@@ -138,6 +138,7 @@ enum {
#define TCP_IS_MPTCP 43 /* Is MPTCP being used? */
#define TCP_RTO_MAX_MS 44 /* max rto time in ms */
#define TCP_RTO_MIN_US 45 /* min rto time in us */
+#define TCP_DELACK_MAX_US 46 /* max delayed ack time in us */
#define TCP_REPAIR_ON 1
#define TCP_REPAIR_OFF 0
@@ -3353,7 +3353,7 @@ int tcp_disconnect(struct sock *sk, int flags)
icsk->icsk_probes_tstamp = 0;
icsk->icsk_rto = TCP_TIMEOUT_INIT;
WRITE_ONCE(icsk->icsk_rto_min, TCP_RTO_MIN);
- icsk->icsk_delack_max = TCP_DELACK_MAX;
+ WRITE_ONCE(icsk->icsk_delack_max, TCP_DELACK_MAX);
tp->snd_ssthresh = TCP_INFINITE_SSTHRESH;
tcp_snd_cwnd_set(tp, TCP_INIT_CWND);
tp->snd_cwnd_cnt = 0;
@@ -3841,6 +3841,14 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
WRITE_ONCE(inet_csk(sk)->icsk_rto_min, rto_min);
return 0;
}
+ case TCP_DELACK_MAX_US: {
+ int delack_max = usecs_to_jiffies(val);
+
+ if (delack_max > TCP_DELACK_MAX || delack_max < TCP_TIMEOUT_MIN)
+ return -EINVAL;
+ WRITE_ONCE(inet_csk(sk)->icsk_delack_max, delack_max);
+ return 0;
+ }
}
sockopt_lock_sock(sk);
@@ -4686,6 +4694,12 @@ int do_tcp_getsockopt(struct sock *sk, int level,
val = jiffies_to_usecs(rto_min);
break;
}
+ case TCP_DELACK_MAX_US: {
+ int delack_max = READ_ONCE(inet_csk(sk)->icsk_delack_max);
+
+ val = jiffies_to_usecs(delack_max);
+ break;
+ }
default:
return -ENOPROTOOPT;
}
@@ -4179,7 +4179,7 @@ u32 tcp_delack_max(const struct sock *sk)
{
u32 delack_from_rto_min = max(tcp_rto_min(sk), 2) - 1;
- return min(inet_csk(sk)->icsk_delack_max, delack_from_rto_min);
+ return min(READ_ONCE(inet_csk(sk)->icsk_delack_max), delack_from_rto_min);
}
/* Send out a delayed ack, the caller does the policy checking
Support adjusting delayed ack max for socket level by using setsockopt(). Signed-off-by: Jason Xing <kerneljasonxing@gmail.com> --- include/uapi/linux/tcp.h | 1 + net/ipv4/tcp.c | 16 +++++++++++++++- net/ipv4/tcp_output.c | 2 +- 3 files changed, 17 insertions(+), 2 deletions(-)