> From: Feifei Wang [mailto:feifei.wa...@arm.com]
> Sent: Wednesday, 4 January 2023 08.31
>
> Add 'tx_fill_sw_ring' and 'rx_flush_descriptor' API into direct rearm
> mode for separate Rx and Tx Operation. And this can support different
> multiple sources in direct rearm mode. For examples, Rx driver is
> ixgbe,
> and Tx driver is i40e.
>
> Suggested-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> Suggested-by: Ruifeng Wang <ruifeng.w...@arm.com>
> Signed-off-by: Feifei Wang <feifei.wa...@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.w...@arm.com>
> Reviewed-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
> ---
This feature looks very promising for performance. I am pleased to see progress
on it.
Please confirm that the fast path functions are still thread safe, i.e. one EAL
thread may be calling rte_eth_rx_burst() while another EAL thread is calling
rte_eth_tx_burst().
A few more comments below.
> lib/ethdev/ethdev_driver.h | 10 ++
> lib/ethdev/ethdev_private.c | 2 +
> lib/ethdev/rte_ethdev.c | 52 +++++++++++
> lib/ethdev/rte_ethdev.h | 174 +++++++++++++++++++++++++++++++++++
> lib/ethdev/rte_ethdev_core.h | 11 +++
> lib/ethdev/version.map | 6 ++
> 6 files changed, 255 insertions(+)
>
> diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
> index 6a550cfc83..bc539ec862 100644
> --- a/lib/ethdev/ethdev_driver.h
> +++ b/lib/ethdev/ethdev_driver.h
> @@ -59,6 +59,10 @@ struct rte_eth_dev {
> eth_rx_descriptor_status_t rx_descriptor_status;
> /** Check the status of a Tx descriptor */
> eth_tx_descriptor_status_t tx_descriptor_status;
> + /** Fill Rx sw-ring with Tx buffers in direct rearm mode */
> + eth_tx_fill_sw_ring_t tx_fill_sw_ring;
What is "Rx sw-ring"? Please confirm that this is not an Intel PMD specific
term and/or implementation detail, e.g. by providing a conceptual
implementation for a non-Intel PMD, e.g. mlx5.
Please note: I do not request the ability to rearm between drivers from
different vendors, I only request that the public ethdev API uses generic terms
and concepts, so any NIC vendor can implement the direct-rearm functions in
their PMDs.
> + /** Flush Rx descriptor in direct rearm mode */
> + eth_rx_flush_descriptor_t rx_flush_descriptor;
descriptor -> descriptors. There are more than one. Both in comment and
function name.
[...]
> diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
> index c129ca1eaf..381c3d535f 100644
> --- a/lib/ethdev/rte_ethdev.h
> +++ b/lib/ethdev/rte_ethdev.h
> @@ -1818,6 +1818,17 @@ struct rte_eth_txq_info {
> uint8_t queue_state; /**< one of RTE_ETH_QUEUE_STATE_*. */
> } __rte_cache_min_aligned;
>
> +/**
> + * @internal
> + * Structure used to hold pointers to internal ethdev Rx rearm data.
> + * The main purpose is to load Rx queue rearm data in direct rearm
> mode.
> + */
> +struct rte_eth_rxq_rearm_data {
> + void *rx_sw_ring;
> + uint16_t *rearm_start;
> + uint16_t *rearm_nb;
> +} __rte_cache_min_aligned;
Please add descriptions to the fields in this structure.
