Linux process scheduler design

Linux, which was primarily developed for desktop systems, has unassumingly evolved into a multi-dimensional operating system with its usage spread across embedded devices, mainframes, and supercomputers to room-sized servers. It has also seamlessly accommodated the ever-evolving diverse computing platforms such as SMP, virtualization, and real-time systems. The diversity of these platforms is brought forth by the kind of processes that run on these systems. For instance, a highly interactive desktop system may run processes that are I/O bound, and a real-time system thrives on deterministic processes. Every kind of process thus calls for a different kind of heuristic when it needs to be fairly scheduled, as a CPU-intensive process may require more CPU time than a normal process, and a real-time process would require deterministic execution. Linux, which caters to a wide spectrum of systems, is thus confronted with addressing the varying scheduling challenges...