From 1280c26228bd7eb14bdecd67dedbdd871f8fdda5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 7 Feb 2025 15:28:30 +0000 Subject: tcp: add tcp_rto_max_ms sysctl Previous patch added a TCP_RTO_MAX_MS socket option to tune a TCP socket max RTO value. Many setups prefer to change a per netns sysctl. This patch adds /proc/sys/net/ipv4/tcp_rto_max_ms Its initial value is 120000 (120 seconds). Keep in mind that a decrease of tcp_rto_max_ms means shorter overall timeouts, unless tcp_retries2 sysctl is increased. Signed-off-by: Eric Dumazet Reviewed-by: Jason Xing Reviewed-by: Neal Cardwell Reviewed-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni --- net/ipv4/sysctl_net_ipv4.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'net/ipv4/sysctl_net_ipv4.c') diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index 42cb5dc9cb24..3a43010d726f 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -28,6 +28,7 @@ static int tcp_adv_win_scale_max = 31; static int tcp_app_win_max = 31; static int tcp_min_snd_mss_min = TCP_MIN_SND_MSS; static int tcp_min_snd_mss_max = 65535; +static int tcp_rto_max_max = TCP_RTO_MAX_SEC * MSEC_PER_SEC; static int ip_privileged_port_min; static int ip_privileged_port_max = 65535; static int ip_ttl_min = 1; @@ -1583,6 +1584,15 @@ static struct ctl_table ipv4_net_table[] = { .proc_handler = proc_dointvec_minmax, .extra1 = SYSCTL_ONE, }, + { + .procname = "tcp_rto_max_ms", + .data = &init_net.ipv4.sysctl_tcp_rto_max_ms, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ONE_THOUSAND, + .extra2 = &tcp_rto_max_max, + }, }; static __net_init int ipv4_sysctl_init_net(struct net *net) -- cgit