Re: [PATCH v1 3/3] net/af_packet: software checksum and tx poll control

Scott Mitchell
2026-01-28T07:06:08Z

> I don't think each driver should be doing its own checksum helper.
> It should be done at application or through libraries.
> All modern hardware does checksum offload, so if it doesn't probably
> a driver bug.

The goal from the app perspective is to set rte_eth_txmode.offloads
consistently across PMDs. Hardware devices are good but software
devices like af_packet don't provide a consistent experience. The
approach in this patch is similar to existing software eth devices tap
[1] and vhost [2]. In v2 I will share checksum code with tap to avoid
duplication and ensure they remain consistent.

[1] https://github.com/DPDK/dpdk/blob/v25.11/drivers/net/tap/rte_eth_tap.c#L559-L624
[2] https://github.com/DPDK/dpdk/blob/v25.11/drivers/net/vhost/rte_eth_vhost.c#L317-L357

> Needs to be a separate patch. Don't do two things in one patch.
> Not sure if some variant of the existing configure thresholds
> could be used for this.

ack, will split txpoll control. I'm not aware of any other way to
prevent poll if dpdk tx is faster than kernel rx.