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From b531d492d5ef1cf9dba0f4888eb5fd8624a6d762 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 7 Jul 2017 17:23:42 +0200
Subject: net: sched: switch default qdisc from pfifo_fast to fq_codel and remove pfifo_fast
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
net/sched/sch_generic.c | 140 ------------------------------------------------
1 file changed, 140 deletions(-)
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -620,230 +620,6 @@ struct Qdisc_ops noqueue_qdisc_ops __rea
.owner = THIS_MODULE,
};
-static const u8 prio2band[TC_PRIO_MAX + 1] = {
- 1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
-};
-
-/* 3-band FIFO queue: old style, but should be a bit faster than
- generic prio+fifo combination.
- */
-
-#define PFIFO_FAST_BANDS 3
-
-/*
- * Private data for a pfifo_fast scheduler containing:
- * - rings for priority bands
- */
-struct pfifo_fast_priv {
- struct skb_array q[PFIFO_FAST_BANDS];
-};
-
-static inline struct skb_array *band2list(struct pfifo_fast_priv *priv,
- int band)
-{
- return &priv->q[band];
-}
-
-static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
- struct sk_buff **to_free)
-{
- int band = prio2band[skb->priority & TC_PRIO_MAX];
- struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
- struct skb_array *q = band2list(priv, band);
- unsigned int pkt_len = qdisc_pkt_len(skb);
- int err;
-
- err = skb_array_produce(q, skb);
-
- if (unlikely(err)) {
- if (qdisc_is_percpu_stats(qdisc))
- return qdisc_drop_cpu(skb, qdisc, to_free);
- else
- return qdisc_drop(skb, qdisc, to_free);
- }
-
- qdisc_update_stats_at_enqueue(qdisc, pkt_len);
- return NET_XMIT_SUCCESS;
-}
-
-static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
-{
- struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
- struct sk_buff *skb = NULL;
- bool need_retry = true;
- int band;
-
-retry:
- for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
- struct skb_array *q = band2list(priv, band);
-
- if (__skb_array_empty(q))
- continue;
-
- skb = __skb_array_consume(q);
- }
- if (likely(skb)) {
- qdisc_update_stats_at_dequeue(qdisc, skb);
- } else if (need_retry &&
- test_bit(__QDISC_STATE_MISSED, &qdisc->state)) {
- /* Delay clearing the STATE_MISSED here to reduce
- * the overhead of the second spin_trylock() in
- * qdisc_run_begin() and __netif_schedule() calling
- * in qdisc_run_end().
- */
- clear_bit(__QDISC_STATE_MISSED, &qdisc->state);
-
- /* Make sure dequeuing happens after clearing
- * STATE_MISSED.
- */
- smp_mb__after_atomic();
-
- need_retry = false;
-
- goto retry;
- } else {
- WRITE_ONCE(qdisc->empty, true);
- }
-
- return skb;
-}
-
-static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
-{
- struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
- struct sk_buff *skb = NULL;
- int band;
-
- for (band = 0; band < PFIFO_FAST_BANDS && !skb; band++) {
- struct skb_array *q = band2list(priv, band);
-
- skb = __skb_array_peek(q);
- }
-
- return skb;
-}
-
-static void pfifo_fast_reset(struct Qdisc *qdisc)
-{
- int i, band;
- struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-
- for (band = 0; band < PFIFO_FAST_BANDS; band++) {
- struct skb_array *q = band2list(priv, band);
- struct sk_buff *skb;
-
- /* NULL ring is possible if destroy path is due to a failed
- * skb_array_init() in pfifo_fast_init() case.
- */
- if (!q->ring.queue)
- continue;
-
- while ((skb = __skb_array_consume(q)) != NULL)
- kfree_skb(skb);
- }
-
- if (qdisc_is_percpu_stats(qdisc)) {
- for_each_possible_cpu(i) {
- struct gnet_stats_queue *q;
-
- q = per_cpu_ptr(qdisc->cpu_qstats, i);
- q->backlog = 0;
- q->qlen = 0;
- }
- }
-}
-
-static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
-{
- struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
-
- memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
- if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
- goto nla_put_failure;
- return skb->len;
-
-nla_put_failure:
- return -1;
-}
-
-static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt,
- struct netlink_ext_ack *extack)
-{
- unsigned int qlen = qdisc_dev(qdisc)->tx_queue_len;
- struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
- int prio;
-
- /* guard against zero length rings */
- if (!qlen)
- return -EINVAL;
-
- for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
- struct skb_array *q = band2list(priv, prio);
- int err;
-
- err = skb_array_init(q, qlen, GFP_KERNEL);
- if (err)
- return -ENOMEM;
- }
-
- /* Can by-pass the queue discipline */
- qdisc->flags |= TCQ_F_CAN_BYPASS;
- return 0;
-}
-
-static void pfifo_fast_destroy(struct Qdisc *sch)
-{
- struct pfifo_fast_priv *priv = qdisc_priv(sch);
- int prio;
-
- for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
- struct skb_array *q = band2list(priv, prio);
-
- /* NULL ring is possible if destroy path is due to a failed
- * skb_array_init() in pfifo_fast_init() case.
- */
- if (!q->ring.queue)
- continue;
- /* Destroy ring but no need to kfree_skb because a call to
- * pfifo_fast_reset() has already done that work.
- */
- ptr_ring_cleanup(&q->ring, NULL);
- }
-}
-
-static int pfifo_fast_change_tx_queue_len(struct Qdisc *sch,
- unsigned int new_len)
-{
- struct pfifo_fast_priv *priv = qdisc_priv(sch);
- struct skb_array *bands[PFIFO_FAST_BANDS];
- int prio;
-
- for (prio = 0; prio < PFIFO_FAST_BANDS; prio++) {
- struct skb_array *q = band2list(priv, prio);
-
- bands[prio] = q;
- }
-
- return skb_array_resize_multiple(bands, PFIFO_FAST_BANDS, new_len,
- GFP_KERNEL);
-}
-
-struct Qdisc_ops pfifo_fast_ops __read_mostly = {
- .id = "pfifo_fast",
- .priv_size = sizeof(struct pfifo_fast_priv),
- .enqueue = pfifo_fast_enqueue,
- .dequeue = pfifo_fast_dequeue,
- .peek = pfifo_fast_peek,
- .init = pfifo_fast_init,
- .destroy = pfifo_fast_destroy,
- .reset = pfifo_fast_reset,
- .dump = pfifo_fast_dump,
- .change_tx_queue_len = pfifo_fast_change_tx_queue_len,
- .owner = THIS_MODULE,
- .static_flags = TCQ_F_NOLOCK | TCQ_F_CPUSTATS,
-};
-EXPORT_SYMBOL(pfifo_fast_ops);
-
struct Qdisc *qdisc_alloc(struct netdev_queue *dev_queue,
const struct Qdisc_ops *ops,
struct netlink_ext_ack *extack)
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