  This paper presents a novel methodology to develop scheduling algorithms. The
scheduling problem is phrased as a control problem, and control-theoretical
techniques are used to design a scheduling algorithm that meets specific
requirements. Unlike most approaches to feedback scheduling, where a controller
integrates a "basic" scheduling algorithm and dynamically tunes its parameters
and hence its performances, our methodology essentially reduces the design of a
scheduling algorithm to the synthesis of a controller that closes the feedback
loop. This approach allows the re-use of control-theoretical techniques to
design efficient scheduling algorithms; it frames and solves the scheduling
problem in a general setting; and it can naturally tackle certain peculiar
requirements such as robustness and dynamic performance tuning. A few
experiments demonstrate the feasibility of the approach on a real-time
benchmark.
