What is the Linux RT kernel?
To explain the RT kernel version, we must understand more about how the regular kernel works. By default, Linux is a general-purpose kernel, initially aimed only at personal computers and servers. If we start any complex and extensive task that needs to use the CPU at 99% load for half an hour, the kernel will do it. Most of the time, our computers stay idle, raising the CPU activity when we do something. You can check this with any system monitor tool, which shows a graph of the system activity. Due to this characteristic, PCs were often slow and unresponsive years ago when a long and complex task was started.
A perfect example is video encoding. Say you want to encode a full HD movie from Blu-ray disk to MP4. While doing it, starting the browser may be slow. This issue was partially resolved over time, thanks to the CFS and its improvements, but it can still happen today. The reason is that a general-purpose kernel tries to do all the work it has,...