Re: [PATCH net-next] net: ucc_geth: Batch RX packets before stack handoff

[Eric Dumazet]

On Thu, May 21, 2026 at 4:29 PM Rosen Penev <rosenp@xxxxxxxxx> wrote:
>
> On Thu, May 21, 2026 at 6:41 AM Eric Dumazet <edumazet@xxxxxxxxxx> wrote:
> >
> > On Wed, May 20, 2026 at 5:39 PM Rosen Penev <rosenp@xxxxxxxxx> wrote:
> > >
> > > On Wed, May 20, 2026 at 4:57 PM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
> > > >
> > > > On Sun, 17 May 2026 12:28:56 -0700 Rosen Penev wrote:
> > > > > Collect received skbs on a local list during RX polling and pass the
> > > > > completed batch to netif_receive_skb_list(). This lets the networking
> > > > > stack process packets from a poll cycle in bulk instead of handing each
> > > > > skb up individually.
> > > >
> > > > GRO should be even better.
> > > GRO will result in slower routing performance because there is no
> > > hardware checksum.
> >
> > Then provide a knob or something, instead of trying to avoid GRO.
> >
> > For end hosts (forwarding not enabled), checksum will need to be
> > computed anyway.
> > GRO should be faster for them.
> >
> > Note that GRO also uses netif_receive_skb_list_internal()
> so you recommend switching to napi_gro_receive even though there's no
> RX hardware checksum?

Certainly.

There is a reason we added support for sw checksum in GRO years ago.

Most linux hosts on this planet do not forward packets.
And if they do, there is a big chance the egress device supports TSO
or tx checksum offload.