Re: [dpdk-dev] [PATCH] net/af_xdp: use single-prod-and-cons ring

["Loftus, Ciara" <ciara.loftus@intel.com>]

> 
> The ring is used only by af_xdp pmd itself, so no need to support
> multi-producer and multi-consumer mode. This patch changes the ring
> to single-producer and single-consumer mode, which could yield better
> performance for addr enqueue and dequeue.
> 
> Signed-off-by: Xiao Wang <xiao.w.wang@intel.com>

LGTM.

I ran some rough numbers and measured a +~6.8% improvement for single-core single-pmd testpmd loopback (IRQs pinned to app core) and +~15.9% for two core (IRQs and app pinned to separate cores).

Tested-by: Ciara Loftus <ciara.loftus@intel.com>

Thanks,
Ciara

> ---
>  drivers/net/af_xdp/rte_eth_af_xdp.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index d903e6c28..683e2a559 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -809,7 +809,7 @@ xsk_umem_info *xdp_umem_configure(struct
> pmd_internals *internals,
>  	umem->buf_ring = rte_ring_create(ring_name,
>  					 ETH_AF_XDP_NUM_BUFFERS,
>  					 rte_socket_id(),
> -					 0x0);
> +					 RING_F_SP_ENQ |
> RING_F_SC_DEQ);
>  	if (umem->buf_ring == NULL) {
>  		AF_XDP_LOG(ERR, "Failed to create rte_ring\n");
>  		goto err;
> --
> 2.15.1