PROCESSOR SAVING SCHEDULING POLICIES FOR MULTIPROCESSOR SYSTEMS

In this paper, processor scheduling policies that ''save'' processors are introduced and studied. In a multiprogrammed parallel system, a '' processor saving'' scheduling policy purposefully keeps some of the av ailable processors idle in the presence of work to be done. The condit ions under which processor saving policies can be more effective than their greedy counterparts, i.e., policies that never leave processors idle in the presence of work to be done, are examined. Sensitivity ana lysis is performed with respect to application speedup, system size, c oefficient of variation of the applications' execution time, variabili ty in the arrival process, and mu[tic[ass workloads. Analytical, simul ation, and experimental results show that processor saving policies ou tperform their greedy counterparts under a variety of system and workl oad characteristics.