20fea08b5f
Qdisc_class_ops are const, and Qdisc_ops are mostly read. Using "const" and "__read_mostly" qualifiers helps to reduce false sharing. Signed-off-by: Eric Dumazet <dada1@cosmosbay.com> Signed-off-by: David S. Miller <davem@davemloft.net>
110 lines
2.5 KiB
C
110 lines
2.5 KiB
C
/*
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* net/sched/sch_fifo.c The simplest FIFO queue.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
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*/
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/skbuff.h>
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#include <net/pkt_sched.h>
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/* 1 band FIFO pseudo-"scheduler" */
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struct fifo_sched_data
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{
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u32 limit;
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};
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static int bfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
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{
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struct fifo_sched_data *q = qdisc_priv(sch);
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if (likely(sch->qstats.backlog + skb->len <= q->limit))
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return qdisc_enqueue_tail(skb, sch);
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return qdisc_reshape_fail(skb, sch);
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}
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static int pfifo_enqueue(struct sk_buff *skb, struct Qdisc* sch)
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{
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struct fifo_sched_data *q = qdisc_priv(sch);
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if (likely(skb_queue_len(&sch->q) < q->limit))
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return qdisc_enqueue_tail(skb, sch);
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return qdisc_reshape_fail(skb, sch);
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}
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static int fifo_init(struct Qdisc *sch, struct rtattr *opt)
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{
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struct fifo_sched_data *q = qdisc_priv(sch);
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if (opt == NULL) {
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u32 limit = sch->dev->tx_queue_len ? : 1;
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if (sch->ops == &bfifo_qdisc_ops)
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limit *= sch->dev->mtu;
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q->limit = limit;
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} else {
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struct tc_fifo_qopt *ctl = RTA_DATA(opt);
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if (RTA_PAYLOAD(opt) < sizeof(*ctl))
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return -EINVAL;
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q->limit = ctl->limit;
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}
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return 0;
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}
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static int fifo_dump(struct Qdisc *sch, struct sk_buff *skb)
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{
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struct fifo_sched_data *q = qdisc_priv(sch);
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struct tc_fifo_qopt opt = { .limit = q->limit };
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RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
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return skb->len;
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rtattr_failure:
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return -1;
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}
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struct Qdisc_ops pfifo_qdisc_ops __read_mostly = {
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.id = "pfifo",
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.priv_size = sizeof(struct fifo_sched_data),
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.enqueue = pfifo_enqueue,
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.dequeue = qdisc_dequeue_head,
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.requeue = qdisc_requeue,
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.drop = qdisc_queue_drop,
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.init = fifo_init,
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.reset = qdisc_reset_queue,
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.change = fifo_init,
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.dump = fifo_dump,
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.owner = THIS_MODULE,
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};
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struct Qdisc_ops bfifo_qdisc_ops __read_mostly = {
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.id = "bfifo",
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.priv_size = sizeof(struct fifo_sched_data),
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.enqueue = bfifo_enqueue,
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.dequeue = qdisc_dequeue_head,
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.requeue = qdisc_requeue,
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.drop = qdisc_queue_drop,
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.init = fifo_init,
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.reset = qdisc_reset_queue,
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.change = fifo_init,
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.dump = fifo_dump,
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.owner = THIS_MODULE,
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};
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EXPORT_SYMBOL(bfifo_qdisc_ops);
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EXPORT_SYMBOL(pfifo_qdisc_ops);
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