULE,
 215 -       .static_flags   =       TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
 216 -};
 217 -EXPORT_SYMBOL(pfifo_fast_ops);
 218 -
 219  static struct lock_class_key qdisc_tx_busylock;
 220  static struct lock_class_key qdisc_running_key;
 221