Re: [PATCH bpf-next v3 1/3] xsk: Support UMEM chunk_size > PAGE_SIZE

[Kal Cutter Conley]

> Here is the comparison between multi-buffer and jumbo frames that I did
> for ZC ice driver. Configured MTU was 8192 as this is the frame size for
> aligned mode when working with huge pages. I am presenting plain numbers
> over here from xdpsock.
>
> Mbuf, packet size = 8192 - XDP_PACKET_HEADROOM
> 885,705pps - rxdrop frame_size=4096
> 806,307pps - l2fwd frame_size=4096
> 877,989pps - rxdrop frame_size=2048
> 773,331pps - l2fwd frame_size=2048
>
> Jumbo, packet size = 8192 - XDP_PACKET_HEADROOM
> 893,530pps - rxdrop frame_size=8192
> 841,860pps - l2fwd frame_size=8192

Thanks so much for sharing these initial results! Do you have similar
measurements for ~9000 byte packets in unaligned mode? We typically
receive packets larger than 8192 bytes.

>
> Kal might say that multi-buffer numbers are imaginary as these patches
> were never shown to the public ;) but now that we have extensive test
> suite I am fixing some last issues that stand out, so we are asking for
> some more patience over here... overall i was expecting that they will be
> much worse when compared to jumbo frames, but then again i believe this
> implementation is not ideal and can be improved. Nevertheless, jumbo
> frames support has its value.

You made me chuckle ;-) Any measurements people can provide are
helpful, even if they must be taken with a grain of salt. ;-). How
much of your test suite can be upstreamed in the future? My assumption
was the difference should be measurable, at least you have confirmed
that. :-)