The OpenMP standard was conceived to parallelize dense array-based applications, and it has achieved much success with that. Recently, a novel tasking proposal to handle unstructured parallelism in OpenMP has been submitted to the OpenMP 3.0 Language Committee. We tested its expressiveness and flexibility, using it to parallelize a number of examples from a variety of different application area...

The OpenMP memory model allows for a temporary view of shared memory that only needs to be made consistent when barrier or flush directives, including those that are implicit, are encountered. While this relaxed memory consistency model is key to developing cluster OpenMP implementations, it means that the memory performance of any given implementation is greatly affected by which memory is use...

Sparse and unstructured computations are widely used in Scientific and Engineering Applications. Such problem inherent in sparse and unstructured computations is called irregular problem. In this paper, we propose some extensions to OpenMP directives, aiming at efficient irregular OpenMP codes to be executed in parallel. These OpenMP directives include scheduling for irregular loops, inspector/...

Analyzing the scalability behavior and the overheads of OpenMP applications is an important step in the development process of scientific software. Unfortunately, few tools are available that allow an exact quantification of OpenMP related overheads and scalability characteristics. We present a methodology in which we define four overhead categories that we can quantify exactly and describe a t...

OpenMP tasking supports parallelization of irregular algorithms. Recent OpenMP specifications extended tasking to increase functionality and to support optimizations, for instance with the taskloop construct. However, task scheduling remains opaque, which leads to inconsistent performance on NUMA architectures. We assess design issues for task affinity and explore several approaches to enable i...

OpenMP has emerged as a widely accepted standard for writing shared memory programs. Hardware-specific extensions such as data placement are usually needed to improve the scalability of applications based on this standard. This paper investigates the implementation of an OpenMP compiler that supports slipstream execution mode, a new optimization mechanism for CMP-based distributed shared memory...

Parallel programming models are evolving so rapidly that it needs to be ensured that OpenMP can be used easily to program multicore devices. There is also effort involved in getting OpenMP to be accepted as a de facto standard in the embedded system community. However, in order to ensure correctness of OpenMP’s implementation, there is a requirement of an up-to-date validation suite. In this pa...

Chip multiprocessors (CMP) are widely used for high performance computing and are being configured in a hierarchical manner to compose a CMP compute node in a CMP system. Such a CMP system provides a natural programming paradigm for hybrid MPI/OpenMP applications. In this paper, we use OpenMP to parallelize a sequential earthquake simulation code for modeling spontaneous earthquake rupture alon...

Deterministic OpenMP Amittai F. Aviram 2012 Researchers widely agree that determinism in parallel programs is desirable. Although experimental parallel programming languages have long featured deterministic semantics, in mainstream parallel environments, developers still build on nondeterministic constructs such as mutexes, leading to timeor schedule-dependent heisenbugs. To make deterministic ...

Heterogeneous supercomputers that incorporate computational accelerators such as GPUs are increasingly popular due to their high peak performance, energy efficiency and comparatively low cost. Unfortunately, the programming models and frameworks designed to extract performance from all computational units still lack the flexibility of their CPU-only counterparts. Accelerated OpenMP improves thi...