QUIC: use sendmmsg() with GSO

[Marcin Wanat]

Hi,

I discovered a patch for QUIC that enables the use of sendmmsg() with
GSO, authored by Roman Arutyunyan:

https://mailman.nginx.org/pipermail/nginx-devel/2023-July/4ZTXGDMY2LC4VRZRBNBXGULYHS5DMR3Z.html

However, for some reason, this patch has never been merged into the
Nginx codebase. According to Cloudflare, it could offer significant
performance improvements:

https://blog.cloudflare.com/accelerating-udp-packet-transmission-for-quic

Could you provide any insights on why this patch has not been merged?

Regards,
Marcin Wanat