On Wed, 18 Feb 2026 16:44:49 -0800 Stephen Hemminger <[email protected]> wrote:
> The documentation for rte_eth_tx_burst() uses the word "sent" to > describe the return value, which is misleading. Packets returned as > consumed may not have been transmitted yet; they have been accepted > by the driver and are no longer the caller's responsibility. > > This matters because the common usage pattern is: > > n = rte_eth_tx_burst(port, txq, mbufs, nb_pkts); > for (i = n; i < nb_pkts; i++) > rte_pktmbuf_free(mbufs[i]); > > For this to work correctly, the contract must be: > - tx_pkts[0..n-1]: ownership transferred to the driver. > - tx_pkts[n..nb_pkts-1]: untouched, still owned by the caller. > > Several drivers (and AI-assisted reviews) misinterpret the current > wording and treat packets with errors as unconsumed, returning a > short count. This causes callers to retry those packets indefinitely. > The correct behavior is that the driver must consume (and free) > erroneous packets, counting them via oerrors. > > Replace "sent" with "consumed" in the return value description, > spell out the mbuf ownership contract, clarify the error handling > expectation, and update the @return block to match. > > Signed-off-by: Stephen Hemminger <[email protected]> > Acked-by: Andrew Rybchenko <[email protected]> > --- FYI - many, many drivers got this wrong. Only a few seem to get it right.
