05501 Abstracts Collection -- Automatic Performance Analysis

From 12.12.05 to 16.12.05, the Dagstuhl Seminar 05501 ``Automatic Performance Analysis\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and open problems were discussed. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are put together in this paper. The first section describes the seminar topics and goals in general. Links to extended abstracts or full papers are provided, if available

An Infrastructure for the Analysis of Communication Patterns in Virtual Topologies

The virtual topology of a parallel application is the neighborhood relationship between communicating processes developed due to specific communication patterns resulting from domain decomposition. We present an infrastructure that allows the usage of topological information for the performance analysis of a parallel application. For this purpose we have implemented an easy to use extension of the KOJAK performance analysis toolkit. The KOJAK toolkit defines communication patterns for parallel applications which describe inefficient behavior. The performance analysis is carried out by calculating the effect of these inefficiency patterns on the application\u27s performance. The distribution of these inefficiency patterns is studied across a three-dimensional performance space. The knowledge of virtual topology can be exploited to explain the occurrence of these inefficiency patterns in terms of higher-level events related to the parallel algorithm implemented in the application. Also, it can be used to visualize the relationships between pattern occurrences and the topological characteristics of the affected processes, To prove these principles, we have used our extensions to KOJAK to analyze two realistic MPI applications

Holistic Hardware Counter Performance Analysis of Parallel Programs

The KOJAK toolkit has been augmented with refined hardware performance counter support, including more convenient measurement specification, additional metric derivations and hierarchical structuring, and an extended algebra for integrating multiple experiments. Comprehensive automated analysis of a hybrid OpenMP/MPI parallel program, the ASC Purple sPPM benchmark, is demonstrated with performance experiments on equisized POWER4-II-based IBM Regatta p690+ cluster, Opteron-based Cray XD1 cluster and UltraSPARC-IV-based Sun Fire E25000 systems. Automatically assessed communication and synchronisation performance properties, combined with a rich set of measured and derived counter metrics, provide a holistic analysis context and facilitate multi-platform comparison