This has been tested internally at Isilon where we end up creating a lot
of long mbuf chains, so the lack of m_defrag working was apparent.
iperf / sysctl results:
```
satella-1# iperf -c 2.0.0.20
------------------------------------------------------------
Client connecting to 2.0.0.20, TCP port 5001
TCP window size: 131 KByte (default)
------------------------------------------------------------
[ 4] local 2.0.0.19 port 10013 connected with 2.0.0.20 port 5001
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-10.0 sec 22.6 GBytes 19.4 Gbits/sec
satella-1# iperf -c 2.0.0.20 -P 5
------------------------------------------------------------
Client connecting to 2.0.0.20, TCP port 5001
TCP window size: 131 KByte (default)
------------------------------------------------------------
[ 7] local 2.0.0.19 port 10017 connected with 2.0.0.20 port 5001
[ 8] local 2.0.0.19 port 10018 connected with 2.0.0.20 port 5001
[ 6] local 2.0.0.19 port 10016 connected with 2.0.0.20 port 5001
[ 4] local 2.0.0.19 port 10014 connected with 2.0.0.20 port 5001
[ 5] local 2.0.0.19 port 10015 connected with 2.0.0.20 port 5001
[ ID] Interval Transfer Bandwidth
[ 4] 0.0-10.0 sec 9.36 GBytes 8.01 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-10.0 sec 8.64 GBytes 7.40 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 7] 0.0-10.0 sec 11.0 GBytes 9.40 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 8] 0.0-10.0 sec 8.74 GBytes 7.48 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 6] 0.0-10.0 sec 8.49 GBytes 7.27 Gbits/sec
[SUM] 0.0-10.0 sec 46.2 GBytes 39.6 Gbits/sec
satella-1# sysctl hw.mlxen1.stat | grep tso_packets
hw.mlxen1.stat.tx_ring23.tso_packets: 381
hw.mlxen1.stat.tx_ring22.tso_packets: 0
hw.mlxen1.stat.tx_ring21.tso_packets: 0
hw.mlxen1.stat.tx_ring20.tso_packets: 307702
hw.mlxen1.stat.tx_ring19.tso_packets: 0
hw.mlxen1.stat.tx_ring18.tso_packets: 0
hw.mlxen1.stat.tx_ring17.tso_packets: 0
hw.mlxen1.stat.tx_ring16.tso_packets: 0
hw.mlxen1.stat.tx_ring15.tso_packets: 1
hw.mlxen1.stat.tx_ring14.tso_packets: 1
hw.mlxen1.stat.tx_ring13.tso_packets: 0
hw.mlxen1.stat.tx_ring12.tso_packets: 0
hw.mlxen1.stat.tx_ring11.tso_packets: 0
hw.mlxen1.stat.tx_ring10.tso_packets: 1269299
hw.mlxen1.stat.tx_ring9.tso_packets: 307674
hw.mlxen1.stat.tx_ring8.tso_packets: 1
hw.mlxen1.stat.tx_ring7.tso_packets: 0
hw.mlxen1.stat.tx_ring6.tso_packets: 1
hw.mlxen1.stat.tx_ring5.tso_packets: 0
hw.mlxen1.stat.tx_ring4.tso_packets: 308278
hw.mlxen1.stat.tx_ring3.tso_packets: 0
hw.mlxen1.stat.tx_ring2.tso_packets: 307541
hw.mlxen1.stat.tx_ring1.tso_packets: 305629
hw.mlxen1.stat.tx_ring0.tso_packets: 1
hw.mlxen1.stat.tso_packets: 2806509
satella-1# iperf -s
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 128 KByte (default)
------------------------------------------------------------
[ 5] local 2.0.0.19 port 5001 connected with 2.0.0.20 port 29913
[ 6] local 2.0.0.19 port 5001 connected with 2.0.0.20 port 48204
[ 8] local 2.0.0.19 port 5001 connected with 2.0.0.20 port 53588
[ 7] local 2.0.0.19 port 5001 connected with 2.0.0.20 port 12372
[ 9] local 2.0.0.19 port 5001 connected with 2.0.0.20 port 52427
[ ID] Interval Transfer Bandwidth
[ 5] 0.0-10.0 sec 9.08 GBytes 7.77 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 6] 0.0-10.0 sec 9.61 GBytes 8.23 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 8] 0.0-10.0 sec 9.23 GBytes 7.90 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 7] 0.0-10.0 sec 9.21 GBytes 7.88 Gbits/sec
[ ID] Interval Transfer Bandwidth
[ 9] 0.0-10.0 sec 9.04 GBytes 7.74 Gbits/sec
[SUM] 0.0-10.0 sec 46.2 GBytes 39.5 Gbits/sec
```