In this paper we present our work on the the parallelization of a matrix multiplication code based on the hypermatrix data structure. We have used OpenMP for the parallelization. We have added OpenMP directives to a few loops and experimented with several features available with OpenMP in the Intel Fortran Compiler: scheduling algorithms, chunk sizes and nested parallelism. We found that the lo...

The OpenMP Architecture Review Board has released version 2.0 of the OpenMP Fortran language specification in November 2000, and version 2.0 of the OpenMP C/C++ language specification in March 2002. This paper discusses the implementation of the OpenMP Fortran 2.0 WORKSHARE construct, NUM THREADS clause, COPYPRIVATE clause, and array REDUCTION clause in the Parallelnavi software package. We foc...

Recent deterministic parallel programming models show promise for their ability to replay computations and reproduce bugs, but they currently require the programmer to adopt restrictive or unfamiliar parallel constructs. Deterministic OpenMP (DOMP) is a new deterministic parallel environment built on the familiar OpenMP framework. By leveraging OpenMP’s block-structured synchronization annotati...

A so-called SPMD style OpenMP program can achieve scalability on ccNUMA systems by means of array privatization, and earlier research has shown good performance under this approach. Since it is hard to write SPMD OpenMP code, we showed a strategy for the automatic translation of many OpenMP constructs into SPMD style in our previous work. In this paper, we first explain how to ensure that the O...

The introduction of tasks in the OpenMP programming model brings a new level of parallelism. This also creates new challenges with respect to its meanings and applicability through an event-based performance profiling. The OpenMP Architecture Review Board (ARB) has approved an interface specification known as the “OpenMP Runtime API for Profiling” to enable performance tools to collect performa...

In this paper, we present an alternative implementation of the NANOS OpenMP runtime library (NthLib) that targets portability and efficient support of multiple levels of parallelism. We have implemented the runtime libraries of available opensource OpenMP compilers on top of NthLib, reducing thus their overheads and providing them with inherent support for nested parallelism. In addition, we pr...

OpenMP is a successful approach to writing threaded parallel applications. This article describes the state of the art in performance profiling OpenMP applications, covering vendor performance tools and platform independent techniques. The features of the OpenMP profiler ompP are described in detail and an outlook of future directions in this area is given.

We present a set of extensions to an existing microbenchmark suite for OpenMP. The new benchmarks measure the overhead of the task construct introduced in the OpenMP 3.0 standard, and associated task synchronisation constructs. We present the results from a variety of compilers and hardware platforms, which demonstrate some significant differences in performance between different OpenMP impleme...

Tasking in OpenMP 3.0 allows irregular parallelism to be expressed much more easily and it is expected to be a major step towards the widespread adoption of OpenMP for multicore programming. We discuss the issues encountered in providing monitoring support for tasking in an existing OpenMP profiling tool with respect to instrumentation, measurement, and result presentation.

A recent trend in mainstream computer nodes is the combined use of general-purpose multicore processors and specialized accelerators such as GPUs and DSPs in order to achieve better performance and to reduce power consumption. To support this trend, the OpenMP Language Committee has approved a set of extensions to OpenMP (referred to as the OpenMP accelerator model). The initial version is the ...