Implementation and Evaluation of One-Sided PGAS Communication in XcalableACC for Accelerated Clusters

Tabuchi, Akihiro; Nakao, Masahiro; Murai, Hitoshi; Boku, Taisuke; Sato, Mitsuhisa

doi:10.1109/ccgrid.2017.81

Cited by 3 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Instead, an advantage of the language extension is that new features can be added without being restricted by functions of the original language. For example, the XACC C language also supports coarray features inherited from Fortran 2008 to issue one-sided communication in ease (Tabuchi et al, 2017).…”

Section: Related Researchmentioning

confidence: 99%

Evaluation of XcalableACC with tightly coupled accelerators/InfiniBand hybrid communication on accelerated cluster

Nakao

Odajima

Murai

et al. 2019

The International Journal of High Performance Computing Applica

Self Cite

View full text Add to dashboard Cite

Accelerated clusters, which are cluster systems equipped with accelerators, are one of the most common systems in parallel computing. In order to exploit the performance of such systems, it is important to reduce communication latency between accelerator memories. In addition, there is also a need for a programming language that facilitates the maintenance of high performance by such systems. The goal of the present article is to evaluate XcalableACC (XACC), a parallel programming language, with tightly coupled accelerators/InfiniBand (TCAs/IB) hybrid communication on an accelerated cluster. TCA/IB hybrid communication is a combination of low-latency communication with TCA and high bandwidth with IB. The XACC language, which is a directive-based language for accelerated clusters, enables programmers to use TCA/IB hybrid communication with ease. In order to evaluate the performance of XACC with TCA/IB hybrid communication, we implemented the lattice quantum chromodynamics (LQCD) mini-application and evaluated the application on our accelerated cluster using up to 64 compute nodes. We also implemented the LQCD mini-application using a combination of CUDA and MPI (CUDA + MPI) and that of OpenACC and MPI (OpenACC + MPI) for comparison with XACC. Performance evaluation revealed that the performance of XACC with TCA/IB hybrid communication is 9% better than that of CUDA + MPI and 18% better than that of OpenACC + MPI. Furthermore, the performance of XACC was found to further increase by 7% by new expansion to XACC. Productivity evaluation revealed that XACC requires much less change from the serial LQCD code to implement the parallel LQCD code than CUDA + MPI and OpenACC + MPI. Moreover, since XACC can perform parallelization while maintaining the sequential code image, XACC is highly readable and shows excellent portability due to its directive-based approach.

show abstract

Section: Related Researchmentioning

confidence: 99%

Evaluation of XcalableACC with tightly coupled accelerators/InfiniBand hybrid communication on accelerated cluster

Nakao

Odajima

Murai

et al. 2019

The International Journal of High Performance Computing Applica

Self Cite

View full text Add to dashboard Cite

show abstract

“…This method achieved better performance than OpenACC + MPI/InfiniBand with the Himeno benchmark, and we demonstrated that the XACC high-level communication description has the capacity to be hardware independent and facilitate high-performance programming. Moreover, we proposed the XACC local-view model [16], which employs a coarray feature for onesided communication on accelerator memories. We implemented both global-view and local-view models using MPI, and evaluated their performance and productivity with the Himeno benchmark and NAS Parallel Benchmarks CG benchmark, as well as discussing their proper use.…”

Section: Related Workmentioning

confidence: 99%

“…We used the PGI compiler as the OpenACC implementation and MVAPICH2 as the MPI implementation. We also used the Omni XACC compiler [10,16], which is a source-to-source XACC compiler based on the Omni compiler infrastructure [14], where Figure 9 shows the compilation flow. An input XACC code was translated into an OpenACC code with XACC runtime calls by using the XACC translator.…”

Section: Performancementioning

confidence: 99%

“…The characteristic feature of XACC is communication between accelerators across nodes, which is not supported by XMP or OpenACC. Previously, we reported that XACC provides good performance and high productivity for some benchmark programs [10,16]. However, in order to assess the usability of XACC, more evaluations are required with various types of practical applications.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Performance evaluation for a hydrodynamics application in XcalableACC PGAS language for accelerated clusters

Tabuchi

Nakao

Murai

et al. 2018

Proceedings of Workshops of HPC Asia

Self Cite

View full text Add to dashboard Cite

Clusters equipped with accelerators such as GPUs and MICs are used widely. To use these clusters, programmers write programs for their applications by combining MPI with one of the accelerator programming models such as CUDA and OpenACC. The accelerator programming component is becoming easier because of a directive-based OpenACC, but complex distributed-memory programming using MPI means that programming is still difficult. In order to simplify the programming process, XcalableACC (XACC) has been proposed as an "orthogonal" integration of the PGAS language XcalableMP (XMP) and OpenACC. XACC provides the original XMP and OpenACC features, as well as their extensions for communication between accelerator memories. In this study, we implemented a hydrodynamics mini-application CloverLeaf in XACC and evaluated the usability of XACC in terms of it performance and productivity. According to the performance evaluation, the XACC version achieved 87-95% of the performance of the MPI+CUDA version and 93-101% of the MPI+OpenACC version with strong scaling, and 88-91% of the MPI+CUDA version and 94-97% of the MPI+OpenACC version with weak scaling. In particular, the halo exchange time was better with XACC than MPI+OpenACC in some cases because the Omni XACC runtime is written in MPI and CUDA, and it is well tuned. The productivity evaluation showed that the application could be implemented after small changes compared with the serial version. These results demonstrate that XACC is a practical programming language for science applications. Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the owner/author(s).

show abstract

Implementing Lattice QCD Application with XcalableACC Language on Accelerated Cluster

Nakao

Murai²,

Iwashita

et al. 2017

2017 IEEE International Conference on Cluster Computing (CLUSTER)

View full text Add to dashboard Cite

Implementation and Evaluation of One-Sided PGAS Communication in XcalableACC for Accelerated Clusters

Cited by 3 publications

References 12 publications

Evaluation of XcalableACC with tightly coupled accelerators/InfiniBand hybrid communication on accelerated cluster

Evaluation of XcalableACC with tightly coupled accelerators/InfiniBand hybrid communication on accelerated cluster

Performance evaluation for a hydrodynamics application in XcalableACC PGAS language for accelerated clusters

Implementing Lattice QCD Application with XcalableACC Language on Accelerated Cluster

Contact Info

Product

Resources

About