Vienna FORTRAN: A FORTRAN language extension for distributed memory multiprocessors

Exploiting the performance potential of distributed memory machines requires a careful distribution of data across the processors. Vienna FORTRAN is a language extension of FORTRAN which provides the user with a wide range of facilities for such mapping of data structures. However, programs in Vienna FORTRAN are written using global data references. Thus, the user has the advantage of a shared memory programming paradigm while explicitly controlling the placement of data. The basic features of Vienna FORTRAN are presented along with a set of examples illustrating the use of these features

High performance FORTRAN without templates: An alternative model for distribution and alignment

Language extensions of FORTRAN are being developed which permit the user to map data structures to the individual processors of distributed memory machines. These languages allow a programming style in which global data references are used. Current efforts are focussed on designing a common basis for such languages, the result of which is known as High Performance Fortran (HPF). One of the central debates in the HPF effort revolves around the concept of templates, introduced as an abstract index space to which data could be aligned. A model for the mapping of data which provides the functionality of High Performance Fortran distributions without the use of templates is presented

A medical geography of endemic goiter in central java

In short, the case study village, already a recipient of iodine supplement efforts is clearly one where the endemic goiter has a large component of active goitrogens in the diet. Prophylaxis based entirely on the hypothesis of absolute iodine deficiency can be overridden by excess iodine. A recommendation is made for government health planners and agencies to carefully investigate the possibility of goitrogens in the diet at the time of the initial goiter survey. A goiter prevention policy should then be develoved for each community which includes an appropriate emphasis on iodine supplements and diet modification

Identification and management of the hyperactive child

It was the purpose of this paper to present and explore an overview of the hyperactive child, how he can be identified and possible means of managing his behavior to assure his development as a whole person and a contributor to society

The roles, skills, training needs and contributions of health library and information professionals

This study aimed to record the experiences of health information professionals practising across Europe, to provide data to aid career planning, support strategic decision-making for information services, and understand the impact health professionals have. Interviews, surveys, and focus groups were used to gather data to understand the roles of information professionals, and how they support healthcare. Roles have developed, encompassing healthcare challenges, often embracing technologies and pushing the boundaries of traditional library roles. Respondents demonstrated the impact mainly through their evidence based skills. This study enhances our understanding of the complexity of the domain, how it is evolving and impacting on healthcare

Center for Programming Models for Scalable Parallel Computing - Towards Enhancing OpenMP for Manycore and Heterogeneous Nodes

OpenMP was not well recognized at the beginning of the project, around year 2003, because of its limited use in DoE production applications and the inmature hardware support for an efficient implementation. Yet in the recent years, it has been graduately adopted both in HPC applications, mostly in the form of MPI+OpenMP hybrid code, and in mid-scale desktop applications for scientific and experimental studies. We have observed this trend and worked deligiently to improve our OpenMP compiler and runtimes, as well as to work with the OpenMP standard organization to make sure OpenMP are evolved in the direction close to DoE missions. In the Center for Programming Models for Scalable Parallel Computing project, the HPCTools team at the University of Houston (UH), directed by Dr. Barbara Chapman, has been working with project partners, external collaborators and hardware vendors to increase the scalability and applicability of OpenMP for multi-core (and future manycore) platforms and for distributed memory systems by exploring different programming models, language extensions, compiler optimizations, as well as runtime library support

Extending HPF for advanced data parallel applications

The stated goal of High Performance Fortran (HPF) was to 'address the problems of writing data parallel programs where the distribution of data affects performance'. After examining the current version of the language we are led to the conclusion that HPF has not fully achieved this goal. While the basic distribution functions offered by the language - regular block, cyclic, and block cyclic distributions - can support regular numerical algorithms, advanced applications such as particle-in-cell codes or unstructured mesh solvers cannot be expressed adequately. We believe that this is a major weakness of HPF, significantly reducing its chances of becoming accepted in the numeric community. The paper discusses the data distribution and alignment issues in detail, points out some flaws in the basic language, and outlines possible future paths of development. Furthermore, we briefly deal with the issue of task parallelism and its integration with the data parallel paradigm of HPF

Evaluating Performance of OpenMP Tasks in a Seismic Stencil Application

Simulations based on stencil computations (widely used in geosciences) have been dominated by the MPI+OpenMP programming model paradigm. Little effort has been devoted to experimenting with task-based parallelism in this context. We address this by introducing OpenMP task parallelism into the kernel of an industrial seismic modeling code, Minimod. We observe that even for these highly regular stencil computations, taskified kernels are competitive with traditional OpenMP-augmented loops, and in some experiments tasks even outperform loop parallelism. This promising result sets the stage for more complex computational patterns. Simulations involve more than just the stencil calculation: a collection of kernels is often needed to accomplish the scientific objective (e.g., I/O, boundary conditions). These kernels can often be computed simultaneously; however, implementing this simultaneous computation with traditional programming models is not trivial. The presented approach will be extended to cover simultaneous execution of several kernels, where we expect to fully exploit the benefits of task-based programming

A Team-Based Methodology of Memory Hierarchy-Aware Runtime Support in Coarray Fortran

International audience—We describe how 2-level memory hierarchies can be exploited to optimize the implementation of teams in the parallel facet of the upcoming Fortran 2015 standard. We focus on reducing the cost associated with moving data within a computing node and between nodes, finding that this distinction is of key importance when looking at performance issues. We introduce a new hardware-aware approach for PGAS, to be used within a runtime system, to optimize the communications in the virtual topologies and clusters that are binding different teams together. We have applied, and implemented into the CAF OpenUH compiler, this methodology to three important collective operations, namely barrier, all-to-all reduction and one-to-all broadcast; this is the first Fortran compiler that both provides teams and handles such a memory hierarchy methodology within teams I. INTRODUCTION The emergence of many-core computing nodes in large-scale distributed systems requires programming model im-plementers to consider more carefully memory hierarchy when looking at performance issues. Most parallel applications are programmed using the Message Passing Interface (MPI) [1], where multiple processes execute in a coordinated manner, communicating by performing send and receive operations. More recently, several languages and libraries have added support for explicit or implicit remote memory access (RMA) using so-called " one-sided communication " , including languages following the Partitioned Global Address Space (PGAS) paradigm as well as MPI (MPI-2 added RMA to the interface and MPI-3 made significant refinements to better support it). Of special note is the Fortran 2008 addition for supporting coarrays, a language mechanism that enables RMA as a natural extension to Fortran's array syntax, informally named CAF 1. In this paradigm, an image is an executing process in a Single Program Multiple Data (SPMD) program with its own cop