Re: [PATCH net-next v3 3/8] bpf: cpumap: switch to GRO from netif_receive_skb_list()

[Jesper Dangaard Brouer]

On 15/01/2025 16.18, Alexander Lobakin wrote:
> cpumap has its own BH context based on kthread. It has a sane batch
> size of 8 frames per one cycle.
> GRO can be used here on its own. Adjust cpumap calls to the upper stack
> to use GRO API instead of netif_receive_skb_list() which processes skbs
> by batches, but doesn't involve GRO layer at all.
> In plenty of tests, GRO performs better than listed receiving even
> given that it has to calculate full frame checksums on the CPU.
> As GRO passes the skbs to the upper stack in the batches of
> @gro_normal_batch, i.e. 8 by default, and skb->dev points to the
> device where the frame comes from, it is enough to disable GRO
> netdev feature on it to completely restore the original behaviour:
> untouched frames will be being bulked and passed to the upper stack
> by 8, as it was with netif_receive_skb_list().
>
> Signed-off-by: Alexander Lobakin<aleksander.lobakin@xxxxxxxxx>
> Tested-by: Daniel Xu<dxu@xxxxxxxxx>
> ---
>   kernel/bpf/cpumap.c | 45 ++++++++++++++++++++++++++++++++++++++++++---
>   1 file changed, 42 insertions(+), 3 deletions(-)

Nice and clean code, I like it! :-)

Acked-by: Jesper Dangaard Brouer <hawk@xxxxxxxxxx>