diff options
| -rw-r--r-- | pkg/tcpip/transport/tcp/rack.go | 16 | ||||
| -rw-r--r-- | pkg/tcpip/transport/tcp/snd.go | 5 |
2 files changed, 15 insertions, 6 deletions
diff --git a/pkg/tcpip/transport/tcp/rack.go b/pkg/tcpip/transport/tcp/rack.go index d969ca23a..439932595 100644 --- a/pkg/tcpip/transport/tcp/rack.go +++ b/pkg/tcpip/transport/tcp/rack.go @@ -39,6 +39,9 @@ type rackControl struct { // sequence. fack seqnum.Value + // minRTT is the estimated minimum RTT of the connection. + minRTT time.Duration + // rtt is the RTT of the most recently delivered packet on the // connection (either cumulatively acknowledged or selectively // acknowledged) that was not marked invalid as a possible spurious @@ -48,7 +51,7 @@ type rackControl struct { // Update will update the RACK related fields when an ACK has been received. // See: https://tools.ietf.org/html/draft-ietf-tcpm-rack-08#section-7.2 -func (rc *rackControl) Update(seg *segment, ackSeg *segment, srtt time.Duration, offset uint32) { +func (rc *rackControl) Update(seg *segment, ackSeg *segment, offset uint32) { rtt := time.Now().Sub(seg.xmitTime) // If the ACK is for a retransmitted packet, do not update if it is a @@ -65,12 +68,21 @@ func (rc *rackControl) Update(seg *segment, ackSeg *segment, srtt time.Duration, return } } - if rtt < srtt { + if rtt < rc.minRTT { return } } rc.rtt = rtt + + // The sender can either track a simple global minimum of all RTT + // measurements from the connection, or a windowed min-filtered value + // of recent RTT measurements. This implementation keeps track of the + // simple global minimum of all RTTs for the connection. + if rtt < rc.minRTT || rc.minRTT == 0 { + rc.minRTT = rtt + } + // Update rc.xmitTime and rc.endSequence to the transmit time and // ending sequence number of the packet which has been acknowledged // most recently. diff --git a/pkg/tcpip/transport/tcp/snd.go b/pkg/tcpip/transport/tcp/snd.go index c55589c45..4c9a86cda 100644 --- a/pkg/tcpip/transport/tcp/snd.go +++ b/pkg/tcpip/transport/tcp/snd.go @@ -1365,9 +1365,6 @@ func (s *sender) handleRcvdSegment(rcvdSeg *segment) { ackLeft := acked originalOutstanding := s.outstanding - s.rtt.Lock() - srtt := s.rtt.srtt - s.rtt.Unlock() for ackLeft > 0 { // We use logicalLen here because we can have FIN // segments (which are always at the end of list) that @@ -1389,7 +1386,7 @@ func (s *sender) handleRcvdSegment(rcvdSeg *segment) { // Update the RACK fields if SACK is enabled. if s.ep.sackPermitted { - s.rc.Update(seg, rcvdSeg, srtt, s.ep.tsOffset) + s.rc.Update(seg, rcvdSeg, s.ep.tsOffset) } s.writeList.Remove(seg) |