We present TaskTorrent, a lightweight distributed task-based runtime in C++. TaskTorrent uses a parametrized task graph to express the task DAG, and one-sided active messages to trigger remote tasks asynchronously. As a result the task DAG is completely distributed and discovered in parallel. It is a C++14 library and only depends on MPI. We explain the API and the implementation. We perform a series of benchmarks against StarPU and ScaLAPACK. Micro benchmarks show it has a minimal overhead compared to other solutions. We then apply it to two large linear algebra problems. TaskTorrent scales very well to thousands of cores, exhibiting good weak and strong scalings.
Cite
@article{arxiv.2009.10697,
title = {TaskTorrent: a Lightweight Distributed Task-Based Runtime System in C++},
author = {Léopold Cambier and Yizhou Qian and Eric Darve},
journal= {arXiv preprint arXiv:2009.10697},
year = {2020}
}