The design, implementation and evaluation of SMART: a scheduler for multimedia applications

Real-time applications such as multimedia audio and video are increasingly populating the workstation desktop. To support the execution of these applications in conjunction with traditional non-realtime applications, we have created SMART, a Scheduler for Multimedia And Real-Time applications. SMART supports applications with time constraints, and provides dynamic feedback to applications to allow them to adapt to the current load. In addition, the support for real-time applications is inte grated with the support for conventional computations. This allows the user to prioritize across real-time and conventional computations, and dictate how the processor is to be shared among applications of the same priority . As the system load changes, SMART adjusts the allocation of resources dynamically and seamlessly. SMAR T is unique in its ability to automatically shed real-time tasks and re gulate their execution rates when the system is overloaded, while providing better value in underloaded conditions than previously proposed schemes. We have implemented SMART in the Solaris UNIX operating system and measured its performance against other schedulers in e xecuting real-time, interacti ve, and batch applications. Our results demonstrate SMART’s superior performance in supporting multimedia applications.