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-rw-r--r--net/ipv4/tcp_bic.c2
-rw-r--r--net/ipv4/tcp_cong.c32
-rw-r--r--net/ipv4/tcp_cubic.c39
-rw-r--r--net/ipv4/tcp_scalable.c3
-rw-r--r--net/ipv4/tcp_veno.c2
-rw-r--r--net/ipv4/tcp_yeah.c2
6 files changed, 42 insertions, 38 deletions
diff --git a/net/ipv4/tcp_bic.c b/net/ipv4/tcp_bic.c
index bb395d46a389..c037644eafb7 100644
--- a/net/ipv4/tcp_bic.c
+++ b/net/ipv4/tcp_bic.c
@@ -150,7 +150,7 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
tcp_slow_start(tp, acked);
else {
bictcp_update(ca, tp->snd_cwnd);
- tcp_cong_avoid_ai(tp, ca->cnt);
+ tcp_cong_avoid_ai(tp, ca->cnt, 1);
}
}
diff --git a/net/ipv4/tcp_cong.c b/net/ipv4/tcp_cong.c
index 27ead0dd16bc..8670e68e2ce6 100644
--- a/net/ipv4/tcp_cong.c
+++ b/net/ipv4/tcp_cong.c
@@ -291,26 +291,32 @@ int tcp_set_congestion_control(struct sock *sk, const char *name)
* ABC caps N to 2. Slow start exits when cwnd grows over ssthresh and
* returns the leftover acks to adjust cwnd in congestion avoidance mode.
*/
-void tcp_slow_start(struct tcp_sock *tp, u32 acked)
+u32 tcp_slow_start(struct tcp_sock *tp, u32 acked)
{
u32 cwnd = tp->snd_cwnd + acked;
if (cwnd > tp->snd_ssthresh)
cwnd = tp->snd_ssthresh + 1;
+ acked -= cwnd - tp->snd_cwnd;
tp->snd_cwnd = min(cwnd, tp->snd_cwnd_clamp);
+
+ return acked;
}
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)
+/* In theory this is tp->snd_cwnd += 1 / tp->snd_cwnd (or alternative w),
+ * for every packet that was ACKed.
+ */
+void tcp_cong_avoid_ai(struct tcp_sock *tp, u32 w, u32 acked)
{
+ tp->snd_cwnd_cnt += acked;
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++;
+ u32 delta = tp->snd_cwnd_cnt / w;
+
+ tp->snd_cwnd_cnt -= delta * w;
+ tp->snd_cwnd += delta;
}
+ tp->snd_cwnd = min(tp->snd_cwnd, tp->snd_cwnd_clamp);
}
EXPORT_SYMBOL_GPL(tcp_cong_avoid_ai);
@@ -329,11 +335,13 @@ void tcp_reno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
return;
/* In "safe" area, increase. */
- if (tp->snd_cwnd <= tp->snd_ssthresh)
- tcp_slow_start(tp, acked);
+ if (tp->snd_cwnd <= tp->snd_ssthresh) {
+ acked = tcp_slow_start(tp, acked);
+ if (!acked)
+ return;
+ }
/* In dangerous area, increase slowly. */
- else
- tcp_cong_avoid_ai(tp, tp->snd_cwnd);
+ tcp_cong_avoid_ai(tp, tp->snd_cwnd, acked);
}
EXPORT_SYMBOL_GPL(tcp_reno_cong_avoid);
diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
index 6b6002416a73..4b276d1ed980 100644
--- a/net/ipv4/tcp_cubic.c
+++ b/net/ipv4/tcp_cubic.c
@@ -93,9 +93,7 @@ struct bictcp {
u32 epoch_start; /* beginning of an epoch */
u32 ack_cnt; /* number of acks */
u32 tcp_cwnd; /* estimated tcp cwnd */
-#define ACK_RATIO_SHIFT 4
-#define ACK_RATIO_LIMIT (32u << ACK_RATIO_SHIFT)
- u16 delayed_ack; /* estimate the ratio of Packets/ACKs << 4 */
+ u16 unused;
u8 sample_cnt; /* number of samples to decide curr_rtt */
u8 found; /* the exit point is found? */
u32 round_start; /* beginning of each round */
@@ -114,7 +112,6 @@ static inline void bictcp_reset(struct bictcp *ca)
ca->bic_K = 0;
ca->delay_min = 0;
ca->epoch_start = 0;
- ca->delayed_ack = 2 << ACK_RATIO_SHIFT;
ca->ack_cnt = 0;
ca->tcp_cwnd = 0;
ca->found = 0;
@@ -205,23 +202,30 @@ static u32 cubic_root(u64 a)
/*
* Compute congestion window to use.
*/
-static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
+static inline void bictcp_update(struct bictcp *ca, u32 cwnd, u32 acked)
{
u32 delta, bic_target, max_cnt;
u64 offs, t;
- ca->ack_cnt++; /* count the number of ACKs */
+ ca->ack_cnt += acked; /* count the number of ACKed packets */
if (ca->last_cwnd == cwnd &&
(s32)(tcp_time_stamp - ca->last_time) <= HZ / 32)
return;
+ /* The CUBIC function can update ca->cnt at most once per jiffy.
+ * On all cwnd reduction events, ca->epoch_start is set to 0,
+ * which will force a recalculation of ca->cnt.
+ */
+ if (ca->epoch_start && tcp_time_stamp == ca->last_time)
+ goto tcp_friendliness;
+
ca->last_cwnd = cwnd;
ca->last_time = tcp_time_stamp;
if (ca->epoch_start == 0) {
ca->epoch_start = tcp_time_stamp; /* record beginning */
- ca->ack_cnt = 1; /* start counting */
+ ca->ack_cnt = acked; /* start counting */
ca->tcp_cwnd = cwnd; /* syn with cubic */
if (ca->last_max_cwnd <= cwnd) {
@@ -283,6 +287,7 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
if (ca->last_max_cwnd == 0 && ca->cnt > 20)
ca->cnt = 20; /* increase cwnd 5% per RTT */
+tcp_friendliness:
/* TCP Friendly */
if (tcp_friendliness) {
u32 scale = beta_scale;
@@ -301,7 +306,6 @@ static inline void bictcp_update(struct bictcp *ca, u32 cwnd)
}
}
- ca->cnt = (ca->cnt << ACK_RATIO_SHIFT) / ca->delayed_ack;
if (ca->cnt == 0) /* cannot be zero */
ca->cnt = 1;
}
@@ -317,11 +321,12 @@ static void bictcp_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (tp->snd_cwnd <= tp->snd_ssthresh) {
if (hystart && after(ack, ca->end_seq))
bictcp_hystart_reset(sk);
- tcp_slow_start(tp, acked);
- } else {
- bictcp_update(ca, tp->snd_cwnd);
- tcp_cong_avoid_ai(tp, ca->cnt);
+ acked = tcp_slow_start(tp, acked);
+ if (!acked)
+ return;
}
+ bictcp_update(ca, tp->snd_cwnd, acked);
+ tcp_cong_avoid_ai(tp, ca->cnt, acked);
}
static u32 bictcp_recalc_ssthresh(struct sock *sk)
@@ -411,20 +416,10 @@ static void hystart_update(struct sock *sk, u32 delay)
*/
static void bictcp_acked(struct sock *sk, u32 cnt, s32 rtt_us)
{
- const struct inet_connection_sock *icsk = inet_csk(sk);
const struct tcp_sock *tp = tcp_sk(sk);
struct bictcp *ca = inet_csk_ca(sk);
u32 delay;
- if (icsk->icsk_ca_state == TCP_CA_Open) {
- u32 ratio = ca->delayed_ack;
-
- ratio -= ca->delayed_ack >> ACK_RATIO_SHIFT;
- ratio += cnt;
-
- ca->delayed_ack = clamp(ratio, 1U, ACK_RATIO_LIMIT);
- }
-
/* Some calls are for duplicates without timetamps */
if (rtt_us < 0)
return;
diff --git a/net/ipv4/tcp_scalable.c b/net/ipv4/tcp_scalable.c
index 6824afb65d93..333bcb2415ff 100644
--- a/net/ipv4/tcp_scalable.c
+++ b/net/ipv4/tcp_scalable.c
@@ -25,7 +25,8 @@ static void tcp_scalable_cong_avoid(struct sock *sk, u32 ack, u32 acked)
if (tp->snd_cwnd <= tp->snd_ssthresh)
tcp_slow_start(tp, acked);
else
- tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT));
+ tcp_cong_avoid_ai(tp, min(tp->snd_cwnd, TCP_SCALABLE_AI_CNT),
+ 1);
}
static u32 tcp_scalable_ssthresh(struct sock *sk)
diff --git a/net/ipv4/tcp_veno.c b/net/ipv4/tcp_veno.c
index a4d2d2d88dca..112151eeee45 100644
--- a/net/ipv4/tcp_veno.c
+++ b/net/ipv4/tcp_veno.c
@@ -159,7 +159,7 @@ static void tcp_veno_cong_avoid(struct sock *sk, u32 ack, u32 acked)
/* In the "non-congestive state", increase cwnd
* every rtt.
*/
- tcp_cong_avoid_ai(tp, tp->snd_cwnd);
+ tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
} 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 cd7273218598..17d35662930d 100644
--- a/net/ipv4/tcp_yeah.c
+++ b/net/ipv4/tcp_yeah.c
@@ -92,7 +92,7 @@ static void tcp_yeah_cong_avoid(struct sock *sk, u32 ack, u32 acked)
} else {
/* Reno */
- tcp_cong_avoid_ai(tp, tp->snd_cwnd);
+ tcp_cong_avoid_ai(tp, tp->snd_cwnd, 1);
}
/* The key players are v_vegas.beg_snd_una and v_beg_snd_nxt.
generated by cgit v1.2.3 (git 2.39.1) at 2024-10-22 14:51:16 +0000