An overview of the BlueGene/L system software organization

BlueGene/L is a 65,536-compute node massively parallel supercomputer, built using system-on-a-chip integration and a cellular architecture. BlueGene/ L represents a major challenge for parallel system software, particularly in the areas of scalability, maintainability, and usability. In this paper, we present the organization of the BlueGene/L system software, with emphasis on the features that address those challenges. The system software was developed in parallel with the hardware, relying on an architecturally accurate simulator of the machine. We validated this approach by demonstrating a working system software stack and high performance on real parallel applications just a few weeks after first hardware availability.