From 758ce5c8d11d6fc57fe5f1dbc237aa8ff6386eac Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Sat, 28 Feb 2009 04:44:37 +0000 Subject: [PATCH] tcp: add helper for AI algorithm MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: David S. Miller --- include/net/tcp.h | 1 + net/ipv4/tcp_bic.c | 11 +---------- net/ipv4/tcp_cong.c | 21 ++++++++++++++------- net/ipv4/tcp_cubic.c | 11 +---------- net/ipv4/tcp_scalable.c | 10 ++-------- net/ipv4/tcp_veno.c | 7 +------ net/ipv4/tcp_yeah.c | 9 +-------- 7 files changed, 21 insertions(+), 49 deletions(-) diff --git a/include/net/tcp.h b/include/net/tcp.h index 218235de8963..0366a559afec 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -685,6 +685,7 @@ extern void tcp_get_allowed_congestion_control(char *buf, size_t len); extern int tcp_set_allowed_congestion_control(char *allowed); extern int tcp_set_congestion_control(struct sock *sk, const char *name); extern void tcp_slow_start(struct tcp_sock *tp); +extern void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w); extern struct tcp_congestion_ops tcp_init_congestion_ops; extern u32 tcp_reno_ssthresh(struct sock *sk); diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c index 7eb7636db0d0..3b53fd1af23f 100644 --- a/net/ipv4/tcp_bic.c +++ b/net/ipv4/tcp_bic.c @@ -149,16 +149,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) tcp_slow_start(tp); else { bictcp_update(ca, tp->snd_cwnd); - - /* In dangerous area, increase slowly. - * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd - */ - if (tp->snd_cwnd_cnt >= ca->cnt) { - 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, ca->cnt); } } 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); diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c index ee467ec40c4f..71d5f2f29fa6 100644 --- a/net/ipv4/tcp_cubic.c +++ b/net/ipv4/tcp_cubic.c @@ -294,16 +294,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) tcp_slow_start(tp); } else { bictcp_update(ca, tp->snd_cwnd); - - /* In dangerous area, increase slowly. - * In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd - */ - if (tp->snd_cwnd_cnt >= ca->cnt) { - 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, ca->cnt); } } diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c index 4660b088a8ce..a76513779e2b 100644 --- a/net/ipv4/tcp_scalable.c +++ b/net/ipv4/tcp_scalable.c @@ -24,14 +24,8 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) if (tp->snd_cwnd <= tp->snd_ssthresh) tcp_slow_start(tp); - else { - tp->snd_cwnd_cnt++; - if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){ - if (tp->snd_cwnd < tp->snd_cwnd_clamp) - tp->snd_cwnd++; - tp->snd_cwnd_cnt = 0; - } - } + else + tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)); } static u32 tcp_scalable_ssthresh(struct sock *sk) diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c index d08b2e855c22..e9bbff746488 100644 --- a/net/ipv4/tcp_veno.c +++ b/net/ipv4/tcp_veno.c @@ -159,12 +159,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) /* In the "non-congestive state", increase cwnd * every rtt. */ - 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); } else { /* In the "congestive state", increase cwnd * every other rtt. diff --git a/net/ipv4/tcp_yeah.c b/net/ipv4/tcp_yeah.c index 9ec843a9bbb2..66b6821b984e 100644 --- a/net/ipv4/tcp_yeah.c +++ b/net/ipv4/tcp_yeah.c @@ -94,14 +94,7 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 in_flight) } else { /* Reno */ - - if (tp->snd_cwnd_cnt < tp->snd_cwnd) - tp->snd_cwnd_cnt++; - - if (tp->snd_cwnd_cnt >= tp->snd_cwnd) { - tp->snd_cwnd++; - tp->snd_cwnd_cnt = 0; - } + tcp_cong_avoid_ai(tp, tp->snd_cwnd); } /* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.