On Tue, 7 Mar 2023 17:07:41 -0500 fwefew 4t4tg <[email protected]> wrote:
> Once I call rte_eth_tx_burst() (Mellanox Connect5-LX) is there a way to > inspect or get a callback when transmitted packets go into the NIC's > completion queue? Not in DPDK. > > This is related to the earlier question on timestamping with rdtsc(). > Ideally I'd take the timestamp as soon (close) to the time the packet is on > the wire. > > I've looked at tx callbacks however this is invoked as the packet is about > to go into the "hardware queue for transmission" meaning there's lot's of > work + serialization of packet's data to electrical signals at NIC > bandwidth to come before the packet is on the wire. > > The ideal time to get run rdtsc() is when the NIC delivers a completion > event to a CQ for packets sent. > > Presumably there's something in the mlx5 driver or perhaps DMA library to > do this? Not that I have ever seen.
