I do wonder if the stream interface is the ultimate incarnation, how cpu-efficient this will be versus perhaps some more radical approach with more obvious memory mapping / RDMA sort of feels.
This is really wandering a bit afar, but this somewhat recalls the recently reposted The World in which IPv6 was a good design (2017), in thinking: maybe here is a place where we could do IPv6 but not atop ethernet. Of course the kernel is not set-up for that. But the idea of protocol acceleration is in general interesting here, generally. Maybe we go higher up the stack: what would it be like if we had a really nice QUIC in the kernel, and could have some kind of super fast QUIC transport over a USB4 connection? https://news.ycombinator.com/item?id=47821429 https://apenwarr.ca/log/20170810
I'll also note that CXL is finally sort of starting to have it's day, especially with memory prices being what they are & the hyperscalers needing massive KV caches & being able to use their old DDR4 in CXL memory expanders. CXL is primarily being used for memory expanders right now it seems like, but I hope we see interesting accelerators and other storage too. More generally though: CXL 3.1 completed a move from a host-based architecture, to CXL as a multi-host fabric. And notable here: also allows for host-to-host connectivity. I love seeing stuff like that so much! A very high speed fabric that computers already speak, no NIC required, that computers and peripherals can plug in to! I hope so much this grows beyond the High Data Keep ultrascalers & shows up for mortals too, some day!
It's lovely to me anytime I see a computer I own able to start offering interesting suites of services to other computers, acting like a very capable device to other computers: that's exudes such a malleable systems wonderment to me.
I remember showing a friend NoHands a decade and a half ago: oh, you want your Linux computer to act like a Bluetooth headset? No Problem! And the look of awe that these things could be possible! The directions of these protocol relationships aren't cast in stone, it's such a delight when we gain flexibility & freedom over our devices & how they connect, when we are free do more, connect as we please. The top down hierarchical relationships growing fuzzy & flexible & becoming free-flowing graph relationships brings such creativity & possibility.