@@ -1196,6 +1196,19 @@ tcp_pingpong_thresh - INTEGER
Default: 1
+tcp_rto_min_us - INTEGER
+ Minimal TCP retransmission timeout (in microseconds). Note that the
+ rto_min route option has the highest precedence for configuring this
+ setting, followed by the TCP_BPF_RTO_MIN socket option, followed by
+ this tcp_rto_min_us sysctl.
+
+ The recommended practice is to use a value less or equal to 200000
+ microseconds.
+
+ Possible Values: 1 - INT_MAX
+
+ Default: 200000
+
UDP variables
=============
@@ -170,6 +170,7 @@ struct netns_ipv4 {
u8 sysctl_tcp_sack;
u8 sysctl_tcp_window_scaling;
u8 sysctl_tcp_timestamps;
+ int sysctl_tcp_rto_min_us;
u8 sysctl_tcp_recovery;
u8 sysctl_tcp_thin_linear_timeouts;
u8 sysctl_tcp_slow_start_after_idle;
@@ -1501,6 +1501,14 @@ static struct ctl_table ipv4_net_table[] = {
.proc_handler = proc_dou8vec_minmax,
.extra1 = SYSCTL_ONE,
},
+ {
+ .procname = "tcp_rto_min_us",
+ .data = &init_net.ipv4.sysctl_tcp_rto_min_us,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = SYSCTL_ONE,
+ },
};
static __net_init int ipv4_sysctl_init_net(struct net *net)
@@ -428,7 +428,8 @@ void tcp_init_sock(struct sock *sk)
INIT_LIST_HEAD(&tp->tsorted_sent_queue);
icsk->icsk_rto = TCP_TIMEOUT_INIT;
- icsk->icsk_rto_min = TCP_RTO_MIN;
+ icsk->icsk_rto_min = usecs_to_jiffies(READ_ONCE(sock_net(sk)->
+ ipv4.sysctl_tcp_rto_min_us));
icsk->icsk_delack_max = TCP_DELACK_MAX;
tp->mdev_us = jiffies_to_usecs(TCP_TIMEOUT_INIT);
minmax_reset(&tp->rtt_min, tcp_jiffies32, ~0U);
@@ -3511,6 +3511,7 @@ static int __net_init tcp_sk_init(struct net *net)
net->ipv4.sysctl_tcp_shrink_window = 0;
net->ipv4.sysctl_tcp_pingpong_thresh = 1;
+ net->ipv4.sysctl_tcp_rto_min_us = jiffies_to_usecs(TCP_RTO_MIN);
return 0;
}