Yasushi Negishi

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Torus networks are commonly used for massively parallel computers, its performance often becomes the constraint on total application performance. Especially in an asymmetric torus network, network traffic along the longest axis is the performance bottleneck for all-to-all communication, so that it is important to schedule the longest-axis traffic smoothly.(More)
Multicore processors are becoming dominant in the high performance computing (HPC) area, so multithread programming with OpenMP is becoming a key to good performance on such processors, though debugging problems remain. In particular, it is difficult to detect data races among threads with nondeterministic results, thus calling for tools to detect data(More)
Video on demand (VOD) systems are becoming popular. They have special requirements for receiving VOD data steadily, but common general communication protocols cannot meet their requirements. Several new protocols have been designed to fulll this service requirement , but it takes a long time for a protocol to be supported from end to end. We propose a VOD(More)
Simultaneous Multi-Thread (SMT) techniques are becoming popular because they increase the efficiency of CPU resource usage by allowing multiple threads to run on a single physical processor at a very fine granularity. Emerging real-time applications, however, may not benefit from the SMT techniques because those techniques often compromise the predictable(More)
To optimize various high performance computing (HPC) programs on complex supercomputer architectures source-to-source optimization tools are becoming important to support network-architecture-specific and application-specific performance optimization in addition to compiler optimizations. Because of try-and-error nature of performance optimization work and(More)