We are trying to use send scheduling on a Connectx-6 LX. If we set no
timestamps on the packet buffers and manually send each packet at approximately
the right time everything works. However if we set timestamps in the buffers
then the first 25 packets are sent and the packets are received at the expected
times but all subsequent calls to rte_eth_tx_burst return 0. If its relevant we
are sending a single packet in each burst with timestamps 125 us apart.
We've tried setting the timestamps to low values and the packets are
transmitted correctly and as expected the tx_pp_timestamp_past_errors value is
incremented. We also set high values and this worked too with
tx_pp_timestamp_future_errors incrementing.
Any ideas where to start debugging this? I couldn't see any API which would
give an error code for rte_eth_tx_burst failing.
We're using DPDK 21.08 with the 5.4.3.1 mellanox driver on ubuntu 20.04.
