Reengineering a server ecosystem for enhanced portability and performance

We describe the design and implementation of the new, little-endian Linux on Power operating environment, with a particular emphasis on its application interfaces. The new environment was designed to simplify porting of applications from other processor architectures to Power. It uses little-endian data formats to reduce the need for code adaptation and debugging during porting, and to simplify the use of commodity off-the-shelf system components, such as I/O adapters and accelerators. We took advantage of introducing a new operating environment to optimize the platform application binary interface (ABI) for new programming patterns and paradigms, resulting in enhanced out-of-the-box performance. The new ABI responds to increasing componentization of applications by reducing the overhead involved in function calls with an emphasis on accelerating calls to short functions as well as calls to runtime-resolved functions, i.e., functions in shared libraries, function pointers, virtual methods, and interface functions.