Quantum Support for Multiprocessor Pfair Scheduling in Linux
John M. Calandrino, James H. Anderson · 2006
This paper discusses several modifications to the Linux operating system in order to support aligned, staggered, and desynchronized quanta across multiple processors, where a quantum is a unit of processor allocation. We also evaluate one approach for supporting aligned quanta. These types of quanta are required for global multiprocessor real-time scheduling algorithms such as PD 2 (a Pfair algorithm). Additionally, we consider the issue of increasing the frequency of timer interrupts to allow for the smallest quantum possible, and discuss impediments to higher timer interrupt frequencies. Smaller quanta are important, as they can increase the efficiency of quantum-based scheduling algorithms; however, they are more sensitive to quantum alignment error.