Linux is not a real-time operating system, however it has been often recently used to implement soft real-time systems such as home multimedia centers. A quantitative study of the Linux kernel responsiveness to hardware interrupts has shown a huge variance in experimental results, however, we argue that a careful selection of the modules inserted in the kernel can greatly reduce this variance and produce a much more predictable system.

In this paper, we focus on one of the major sources of unresponsiveness in the kernel, namely the presence of nonpreemptible code sections, and we quantify its effects with a series of micro-benchmarks. Our extensive set of experiments allowed us to identify which Linux kernel?s modules can cause erratic behavior with respect to the responsiveness of the Linux kernel to hardware interrupts.