Re: [PATCH v1] app/testpmd: use Tx preparation in txonly engine

[Stephen Hemminger <stephen@networkplumber.org>]

On Wed,  3 Jan 2024 09:29:12 +0800
Kaiwen Deng <kaiwenx.deng@intel.com> wrote:

>  
> -	nb_tx = common_fwd_stream_transmit(fs, pkts_burst, nb_pkt);
> +	nb_prep = rte_eth_tx_prepare(fs->tx_port, fs->tx_queue,
> +		pkts_burst, nb_pkt);
> +	if (unlikely(nb_prep != nb_pkt)) {
> +		fprintf(stderr,
> +			"Preparing packet burst to transmit failed: %s\n",
> +			rte_strerror(rte_errno));

The main failure likely is mismatched offload flags, so it might be helpful
to print offload flags of that mbuf.

> +		fs->fwd_dropped += (nb_pkt - nb_prep);

Nit: no parenthesis needed here.

> +		rte_pktmbuf_free_bulk(&pkts_burst[nb_prep], nb_pkt - nb_prep);
> +	}
> +
> +	nb_tx = common_fwd_stream_transmit(fs, pkts_burst, nb_prep);
>