AIRS: Supporting Interactive Real-Time Applications on Multicore Platforms

Modern real-time systems increasingly operate with multi-ple interactive applications. While these systems often require reliable quality of service (QoS) for the applications, even un-der heavy workloads, many existing CPU schedulers are not very capable of satisfying such requirements. In this paper, we design and implement an Advanced Interactive and Real-time Scheduler, called AIRS. AIRS is aimed at supporting systems that run multiple interactive real-time applications, particularly on multicore platforms. It provides a new CPU reservation mechanism to enhance the QoS of the overall sys-tem. The reservation algorithm is based on the prior Con-stant Bandwidth Server (CBS) algorithm, but is more flexible and efficient, when multiple applications reserve CPU band-width. It also provides a new multicore scheduler to improve the absolute CPU bandwidth available for the applications to perform well. The scheduling algorithm is subject to the prior Earliest Deadline First with Window-constraint Migra-tion (EDF-WM) algorithm, but is extended to work with the new CPU reservation mechanism. Experimental evaluation shows that AIRS delivers higher quality to simultaneous play-back of multiple movies than the existing real-time scheduler. It also demonstrates that AIRS offers hard timing guarantees for randomly-generated task sets with heavy workloads.