Re: [PATCH 2/3] net/af_xdp: Fix mbuf alloc failed statistic

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 10 May 2024 10:03:57 +0000
Ciara Loftus <ciara.loftus@intel.com> wrote:

> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index fee0d5d5f3..968bbf6d45 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -124,6 +124,7 @@ struct rx_stats {
>  	uint64_t rx_pkts;
>  	uint64_t rx_bytes;
>  	uint64_t rx_dropped;
> +	uint64_t alloc_failed;
>  };

You don't have to use local statistic for this, there already is one in the dev struct
i.e dev->data->rx_mbuf_alloc_failed. The problem is you need the DPDK port number to find
what dev is.

And the code in ethdev for stats get will put it in the right place.


PS: what is the point of rxq->stats.rx_dropped? It is never incremented.

PPS: Looks like AF_XDP considers kernel full as an error (ie tx_dropped gets counted as error).
This is not what real hardware does.