_Performance Testing issues_

Branch: dpdk-next-net

54a5d136228864e3549edb86211c45a3c373bfe1 --> performance testing fail

Test environment and result as below:

Ubuntu 18.04
Kernel: 4.15.0-generic
GCC: 7.4
NIC: Mellanox ConnectX-5 100000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 1/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -3.409                              |
+------------+---------+-------------------------------------+
| 128        | 256     | -0.861                              |
+------------+---------+-------------------------------------+
| 256        | 256     | -0.438                              |
+------------+---------+-------------------------------------+
| 512        | 256     | 0.177                               |
+------------+---------+-------------------------------------+
| 1024       | 256     | -0.060                              |
+------------+---------+-------------------------------------+
| 1518       | 256     | 0.003                               |
+------------+---------+-------------------------------------+

Ubuntu 18.04
Kernel: 4.15.0-generic
GCC: 7.4
NIC: Mellanox ConnectX-4 Lx 40000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 3/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -2.370                              |
+------------+---------+-------------------------------------+
| 128        | 256     | -2.475                              |
+------------+---------+-------------------------------------+
| 256        | 256     | -1.283                              |
+------------+---------+-------------------------------------+
| 512        | 256     | -0.003                              |
+------------+---------+-------------------------------------+
| 1024       | 256     | -0.001                              |
+------------+---------+-------------------------------------+
| 1518       | 256     | 0.006                               |
+------------+---------+-------------------------------------+

Ubuntu 18.04
Kernel: 4.15.0-generic
GCC: 7.4
NIC: Mellanox ConnectX-4 Lx 25000 Mbps
Target: x86_64-native-linuxapp-gcc
Fail/Total: 2/6

Detail performance results: 
+------------+---------+-------------------------------------+
| frame_size | txd/rxd | throughput difference from expected |
+============+=========+=====================================+
| 64         | 256     | -1.250                              |
+------------+---------+-------------------------------------+
| 128        | 256     | -1.188                              |
+------------+---------+-------------------------------------+
| 256        | 256     | -0.013                              |
+------------+---------+-------------------------------------+
| 512        | 256     | 0.016                               |
+------------+---------+-------------------------------------+
| 1024       | 256     | -0.006                              |
+------------+---------+-------------------------------------+
| 1518       | 256     | -0.004                              |
+------------+---------+-------------------------------------+

https://lab.dpdk.org/results/dashboard/tarballs/7050/

UNH-IOL DPDK Performance Test Lab

To manage your email subscriptions visit: 
https://lab.dpdk.org/results/dashboard/preferences/subscriptions/