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Jia, Yulu

Publications and source records attributed to Jia, Yulu.

4 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

In Situ Data Infrastructure for Scientific Unit Testing Platform

Testing is a significant software development process for the management of software systems and scientific code. However, as the complexity of scientific codes increases, extra checks are needed to monitor impacts to dependent models and to verify system constraints. The software complexity also impedes the efforts of module developers and software engineers to rapidly develop and extend their code. Recently, we have developed an automatic methodology and prototype platform to facilitate scientific verification of individual functions within complex scientific codes. With this system, the scientific module builders are able to track variables conveniently in one module or track variables’ changes among different modules. In this paper, we present a procedure for automatic unit testing generation. For the interest of a general audience of this conference, we are emphasizing the technical details of integrating the In Situ data infrastructure into our platform. At the end of this paper, we have included an implementation of unit testing for the ACME Land Model (ALM) to demonstrate the usefulness and correctness of the platform. We have also used single- and multipoint checks to demonstrate the efficient variable tracking capability of this platform.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2015

HPC Programming on Intel Many-Integrated-Core Hardware with MAGMA Port to Xeon Phi

This paper presents the design and implementation of several fundamental dense linear algebra (DLA) algorithms for multicore with Intel Xeon Phi coprocessors. In particular, we consider algorithms for solving linear systems. Further, we give an overview of the MAGMA MIC library, an open source, high performance library, that incorporates the developments presented here and, more broadly, provides the DLA functionality equivalent to that of the popular LAPACK library while targeting heterogeneous architectures that feature a mix of multicore CPUs and coprocessors. The LAPACK-compliance simplifies the use of the MAGMA MIC library in applications, while providing them with portably performant DLA. High performance is obtained through the use of the high-performance BLAS, hardware-specific tuning, and a hybridization methodology whereby we split the algorithm into computational tasks of various granularities. Execution of those tasks is properly scheduled over the heterogeneous hardware by minimizing data movements and mapping algorithmic requirements to the architectural strengths of the various heterogeneous hardware components. Our methodology and programming techniques are incorporated into the MAGMA MIC API, which abstracts the application developer from the specifics of the Xeon Phi architecture and is therefore applicable to algorithms beyond the scope of DLA.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2013

Parallel reduction to hessenberg form with algorithm-based fault tolerance

This paper studies the resilience of a two-sided factorization and presents a generic algorithm-based approach capable of making two-sided factorizations resilient. We establish the theoretical proof of the correctness and the numerical stability of the approach in the context of a Hessenberg Reduction (HR) and present the scalability and performance results of a practical implementation. Our method is a hybrid algorithm combining an Algorithm Based Fault Tolerance (ABFT) technique with diskless checkpointing to fully protect the data. We protect the trailing and the initial part of the matrix with checksums, and protect finished panels in the panel scope with diskless checkpoints. Compared with the original HR (the ScaLAPACK PDGEHRD routine) our fault-tolerant algorithm introduces very little overhead, and maintains the same level of scalability. We prove that the overhead shows a decreasing trend as the size of the matrix or the size of the process grid increases.

Computer Science↗