@@ -708,6 +708,8 @@ static inline void tcp_fast_path_check(struct sock *sk)
tcp_fast_path_on(tp);
}
+u32 tcp_delack_max(const struct sock *sk);
+
/* Compute the actual rto_min value */
static inline u32 tcp_rto_min(struct sock *sk)
{
@@ -3793,7 +3793,8 @@ void tcp_get_info(struct sock *sk, struct tcp_info *info)
info->tcpi_options |= TCPI_OPT_SYN_DATA;
info->tcpi_rto = jiffies_to_usecs(icsk->icsk_rto);
- info->tcpi_ato = jiffies_to_usecs(icsk->icsk_ack.ato);
+ info->tcpi_ato = jiffies_to_usecs(min(icsk->icsk_ack.ato,
+ tcp_delack_max(sk)));
info->tcpi_snd_mss = tp->mss_cache;
info->tcpi_rcv_mss = icsk->icsk_ack.rcv_mss;
@@ -3911,6 +3911,20 @@ int tcp_connect(struct sock *sk)
}
EXPORT_SYMBOL(tcp_connect);
+u32 tcp_delack_max(const struct sock *sk)
+{
+ const struct dst_entry *dst = __sk_dst_get(sk);
+ u32 delack_max = inet_csk(sk)->icsk_delack_max;
+
+ if (dst && dst_metric_locked(dst, RTAX_RTO_MIN)) {
+ u32 rto_min = dst_metric_rtt(dst, RTAX_RTO_MIN);
+ u32 delack_from_rto_min = max_t(int, 1, rto_min - 1);
+
+ delack_max = min_t(u32, delack_max, delack_from_rto_min);
+ }
+ return delack_max;
+}
+
/* Send out a delayed ack, the caller does the policy checking
* to see if we should even be here. See tcp_input.c:tcp_ack_snd_check()
* for details.
@@ -3946,7 +3960,7 @@ void tcp_send_delayed_ack(struct sock *sk)
ato = min(ato, max_ato);
}
- ato = min_t(u32, ato, inet_csk(sk)->icsk_delack_max);
+ ato = min_t(u32, ato, tcp_delack_max(sk));
/* Stay within the limit we were given */
timeout = jiffies + ato;