Akio Shimada

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The increasing prevalence of co-processors such as the Intel Xeon Phi, has been reshaping the high performance computing (HPC) landscape. The Xeon Phi comes with a large number of power efficient CPU cores, but at the same time, it's a highly memory constraint environment leaving the task of memory management entirely up to application developers. To reduce(More)
The process oversubscription, which binds multiple parallel processes to one CPU core, can hide the communication latency and reduce CPU idle time. However, the lightweight OS kernels for Exascale systems may no longer support OS task scheduling. Without OS task scheduling, only one parallel process per CPU core is allowed, and then the process(More)
Many-core processors are gathering attention in the areas of embedded systems due to their power-performance ratios. To utilize cores of a many-core processor in parallel, programmers build multi-task applications that use the task models provided by operating systems. However, the conventional task models cause some scalability problems when multi-task(More)
This paper proposes a novel parallel task model for an exascale heterogeneous computing environment consisting of multi-core and many-core CPUs. In the proposed environment, "Multiple Partitioned Virtual Address Space (Multiple PVAS)," all PVAS tasks on the hybrid system share the same virtual address space, so any PVAS task can access the data owned by the(More)
Single-particle coherent X-ray diffraction imaging using an X-ray free-electron laser has the potential to reveal the three-dimensional structure of a biological supra-molecule at sub-nanometer resolution. In order to realise this method, it is necessary to analyze as many as 1 × 10(6) noisy X-ray diffraction patterns, each for an unknown random target(More)
In many-core environments, the performance and memory footprint of MPI intra-node communications are both important issues. In this paper, we contend that the address space boundaries between MPI processes are detrimental to efficient intra-node communication and should be removed as we advance into the many-core era. We confirmed this contention by using(More)
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