On 8/4/2025 3:42 AM, Morten Brørup wrote:
> When an ethdev port is configured for fast mbuf release, the driver can
> use a TX burst function relying on the fast mbuf release preconditions.
> Thus, also configuring this port or a queue on the port for transmitting
> segmented packets is prohibited.
> Checks for these conflicting configurations have been added to the ethdev
> library, so the drivers don't have to implement them.
I think the new comment part of ombuf-fast-free and multi-seg in '[PATCH v3
2/3] ethdev: Improve descriptions of RX and TX offloads'
could drop or within this commit.
>
> Signed-off-by: Morten Brørup <m...@smartsharesystems.com>
> Acked-by: Bruce Richardson <bruce.richard...@intel.com>
> Acked-by: Andrew Rybchenko <andrew.rybche...@oktetlabs.ru>
> Acked-by: Konstantin Ananyev <konstantin.anan...@huawei.com>
> ---
> v3:
> * Shorten the added log messages. (Stephen Hemminger, Ivan Malov)
> ---
> lib/ethdev/rte_ethdev.c | 37 +++++++++++++++++++++++++++++++++++++
> 1 file changed, 37 insertions(+)
>
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index dd7c00bc94..00afda873f 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -1531,6 +1531,18 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t
> nb_rx_q, uint16_t nb_tx_q,
> goto rollback;
> }
>
> + /* MBUF_FAST_FREE preconditions conflict with MULTI_SEGS support. */
> + if ((dev_conf->txmode.offloads & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) &&
> + (dev_conf->txmode.offloads & RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) {
> + RTE_ETHDEV_LOG_LINE(ERR,
> + "id=%d offload clash, %s vs %s",
Suggest keep the same trace fmt. e.g.: Ethdev port_id=%u
The same below
> + port_id,
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MULTI_SEGS),
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE));
> + ret = -EINVAL;
> + goto rollback;
> + }
> +
> dev->data->dev_conf.rx_adv_conf.rss_conf.rss_hf =
> rte_eth_rss_hf_refine(dev_conf->rx_adv_conf.rss_conf.rss_hf);
>
> @@ -2709,6 +2721,31 @@ rte_eth_tx_queue_setup(uint16_t port_id, uint16_t
> tx_queue_id,
> return -EINVAL;
> }
>
> + /*
> + * If the driver uses a Tx function with MBUF_FAST_FREE preconditions,
> + * per-queue MULTI_SEGS support is not possible.
> + */
> + if ((dev->data->dev_conf.txmode.offloads &
> RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE) &&
> + (local_conf.offloads & RTE_ETH_TX_OFFLOAD_MULTI_SEGS)) {
> + RTE_ETHDEV_LOG_LINE(ERR,
> + "id=%d txq=%d offload clash, per-queue %s vs per-port
> %s",
> + port_id, tx_queue_id,
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MULTI_SEGS),
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE));
> + return -EINVAL;
> + }
> + /*
> + * If the driver uses a Tx function with MULTI_SEGS support,
> + * runtime support for per-queue MBUF_FAST_FREE optimization depends on
> the driver.
> + */
> + if ((dev->data->dev_conf.txmode.offloads &
> RTE_ETH_TX_OFFLOAD_MULTI_SEGS) &&
> + (local_conf.offloads &
> RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE))
> + RTE_ETHDEV_LOG_LINE(DEBUG,
> + "id=%d txq=%d potential offload clash, per-queue %s vs
> per-port %s: PMD to decide",
> + port_id, tx_queue_id,
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE),
> +
> rte_eth_dev_tx_offload_name(RTE_ETH_TX_OFFLOAD_MULTI_SEGS));
1\ The global port configuration will take effect on all queues.
If it don't support both MBUF_FAST_FREE and MULTI_SEG, why don't ban it here?
2\ Debug level is easy to ignore, how about warning?
> +
> rte_ethdev_trace_txq_setup(port_id, tx_queue_id, nb_tx_desc, tx_conf);
> return eth_err(port_id, dev->dev_ops->tx_queue_setup(dev,
> tx_queue_id, nb_tx_desc, socket_id, &local_conf));
