Frank D. Anger

Scheduling precedence graphs in systems with interprocessor communication times

The problem of nonpreemptively scheduling a set of m partially ordered tasks on n identical processors subject to interprocessor communication delays is studied in an effort to minimize the makespan. A new heuristic, called Earliest Task First (ETF), is designed and analyzed. It is shown that the makespan

Scheduling with sufficient loosely coupled processors

\omega _{{\text{ETF}}}

On Lamport's interprocessor communication model

generated by ETF always satisfies

Temporal reasoning: A relativistic model

\omega _{{\text{ETF}}} \leqq ({{2 - 1} / n})\omega _{{\text{opt}}}^{(i)} + C

Temporal complexity and software faults

, where

New and used temporal models: An issue of time

\omega _{{\text{opt}}}^{(i)}

Time, Tense and Relativity Revisited

is the optimal makespan without considering communication delays and C is the communication requirements over some immediate predecessor-immediate successor pairs along one chain. An algorithm is also provided to calculate C. The time complexity of Algorithm ETF is

Space, time, and computation: Trends and problems

O(nm^2 )

Effective Scheduling of Tasks under Weak Temporal Interval Constraints

.

An Analysis of the Temporal Relations of Intervals in Relativistic Space-Time

Abstract Finding optimal schedules for precedence-related tasks on a multiprocessor system is, in general, an NP-hard problem. With unit-time tasks and tree precedences, however, the problem is known to be solvable in polynomial time. With the introduction of communication delays due to message passing between processors, even this restricted case may again become difficult. This paper shows that when there are enough processors to run all available tasks and when communication delays are no longer than the shortest task processing time, then there is a linear-time optimal algorithm. The basic algorithm, Join Latest Predecessor, and some extensions are presented giving optimal solutions for a variety of cases.