Developing Monitoring and Debugging Tools for the AP1000 Array Multiprocessor

Abstract

The LERP project aims to assist the ap1000 programmer with essential monitoring and debugging tools. LERP is based on off-line analysis and replay of an event trace. A common event trace format includes both low level system events and user-defined events. In this paper we address the issues of instrumentation of ap1000 programs with minimal interference, and presentation of traced program behaviour to the user. We describe an interface to the existing display tools ParaGraph and Upshot, and a new compound event analysis tool suited to machines of the ap1000 scale. 1 Introduction The ap1000 is a pioneering member of a class of MIMD wormhole message-passing machines with many hundreds of processors (each of which is a general purpose microprocessor with significant speed and memory in its own right), connected by three communications networks. We may term this class the "kilo-processor" machines. 1 It provides significant challenges to programmers who need to develop correct and effi..