RIKEN Center for Computational Science ANNUAL REPORT A N FY2017 N U A L R E P O R T F RIKEN Advanced Institute for Computational Science Y 2 0 1 7 ANNUAL REPORT FY2017 A I AICS Research Activities C S R e s e a r c h A c t i v i t i e s 7-1-26, Minatojima-minami-machi, Chuo-ku, Kobe, Hyogo 650-0047 Japan https://www.r-ccs.riken.jp/en/ RIKEN 2018-076 Copyright 2018 RIKEN Center for Computational Science AICS was renamed R-CCS in 2018. This reports the activities of AICS in FY 2017. RIKEN AICS Annual Report FY2017 AICS Research Activities February 28, 2019 2 Preface Welcome to the AICS Annual Report for 2017. Our institute, RIKEN AICS, is the Japanese flagship research institution in computational science and is meant to be the center of excellence for various simulation fields such as weather and climate, cosmology, biology, physics, chemistry, engineering etc. We also focus on computer science such as processor design and system software as well as fundamental technologies including programming framework and visualization. By achieving outstanding results through strong collaborations between computer scientists and computational scientists, AICS wants to be a world hub for computer and computational sciences. The K computer started full service in September 2012. In many areas, we see many great results. Many projects that use the K computer would be difficult or impossible to do elsewhere. In addition AICS research teams have developed common computing techniques for utilization of the K computer and coded the very efficient parallelized application program packages. Now the K computer is being used in many different fronts and extending the boundaries of computational science. As you see in this report, our AICS research teams made a great contribution to produce many of these exciting results. The K computer has established massively parallel computation in Japan. The K computer also enhanced the resolution both in precision and the system size significantly through massively parallel computation. In ad- dition, capacity computing opened the possibility of prediction in complex and non-linear/chaotic phenomena. We are now tackling highly complex scientific and social problems with inherent uncertainties and unpredictabil- ity. The way to deal with such uncertainty is to simultaneously run multiple ensembles, using many different combinations of parameters, and thus be able to explore the solution. The K computer significantly enhanced the capacity computing in addition to the capability computing. Supercomputer has become a fundamental technology which supports the society today, and pioneers the society of tomorrow. Continued development of world top-class supercomputer is vital for the world leadership in science and technology. AICS is charged with the development of the post K computer. The flagship 2020 project division is developing a world ’s top-class supercomputer, “ post K ” launching in around 2021 to spearhead the quest for knowledge of human kind, and contribute to the world at large. Our aim is to balance various factors, such as power consumption, computational performance, user con- venience, and ability to produce ground-breaking results. Post K supercomputer will be characterized by its all-round capabilities compared to any other system in the world in the 2020 ’s. The post K will extend the fields pioneered by the K computer and also challenge new areas. We are very looking forward to the post K supercomputer. We hope you enjoy reading all the wonderful advances made by AICS. AICS has been renamed RIKEN-Center for Computational Science (R-CCS). With the new leadership, R- CCS has started a new era as the world ’s leading center of high-performance computing. We appreciate your continued support. Kimihiko Hirao, Director 3 Organization Application Tuning Development Team HPC Usability Development Team ii Contents I Research Division 13 1 System Software Research Team 15 1.1 Members ................................................. 15 1.2 Research Activities ............................................ 15 1.3 Research Results and Achievements .................................. 15 1.3.1 Persistent Collectives ....................................... 15 1.3.2 Data Transfer Framework .................................... 17 1.3.3 Sharing Virtual Address Space ................................. 20 1.3.4 IHK/McKernel .......................................... 22 1.3.5 Utility Thread Offloading Interface ............................... 25 1.4 Schedule and Future Plan ........................................ 26 1.5 Publications ................................................ 26 2 Programming Environment Research Team 29 2.1 Members ................................................. 29 2.2 Research Activities ............................................ 29 2.3 Research Results and Achievements .................................. 31 2.3.1 XcalableACC for Lattice QCD ................................. 31 2.3.2 XcalableMP 2.0 for task-parallelism in distributed memory systems ............ 33 2.3.3 SPPEXA MXY project ..................................... 37 2.3.4 Performance study of NEST on K computer using Scalasca ................. 38 2.4 Schedule and Future Plan ........................................ 38 2.5 Publications ................................................ 39 2.5.1 Journal Articles .......................................... 39 2.5.2 Conference Papers ........................................ 39 2.5.3 Invited Talks ........................................... 39 2.5.4 Posters and Presentations .................................... 40 2.5.5 Patents and Deliverables ..................................... 40 3 Processor Research Team 41 3.1 Members ................................................. 41 3.2 Research Activities ............................................ 41 3.2.1 Data-flow accelerators with custom computing circuits on FPGAs ............. 42 3.2.2 Data-flow hardware compiler for custom computing with FPGA .............. 43 3.2.3 Hardware-based bandwidth compressor ............................ 44 3.3 Schedule and Future Plan ........................................ 45 3.3.1 Articles .............................................. 46 3.3.2 Invited Talks ........................................... 46 3.3.3 Papers (non-reviewed) ...................................... 46 3.3.4 Other publications ........................................ 47 5 6 CONTENTS 4 Large-scale Parallel Numerical Computing Technology Research Team 49 4.1 Members ................................................. 49 4.2 Research Activities ............................................ 50 4.2.1 Communication avoiding optimization ............................. 50 4.2.2 New scheduling policy based on a Batched BLAS ....................... 51 4.2.3 Block Jacobi eigensolver ..................................... 51 4.2.4 Sparse tensor decomposition ................................... 52 4.2.5 Energy efficient FPGA-based matrix multiplier ........................ 53 4.2.6 Other activities .......................................... 54 4.3 Schedule and Future Plan ........................................ 54 4.4 Publications ................................................ 55 4.4.1 Articles .............................................. 55 4.4.2 Oral talks and Poster presentations ............................... 56 4.4.3 Invited Talks ........................................... 57 4.4.4 Software .............................................. 57 5 HPC Usability Research Team 59 5.1 Members ................................................. 59 5.2 Research Activities ............................................ 59 5.2.1 Simulation of K Computer Cooling Facilities ......................... 60 5.2.2 Efficient Execution of Simulations for Reinforcement Learning ................ 60 5.2.3 Other Activities ......................................... 61 5.3 Schedule and Future Plan ........................................ 62 5.4 Publications ................................................ 62 5.4.1 Patents .............................................. 62 5.4.2 Invited Talks ........................................... 62 5.4.3 Presentations ........................................... 62 6 Field Theory Research Team 63 6.1 Members ................................................. 63 6.2 Research Activities ............................................ 63 6.2.1 QCD at finite temperature and finite density ......................... 64 6.2.2 Nucleon form factors ....................................... 64 6.2.3 Tensor network scheme in path-integral formalism ...................... 65 6.3 Schedule and Future Plan ........................................ 66 6.3.1 QCD at finite temperature and finite density ......................... 66 6.3.2 Nucleon form factors ....................................... 66 6.3.3 Tensor network scheme in path-integral formalism ...................... 66 6.4 Publications ................................................ 66 6.4.1 Articles .............................................. 66 6.4.2 Conference Papers ........................................ 67 6.4.3 Invited talks ........................................... 67 6.4.4 Posters and Presentations .................................... 68 7 Discrete-Event Simulation Research Team 69 7.1 Members ................................................. 69 7.2 Research Activities ............................................ 69 7.2.1 Parameter-space explorer: OACIS and CARAVAN ...................... 70 7.2.2 Social