The Design of a Supporting Environment for On-Line Parallel Debugging

On-line parallel debugging can provide very accurate and reliable information in diagnosis of parallel programs. Unfortunately, commercially available tools for on-line parallel debugging are hardly seen. This is mainly due to the lack of a suitable environment for multiprogramming of mixed parallel and sequential workloads so that the resources cannot be utilised efficiently. In this paper we present a two-level scheduling scheme for mixed parallel and sequential workloads on parallel machines -- a key step in the establishment of a proper environment for online parallel debugging. 1 Introduction On-line parallel debugging is defined as debugging a parallel program during its execution on a real parallel system. It is in contrast to off-line parallel debugging which means the debugging of parallel programs is done by running a simulator on a sequential machine, or by accumulating trace data during the program execution and then analysing them post-mortem. There are several problems a..