Trace-based Performance Analysis on Cell BE

The transition to multicore architectures creates significant challenges for programming systems. Taking advantage of specialized processing cores such as those in the Cell BE processor and managing all the required data movement inside the processor cannot be done efficiently without help from the software infrastructure. Alongside new programming models and compiler support for multicores, programmers need performance evaluation and analysis tools. In this paper, we present tools that help analyze the performance of applications executing on the Cell platform. The performance debugging tool (PDT) provides a means for recording significant events during program execution, maintaining the sequential order of events, and preserving important runtime information such as core assignment and relative timing of events. The trace analyzer (TA) reads and visualizes the PDT traces. We describe the architecture of the PDT and present several important use cases demonstrating the usage of PDT and TA to understand the performance of several workloads. We also discuss the overhead of tracing and its impact on the benchmark execution and performance analysis.