// SPDX-License-Identifier: GPL-2.0-only
|
/* Tom Kelly's Scalable TCP
|
*
|
* See http://www.deneholme.net/tom/scalable/
|
*
|
* John Heffner <jheffner@sc.edu>
|
*/
|
|
#include <linux/module.h>
|
#include <net/tcp.h>
|
|
/* These factors derived from the recommended values in the aer:
|
* .01 and 7/8.
|
*/
|
#define TCP_SCALABLE_AI_CNT 100U
|
#define TCP_SCALABLE_MD_SCALE 3
|
|
static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked)
|
{
|
struct tcp_sock *tp = tcp_sk(sk);
|
|
if (!tcp_is_cwnd_limited(sk))
|
return;
|
|
if (tcp_in_slow_start(tp)) {
|
acked = tcp_slow_start(tp, acked);
|
if (!acked)
|
return;
|
}
|
tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT),
|
acked);
|
}
|
|
static u32 tcp_scalable_ssthresh(struct sock *sk)
|
{
|
const struct tcp_sock *tp = tcp_sk(sk);
|
|
return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U);
|
}
|
|
static struct tcp_congestion_ops tcp_scalable __read_mostly = {
|
.ssthresh = tcp_scalable_ssthresh,
|
.undo_cwnd = tcp_reno_undo_cwnd,
|
.cong_avoid = tcp_scalable_cong_avoid,
|
|
.owner = THIS_MODULE,
|
.name = "scalable",
|
};
|
|
static int __init tcp_scalable_register(void)
|
{
|
return tcp_register_congestion_control(&tcp_scalable);
|
}
|
|
static void __exit tcp_scalable_unregister(void)
|
{
|
tcp_unregister_congestion_control(&tcp_scalable);
|
}
|
|
module_init(tcp_scalable_register);
|
module_exit(tcp_scalable_unregister);
|
|
MODULE_AUTHOR("John Heffner");
|
MODULE_LICENSE("GPL");
|
MODULE_DESCRIPTION("Scalable TCP");
|
