[PATCH V2] net/memif: fix extra mbuf refcnt update in zero copy Tx

[Ferruh Yigit]

On 2/14/2024 12:36 AM, Wathsala Vithanage wrote:
> The refcnt update of stored mbufs in memif driver is redundant since
> those mbufs are only freed in eth_memif_tx_zc(). No other place can
> free those stored mbufs quietly. By removing this redundant update
> single core dpdk memif performance can be improved by 7.5%.
> 
> testpmd stats on Arm Neoverse N1 (Ampere Altra)
> +-----------------------------+-----------------------+
> |        | With refcnt update | Without refcnt update |
> +--------+--------------------+-----------------------+
> | Rx-pps |      2748851       |         2955487       |
> +--------+--------------------+-----------------------+
> | Tx-pps |      2748812       |         2955436       |
> +--------+--------------------+-----------------------+
> 
> Fixes: 43b815d88188 ("net/memif: support zero-copy slave")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Liangxing Wang <liangxing.wang at arm.com>
> Signed-off-by: Wathsala Vithanage <wathsala.vithanage at arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang at arm.com>
>

Acked-by: Ferruh Yigit <ferruh.yigit at amd.com>

Applied to dpdk-next-net/main, thanks.