To be clear, was FreeBSD used because of historical reasons or because similar performance can't be/harder to achieve on Linux?
The gist is that the sendfile() call stages the pages waiting to be read in the socket buffer, and marks the mbufs with M_NOTREADY (so they cannot be sent by TCP). When the disk read completes, a sendfile callback happens in the context of the disk ithread. This clears the M_NOTREADY flag and tells TCP they are ready to be sent. See https://www.nginx.com/blog/nginx-and-netflix-contribute-new-...
The overall idea is to copy bytes from disk to the socket with almost no allocation and not blocking, this is the idea right?
I've been doing this for stuff like SMTPE authority servers and ntpd and things that absolutely cannot go down, for over a decade.
There are also VirtIO drivers involved, and according to the article, they had effect too.
So, could Linux be tweaked and made as performant for _this_ use case. I expect so. The question to be answered is _why_.
Do you have any additional references around this? I'm aware that most rarely used functionality is often broken and therefore usually don't recommend people to use it, but would like to learn about kTLS in particular. I think for Linux OpenSSL 3 now added support for it in userspace. But there's also the kernel components as well as drivers - all of them could have their set of issues.
Well, the printers wouldn't pair with the new APs, certain laptops with fruit logos would intermittently drop connection, and so on.
I probably will never use that brand again, even though they escalated and promised patches quickly - within 6 hours they had found the issue and we're working on fixing it, but the damage to my reputation was already done.
Since then I've always demanded to be able to test any new idea/kit/service for at least a week or two just to see if I can break it.