2 * This file is part of the GROMACS molecular simulation package.
4 * Copyright (c) 2016,2017,2018,2019,2020, by the GROMACS development team, led by
5 * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
6 * and including many others, as listed in the AUTHORS file in the
7 * top-level source directory and at http://www.gromacs.org.
9 * GROMACS is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public License
11 * as published by the Free Software Foundation; either version 2.1
12 * of the License, or (at your option) any later version.
14 * GROMACS is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * Lesser General Public License for more details.
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with GROMACS; if not, see
21 * http://www.gnu.org/licenses, or write to the Free Software Foundation,
22 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
24 * If you want to redistribute modifications to GROMACS, please
25 * consider that scientific software is very special. Version
26 * control is crucial - bugs must be traceable. We will be happy to
27 * consider code for inclusion in the official distribution, but
28 * derived work must not be called official GROMACS. Details are found
29 * in the README & COPYING files - if they are missing, get the
30 * official version at http://www.gromacs.org.
32 * To help us fund GROMACS development, we humbly ask that you cite
33 * the research papers on the package. Check out http://www.gromacs.org.
37 * \brief Implements high-level PME GPU functions which do not require GPU framework-specific code.
39 * \author Aleksei Iupinov <a.yupinov@gmail.com>
40 * \ingroup module_ewald
49 #include "gromacs/ewald/ewald_utils.h"
50 #include "gromacs/ewald/pme.h"
51 #include "gromacs/fft/parallel_3dfft.h"
52 #include "gromacs/math/invertmatrix.h"
53 #include "gromacs/mdlib/gmx_omp_nthreads.h"
54 #include "gromacs/mdtypes/enerdata.h"
55 #include "gromacs/mdtypes/forceoutput.h"
56 #include "gromacs/mdtypes/inputrec.h"
57 #include "gromacs/utility/exceptions.h"
58 #include "gromacs/utility/fatalerror.h"
59 #include "gromacs/utility/gmxassert.h"
60 #include "gromacs/utility/stringutil.h"
62 #include "pme_gpu_internal.h"
63 #include "pme_gpu_settings.h"
64 #include "pme_gpu_timings.h"
65 #include "pme_gpu_types_host.h"
67 #include "pme_internal.h"
68 #include "pme_solve.h"
71 * Finds out if PME is currently running on GPU.
73 * \todo The GPU module should not be constructed (or at least called)
74 * when it is not active, so there should be no need to check whether
75 * it is active. An assertion that this is true makes sense.
77 * \param[in] pme The PME structure.
78 * \returns True if PME runs on GPU currently, false otherwise.
80 static inline bool pme_gpu_active(const gmx_pme_t* pme)
82 return (pme != nullptr) && (pme->runMode != PmeRunMode::CPU);
85 void pme_gpu_reset_timings(const gmx_pme_t* pme)
87 if (pme_gpu_active(pme))
89 pme_gpu_reset_timings(pme->gpu);
93 void pme_gpu_get_timings(const gmx_pme_t* pme, gmx_wallclock_gpu_pme_t* timings)
95 if (pme_gpu_active(pme))
97 pme_gpu_get_timings(pme->gpu, timings);
101 int pme_gpu_get_padding_size(const gmx_pme_t* pme)
104 if (!pme || !pme_gpu_active(pme))
110 return pme_gpu_get_atom_data_alignment(pme->gpu);
115 * A convenience wrapper for launching either the GPU or CPU FFT.
117 * \param[in] pme The PME structure.
118 * \param[in] gridIndex The grid index - should currently always be 0.
119 * \param[in] dir The FFT direction enum.
120 * \param[in] wcycle The wallclock counter.
122 void inline parallel_3dfft_execute_gpu_wrapper(gmx_pme_t* pme,
124 enum gmx_fft_direction dir,
125 gmx_wallcycle_t wcycle)
127 GMX_ASSERT(gridIndex == 0, "Only single grid supported");
128 if (pme_gpu_settings(pme->gpu).performGPUFFT)
130 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
131 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
132 pme_gpu_3dfft(pme->gpu, dir, gridIndex);
133 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
134 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
138 wallcycle_start(wcycle, ewcPME_FFT_MIXED_MODE);
139 #pragma omp parallel for num_threads(pme->nthread) schedule(static)
140 for (int thread = 0; thread < pme->nthread; thread++)
142 gmx_parallel_3dfft_execute(pme->pfft_setup[gridIndex], dir, thread, wcycle);
144 wallcycle_stop(wcycle, ewcPME_FFT_MIXED_MODE);
148 /* The PME computation code split into a few separate functions. */
150 void pme_gpu_prepare_computation(gmx_pme_t* pme,
151 bool needToUpdateBox,
153 gmx_wallcycle* wcycle,
155 bool useGpuForceReduction)
157 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
158 GMX_ASSERT(pme->nnodes > 0, "");
159 GMX_ASSERT(pme->nnodes == 1 || pme->ndecompdim > 0, "");
161 PmeGpu* pmeGpu = pme->gpu;
162 pmeGpu->settings.currentFlags = flags;
163 // TODO these flags are only here to honor the CPU PME code, and probably should be removed
164 pmeGpu->settings.useGpuForceReduction = useGpuForceReduction;
166 bool shouldUpdateBox = false;
167 for (int i = 0; i < DIM; ++i)
169 for (int j = 0; j <= i; ++j)
171 shouldUpdateBox |= (pmeGpu->common->previousBox[i][j] != box[i][j]);
172 pmeGpu->common->previousBox[i][j] = box[i][j];
176 if (needToUpdateBox || shouldUpdateBox) // || is to make the first computation always update
178 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
179 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
180 pme_gpu_update_input_box(pmeGpu, box);
181 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
182 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
184 if (!pme_gpu_settings(pmeGpu).performGPUSolve)
186 // TODO remove code duplication and add test coverage
188 pmeGpu->common->boxScaler->scaleBox(box, scaledBox);
189 gmx::invertBoxMatrix(scaledBox, pme->recipbox);
190 pme->boxVolume = scaledBox[XX][XX] * scaledBox[YY][YY] * scaledBox[ZZ][ZZ];
195 void pme_gpu_launch_spread(gmx_pme_t* pme, GpuEventSynchronizer* xReadyOnDevice, gmx_wallcycle* wcycle)
197 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
198 GMX_ASSERT(xReadyOnDevice || !pme->bPPnode || (GMX_GPU != GMX_GPU_CUDA),
199 "Need a valid xReadyOnDevice on PP+PME ranks with CUDA.");
201 PmeGpu* pmeGpu = pme->gpu;
203 const unsigned int gridIndex = 0;
204 real* fftgrid = pme->fftgrid[gridIndex];
205 if (pmeGpu->settings.currentFlags & GMX_PME_SPREAD)
207 /* Spread the coefficients on a grid */
208 const bool computeSplines = true;
209 const bool spreadCharges = true;
210 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
211 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
212 pme_gpu_spread(pmeGpu, xReadyOnDevice, gridIndex, fftgrid, computeSplines, spreadCharges);
213 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
214 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
218 void pme_gpu_launch_complex_transforms(gmx_pme_t* pme, gmx_wallcycle* wcycle)
220 PmeGpu* pmeGpu = pme->gpu;
221 const auto& settings = pmeGpu->settings;
222 const bool computeEnergyAndVirial = (settings.currentFlags & GMX_PME_CALC_ENER_VIR) != 0;
223 const bool performBackFFT = (settings.currentFlags & (GMX_PME_CALC_F | GMX_PME_CALC_POT)) != 0;
224 const unsigned int gridIndex = 0;
225 t_complex* cfftgrid = pme->cfftgrid[gridIndex];
227 if (settings.currentFlags & GMX_PME_SPREAD)
229 if (!settings.performGPUFFT)
231 wallcycle_start(wcycle, ewcWAIT_GPU_PME_SPREAD);
232 pme_gpu_sync_spread_grid(pme->gpu);
233 wallcycle_stop(wcycle, ewcWAIT_GPU_PME_SPREAD);
239 if (settings.currentFlags & GMX_PME_SOLVE)
242 parallel_3dfft_execute_gpu_wrapper(pme, gridIndex, GMX_FFT_REAL_TO_COMPLEX, wcycle);
244 /* solve in k-space for our local cells */
245 if (settings.performGPUSolve)
247 // TODO grid ordering should be set up at pme init time.
248 const auto gridOrdering =
249 settings.useDecomposition ? GridOrdering::YZX : GridOrdering::XYZ;
250 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
251 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
252 pme_gpu_solve(pmeGpu, cfftgrid, gridOrdering, computeEnergyAndVirial);
253 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
254 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
258 wallcycle_start(wcycle, ewcPME_SOLVE_MIXED_MODE);
259 #pragma omp parallel for num_threads(pme->nthread) schedule(static)
260 for (int thread = 0; thread < pme->nthread; thread++)
262 solve_pme_yzx(pme, cfftgrid, pme->boxVolume, computeEnergyAndVirial,
263 pme->nthread, thread);
265 wallcycle_stop(wcycle, ewcPME_SOLVE_MIXED_MODE);
271 parallel_3dfft_execute_gpu_wrapper(pme, gridIndex, GMX_FFT_COMPLEX_TO_REAL, wcycle);
274 GMX_CATCH_ALL_AND_EXIT_WITH_FATAL_ERROR;
277 void pme_gpu_launch_gather(const gmx_pme_t* pme, gmx_wallcycle gmx_unused* wcycle, PmeForceOutputHandling forceTreatment)
279 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
281 if (!pme_gpu_settings(pme->gpu).performGPUGather)
286 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
287 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
288 const unsigned int gridIndex = 0;
289 real* fftgrid = pme->fftgrid[gridIndex];
290 pme_gpu_gather(pme->gpu, forceTreatment, reinterpret_cast<float*>(fftgrid));
291 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
292 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
295 //! Accumulate the \c forcesToAdd to \c f, using the available threads.
296 static void sum_forces(gmx::ArrayRef<gmx::RVec> f, gmx::ArrayRef<const gmx::RVec> forceToAdd)
298 const int end = forceToAdd.size();
300 int gmx_unused nt = gmx_omp_nthreads_get(emntPME);
301 #pragma omp parallel for num_threads(nt) schedule(static)
302 for (int i = 0; i < end; i++)
304 f[i] += forceToAdd[i];
308 //! Reduce quantities from \c output to \c forceWithVirial and \c enerd.
309 static void pme_gpu_reduce_outputs(const int flags,
310 const PmeOutput& output,
311 gmx_wallcycle* wcycle,
312 gmx::ForceWithVirial* forceWithVirial,
313 gmx_enerdata_t* enerd)
315 wallcycle_start(wcycle, ewcPME_GPU_F_REDUCTION);
316 GMX_ASSERT(forceWithVirial, "Invalid force pointer");
318 const bool haveComputedEnergyAndVirial = (flags & GMX_PME_CALC_ENER_VIR) != 0;
319 if (haveComputedEnergyAndVirial)
321 GMX_ASSERT(enerd, "Invalid energy output manager");
322 forceWithVirial->addVirialContribution(output.coulombVirial_);
323 enerd->term[F_COUL_RECIP] += output.coulombEnergy_;
325 if (output.haveForceOutput_)
327 sum_forces(forceWithVirial->force_, output.forces_);
329 wallcycle_stop(wcycle, ewcPME_GPU_F_REDUCTION);
332 bool pme_gpu_try_finish_task(gmx_pme_t* pme,
334 gmx_wallcycle* wcycle,
335 gmx::ForceWithVirial* forceWithVirial,
336 gmx_enerdata_t* enerd,
337 GpuTaskCompletion completionKind)
339 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
340 GMX_ASSERT(!pme->gpu->settings.useGpuForceReduction,
341 "GPU force reduction should not be active on the pme_gpu_try_finish_task() path");
343 // First, if possible, check whether all tasks on the stream have
344 // completed, and return fast if not. Accumulate to wcycle the
345 // time needed for that checking, but do not yet record that the
346 // gather has occured.
347 bool needToSynchronize = true;
348 constexpr bool c_streamQuerySupported = (GMX_GPU == GMX_GPU_CUDA);
349 // TODO: implement c_streamQuerySupported with an additional GpuEventSynchronizer per stream (#2521)
350 if ((completionKind == GpuTaskCompletion::Check) && c_streamQuerySupported)
352 wallcycle_start_nocount(wcycle, ewcWAIT_GPU_PME_GATHER);
353 // Query the PME stream for completion of all tasks enqueued and
354 // if we're not done, stop the timer before early return.
355 const bool pmeGpuDone = pme_gpu_stream_query(pme->gpu);
356 wallcycle_stop(wcycle, ewcWAIT_GPU_PME_GATHER);
362 needToSynchronize = false;
365 wallcycle_start(wcycle, ewcWAIT_GPU_PME_GATHER);
366 // If the above check passed, then there is no need to make an
367 // explicit synchronization call.
368 if (needToSynchronize)
370 // Synchronize the whole PME stream at once, including D2H result transfers.
371 pme_gpu_synchronize(pme->gpu);
373 pme_gpu_update_timings(pme->gpu);
374 PmeOutput output = pme_gpu_getOutput(*pme, flags);
375 wallcycle_stop(wcycle, ewcWAIT_GPU_PME_GATHER);
377 GMX_ASSERT(pme->gpu->settings.useGpuForceReduction == !output.haveForceOutput_,
378 "When forces are reduced on the CPU, there needs to be force output");
379 pme_gpu_reduce_outputs(flags, output, wcycle, forceWithVirial, enerd);
384 // This is used by PME-only ranks
385 PmeOutput pme_gpu_wait_finish_task(gmx_pme_t* pme, const int flags, gmx_wallcycle* wcycle)
387 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
389 wallcycle_start(wcycle, ewcWAIT_GPU_PME_GATHER);
391 // Synchronize the whole PME stream at once, including D2H result transfers
392 // if there are outputs we need to wait for at this step; we still call getOutputs
393 // for uniformity and because it sets the PmeOutput.haveForceOutput_.
394 const bool haveComputedEnergyAndVirial = (flags & GMX_PME_CALC_ENER_VIR) != 0;
395 if (!pme->gpu->settings.useGpuForceReduction || haveComputedEnergyAndVirial)
397 pme_gpu_synchronize(pme->gpu);
400 PmeOutput output = pme_gpu_getOutput(*pme, flags);
401 wallcycle_stop(wcycle, ewcWAIT_GPU_PME_GATHER);
405 // This is used when not using the alternate-waiting reduction
406 void pme_gpu_wait_and_reduce(gmx_pme_t* pme,
408 gmx_wallcycle* wcycle,
409 gmx::ForceWithVirial* forceWithVirial,
410 gmx_enerdata_t* enerd)
412 PmeOutput output = pme_gpu_wait_finish_task(pme, flags, wcycle);
413 GMX_ASSERT(pme->gpu->settings.useGpuForceReduction == !output.haveForceOutput_,
414 "When forces are reduced on the CPU, there needs to be force output");
415 pme_gpu_reduce_outputs(flags, output, wcycle, forceWithVirial, enerd);
418 void pme_gpu_reinit_computation(const gmx_pme_t* pme, gmx_wallcycle* wcycle)
420 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
422 wallcycle_start_nocount(wcycle, ewcLAUNCH_GPU);
423 wallcycle_sub_start_nocount(wcycle, ewcsLAUNCH_GPU_PME);
425 pme_gpu_update_timings(pme->gpu);
427 pme_gpu_clear_grids(pme->gpu);
428 pme_gpu_clear_energy_virial(pme->gpu);
430 wallcycle_sub_stop(wcycle, ewcsLAUNCH_GPU_PME);
431 wallcycle_stop(wcycle, ewcLAUNCH_GPU);
434 void* pme_gpu_get_device_f(const gmx_pme_t* pme)
436 if (!pme || !pme_gpu_active(pme))
440 return pme_gpu_get_kernelparam_forces(pme->gpu);
443 void pme_gpu_set_device_x(const gmx_pme_t* pme, DeviceBuffer<float> d_x)
445 GMX_ASSERT(pme != nullptr, "Null pointer is passed as a PME to the set coordinates function.");
446 GMX_ASSERT(pme_gpu_active(pme), "This should be a GPU run of PME but it is not enabled.");
448 pme_gpu_set_kernelparam_coordinates(pme->gpu, d_x);
451 void* pme_gpu_get_device_stream(const gmx_pme_t* pme)
453 if (!pme || !pme_gpu_active(pme))
457 return pme_gpu_get_stream(pme->gpu);
460 void* pme_gpu_get_device_context(const gmx_pme_t* pme)
462 if (!pme || !pme_gpu_active(pme))
466 return pme_gpu_get_context(pme->gpu);
469 GpuEventSynchronizer* pme_gpu_get_f_ready_synchronizer(const gmx_pme_t* pme)
471 if (!pme || !pme_gpu_active(pme))
476 return pme_gpu_get_forces_ready_synchronizer(pme->gpu);