Argobots: A Lightweight Low-Level Threading and Tasking Framework

• Published in: IEEE transactions on parallel and distributed systems Vol. 29; no. 3; pp. 512 - 526
• Main Authors: Sangmin Seo, Amer, Abdelhalim, Balaji, Pavan, Bordage, Cyril, Bosilca, George, Brooks, Alex, Carns, Philip, Castello, Adrian, Genet, Damien, Herault, Thomas, Iwasaki, Shintaro, Jindal, Prateek, Kale, Laxmikant V., Krishnamoorthy, Sriram, Lifflander, Jonathan, Huiwei Lu, Meneses, Esteban, Snir, Marc, Yanhua Sun, Taura, Kenjiro, Beckman, Pete
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.03.2018; The Institute of Electrical and Electronics Engineers, Inc. (IEEE); Institute of Electrical and Electronics Engineers
• Subjects: Argobots; Computer Science; Context; context switch; Distributed, Parallel, and Cluster Computing; End users; ENGINEERING; I/O; Interoperability; Level (quantity); Libraries; Lightweight; Message systems; MPI; OpenMP; Run time (computers); Runtime; stackable scheduler; State of the art; Substrates; Synchronism; Synchronization; tasklet; user-level thread; Weight reduction; Lightweight; OpenMP; Argobots; Stackable scheduler; MPI; I/O; Interoperability; Tasklet; Context switch; User-level thread
• ISSN: 1045-9219; 1558-2183
• DOI: 10.1109/TPDS.2017.2766062

In the past few decades, a number of user-level threading and tasking models have been proposed in the literature to address the shortcomings of OS-level threads, primarily with respect to cost and flexibility. Current state-of-the-art user-level threading and tasking models, however, either are too specific to applications or architectures or are not as powerful or flexible. In this paper, we present Argobots, a lightweight, low-level threading and tasking framework that is designed as a portable and performant substrate for high-level programming models or runtime systems. Argobots offers a carefully designed execution model that balances generality of functionality with providing a rich set of controls to allow specialization by end users or high-level programming models. We describe the design, implementation, and performance characterization of Argobots and present integrations with three high-level models: OpenMP, MPI, and colocated I/O services. Evaluations show that (1) Argobots, while providing richer capabilities, is competitive with existing simpler generic threading runtimes; (2) our OpenMP runtime offers more efficient interoperability capabilities than production OpenMP runtimes do; (3) when MPI interoperates with Argobots instead of Pthreads, it enjoys reduced synchronization costs and better latency-hiding capabilities; and (4) I/O services with Argobots reduce interference with colocated applications while achieving performance competitive with that of a Pthreads approach.