The Linux operating system was for a very long time seen as a GPOS, but in the last couple of years, some projects tried to change this by modifying the Linux kernel into a RTOS. One such project is the PREEMPT_RT patch, which was mentioned previously.

In this section of the chapter, I will discuss a series of tests that could be executed for both versions of the Linux OS with or without applying the PREEMPT_RT patches. I should mention that for those of you who are interested in some actual results, there are a number of papers available that try to investigate the latency effect of the PREEMPT_RT or its advantages or disadvantages. One such example is available at http://www.versalogic.com/downloads/whitepapers/real-time_linux_benchmark.pdf.

Before continuing further, I believe it is my duty to define a number of technical terms that are necessary to properly understand some information: