Commit 6bed5e26 authored by David S. Miller's avatar David S. Miller

Merge branch 'fix-DCTCP-delayed-ACK'

Yuchung Cheng says:

====================
fix DCTCP delayed ACK

This patch series addresses the issue that sometimes DCTCP
fail to acknowledge the latest sequence and result in sender timeout
if inflight is small.
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parents 5fc853cc a69258f7
...@@ -912,8 +912,6 @@ enum tcp_ca_event { ...@@ -912,8 +912,6 @@ enum tcp_ca_event {
CA_EVENT_LOSS, /* loss timeout */ CA_EVENT_LOSS, /* loss timeout */
CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */ CA_EVENT_ECN_NO_CE, /* ECT set, but not CE marked */
CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */ CA_EVENT_ECN_IS_CE, /* received CE marked IP packet */
CA_EVENT_DELAYED_ACK, /* Delayed ack is sent */
CA_EVENT_NON_DELAYED_ACK,
}; };
/* Information about inbound ACK, passed to cong_ops->in_ack_event() */ /* Information about inbound ACK, passed to cong_ops->in_ack_event() */
......
...@@ -55,7 +55,6 @@ struct dctcp { ...@@ -55,7 +55,6 @@ struct dctcp {
u32 dctcp_alpha; u32 dctcp_alpha;
u32 next_seq; u32 next_seq;
u32 ce_state; u32 ce_state;
u32 delayed_ack_reserved;
u32 loss_cwnd; u32 loss_cwnd;
}; };
...@@ -96,7 +95,6 @@ static void dctcp_init(struct sock *sk) ...@@ -96,7 +95,6 @@ static void dctcp_init(struct sock *sk)
ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA); ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA);
ca->delayed_ack_reserved = 0;
ca->loss_cwnd = 0; ca->loss_cwnd = 0;
ca->ce_state = 0; ca->ce_state = 0;
...@@ -134,7 +132,8 @@ static void dctcp_ce_state_0_to_1(struct sock *sk) ...@@ -134,7 +132,8 @@ static void dctcp_ce_state_0_to_1(struct sock *sk)
/* State has changed from CE=0 to CE=1 and delayed /* State has changed from CE=0 to CE=1 and delayed
* ACK has not sent yet. * ACK has not sent yet.
*/ */
if (!ca->ce_state && ca->delayed_ack_reserved) { if (!ca->ce_state &&
inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
u32 tmp_rcv_nxt; u32 tmp_rcv_nxt;
/* Save current rcv_nxt. */ /* Save current rcv_nxt. */
...@@ -164,7 +163,8 @@ static void dctcp_ce_state_1_to_0(struct sock *sk) ...@@ -164,7 +163,8 @@ static void dctcp_ce_state_1_to_0(struct sock *sk)
/* State has changed from CE=1 to CE=0 and delayed /* State has changed from CE=1 to CE=0 and delayed
* ACK has not sent yet. * ACK has not sent yet.
*/ */
if (ca->ce_state && ca->delayed_ack_reserved) { if (ca->ce_state &&
inet_csk(sk)->icsk_ack.pending & ICSK_ACK_TIMER) {
u32 tmp_rcv_nxt; u32 tmp_rcv_nxt;
/* Save current rcv_nxt. */ /* Save current rcv_nxt. */
...@@ -248,25 +248,6 @@ static void dctcp_state(struct sock *sk, u8 new_state) ...@@ -248,25 +248,6 @@ static void dctcp_state(struct sock *sk, u8 new_state)
} }
} }
static void dctcp_update_ack_reserved(struct sock *sk, enum tcp_ca_event ev)
{
struct dctcp *ca = inet_csk_ca(sk);
switch (ev) {
case CA_EVENT_DELAYED_ACK:
if (!ca->delayed_ack_reserved)
ca->delayed_ack_reserved = 1;
break;
case CA_EVENT_NON_DELAYED_ACK:
if (ca->delayed_ack_reserved)
ca->delayed_ack_reserved = 0;
break;
default:
/* Don't care for the rest. */
break;
}
}
static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev) static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
{ {
switch (ev) { switch (ev) {
...@@ -276,10 +257,6 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev) ...@@ -276,10 +257,6 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
case CA_EVENT_ECN_NO_CE: case CA_EVENT_ECN_NO_CE:
dctcp_ce_state_1_to_0(sk); dctcp_ce_state_1_to_0(sk);
break; break;
case CA_EVENT_DELAYED_ACK:
case CA_EVENT_NON_DELAYED_ACK:
dctcp_update_ack_reserved(sk, ev);
break;
default: default:
/* Don't care for the rest. */ /* Don't care for the rest. */
break; break;
......
...@@ -3523,8 +3523,6 @@ void tcp_send_delayed_ack(struct sock *sk) ...@@ -3523,8 +3523,6 @@ void tcp_send_delayed_ack(struct sock *sk)
int ato = icsk->icsk_ack.ato; int ato = icsk->icsk_ack.ato;
unsigned long timeout; unsigned long timeout;
tcp_ca_event(sk, CA_EVENT_DELAYED_ACK);
if (ato > TCP_DELACK_MIN) { if (ato > TCP_DELACK_MIN) {
const struct tcp_sock *tp = tcp_sk(sk); const struct tcp_sock *tp = tcp_sk(sk);
int max_ato = HZ / 2; int max_ato = HZ / 2;
...@@ -3581,8 +3579,6 @@ void tcp_send_ack(struct sock *sk) ...@@ -3581,8 +3579,6 @@ void tcp_send_ack(struct sock *sk)
if (sk->sk_state == TCP_CLOSE) if (sk->sk_state == TCP_CLOSE)
return; return;
tcp_ca_event(sk, CA_EVENT_NON_DELAYED_ACK);
/* We are not putting this on the write queue, so /* We are not putting this on the write queue, so
* tcp_transmit_skb() will set the ownership to this * tcp_transmit_skb() will set the ownership to this
* sock. * sock.
......
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