APRIX: A Master-Slave Operating System Architecture for Multiprocessor Embedded Systems

The recent emergence of heterogeneous chip multiprocessors requires a different operating system organization from the usual SMP (symmetric multiprocessing) organization. Although the SMP organization has been widely adopted in modern multiprocessor operating systems, it is restricted to homogeneous processors with a global shared memory. On the other hand, the master-slave organization has little dependency upon the underlying hardware architecture, thus having great potential to cope with heterogeneous multiprocessors. This motivated us to reexamine the master-slave approach. In this paper, we attempt to address real-time and performance issues associated with the master-slave approach. Specifically, we first describe our previous design of a master-slave architecture, called APRIX. We then present an improved communication mechanism between the master and slave, which allows the master to provide priority-based system call services to slave kernels and also improves the overall multiprocessing performance.