realtime just means execution time is bounded. It doesn't necessarily mean the latency is low. Though, in this sense RT-linux should probably be mostly thought

realtime just means execution time is bounded. It doesn't necessarily mean the latency is low. Though, in this sense RT-linux should probably be mostly thought of as low-latency linux, and the improvement in realtime guarantees is mostly in reducing the amount of things that can cause you to miss a deadline as opposed to allowing you to guarantee any particular deadline, even a long one.