* John Heffner <jheffner@psc.edu>
*/
-#include <linux/config.h>
#include <linux/module.h>
#include <net/tcp.h>
* with fixed-point MD scaled <<8.
*/
static const struct hstcp_aimd_val {
- unsigned int cwnd;
- unsigned int md;
+ unsigned int cwnd;
+ unsigned int md;
} hstcp_aimd_vals[] = {
{ 38, 128, /* 0.50 */ },
{ 118, 112, /* 0.44 */ },
tp->snd_cwnd_clamp = min_t(u32, tp->snd_cwnd_clamp, 0xffffffff/128);
}
-static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 rtt,
- u32 in_flight, u32 pkts_acked)
+static void hstcp_cong_avoid(struct sock *sk, u32 adk, u32 in_flight)
{
struct tcp_sock *tp = tcp_sk(sk);
struct hstcp *ca = inet_csk_ca(sk);
if (tp->snd_cwnd <= tp->snd_ssthresh)
tcp_slow_start(tp);
else {
- /* Update AIMD parameters */
+ /* Update AIMD parameters.
+ *
+ * We want to guarantee that:
+ * hstcp_aimd_vals[ca->ai-1].cwnd <
+ * snd_cwnd <=
+ * hstcp_aimd_vals[ca->ai].cwnd
+ */
if (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd) {
while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
- ca->ai < HSTCP_AIMD_MAX)
+ ca->ai < HSTCP_AIMD_MAX - 1)
ca->ai++;
- } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
- while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
- ca->ai > 0)
+ } else if (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd) {
+ while (ca->ai && tp->snd_cwnd <= hstcp_aimd_vals[ca->ai-1].cwnd)
ca->ai--;
}
/* Do additive increase */
if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
- tp->snd_cwnd_cnt += ca->ai;
+ /* cwnd = cwnd + a(w) / cwnd */
+ tp->snd_cwnd_cnt += ca->ai + 1;
if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
- tp->snd_cwnd++;
tp->snd_cwnd_cnt -= tp->snd_cwnd;
+ tp->snd_cwnd++;
}
}
}
static int __init hstcp_register(void)
{
- BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
+ BUILD_BUG_ON(sizeof(struct hstcp) > ICSK_CA_PRIV_SIZE);
return tcp_register_congestion_control(&tcp_highspeed);
}