An interesting idea! Sending signals to all processes sounds expensive as hell though. All that work just to make a system call again to flush a buffer. Maybe a mechanism can be added to make the kernel aware of the user space buffer so it can directly fetch stuff from there when it's idle? Is it kind of like io_uring https://man7.org/linux/man-pages/man3/io_uring_register_buff...

> Sending signals to all processes sounds expensive as hell though.

You'd only send signals to processes who had run any code since the CPU was last idle (if the process hasn't executed, it can't have buffered anything).

There could also be some kind of "I have buffered something" flag a process could set on itself, for example at a well-known memory address.