Multiple Tx-Queues not working as expected

[Stephen Hemminger]

On Fri, 17 Feb 2023 11:30:14 +0530
Rajasekhar Pulluru <pullururajasekhar at gmail.com> wrote:

> Ok Stephen, thanks for the information, I can try that.
> 
> One of the problems I see with single Tx Queue mode is that Ixia reports
> packet drops, though I confirmed with the help of counters (before invoking
> tx burst) that all packets are being sent-out. Dumping HW counters don't
> report any drops in TX.
> Is there a mechanism in DPDK to debug this?
> 
> Thanks & Regards,
> Rajasekhar

The common usage in DPDK is to have one transmit queue per DPDK thread doing
transmits.  If the transmit queue is not configured with enough depth.

The most common packet flow in DPDK is packets getting received, modified
then transmitted. With that pattern, packet loss is at the receiver when
the CPU can't keep up with the packet rate arriving.