Virtual links for multicomputers

Abstract

(Uncorrected OCR) Abstract of Thesis entitled 'Virtual Links for Multicomputers' Submitted by

Siu Kit Wai

for the degree of

Master of Philosophy at Univsersity of Hong Kong in October 1996

In order to increase computation power, multiple autonomous computers or processors are connected to form a multicomputer. The performance boost is the result of exploiting in parallel the processing power available in individual processors. Parallel processing, however, requires the cooperation among the processors, which implies interprocessor communication. The efficiency of such communications is limited by the bandwidth and number of communication channels between directly connected processors.

Multiple processes on a processor share a few hardware communication links/channels to communication with processes executing on a different processor. Effective and efficient sharing of channels is important for the overall system performance; hence it is important that the sharing be properly managed. When the sharing is not provided by the hardware, it can be provided in software at system level. Without a managing component, processes need to be programmed to flight for and gain exclusive access to the communication links. This is usually not effective, error-prone, and could reduce the overall performance of processes executing in the processor.

Flexibility is a main advantage of providing a channel-sharing mechanism at system level. Parameters such as packet size, and configuration of the system can be customized and tuned to meet the communication characteristics of different applications.

In this project, we investigate how link sharing can be provided at system level. Our approach is based on idea of virtual links. The system is designed to be as transparent and easy to be used as possible. We will discuss how different

parameters and configurations affect the system functionality and performance. We also compare this software solution to other existing solutions including a hardware solution.

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