Applying backfilling over a non-dedicated cluster

The resource utilization level in open laboratories of several universities has been shown to be very low. Our aim is to take advantage of those idle resources for parallel computation without disturbing the local load. In order to provide a system that lets us execute parallel applications in such a non-dedicated cluster, we use an integral scheduling system that considers both Space and Time sharing concerns. For dealing with the Time Sharing (TS) aspect, we use a technique based on the communication-driven coscheduling principle. This kind of TS system has some implications on the Space Sharing (SS) system, that force us to modify the way job scheduling is traditionally done. In this paper, we analyze the relation between the TS and the SS systems in a non-dedicated cluster. As a consequence of this analysis, we propose a new technique, termed 3DBackfilling. This proposal implements the well known SS technique of backfilling, but applied to an environment with a MultiProgramming Level (MPL) of the parallel applications that is greater than one. Besides, 3DBackfilling considers the requirements of the local workload running on each node. Our proposal was evaluated in a PVM/MPI Linux cluster, and it was compared with several more traditional SS policies applied to non-dedicated environmentsVI Workshop de Procesamiento Distribuido y Paralelo (WPDP)Red de Universidades con Carreras en Informática (RedUNCI

Studies of some feedback control mechanisms in operating systems

PhD ThesisThe possibility of enhancing the effectiveness of an operating system by the introduction of appropriate feedback controls is explored by examining some resource allocation problems. The allocation of and I/O processors in a multiprogramming core, CPU demand paging environment is studied in terms of feedback control. A major part of this study is devoted to the application of feedback control concepts to core allocation to prevent thrashing and develop algorithms of practical value. To aid this study a simulator is developed which uses probability distributions to represent program behaviour. Successful algorithms are developed employing a two stage page replacement function which selects a process from which a page is then chosen to be replaced. Improving the performance of these algorithms by using a 'drain process' to aid the dynamic determination of the current locality of a process is also discussed. The complexity of the overall resource allocation problem is dealt with by employing a hierarchy of individual resource allocation policies. These control scheduling, core allocation and dispatching. By considering the levels of the hierarchy as separate feedback control systems the restrictions which must be placed upon the individual levels are derived. The extension of these results to further levels is also discussed.Science Research Counci

Program relocation in a multiprogramming environment.

Various methods are studied for the relocation, or movement, including address mapping, of programs within a multiprogrammed digital computer. The aim of doing so is to determine the best method for use in the limited time-shared computing system proposed for development in the Digital Control Laboratory of the Naval Postgraduate School. In this light, the concepts of time-sharing and multiprogramming are discussed, as is the implementation of relocation in a very large computer obtained for the School's main computer facility. The features and requirements of the D.C.L. are then established and evaluated. It is found for the Laboratory that complete job swapping will be a fully satisfactory method of relocation. The time taken will not be excessive, and this method will be the easiest to incorporate in the timesharing system. Details of a possible implementation are given in an appendix to the thesis.http://www.archive.org/details/programrelocatio00stewCaptain, United States Marine Corp