Tmon: A performance monitor for transputer‐based multicomputers
Alan Wagner, J. Jiang, Samuel T. Chanson · Concurrency Practice and Experience · 1993
Abstract The paper describes a new performance monitoring tool, calledTmon, that has been developed to help application programmers understand the run‐time behavior of a parallel system and tune the performance of their programs. Tmon measures resource utilization and traces process activities transparently during execution. A global interrupt technique used by Tmon allows measurement tasks to be executed simultaneously on different processors and an accurate global clock to be maintained with minimal overhead. Experimental results indicate that both the accuracy and the overhead of the monitor are well within an acceptable range. We introduce a performance model from which it is possible to derive several different parallel programming metrics. A weighted critical path analysis tool is also presented that focusses the user's attention on those parts of the program whose modification would most improve performance. An example in which the tool is used successfully to improve the performance of a parallel application is also presented. Tmon is currently implemented on top of the Trollius Operating System and runs on a 74‐node transputer‐based multicomputer.