Created attachment 266 [details]
dpdk imitation log in data-plane pod

Our product used the DPDK as a lib for data-plane pod in the vcloud platform.
We observed that if data-plane pod doesn't mount the host path /sys/device to
the container, then "rx_missed_errors" counter always shows zero no matter how
large the traffic was generated on Mellanox NIC. But our customers don't like
application need  to access any host paths, therefore we have to remove the
mount path /sys/device. 

The outcome is data-plane pod would miss the "rx_missed_errors" metric, it
might have a degradation regarding the debuggability for packet loss.

I have got through the dpdk code about the function "mlx5_os_read_dev_stat",
and gdb the dpdk process. It shows that the point of "priv-gcounters" is NULL
and below two paths have no file of "out_of_buffer"

(gdb)  p priv->q_counters
$4 = (struct mlx5_devx_obj *) 0x0

(gdb) info local
mkstr_size_path1 = 54
path1 = "/sys/class/infiniband/mlx5_2/hw_counters/out_of_buffer"
mkstr_size_path = 62
path = "/sys/class/infiniband/mlx5_2/ports/1/hw_counters/out_of_buffer"

Note: Our NIC is Mellanox and SRIOV VFs are used for POD.

We expect that Statistic counter "rx_missed_errors" can work well without
mounting host path /sys/device on Mellanox NICs.