tcp with dpdk gpudirect performance

[masaruito110]

Performance on VMWare VM.

VM has RTX A6000 Ampere arch, ConnectX6, PCIe gen2, CPU is Intel(R) Xeon(R) Silver 4214R CPU @ 2.40GHz

Used program is 722a917

process	session/process	chunk size [MByte]	Gbps/session
1	1	1	42.92
1	1	2	52.61
1	1	4	56.45
1	1	8	57.31
1	1	16	58.14
1	1	32	57.86
1	1	40	57.63
1	1	48	57.35
1	1	60	57.95

[masaruito110]

when chunk size is over 10MByte, sometimes illegal memory access happens. The performance looks saturated over 4MByte chunk size. I think 4MByte chunk size is enough.