A new kernel polling interface (LWN)

[Barret Rhoden]

https://lwn.net/Articles/743714/

this is about a year old, but interesting in light of akaros's events.
short version: it's a method to poll on linux AIO completions, using a
ring buffer in shared memory. not sure if it ever got merged - i'm
almost always a year behind on my LWN reading.

one of the main things behind akaros's events and async syscalls was
to avoid the proliferation of AIO/epoll/select mechanisms (and largely
replace that with fast uthreads). the model they are using here is
somewhat similar to requesting an event for an akaros syscall (though
we allow someone to ask for the event *after* io_submit).

the other thing they note is a bigger improvement from avoiding
kernel crossings with the KPTI/KAISER mitigations.

one of the comments talks about userspace's need to prioritize various
events (e.g. FD completions for systemd). that seems like a nice job
for a 2LS.

barret