[dpdk-dev] ixgbe: use of multiple tx queues

[Shubhachint, Chaitanya]

Hello,

I am working on a test code for generating packets. I am using an old NIC (Intel x520-LR1). The port is bound to igb_uio.
rte_eth_dev_info_get reports  dev_info.max_tx_queues as 40 but the application is only configuring two tx queues (rte_eth_dev_configure). App feeds packets to both the queues. All packets are accounted for on the wire, but rte_eth_xstats_get show them only for queue-zero. See below, note the tx_q1 counts:

App Count:
tx_count[0] = 744048640
tx_count[1] = 744046592

rte_eth_xstats_get:
0: rx_good_packets: 0
1: tx_good_packets: 1488095232
.....
11: tx_q0packets: 1488095232
12: tx_q0bytes: 89285713920
13: tx_q1packets: 0
14: tx_q1bytes: 0
15: rx_crc_errors: 0

Same application when run inside a vm with vmxnet3 port, shows equal distribution between the two tx-queues.

App Counts:
tx_count[0] = 372023808
tx_count[1] = 372023808

rte_eth_xstats_get:
0: rx_good_packets: 2
1: tx_good_packets: 744047616
2: rx_good_bytes: 120
3: tx_good_bytes: 44642856960
-----
11: tx_q0packets: 372023808
12: tx_q0bytes: 22321428480
13: tx_q1packets: 372023808
14: tx_q1bytes: 22321428480
15: rx_q0_drop_total: 0
16: rx_q0_drop_err: 0

Do I need to modify any configuration when running with real adapters for using both tx-queues? Appreciate your advise.
Regards,
Chaitanya.