I have not looked at the io_uring implementation to see if it really has improvements from this point of view, but something that has changed during the quarter

I have not looked at the io_uring implementation to see if it really has improvements from this point of view, but something that has changed during the quarter of century from the design of kqueue until now is that currently it has become much more important than before to minimize the number of context switches caused by system calls in the programs that desire to reach a high performance for input/output. The reason is that with faster CPU cores, more cores sharing the memory, bigger CPU core states and relatively slower memory in comparison with the CPU cores, the time wasted by a context switch has become relatively greater in comparison with the time used by a CPU core to do useful work. So hopefully, implementing some I/O task using io_uring should require less system calls than when using kqueue or epoll. According to the io_uring man page, this should be true.