Re: [PATCH net-next v2] wireguard: Wire-up big tcp support

[Daniel Borkmann <daniel@iogearbox.net>]

Hi Jason,

On 10/7/24 6:42 PM, Jason A. Donenfeld wrote:
> On Fri, Oct 04, 2024 at 06:55:18PM +0200, Daniel Borkmann wrote:
>> Advertise GSO_MAX_SIZE as TSO max size in order support BIG TCP for wireguard.
>> This helps to improve wireguard performance a bit when enabled as it allows
>> wireguard to aggregate larger skbs in wg_packet_consume_data_done() via
>> napi_gro_receive(), but also allows the stack to build larger skbs on xmit
>> where the driver then segments them before encryption inside wg_xmit().
> 
> Thanks, I'll queue this up. Do you have any perf numbers on the speedup,
> btw?

Awesome, thanks! Few weeks back we had an LPC session with some initial work
around wireguard performance (https://lpc.events/event/18/contributions/1968/)
including benchmarks. It depends on the specific scenario, but this as well as
an L2 GRO implementation (yet to come as patches in the next weeks) we got
~+15% for host-host in case of TCP STREAM. In case of Cilium I haven't done
the measurement yet, but I expect that there would be further gains as bigger
packets can traverse the stack and thus less processing in upper layers (e.g.
our tcx BPF code).

Thanks,
Daniel