Report Number: CS-TR-73-353
Institution: Stanford University, Department of Computer Science
Title: Random arrivals and MTPT disk scheduling disciplines.
Author: Fuller, Samuel H.
Date: August 1972
Abstract: This article investigates the application of minimal-total-processing-time (MTPT) scheduling disciplines to rotating storage units when random arrival of requests is allowed. Fixed-head drum and moving-head disk storage units are considered and particular emphasis is placed on the relative merits of the MTPT scheduling discipline with respect to the shortest-latency-time-first (SLTF) scheduling discipline. The data presented are the results of simulation studies. Situations are discovered in which the MTPT discipline is superior to the SLTF discipline, and situations are also discovered in which the opposite is true. An implementation of the MTPT scheduling algorithm is presented and the computational requirements of the algorithm are discussed. It is shown that the sorting procedure is the most time consuming phase of the algorithm.