An interactive interface and RT-Mach support for monitoring and controlling resource management

Real-time applications in dynamic systems such as multimedia systems may change their timing characteristics on the fly and may be created and terminated at any time. A priori resource allocation decisions may not hold throughout the lifetime of such applications because of changing user needs and interests. The ability to monitor and control system resources dynamically is fundamental to building flexible and dynamic multimedia systems. In this paper, we describe the mechanisms and tools we have built for monitoring and controlling operating system resource reserves in Real-Time Mach. The system supports a resource reservation abstraction called 'processor capacity reserves', and an interactive tool named 'rmon' uses these mechanisms to display the processor usage for each reserved activity in the system and to allow the user to change the processor reservation dynamically; it can also coordinate the reservation change requests with a separate quality-of-service manager which makes policy decisions regarding which requests are granted.