Move all the code that does linear TCP slowstart to one
inline function to ease later patch to add ABC support.
Signed-off-by: Stephen Hemminger <[EMAIL PROTECTED]>
--- net-2.6.orig/include/net/tcp.h
+++ net-2.6/include/net/tcp.h
@@ -762,6 +762,16 @@ static inline __u32 tcp_current_ssthresh
(tp->snd_cwnd >> 2)));
}
+/*
+ * Linear increase during slow start
+ */
+static inline void tcp_slow_start(struct tcp_sock *tp)
+{
+ if (tp->snd_cwnd < tp->snd_cwnd_clamp)
+ tp->snd_cwnd++;
+}
+
+
static inline void tcp_sync_left_out(struct tcp_sock *tp)
{
if (tp->rx_opt.sack_ok &&
--- net-2.6.orig/net/ipv4/tcp_bic.c
+++ net-2.6/net/ipv4/tcp_bic.c
@@ -216,24 +216,20 @@ static void bictcp_cong_avoid(struct soc
bictcp_low_utilization(sk, data_acked);
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
- /* In "safe" area, increase. */
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- } else {
- bictcp_update(ca, tp->snd_cwnd);
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
+ return tcp_slow_start(tp);
- /* 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++;
- }
+ 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++;
}
/*
--- net-2.6.orig/net/ipv4/tcp_cong.c
+++ net-2.6/net/ipv4/tcp_cong.c
@@ -185,21 +185,19 @@ void tcp_reno_cong_avoid(struct sock *sk
{
struct tcp_sock *tp = tcp_sk(sk);
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
- /* In "safe" area, increase. */
+ /* In "safe" area, increase. */
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
+ return tcp_slow_start(tp);
+
+ /* In dangerous area, increase slowly.
+ * 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++;
- } else {
- /* In dangerous area, increase slowly.
- * 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++;
- }
+ tp->snd_cwnd_cnt = 0;
+ } else
+ tp->snd_cwnd_cnt++;
}
EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
--- net-2.6.orig/net/ipv4/tcp_highspeed.c
+++ net-2.6/net/ipv4/tcp_highspeed.c
@@ -115,28 +115,26 @@ static void hstcp_cong_avoid(struct sock
struct tcp_sock *tp = tcp_sk(sk);
struct hstcp *ca = inet_csk_ca(sk);
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- } else {
- /* Update AIMD parameters */
- 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++;
- } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
- while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
- ca->ai > 0)
- ca->ai--;
- }
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
+ return tcp_slow_start(tp);
- /* Do additive increase */
- if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
- tp->snd_cwnd_cnt += ca->ai;
- if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt -= tp->snd_cwnd;
- }
+ /* Update AIMD parameters */
+ 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++;
+ } else if (tp->snd_cwnd < hstcp_aimd_vals[ca->ai].cwnd) {
+ while (tp->snd_cwnd > hstcp_aimd_vals[ca->ai].cwnd &&
+ ca->ai > 0)
+ ca->ai--;
+ }
+
+ /* Do additive increase */
+ if (tp->snd_cwnd < tp->snd_cwnd_clamp) {
+ tp->snd_cwnd_cnt += ca->ai;
+ if (tp->snd_cwnd_cnt >= tp->snd_cwnd) {
+ tp->snd_cwnd++;
+ tp->snd_cwnd_cnt -= tp->snd_cwnd;
}
}
}
--- net-2.6.orig/net/ipv4/tcp_htcp.c
+++ net-2.6/net/ipv4/tcp_htcp.c
@@ -206,29 +206,26 @@ static void htcp_cong_avoid(struct sock
struct tcp_sock *tp = tcp_sk(sk);
struct htcp *ca = inet_csk_ca(sk);
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
- /* In "safe" area, increase. */
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
+ return tcp_slow_start(tp);
+
+ measure_rtt(sk);
+
+ /* keep track of number of round-trip times since last backoff event */
+ if (ca->snd_cwnd_cnt2++ > tp->snd_cwnd) {
+ ca->ccount++;
+ ca->snd_cwnd_cnt2 = 0;
+ htcp_alpha_update(ca);
+ }
+
+ /* In dangerous area, increase slowly.
+ * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
+ */
+ if ((tp->snd_cwnd_cnt++ * ca->alpha)>>7 >= tp->snd_cwnd) {
if (tp->snd_cwnd < tp->snd_cwnd_clamp)
tp->snd_cwnd++;
- } else {
- measure_rtt(sk);
-
- /* keep track of number of round-trip times since last backoff
event */
- if (ca->snd_cwnd_cnt2++ > tp->snd_cwnd) {
- ca->ccount++;
- ca->snd_cwnd_cnt2 = 0;
- htcp_alpha_update(ca);
- }
-
- /* In dangerous area, increase slowly.
- * In theory this is tp->snd_cwnd += alpha / tp->snd_cwnd
- */
- if ((tp->snd_cwnd_cnt++ * ca->alpha)>>7 >= tp->snd_cwnd) {
- if (tp->snd_cwnd < tp->snd_cwnd_clamp)
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt = 0;
- ca->ccount++;
- }
+ tp->snd_cwnd_cnt = 0;
+ ca->ccount++;
}
}
--- net-2.6.orig/net/ipv4/tcp_scalable.c
+++ net-2.6/net/ipv4/tcp_scalable.c
@@ -20,17 +20,14 @@ static void tcp_scalable_cong_avoid(stru
{
struct tcp_sock *tp = tcp_sk(sk);
- if (tp->snd_cwnd <= tp->snd_ssthresh) {
+ if (tp->snd_cwnd <= tp->snd_ssthresh)
+ return tcp_slow_start(tp);
+
+ tp->snd_cwnd_cnt++;
+ if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
tp->snd_cwnd++;
- } else {
- tp->snd_cwnd_cnt++;
- if (tp->snd_cwnd_cnt > min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT)){
- tp->snd_cwnd++;
- tp->snd_cwnd_cnt = 0;
- }
+ tp->snd_cwnd_cnt = 0;
}
- tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
- tp->snd_cwnd_stamp = tcp_time_stamp;
}
static u32 tcp_scalable_ssthresh(struct sock *sk)
--- net-2.6.orig/net/ipv4/tcp_vegas.c
+++ net-2.6/net/ipv4/tcp_vegas.c
@@ -195,7 +195,7 @@ static void tcp_vegas_cong_avoid(struct
if (after(ack, vegas->beg_snd_nxt)) {
/* Do the Vegas once-per-RTT cwnd adjustment. */
u32 old_wnd, old_snd_cwnd;
-
+ u32 rtt, target_cwnd, diff;
/* Here old_wnd is essentially the window of data that was
* sent during the previous RTT, and has all
@@ -231,15 +231,9 @@ static void tcp_vegas_cong_avoid(struct
* If we have 3 samples, we should be OK.
*/
- if (vegas->cntRTT <= 2) {
- /* We don't have enough RTT samples to do the Vegas
- * calculation, so we'll behave like Reno.
- */
- if (tp->snd_cwnd > tp->snd_ssthresh)
- tp->snd_cwnd++;
- } else {
- u32 rtt, target_cwnd, diff;
-
+ if (vegas->cntRTT <= 2)
+ tcp_reno_cong_avoid(sk, ack, seq_rtt, flag);
+ else {
/* We have enough RTT samples, so, using the Vegas
* algorithm, we determine if we should increase or
* decrease cwnd, and by how much.
@@ -293,6 +287,9 @@ static void tcp_vegas_cong_avoid(struct
(target_cwnd >>
V_PARAM_SHIFT)+1);
+ } else {
+ /* Normal Reno style slow start
increase */
+ tcp_slow_start(tp);
}
} else {
/* Congestion avoidance. */
@@ -326,37 +323,17 @@ static void tcp_vegas_cong_avoid(struct
else if (next_snd_cwnd < tp->snd_cwnd)
tp->snd_cwnd--;
}
- }
- /* Wipe the slate clean for the next RTT. */
- vegas->cntRTT = 0;
- vegas->minRTT = 0x7fffffff;
+ if (tp->snd_cwnd < 2)
+ tp->snd_cwnd = 2;
+ else if (tp->snd_cwnd > tp->snd_cwnd_clamp)
+ tp->snd_cwnd = tp->snd_cwnd_clamp;
+ }
}
- /* The following code is executed for every ack we receive,
- * except for conditions checked in should_advance_cwnd()
- * before the call to tcp_cong_avoid(). Mainly this means that
- * we only execute this code if the ack actually acked some
- * data.
- */
-
- /* If we are in slow start, increase our cwnd in response to this ACK.
- * (If we are not in slow start then we are in congestion avoidance,
- * and adjust our congestion window only once per RTT. See the code
- * above.)
- */
- if (tp->snd_cwnd <= tp->snd_ssthresh)
- tp->snd_cwnd++;
-
- /* to keep cwnd from growing without bound */
- tp->snd_cwnd = min_t(u32, tp->snd_cwnd, tp->snd_cwnd_clamp);
-
- /* Make sure that we are never so timid as to reduce our cwnd below
- * 2 MSS.
- *
- * Going below 2 MSS would risk huge delayed ACKs from our receiver.
- */
- tp->snd_cwnd = max(tp->snd_cwnd, 2U);
+ /* Wipe the slate clean for the next RTT. */
+ vegas->cntRTT = 0;
+ vegas->minRTT = 0x7fffffff;
}
/* Extract info for Tcp socket info provided via netlink. */
--
Stephen Hemminger <[EMAIL PROTECTED]>
OSDL http://developer.osdl.org/~shemminger
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