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authorIlpo Järvinen <ilpo.jarvinen@helsinki.fi>2009-02-28 04:44:37 +0000
committerDavid S. Miller <davem@davemloft.net>2009-03-02 03:00:15 -0800
commit758ce5c8d11d6fc57fe5f1dbc237aa8ff6386eac (patch)
tree45b3dff5ca179712d50cdeae45846db8ffd51caa /net/ipv4/tcp_cong.c
parent571a5dd8d01f2a7e279c502fa220a69262d73694 (diff)
downloadlwn-758ce5c8d11d6fc57fe5f1dbc237aa8ff6386eac.tar.gz
lwn-758ce5c8d11d6fc57fe5f1dbc237aa8ff6386eac.zip
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>
Diffstat (limited to 'net/ipv4/tcp_cong.c')
-rw-r--r--net/ipv4/tcp_cong.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 4ec5b4e97c4e..e92beb9e55e0 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -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);