_Performance Testing issues_

Branch: dpdk-next-net-mlx

e0600438396f1d8c6c1e716dc048be01e9029716 --> performance testing fail

Test environment and result as below:

Ubuntu 16.04
Kernel: 4.4.0-109-generic
GCC: 5.4.0-6ubuntu1~16.04.6
NIC: Mellanox ConnectX-4 Lx 40000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 6/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -27.018                             |
+------------+---------+-------------------------------------+
| 128        | 256     | -26.417                             |
+------------+---------+-------------------------------------+
| 256        | 256     | -24.553                             |
+------------+---------+-------------------------------------+
| 512        | 256     | -18.775                             |
+------------+---------+-------------------------------------+
| 1024       | 256     | -9.581                              |
+------------+---------+-------------------------------------+
| 1518       | 256     | -6.500                              |
+------------+---------+-------------------------------------+

Ubuntu 16.04
Kernel: 4.4.0-109-generic
GCC: 5.4.0-6ubuntu1~16.04.6
NIC: Mellanox ConnectX-5 100000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 6/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -55.744                             |
+------------+---------+-------------------------------------+
| 128        | 256     | -50.360                             |
+------------+---------+-------------------------------------+
| 256        | 256     | -37.739                             |
+------------+---------+-------------------------------------+
| 512        | 256     | -22.170                             |
+------------+---------+-------------------------------------+
| 1024       | 256     | -11.509                             |
+------------+---------+-------------------------------------+
| 1518       | 256     | -8.586                              |
+------------+---------+-------------------------------------+

Ubuntu 16.04
Kernel: 4.4.0-109-generic
GCC: 5.4.0-6ubuntu1~16.04.6
NIC: Mellanox ConnectX-4 Lx 25000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 6/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -28.744                             |
+------------+---------+-------------------------------------+
| 128        | 256     | -25.855                             |
+------------+---------+-------------------------------------+
| 256        | 256     | -19.212                             |
+------------+---------+-------------------------------------+
| 512        | 256     | -11.749                             |
+------------+---------+-------------------------------------+
| 1024       | 256     | -5.985                              |
+------------+---------+-------------------------------------+
| 1518       | 256     | -4.063                              |
+------------+---------+-------------------------------------+

https://lab.dpdk.org/results/dashboard/tarballs/4041/

UNH-IOL DPDK Performance Test Lab