An Interactive Interface and RT-Mach Support for Monitoring and
Controlling Resource Management

Clifford W. Mercer and Ragunathan Rajkumar

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
sys tem resources dynamically is fundamental to building flexi ble and
dynamic multimedia systems. In this paper, we describe the mechanisms
and tools we have built for moni toring and controlling operating
system resource reserves in Real-Time Mach. The system supports a
resource reservation abstraction called processor capacity reserves,
and an inter active 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.

Keywords: real-time, multimedia, operating system, performance monitor,
interactive resource management