diff options
| author | Richard Scheffenegger <rscheff@FreeBSD.org> | 2023-11-30 04:33:50 +0000 |
|---|---|---|
| committer | Richard Scheffenegger <rscheff@FreeBSD.org> | 2023-11-30 04:38:16 +0000 |
| commit | 34c45bc6a3940ccfddb60207cb103f73bf87c4a6 (patch) | |
| tree | 53f58e22399ef2bd4bebc56ef16b886c8b9d0a7a | |
| parent | 839999e7efdc980d5ada92ea93719c7e29765809 (diff) | |
tcp: enable LRD by default
Lost Retransmission Detection was added as a
feature in May 2021, but disabled by default.
Enabling the feature by default to reduce the
flow completion time by avoiding RTOs when
retransmissions get lost too.
Reviewed By: tuexen, #transport, zlei
MFC after: 10 weeks
Sponsored by: NetApp, Inc.
Differential Revision: https://reviews.freebsd.org/D42845
| -rw-r--r-- | share/man/man4/tcp.4 | 4 | ||||
| -rw-r--r-- | sys/netinet/tcp_input.c | 2 |
2 files changed, 3 insertions, 3 deletions
diff --git a/share/man/man4/tcp.4 b/share/man/man4/tcp.4 index 3f54d904abc8..317ee818f3a4 100644 --- a/share/man/man4/tcp.4 +++ b/share/man/man4/tcp.4 @@ -31,7 +31,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.Dd November 17, 2023 +.Dd November 30, 2023 .Dt TCP 4 .Os .Sh NAME @@ -465,7 +465,7 @@ Maximum amount of time, in milliseconds, before a delayed ACK is sent. .It Va delayed_ack Delay ACK to try and piggyback it onto a data packet or another ACK. .It Va do_lrd -Enable Lost Retransmission Detection for SACK-enabled sessions, disabled by +Enable Lost Retransmission Detection for SACK-enabled sessions, enabled by default. Under severe congestion, a retransmission can be lost which then leads to a mandatory Retransmission Timeout (RTO), followed by slow-start. diff --git a/sys/netinet/tcp_input.c b/sys/netinet/tcp_input.c index e20c09f981cd..a75dbd1547b0 100644 --- a/sys/netinet/tcp_input.c +++ b/sys/netinet/tcp_input.c @@ -162,7 +162,7 @@ SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_prr, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_do_prr), 1, "Enable Proportional Rate Reduction per RFC 6937"); -VNET_DEFINE(int, tcp_do_lrd) = 0; +VNET_DEFINE(int, tcp_do_lrd) = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_lrd, CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(tcp_do_lrd), 1, "Perform Lost Retransmission Detection"); |