linux/include/net/codel_qdisc.h
Eric Dumazet 008830bc32 net_sched: fq_codel: cache skb->truesize into skb->cb
Now we defer skb drops, it makes sense to keep a copy
of skb->truesize in struct codel_skb_cb to avoid one
cache line miss per dropped skb in fq_codel_drop(),
to reduce latencies a bit further.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-06-25 12:19:35 -04:00

75 lines
2.9 KiB
C

#ifndef __NET_SCHED_CODEL_QDISC_H
#define __NET_SCHED_CODEL_QDISC_H
/*
* Codel - The Controlled-Delay Active Queue Management algorithm
*
* Copyright (C) 2011-2012 Kathleen Nichols <nichols@pollere.com>
* Copyright (C) 2011-2012 Van Jacobson <van@pollere.net>
* Copyright (C) 2012 Michael D. Taht <dave.taht@bufferbloat.net>
* Copyright (C) 2012,2015 Eric Dumazet <edumazet@google.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, provided that this notice is retained in full, this
* software may be distributed under the terms of the GNU General
* Public License ("GPL") version 2, in which case the provisions of the
* GPL apply INSTEAD OF those given above.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*
*/
/* Controlling Queue Delay (CoDel) algorithm
* =========================================
* Source : Kathleen Nichols and Van Jacobson
* http://queue.acm.org/detail.cfm?id=2209336
*
* Implemented on linux by Dave Taht and Eric Dumazet
*/
/* Qdiscs using codel plugin must use codel_skb_cb in their own cb[] */
struct codel_skb_cb {
codel_time_t enqueue_time;
unsigned int mem_usage;
};
static struct codel_skb_cb *get_codel_cb(const struct sk_buff *skb)
{
qdisc_cb_private_validate(skb, sizeof(struct codel_skb_cb));
return (struct codel_skb_cb *)qdisc_skb_cb(skb)->data;
}
static codel_time_t codel_get_enqueue_time(const struct sk_buff *skb)
{
return get_codel_cb(skb)->enqueue_time;
}
static void codel_set_enqueue_time(struct sk_buff *skb)
{
get_codel_cb(skb)->enqueue_time = codel_get_time();
}
#endif