Coscheduling through synchronized scheduling servers—a prototype and experiments

Abstract. Predictable network computing still involves a number of open questions. One such question is providing a controlled amount of CPU time to distributed processes. Mechanisms to control the CPU share given to a single process have been proposed before. Directly applying this work to distributed programs leads to unacceptable performance, since the execution of processes on distributed machines is not coordi-nated in time. This paper discusses how coscheduling can be achieved with share-controlling scheduling servers. The performance impact of scheduling control is evaluated for BSP-style programs. These experi-ments show that synchronization mechanisms are indispensable and that coscheduling can be achieved for unmodied programs, but also that a performance overhead has to be paid for the control over CPU share.