This IBM® Redbooks® publication provides advice and technical information about optimizing and tuning application code to run on systems that are based on the IBM POWER7® and POWER7+™ processors. This advice is drawn from application optimization efforts across many different types of code that runs under the IBM AIX® and Linux operating systems, focusing on the more pervasive performance opportunities that are identified, and how to capitalize on them. The technical information was developed by a set of domain experts at IBM.

The focus of this book is to gather the right technical information, and lay out simple guidance for optimizing code performance on the IBM POWER7 and POWER7+ systems that run the AIX or Linux operating systems. This book contains a large amount of straightforward performance optimization that can be performed with minimal effort and without previous experience or in-depth knowledge. This optimization work can:

• Improve the performance of the application that is being optimized for the POWER7 system
• Carry over improvements to systems that are based on related processor chips
• Improve performance on other platforms

The audience of this book is those personnel who are responsible for performing migration and implementation activities on IBM POWER7-based servers, which includes system administrators, system architects, network administrators, information architects, and database administrators (DBAs).

Chapter 1. Optimization and tuning on IBM POWER7 and IBM POWER7+

Chapter 2. The POWER7 processor

Chapter 3. The POWER Hypervisor

Chapter 4. AIX

Chapter 5. Linux

Chapter 6. Compilers and optimization tools for C, C++, and Fortran

Chapter 7. Java

Chapter 8. DB2

Chapter 9. WebSphere

Application Server

Appendix A. Analyzing malloc usage under AIX

Appendix B. Performance tooling and empirical performance analysis

Appendix C. POWER7 optimization and tuning with third-party applications