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authorDavid S. Miller <davem@davemloft.net>2018-07-14 03:30:19 +0200
committerDavid S. Miller <davem@davemloft.net>2018-07-14 03:30:19 +0200
commit6bed5e260709897cf918ca262b8e68a17227ec4b (patch)
treee2c8dcd7afb92e790d652b6d096cafe837946faa /net/ipv4
parentqlogic: check kstrtoul() for errors (diff)
parenttcp: remove DELAYED ACK events in DCTCP (diff)
downloadlinux-6bed5e260709897cf918ca262b8e68a17227ec4b.tar.xz
linux-6bed5e260709897cf918ca262b8e68a17227ec4b.zip
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: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/tcp_dctcp.c31
-rw-r--r--net/ipv4/tcp_output.c4
2 files changed, 4 insertions, 31 deletions
diff --git a/net/ipv4/tcp_dctcp.c b/net/ipv4/tcp_dctcp.c
index 5f5e5936760e..5869f89ca656 100644
--- a/net/ipv4/tcp_dctcp.c
+++ b/net/ipv4/tcp_dctcp.c
@@ -55,7 +55,6 @@ struct dctcp {
u32 dctcp_alpha;
u32 next_seq;
u32 ce_state;
- u32 delayed_ack_reserved;
u32 loss_cwnd;
};
@@ -96,7 +95,6 @@ static void dctcp_init(struct sock *sk)
ca->dctcp_alpha = min(dctcp_alpha_on_init, DCTCP_MAX_ALPHA);
- ca->delayed_ack_reserved = 0;
ca->loss_cwnd = 0;
ca->ce_state = 0;
@@ -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
* 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;
/* Save current rcv_nxt. */
@@ -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
* 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;
/* Save current rcv_nxt. */
@@ -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)
{
switch (ev) {
@@ -276,10 +257,6 @@ static void dctcp_cwnd_event(struct sock *sk, enum tcp_ca_event ev)
case CA_EVENT_ECN_NO_CE:
dctcp_ce_state_1_to_0(sk);
break;
- case CA_EVENT_DELAYED_ACK:
- case CA_EVENT_NON_DELAYED_ACK:
- dctcp_update_ack_reserved(sk, ev);
- break;
default:
/* Don't care for the rest. */
break;
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index 8e08b409c71e..00e5a300ddb9 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -3523,8 +3523,6 @@ void tcp_send_delayed_ack(struct sock *sk)
int ato = icsk->icsk_ack.ato;
unsigned long timeout;
- tcp_ca_event(sk, CA_EVENT_DELAYED_ACK);
-
if (ato > TCP_DELACK_MIN) {
const struct tcp_sock *tp = tcp_sk(sk);
int max_ato = HZ / 2;
@@ -3581,8 +3579,6 @@ void tcp_send_ack(struct sock *sk)
if (sk->sk_state == TCP_CLOSE)
return;
- tcp_ca_event(sk, CA_EVENT_NON_DELAYED_ACK);
-
/* We are not putting this on the write queue, so
* tcp_transmit_skb() will set the ownership to this
* sock.