The Integration of Application and System Based Metrics in a Parallel Program Performance Tool

The IPS-2 parallel program measurement tools pro-vide performance data from application programs, the operating system, hardware, network, and other sources. Previous versions of IPS-2 allowed programmers to collect information about an application based only on what could be collected by software instrumentation inserted into the program (and system call libraries). We have developed an open interface, called the “external time histogram”, pro-viding a graceful way to include external data from many sources. The user can tell IPS-2 of new sources of perfor-mance data through an extensible metric description language. The data from these external sources is automat-ically collected when the application program is run. IPS-2 provides a library to simplify constructing the external data collectors. The new version of IPS-2 can measure shared-memory and message-passing parallel programs running on a heterogeneous collection of machines. Data from C or Fortran programs, and data from simulations ean be pro-cessed by the same tool. As a result of including the new external performance data, IPS-2 now can report on a whole new set of performance problems. We describe the results of using IPS-2 on two real applications: a shared-memory database join utility, and a multi-processor interconnection network simulator. Even though these applications previously went through careful tuning, we were able to precisely identify performance problems and extract additional performance improvements of about 30%