Abstract
The computational power of graphics processing units (GPUs) and their availability on high performance computing (HPC) systems is rapidly evolving. However, HPC applications need to be ported to be executable on such hardware. This paper is a report on our experience of porting the MPI + OpenMP parallelized large-eddy simulation model (PALM) to a multi-GPU environment using the directive based high level programming paradigm OpenACC. PALM is a Fortran-based computational fluid dynamics software package, used for the simulation of atmospheric and oceanic boundary layers to answer questions linked to fundamental atmospheric turbulence research, urban climate, wind energy and cloud physics. Development on PALM started in 1997, the project currently entails 140 kLOC and is used on HPC farms of up to 43200 cores. The porting took place during the GPU Hackathon TU Dresden/Forschungszentrum Jülich in Dresden, Germany, in 2016. The main challenges we faced are the legacy code base of PALM and its size. We report the methods used to disentangle performance effects from logical code defects as well as our experiences with state-of-the-art profiling tools. We present detailed performance tests showing an overall performance on one GPU that can easily compete with up to ten CPU cores.
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The C++ reference is available online at http://en.cppreference.com/w/.
References
TOP500 Supercomputer Site. http://www.top500.org/list/2015/11/
Adams, J.C., Brainerd, W.S., Martin, J.T., Smith, B.T., Wagener, J.L.: Fortran 95 Handbook: Complete ISO/ANSI Reference. MIT Press, Cambridge (1998)
Doar, M.B.: Practical Development Environments. O’Reilly Media Inc., Sebastopol (2005)
Feathers, M.C.: Working effectively with legacy code. In: Zannier, C., Erdogmus, H., Lindstrom, L. (eds.) XP/Agile Universe 2004. LNCS, vol. 3134, p. 217. Springer, Heidelberg (2004). http://dx.doi.org/10.1007/978-3-540-27777-4_42
Gronemeier, T., Inagaki, A., Gryschka, M., Kanda, M.: Large-eddy simulation of an urban canopy using a synthetic turbulence inflow generation method. JJSCE B1 71(4), I_43–I_48 (2015). http://dx.doi.org/10.2208/jscejhe.71.i_43
Hoffmann, F., Raasch, S., Noh, Y.: Entrainment of aerosols and their activation in a shallow cumulus cloud studied with a coupled LCM-LES approach. Atmos. Res. 156, 43–57 (2015). http://dx.doi.org/10.1016/j.atmosres.2014.12.008
Knigge, C., Raasch, S.: Improvement and development of one- and two-dimensional discrete gust models using a large-eddy simulation model. J. Wind Eng. Ind. Aerodyn. 153, 46–59 (2016). http://dx.doi.org/10.1016/j.jweia.2016.03.004
Knigge, C., Auerswald, T., Raasch, S., Bange, J.: Comparison of two methods simulating highly resolved atmospheric turbulence data for study of stall effects. Comput. Fluids 108, 57–66 (2015). http://dx.doi.org/10.1016/j.compfluid.2014.11.005
Knüpfer, A., Brunst, H., Doleschal, J., Jurenz, M., Lieber, M., Mickler, H., Müller, M.S., Nagel, W.E.: The Vampir performance analysis tool-set. In: Resch, M., Keller, R., Himmler, V., Krammer, B., Schulz, A. (eds.) Tools for High Performance Computing, pp. 139–155. Springer, Heidelberg (2008). http://dx.doi.org/10.1007/978-3-540-68564-7_9
Knüpfer, A., Rössel, C., an Mey, D., Biersdorff, S., Diethelm, K., Eschweiler, D., Geimer, M., Gerndt, M., Lorenz, D., Malony, A., Nagel, W.E., Oleynik, Y., Philippen, P., Saviankou, P., Schmidl, D., Shende, S., Tschüter, R., Wagner, M., Wesarg, B., Wolf, F.: Score-P: a joint performance measurement run-time infrastructure for Periscope, Scalasca, TAU, and Vampir. In: Brunst, H., Müller, M.S., Nagel, W.E., Resch, M.M. (eds.) Tools for High Performance Computing 2011, pp. 79–91. Springer, Heidelberg (2012). http://dx.doi.org/10.1007/978-3-642-31476-6_7
Krizhevsky, A., Sutskever, I., Hinton, G.E.: ImageNet classification with deep convolutional neural networks. In: Pereira, F., Burges, C.J.C., Bottou, L., Weinberger, K.Q. (eds.) Advances in Neural Information Processing Systems, vol. 25, pp. 1097–1105. Curran Associates, Inc. (2012). http://papers.nips.cc/paper/4824-imagenet-classification-with-deep-convolutional-neural-networks.pdf
Letzel, M.O., Helmke, C., Ng, E., An, X., Lai, A., Raasch, S.: LES case study on pedestrian level ventilation in two neighbourhoods in Hong Kong. Meteorol. Z. 21(6), 575–589 (2012). http://dx.doi.org/10.1127/0941-2948/2012/0356
Maronga, B., Gryschka, M., Heinze, R., Hoffmann, F., Kanani-Sühring, F., Keck, M., Ketelsen, K., Letzel, M.O., Sühring, M., Raasch, S.: The Parallelized Large-Eddy Simulation Model (PALM) version 4.0 for atmospheric and oceanic flows: model formulation recent developments, and future perspectives. Geosci. Model Dev. 8(8), 2515–2551 (2015). http://dx.doi.org/10.5194/gmd-8-2515-2015
Maronga, B., Hartogensis, O.K., Raasch, S., Beyrich, F.: The effect of surface heterogeneity on the structure parameters of temperature and specific humidity: a large-eddy simulation case study for the LITFASS-2003 experiment. Bound. Layer Meteorol. 153(3), 441–470 (2014). http://dx.doi.org/10.1007/s10546-014-9955-x
Martin, K., Hoffman, B.: Mastering CMake, 4th edn. Kitware Inc., New York (2008)
an Mey, D., Biersdorff, S., Bischof, C., Diethelm, K., Eschweiler, D., Gerndt, M., Knüpfer, A., Lorenz, D., Malony, A.D., Nagel, W.E., Oleynik, Y., Rössel, C., Saviankou, P., Schmidl, D., Shende, S.S., Wagner, M., Wesarg, B., Wolf, F.: Score-P: a unified performance measurement system for petascale applications. In: Bischof, C., Hegering, H.-G., Nagel, W.E., Wittum, G. (eds.) Competence in High Performance Computing 2010, pp. 85–97. Springer, Heidelberg (2012). http://www.springerlink.com/content/t041605372024474/?MUD=MP
OpenACC-Standard.org: The OpenACC Application Programming Interface, 2.5 edn. (2015). http://www.openacc.org/sites/default/files/OpenACC_2pt5.pdf
Páll, S., Abraham, M.J., Kutzner, C., Hess, B., Lindahl, E.: Tackling exascale software challenges in molecular dynamics simulations with GROMACS. In: Markidis, S., Laure, E. (eds.) EASC 2014. LNCS, vol. 8759, pp. 3–27. Springer, Heidelberg (2015). http://dx.doi.org/10.1007/978-3-319-15976-8_1
PGI: PGI CUDA Fortran Compiler. http://www.pgroup.com/resources/cudafortran.htm
Reid, J.: The new features of Fortran 2003. SIGPLAN Fortran Forum 26(1), 10–33 (2007). http://dx.doi.org/10.1145/1243413.1243415
Stallman, R.M., McGrath, R., Smith, P.D.: GNU make: a program for directing recompilation, for version 3.81. Free Software Foundation (2004)
Acknowledgments
We would like to thank the Oak Ridge National Laboratory (US), Nvidia Corporation Inc. (US), the Portland Group Inc. (US), the standards OpenACC committee as well as the Center for Information Services and High Performance Computing (ZIH) at Technische Universität Dresden and the Forschungszentrum Jülich for organizing the OpenACC Hackathon in March 2016. We would like to thank personally Fernanda Foertter, Guido Juckeland and Dirk Pleiter for organizing the Hackathon in Dresden. Further, we express our deep gratitude to Dave Norton (Portland Group) and Alexander Grund (HZDR; Rossendorf) for their instrumental contribution as members of the mentoring team during the Hackathon. The author team consists of three PALM developers (Knoop, Gronemeier, and Knigge) and one mentor of the Hackathon (Steinbach).
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Knoop, H., Gronemeier, T., Knigge, C., Steinbach, P. (2016). Porting the MPI Parallelized LES Model PALM to Multi-GPU Systems – An Experience Report. In: Taufer, M., Mohr, B., Kunkel, J. (eds) High Performance Computing. ISC High Performance 2016. Lecture Notes in Computer Science(), vol 9945. Springer, Cham. https://doi.org/10.1007/978-3-319-46079-6_35
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