In Fedora Linux, the real-time kernel is provided by the Planet CCRMA at Home software repositories. Along with the warnings in the Planet CCRMA at Home chapter (see
Section 4.2.2, “Security and Stability”), here is one more to consider: the real-time kernel is used by fewer people than the standard kernel, so it is less well-tested. The chances of something going wrong are relatively low, but be aware that using a real-time kernel increases the level of risk. Always leave a non-real-time option available, in case the real-time kernel stops working.