Abstract
Designing and refactoring complex scientific code, such as the E3SM land model (ELM), for new computing architectures is challenging. This paper presents design strategies and technical approaches to develop a data-oriented, GPU-ready ELM model using compiler directives (OpenACC/OpenMP). We first analyze the datatypes and processes in the original ELM code. Then we present design considerations for ultrahigh-resolution ELM (uELM) development for massive GPU systems. These techniques include the global data-oriented simulation workflow, domain partition, code porting and data copy, memory reduction, parallel loop restructure and flattening, and race condition detection. We implemented the first version of uELM using OpenACC targeting the NVidia GPUs in the Summit supercomputer at Oak Ridge National Laboratory. During the implementation, we developed a software tool (named SPEL) to facilitate code generation, verification, and performance tuning using these techniques. The first uELM implementation for Nvidia GPUs on Summit delivered promising results: 1) over 98% of the ELM code was automatically generated and tuned by scripts. Most ELM modules had better computational performances than the original ELM code for CPUs. The GPU-ready uELM is more scalable than the CPU code on fully-loaded Summit nodes. Example profiling results from several modules are also presented to illustrate the performance improvements and race condition detection. The lessons learned and toolkit developed in the study are also suitable for further uELM deployment using OpenMP on the first US exascale computer, Frontier, equipped with AMD CPUs and GPUs.
Original language | English |
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Title of host publication | Computational Science and Its Applications – ICCSA 2023 - 23rd International Conference, Proceedings |
Editors | Osvaldo Gervasi, Beniamino Murgante, David Taniar, Bernady O. Apduhan, Ana Cristina Braga, Chiara Garau, Anastasia Stratigea |
Publisher | Springer Science and Business Media Deutschland GmbH |
Pages | 277-290 |
Number of pages | 14 |
ISBN (Print) | 9783031368042 |
DOIs | |
State | Published - 2023 |
Event | 23rd International Conference on Computational Science and Its Applications , ICCSA 2023 - Athens, Greece Duration: Jul 3 2023 → Jul 6 2023 |
Publication series
Name | Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) |
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Volume | 13956 LNCS |
ISSN (Print) | 0302-9743 |
ISSN (Electronic) | 1611-3349 |
Conference
Conference | 23rd International Conference on Computational Science and Its Applications , ICCSA 2023 |
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Country/Territory | Greece |
City | Athens |
Period | 07/3/23 → 07/6/23 |
Funding
Acknowledgments. This work has been supported by FCT - Funda¸cão para a Ciência e Tecnologia within the R&D Units Project Scope: UIDB/00319/2020 and the project “QOMPASS .: Solu¸cão de Gestão de Servi¸cos de Atendimento multi-entidade, multi-servi¸co e multi-idioma” within the Project Scope NORTE-01-0247-FEDER-038462. Acknowledgments. This study was grant No. 21-71-00039. Acknowledgement. This work was supported in part by Sunway University and Sunway Business School under Kick Start Grant Scheme (KSGS) NO: GRTIN-KSGS-DBA[S]-02-2022. This work is also part of the Sustainable Business Research Cluster and Research Centre for Human-Machine Collaboration (HUMAC) at Sunway University. We also wish to thank those who have supported this research. Supported by organization Conselho Nacional de Desenvolvimento Científico e Tec-nológico (CNPq). Acknowledgements. This study was financed in part by the Coordena¸cão de Aper-fei¸coamento de Pessoal de Ńıvel Superior - Brasil (CAPES). ICCSA 2023 was organized by the National Technical University of Athens (Greece), the University of the Aegean (Greece), the University of Perugia (Italy), the University of Basilicata (Italy), Monash University (Australia), Kyushu Sangyo University (Japan), the University of Minho (Portugal). The conference was supported by two NTUA Schools, namely the School of Rural, Surveying and Geoinformatics Engineering and the School of Electrical and Computer Engineering. This study was nanced in part by the Coordenac ao de Aperfeicoamento de Pessoal de Nvel Superior - Brasil (CAPES) - Finance Code 001. This work was partially funded by CNPq, CAPES, FINEP and Fapemig. Acknowledgement. This research was supported by the MUNI Award in Science and Humanities (MASH Belarus) of the Grant Agency of Masaryk University under the Digital City project (MUNI/J/0008/2021). The work of Stanislav Sobolevsky was also partially supported by ERDF “CyberSecurity, CyberCrime and Critical Information Infrastructures Center of Excellence” (No. CZ.02.1.01/0.0/0.0/16 019/0000822). Acknowledgements. The author sincerely acknowledges the financial support under Supported by organization LNCC/SEPAD. University of Perugia, Italy Universidade Nova de Lisboa, Portugal University of Beira Interior, Portugal University of Almeria, Spain University of Salerno, Italy Erciyes University, Turkey University of Naples “Federico II”, Italy Sungkyunkwan University, Korea Sunway University, Malaysia Sungkyunkwan University, Korea Polytechnic Institute of Viana do Castelo, Portugal Federal University of Bahia, Brazil INFN, Italy Universidade Federal do Rio Grande do Sul, Brazil The Council for Scientific and Industrial Research (CSIR), South Africa Instituto Tecnológico de Informática, Spain Kausan University of Technology, Lithuania London South Bank University, UK Memorial University of Newfoundland, Canada University of Coimbra, Portugal University of L’Aquila, Italy NetApp, India/USA University of Perugia, Italy University of Minho, Portugal U.S. DOE Ames Laboratory, USA Polytechnic Institute of Bragança, Portugal National Centre for Biotechnology, CSIS, Spain Polytechnic Institute of Bragança, Portugal University of Aveiro, Portugal by the Russian Science Foundation Acknowledgements. The authors would like to thank Conselho Nacional de Desen-volvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pes-soal de Nível Superior (Capes) and Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) for their financial support. Supported by the Government of Spain, Department of Science, Innovation and Universities; European Commision project: PID2021-125871NB-I00.
Keywords
- Compiler Directives
- E3SM Land Model
- Exascale Energy Earth System Model
- OpenACC
- Ultrahigh-Resolution ELM