Abstract: "The Paros Operating System Microkernel"

Authors: Jesus Labarta, Sergi Girona, Toni Cortes, Judit Gimenez, Cristina Pujol and Luis Gregoris

This paper describes the concepts and rationale of Paros, an operating system microkernel specifically targeted to distributed memory parallel computers.The Paros microkernel has been designed to provide dynamic support for general purpose parallel applications and operating systems under the distributed memory programming model. Fine grain parallelism in machines with large numbers of node is directly supported by Paros. The ability to support efficiently many users and different environments concurrently has been one of the objective of the design. A prototype implementation on transputer based machines has been implemented.The system offers fast and flexible resource management mechanisms and policies. This characteristics make Paros an important research tool for both application developers and system programmers on topics such as process mappings, loadbalance, communication delays, overheads and subsystems as fileservers. One of our objectives is to support systems in which good balance between individual application speed and global throughput are compromised to acceptable levels and thus achieve good utilization of all the components in a parallel machine.Applications both at source and binary level have been ported from different transputer programming environments to Paros with little effort, achieving good performance and higher throughput than in the original system.A good example is the implementation of a parallel make.In the first part we present the objectives and rationale followed by a description of basic concepts and functionalities supported by the Paros microkernel. Afterwards, the present environment of Paros is described. We conclude with a section showing performance figures that are representative of theclass of problems we want to further research.

This paper can be found as a CEPBA/UPC Report No. RR-94/05.