UPCBLAS : a numerical library for unified parallel C with architecture-aware optimizations

[Abstract] The popularity of Partitioned Global Address Space (PGAS) languages has increased during the last years thanks to their high programmability and performance through an efficient exploitation of data locality, especially on hierarchical architectures like multicore clusters. This PhD Thesis describes UPCBLAS, a parallel library for numerical computation using the PGAS Unified Parallel C (UPC) language. The routines are built on top of sequential BLAS and SparseBLAS functions and exploit the particularities of the PGAS paradigm, taking into account data locality in order to achieve a good performance. However, the growing complexity in computer system hierarchies due to the increase in the number of cores per processor, levels of cache (some of them shared) and the number of processors per node, as well as the high-speed interconnects, demands the use of new optimization techniques and libraries that take advantage of their features. For this reason, this Thesis also presents Servet, a suite of benchmarks focused on detecting a set of parameters with high in uence on the overall performance of multicore systems. UPCBLAS routines use the hardware parameters provided by Servet to implement optimization techniques that improve their performance. The performance of the library has been experimentally evaluated on several multicore supercomputers and compared to message-passing-based parallel numerical libraries, demonstrating good scalability and efficiency. UPCBLAS has also been used to develop more complex numerical codes in order to demonstrate that it is a good alternative to MPI-based libraries for increasing the productivity of numerical application developers

UPCBLAS: a library for parallel matrix computations in Unified Parallel C

This is the peer reviewed version of the following article: González‐Domínguez, J. , Martín, M. J., Taboada, G. L., Touriño, J. , Doallo, R. , Mallón, D. A. and Wibecan, B. (2012), UPCBLAS: a library for parallel matrix computations in Unified Parallel C. Concurrency Computat.: Pract. Exper., 24: 1645-1667. doi:10.1002/cpe.1914, which has been published in final form at https://doi.org/10.1002/cpe.1914. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.[Abstract] The popularity of Partitioned Global Address Space (PGAS) languages has increased during the last years thanks to their high programmability and performance through an efficient exploitation of data locality, especially on hierarchical architectures such as multicore clusters. This paper describes UPCBLAS, a parallel numerical library for dense matrix computations using the PGAS Unified Parallel C language. The routines developed in UPCBLAS are built on top of sequential basic linear algebra subprograms functions and exploit the particularities of the PGAS paradigm, taking into account data locality in order to achieve a good performance. Furthermore, the routines implement other optimization techniques, several of them by automatically taking into account the hardware characteristics of the underlying systems on which they are executed. The library has been experimentally evaluated on a multicore supercomputer and compared with a message‐passing‐based parallel numerical library, demonstrating good scalability and efficiency.Ministerio de Ciencia e Innovación; TIN2010-16735Ministerio de Educación; AP2008-0157

Parallel and Scalable Short-Read Alignment on Multi-Core Clusters Using UPC++

[Abstract]: The growth of next-generation sequencing (NGS) datasets poses a challenge to the alignment of reads to reference genomes in terms of alignment quality and execution speed. Some available aligners have been shown to obtain high quality mappings at the expense of long execution times. Finding fast yet accurate software solutions is of high importance to research, since availability and size of NGS datasets continue to increase. In this work we present an efficient parallelization approach for NGS short-read alignment on multi-core clusters. Our approach takes advantage of a distributed shared memory programming model based on the new UPC++ language. Experimental results using the CUSHAW3 aligner show that our implementation based on dynamic scheduling obtains good scalability on multi-core clusters. Through our evaluation, we are able to complete the single-end and paired-end alignments of 246 million reads of length 150 base-pairs in 11.54 and 16.64 minutes, respectively, using 32 nodes with four AMD Opteron 6272 16-core CPUs per node. In contrast, the multi-threaded original tool needs 2.77 and 5.54 hours to perform the same alignments on the 64 cores of one node. The source code of our parallel implementation is publicly available at the CUSHAW3 homepage (http://cushaw3.sourceforge.net).[Resumen]: El crecimiento de los conjuntos de datos de "secuenciamiento de próxima generación" (NGS por sus siglas en inglés) es un reto respecto a la calidad y a la velocidad de alineamientos de secuencias a genomas de referencia. Algunos alineadores disponibles obtienen mapeados de alta calidad a expensas de largos tiempos de ejecución. Desarrollar software rápido y preciso es muy importante para la investigación, ya que la disponibilidad y tamaño de los conjuntos NGS continua creciendo. En este trabajo presentamos una paralelización eficiente para el alineamiento de secuencias cortas de NGS en sistemas con nodos de múltiples núcleos de computación. Nuestra aproximación se aprovecha de un modelo de programación distribuida-compartida basado en el nuevo lenguaje UPC++. Los resultados experimentales usando el alineador CUSHAW3 muestran que nuestra implementación basada en reparto dinámico de trabajo obtiene buena escalabilidad. En nuestra evaluación somos capaces de completar alineamientos sencillos y en parejas de 246 millones de secuencias de longitud 150 en 11.54 y 16.64 minutos, respectivamente, usando 32 nodos con cuatro AMD Opteron 6272 y 16 núcleos de CPU cada uno. Sin embargo, la herramienta multi-hilo original necesita 2.77 y 5.54 horas para completar los mismos alineamientos en los 64 núcleos de un nodo. El código fuente de nuestra implementación paralela está disponible públicamente en la web de CUSHAW3 (http://cushaw3.sourceforge.net).[Resumo]: O medre dos conxuntos de datos de "secuenzamento de próxima xeración" (NGS polas súas siglas en inglés) é un reto respecto á calidade e á velocidade dos aliñamentos de secuencias a xenomas de referencia. Algúns aliñadores disponibles obteñen mapeados de alta calidade a expensas de largos tempos de execución. Desenvolver software rápido e preciso é moi importante para a investigación, xa que a disponibilidade e tamaño dos conxuntos NGS continua a medrar. Neste traballo presentamos unha paralelización eficiente para o aliñamiento de secuencias cortas de NGS en sistemas con nodos de múltiples núcleos de computación. A nosa aproximación aproveitase dun modelo de programación distribuida-compartida basado na nova linguaxe UPC++. Os resultados experimentais que fan uso do aliñador CUSHAW3 mostran que a nosa implementación baseada en reparto dinámico de traballo obtén boa escalabilidade. Na nosa avaliación somos capaces de completar aliñamentos sinxelos e en parellas de 246 millóns de secuencias de lonxitude 150 en 11.54 e 16.64 minutos, respectivamente, empregando 32 nodos con catro AMD Opteron 6272 e 16 núcleos de CPU cada un. Sen embargo, a ferramenta multi-fío oxiginal necesita 2.77 e 5.54 horas para completar os mesmos aliñamientos nos 64 núcleos dun nodo. O código fonte da nosa implementación paralela está disponible públicamente na web de CUSHAW3 (http://cushaw3.sourceforge.net)