On the development of an efficient coscheduling system

Applying gang scheduling can alleviate the blockade problem caused by exclusively space-sharing scheduling. To simply allow jobs to run simultaneously on the same processors as in the conventional gang scheduling, however, may introduce a large number of time slots in the system. In consequence the cost of context switches will be greatly increased, and each running job can only obtain a small portion of resources including memory space and processor utilisation and so no jobs can finish their computations quickly. In this paper we present some experimental results to show that to properly divide jobs into different classes and to apply different scheduling strategies to jobs of different classes can greatly reduce the average number of time slots in the system and significantly improve the performance in terms of average slowdown.