Learn More
Jalapeño is a virtual machine for Java TM servers written in the Java language. To be able to address the requirements of servers (performance and scalability in particular), Jalapeño was designed " from scratch " to be as self-sufficient as possible. Jalapeño's unique object model and memory layout allows a hardware null-pointer check as well as fast(More)
Jalapeño is a virtual machine for Java#8482; servers written in Java. A running Java program involves four layers of functionality: the user code, the virtual-machine, the operating system, and the hardware. By drawing the Java / non-Java boundary below the virtual machine rather than above it, Jalapeño reduces the boundary-crossing overhead and(More)
With up to 65,536 compute nodes and a peak performance of more than 360 teraflops, the Blue Genet/L (BG/L) supercomputer represents a new level of massively parallel systems. The system software stack for BG/L creates a programming and operating environment that harnesses the raw power of this architecture with great effectiveness. The design and(More)
In December 1999, IBM announced the start of a five-year effort to build a massively parallel computer, to be applied to the study of biomolecular phenomena such as protein folding. The project has two main goals: to advance our understanding of the mechanisms behind protein folding via large-scale simulation, and to explore novel ideas in massively(More)
Single superclass inheritance enables simple and efficient table-driven virtual method dispathc. However, virtual method table dispatch does not handle multiple inheritance and interfaces. This complication has led to a widespread misimpression that interface method dispatch is inherently inefficient. This paper argues that with proper implementation(More)
In this paper, we give an overview of the Jalape~ no Java Virtual Machine (JVM) research project at the IBM T. J. Watson Research Center. The goal of Jalape~ no is to expand the frontier of JVM technologies for server machines. As reported in the paper, several of the design and implementation decisions in Jalape~ no depend heavily on compiler support. Two(More)
Blue Gene/L is currently the world's fastest and most scalable supercomputer. It has demonstrated essentially linear scaling all the way to 131,072 processors in several benchmarks and real applications. The operating systems for the compute and I/O nodes of Blue Gene/L, are among the components responsible for that scalability. Compute nodes are dedicated(More)
This paper gives an overview of the BlueGene/L Supercomputer. This is a jointly funded research partnership between IBM and the Lawrence Livermore National Laboratory as part of the United States Department of Energy ASCI Advanced Architecture Research Program. Application performance and scaling studies have recently been initiated with partners at a(More)
Many fundamental tests performed by geometric algorithms can be formulated in terms of finding the sign of a determinant. When these tests are implemented using fixed precision arithmetic such as floating point, they can produce incorrect answers; when they are implemented using arbitrary-precision arithmetic, they are expensive to compute. We present(More)
The Blue Gene machines in production today run a small single-user, single-process kernel (CNK) having a limited functionality. Motivated by the desire to provide applications with a much richer operating environment, we evaluate the effect of replacing CNK with a standard Linux kernel on the compute nodes of Blue Gene/L. We show that with a relatively(More)