Overview
Emerging multicore platforms introduce a challenge to the development cycle. The sole purpose of many multicore platforms is to provide better performance. On these platforms, performance debugging and performance analysis have become essential to the development cycle, as correctness pertaining to a single core no longer suffices.
Performance debugging is different from traditional correctness debugging since regular debuggers cannot intercept any of these:
- Delays from synchronization effects between running threads
- Delays from improper load balancing on CPUs
- Delays from memory affinity
- Delays from mutual cache invalidations of global shared data
- Delays from pipeline stalls in each core
- Potential for parallelization and simultaneous execution
HOPC is a complete service provided by HRL performance experts that includes:
- Effective and practical performance debugging for the IBM UNIX systems while working together with the customer
- Isolation and resolution of performance issues and complicated development bugs in multicore applications on IBM POWER platforms
- Recommendations for development patterns and compilation options
To provide this support, the team uses these tools:
- The Trace Analyzer tool, developed by the MPT (Multicore Performance Technologies) group.
- The Code Analyzer tool, developed by the PQS team for the purpose of performance consultancy, which includes performance comments on the source code. The performance comments of Code Analyzer can be displayed together with gathered profiling to help developers zoom in on the real bottlenecks.
- Expert System for Tuning Options (ESTO) is proprietary tool tailored to automatically search for a set of optimal values for the AIX OS tuning parameters, thereby yielding significant performance improvements for large sub-systems running on AIX.