69 lines
1.6 KiB
C
69 lines
1.6 KiB
C
|
/* Tom Kelly's Scalable TCP
|
||
|
|
*
|
||
|
|
* See htt://www-lce.eng.cam.ac.uk/~ctk21/scalable/
|
||
|
|
*
|
||
|
|
* John Heffner <jheffner@sc.edu>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <linux/config.h>
|
||
|
|
#include <linux/module.h>
|
||
|
|
#include <net/tcp.h>
|
||
|
|
|
||
|
|
/* These factors derived from the recommended values in the aer:
|
||
|
|
* .01 and and 7/8. We use 50 instead of 100 to account for
|
||
|
|
* delayed ack.
|
||
|
|
*/
|
||
|
|
#define TCP_SCALABLE_AI_CNT 50U
|
||
|
|
#define TCP_SCALABLE_MD_SCALE 3
|
||
|
|
|
||
|
|
static void tcp_scalable_cong_avoid(struct tcp_sock *tp, u32 ack, u32 rtt,
|
||
|
|
u32 in_flight, int flag)
|
||
|
|
{
|
||
|
|
if (in_flight < tp->snd_cwnd)
|
||
|
|
return;
|
||
|
|
|
||
|
|
if (tp->snd_cwnd <= tp->snd_ssthresh) {
|
||
|
|
tp->snd_cwnd++;
|
||
|
|
} else {
|
||
|
|
tp->snd_cwnd_cnt++;
|
||
|
|
if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
|
||
|
|
tp->snd_cwnd++;
|
||
|
|
tp->snd_cwnd_cnt = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
|
||
|
|
tp->snd_cwnd_stamp = tcp_time_stamp;
|
||
|
|
}
|
||
|
|
|
||
|
|
static u32 tcp_scalable_ssthresh(struct tcp_sock *tp)
|
||
|
|
{
|
||
|
|
return max(tp->snd_cwnd - (tp->snd_cwnd>>TCP_SCALABLE_MD_SCALE), 2U);
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
static struct tcp_congestion_ops tcp_scalable = {
|
||
|
|
.ssthresh = tcp_scalable_ssthresh,
|
||
|
|
.cong_avoid = tcp_scalable_cong_avoid,
|
||
|
|
.min_cwnd = tcp_reno_min_cwnd,
|
||
|
|
|
||
|
|
.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");
|