POSIX Threads and OpenMP were used to implement parallelism in the nuclear reactor transient analysis code PARCS on multiprocessor SUN and SGI workstations. The achievable parallel performance for practical applications is compared for each of the code modules using POSIX threads and OpenMP. A detailed analysis of the cache misses was performed on the SGI to explain the observed performance. Co...

In this paper we present the general approach adopted in the INTONE project for performance analysis and optimization of OpenMP applications. The approach considers the following components: runtime interface (instrumentation and threading support) and its library implementation, compilation environments for Fortran90 and C/C++, and an extension of the VAMPIR graphical tool. The paper also incl...

This paper presents a new version of the OMPi OpenMP C compiler, enhanced by lightweight runtime support based on user-level multithreading. A large number of threads can be spawned for a parallel region and multiple levels of parallelism are supported efficiently, without introducing additional overheads to the OpenMP library. Management of nested parallelism is based on an adaptive distributi...

Tuning parallel code can be a time-consuming and difficult task. We present our approach to automate the performance analysis of OpenMP applications that is based on the notion of performance properties. Properties are formally specified in the APART specification language (ASL) with respect to a specific data model. We describe a data model for summary (profiling) data of OpenMP applications a...

Programs written in C++ and OpenMP are still relatively rare. This paper shows some problems with the current state of the OpenMP specification regarding C++. We illustrate the problems with various implementations of the singleton pattern, measure their performance and describe workarounds and possible changes to the specification. The singletons are available in the AthenaMP open-source project.

This paper proposes an interactive parallelizing assistance tool for OpenMP called iPat/OMP. This tool provides users with the assistance needed for OpenMP parallelization of a sequential program. All of the assistance capabilities are implemented as Emacs functions and are available in the Emacs editor environment in an interactive manner.

In this paper, we introduce a design and implementation of the free agent threads for OpenMP. These increase malleability OpenMP programming model, offering resource managers runtime systems flexibility to manage resources efficiently. We demonstrate how can address load imbalances problems at level an MPI or higher. use two mini-apps extracted from real HPC applications representative real-wor...

Approaching the theoretical performance of hierarchical multicore machines requires a very careful distribution of threads and data among the underlying non-uniform architecture in order to minimize cache misses and NUMA penalties. While it is acknowledged that OpenMP can enhance the quality of thread scheduling on such architectures in a portable way, by transmitting precious information about...

With the increasing popularity of small to large-scale symmetric multiprocessor (SMP) systems, there has been a dire need to have sophisticated, and flexible development and runtime environments for efficient and rapid development of parallel applications. To this end, OpenMP has emerged as the standard for parallel programming on shared-memory systems. It is very important to evaluate the perf...