tcp: add helper for AI algorithm

It seems that implementation in yeah was inconsistent to what
other did as it would increase cwnd one ack earlier than the
others do.

Size benefits:

  bictcp_cong_avoid |  -36
  tcp_cong_avoid_ai |  +52
  bictcp_cong_avoid |  -34
  tcp_scalable_cong_avoid |  -36
  tcp_veno_cong_avoid |  -12
  tcp_yeah_cong_avoid |  -38

= -104 bytes total

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ilpo Järvinen
2009-02-28 04:44:37 +00:00
committed by David S. Miller
parent 571a5dd8d0
commit 758ce5c8d1
7 changed files with 21 additions and 49 deletions

View File

@@ -336,6 +336,19 @@ void tcp_slow_start(struct tcp_sock *tp)
}
EXPORT_SYMBOL_GPL(tcp_slow_start);
/* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd (or alternative w) */
void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w)
{
if (tp->snd_cwnd_cnt >= w) {
if (tp->snd_cwnd < tp->snd_cwnd_clamp)
tp->snd_cwnd++;
tp->snd_cwnd_cnt = 0;
} else {
tp->snd_cwnd_cnt++;
}
}
EXPORT_SYMBOL_GPL(tcp_cong_avoid_ai);
/*
* TCP Reno congestion control
* This is special case used for fallback as well.
@@ -365,13 +378,7 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight)
tp->snd_cwnd++;
}
} else {
/* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd */
if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
if (tp->snd_cwnd < tp->snd_cwnd_clamp)
tp->snd_cwnd++;
tp->snd_cwnd_cnt = 0;
} else
tp->snd_cwnd_cnt++;
tcp_cong_avoid_ai(tp, tp->snd_cwnd);
}
}
EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);