The Spring scheduling co-processor: Design, use, and performance

We present a novel VLSI co-processor for real-time multiprocessor scheduling. The co-processor can be used for sophisticated static scheduling as well as for online scheduling using many different algorithms such as earliest deadline first, highest value first, or the Spring scheduling algorithm. When such an algorithm is used online it is important to assess the performance impact of the interface of the co-processor to the host system, in this case, the Spring kernel. We focus on the interface and its implications for overall scheduling performance. We show that the current VLSI chip speeds up the main portion of the scheduling operation by over three orders of magnitude and speeds up the overall scheduling operation 30 fold. The parallel VLSI architecture for scheduling is briefly presented. This architecture can be scaled for different numbers of tasks, resources, and internal word lengths. The implementation uses an advanced clocking scheme to allow further scaling using future IC technologies