Optimal Parallel Algorithms for Two Processor Scheduling with Tree Precedence Constraints

Ernst W. Mayr and Hans Stadtherr

Technical Report TUM-I9531
Institut für Informatik
Technische Universität München
November 1995


Abstract. Consider the problem of finding a minimum length schedule for n unit execution time tasks on m processors with tree-like precedence constraints. A sequential algorithm can solve this problem in linear time. The fastest known parallel algorithm needs O(log(n)) time using n2 processors. For the case m=2, we present two work optimal parallel algorithms that produce greedy optimal schedules for intrees and outtrees. Both run in O(log(n)) time using n/log(n) processors of an EREW PRAM.

Hans Stadtherr, 1997/09/16