Group system: An efficient dynamic memory management scheme for real-time systems

Abstract

While dynamic memory management (DMM) has been widely used as one of the basic elements of computer systems, it has been rarely used in real-time systems. DMM in real-time systems must exhibit fast execution, high memory efficiency, and predictable execution time. However, it is difficult to design a DMM scheme that simultaneously satisfies all of these requirements, and therefore DMM has not been widely used in real-time systems. This study proposes a new DMM scheme, named group system, that simultaneously satisfies the three requirements of real-time systems. The new DMM scheme is an extension of buddy systems and provides significantly improved memory efficiency compared to buddy systems while maintaining the advantage of the predictable execution time of buddy systems. Group system shows a slightly better worst-case execution time (WCET) than buddy systems that are known to exhibit excellent execution time, and shows memory efficiency that is close to that of the best fit scheme that is known to have excellent memory efficiency.