Pajé, an interactive visualization tool for tuning multi-threaded parallel applications

This paper describes Pajé, an interactive visualization tool for displaying the execution of parallel applications where a potentially large number of communicating threads of various life-times execute on each node of a distributed memory parallel system. Pajé is capable of representing a wide variety of interactions between threads. The main characteristics of Pajé, interactivity and scalability, are exemplified by the performance tuning of a molecular dynamics application. In order to be easily extensible, the architecture of the system was based on components which are connected in a data flow graph to produce a given visualization tool. Innovative components were designed, in addition to “classical” components existing in similar visualization systems, to support scalability and interactivity.