Mapping OpenMP to a Distributed Tasking Runtime.

Tasking was introduced in OpenMP 3.0 and every major release since has added features for tasks. However, OpenMP tasks coexist with other forms of parallelism which have influenced the design of their features. HPX is one of a new generation of task-based frameworks with the goal of extreme scalability. It is designed from the ground up to provide a highly asynchronous task-based interface for shared memory that also extends to distributed memory. This work introduces a new OpenMP runtime called OMPX, which provides a means to run OpenMP applications that do not use its accelerator features on top of HPX in shared memory. We describe the OpenMP and HPX execution models, and use microbenchmarks and application kernels to evaluate OMPX and compare their performance.