[PATCH net-next 12/17] tcp: add helper for AI algorithm
From: Ilpo Järvinen <hidden>
Date: 2009-02-28 14:44:53
Subsystem:
networking [general], networking [tcp], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Neal Cardwell, Linus Torvalds
From: Ilpo Järvinen <redacted> 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 <redacted> --- 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 218235d..0366a55 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 7eb7636..3b53fd1 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 4ec5b4e..e92beb9 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 ee467ec..71d5f2f 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 4660b08..a765137 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 d08b2e8..e9bbff7 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 9ec843a..66b6821 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.
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1.5.6.5