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38 /*! \libinternal \file
40 * \brief This file contains function declarations necessary for
41 * computing energies and forces for the PME long-ranged part (Coulomb
44 * \author Berk Hess <hess@kth.se>
46 * \ingroup module_ewald
49 #ifndef GMX_EWALD_PME_H
50 #define GMX_EWALD_PME_H
54 #include "gromacs/gpu_utils/devicebuffer_datatype.h"
55 #include "gromacs/gpu_utils/gpu_macros.h"
56 #include "gromacs/math/vectypes.h"
57 #include "gromacs/utility/arrayref.h"
58 #include "gromacs/utility/basedefinitions.h"
59 #include "gromacs/utility/real.h"
66 struct gmx_wallclock_gpu_pme_t;
67 struct DeviceInformation;
68 struct gmx_enerdata_t;
74 enum class GpuTaskCompletion;
76 class GpuEventSynchronizer;
80 class ForceWithVirial;
82 enum class PinningPolicy : int;
92 /*! \brief Possible PME codepaths on a rank.
93 * \todo: make this enum class with gmx_pme_t C++ refactoring
97 None, //!< No PME task is done
98 CPU, //!< Whole PME computation is done on CPU
99 GPU, //!< Whole PME computation is done on GPU
100 Mixed, //!< Mixed mode: only spread and gather run on GPU; FFT and solving are done on CPU.
103 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
104 int minimalPmeGridSize(int pmeOrder);
106 //! Return whether the grid of \c pme is identical to \c grid_size.
107 bool gmx_pme_grid_matches(const gmx_pme_t& pme, const ivec grid_size);
109 /*! \brief Check restrictions on pme_order and the PME grid nkx,nky,nkz.
111 * With errorsAreFatal=true, an exception or fatal error is generated
112 * on violation of restrictions.
113 * With errorsAreFatal=false, false is returned on violation of restrictions.
114 * When all restrictions are obeyed, true is returned.
115 * Argument useThreads tells if any MPI rank doing PME uses more than 1 threads.
116 * If at calling useThreads is unknown, pass true for conservative checking.
118 * The PME GPU restrictions are checked separately during pme_gpu_init().
120 bool gmx_pme_check_restrictions(int pme_order,
124 int numPmeDomainsAlongX,
126 bool errorsAreFatal);
128 /*! \brief Construct PME data
130 * \throws gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
131 * \returns Pointer to newly allocated and initialized PME data.
133 * \todo We should evolve something like a \c GpuManager that holds \c
134 * DeviceInformation* and \c PmeGpuProgram* and perhaps other
135 * related things whose lifetime can/should exceed that of a task (or
136 * perhaps task manager). See Redmine #2522.
138 gmx_pme_t* gmx_pme_init(const t_commrec* cr,
139 const NumPmeDomains& numPmeDomains,
140 const t_inputrec* ir,
141 gmx_bool bFreeEnergy_q,
142 gmx_bool bFreeEnergy_lj,
143 gmx_bool bReproducible,
149 const DeviceInformation* deviceInfo,
150 const PmeGpuProgram* pmeGpuProgram,
151 const gmx::MDLogger& mdlog);
153 /*! \brief As gmx_pme_init, but takes most settings, except the grid/Ewald coefficients, from
154 * pme_src. This is only called when the PME cut-off/grid size changes.
156 void gmx_pme_reinit(gmx_pme_t** pmedata,
159 const t_inputrec* ir,
160 const ivec grid_size,
164 /*! \brief Destroys the PME data structure.*/
165 void gmx_pme_destroy(gmx_pme_t* pme);
167 /*! \brief Do a PME calculation on a CPU for the long range electrostatics and/or LJ.
169 * Computes the PME forces and the energy and viral, when requested,
170 * for all atoms in \p coordinates. Forces, when requested, are added
171 * to the buffer \p forces, which is allowed to contain more elements
172 * than the number of elements in \p coordinates.
173 * The meaning of \p flags is defined above, and determines which
174 * parts of the calculation are performed.
176 * \return 0 indicates all well, non zero is an error code.
178 int gmx_pme_do(struct gmx_pme_t* pme,
179 gmx::ArrayRef<const gmx::RVec> coordinates,
180 gmx::ArrayRef<gmx::RVec> forces,
192 gmx_wallcycle* wcycle,
201 const gmx::StepWorkload& stepWork);
203 /*! \brief Calculate the PME grid energy V for n charges.
205 * The potential (found in \p pme) must have been found already with a
206 * call to gmx_pme_do(). Note that the charges are not spread on the grid in the
207 * pme struct. Currently does not work in parallel or with free
210 void gmx_pme_calc_energy(gmx_pme_t* pme, gmx::ArrayRef<const gmx::RVec> x, gmx::ArrayRef<const real> q, real* V);
213 * This function updates the local atom data on GPU after DD (charges, coordinates, etc.).
214 * TODO: it should update the PME CPU atom data as well.
215 * (currently PME CPU call gmx_pme_do() gets passed the input pointers for each computation).
217 * \param[in,out] pme The PME structure.
218 * \param[in] numAtoms The number of particles.
219 * \param[in] charges The pointer to the array of particle charges.
221 void gmx_pme_reinit_atoms(gmx_pme_t* pme, int numAtoms, const real* charges);
223 /* A block of PME GPU functions */
225 /*! \brief Checks whether the GROMACS build allows to run PME on GPU.
226 * TODO: this partly duplicates an internal PME assert function
227 * pme_gpu_check_restrictions(), except that works with a
228 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
230 * \param[out] error If non-null, the error message when PME is not supported on GPU.
232 * \returns true if PME can run on GPU on this build, false otherwise.
234 bool pme_gpu_supports_build(std::string* error);
236 /*! \brief Checks whether the detected (GPU) hardware allows to run PME on GPU.
238 * \param[in] hwinfo Information about the detected hardware
239 * \param[out] error If non-null, the error message when PME is not supported on GPU.
241 * \returns true if PME can run on GPU on this build, false otherwise.
243 bool pme_gpu_supports_hardware(const gmx_hw_info_t& hwinfo, std::string* error);
245 /*! \brief Checks whether the input system allows to run PME on GPU.
246 * TODO: this partly duplicates an internal PME assert function
247 * pme_gpu_check_restrictions(), except that works with a
248 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
250 * \param[in] ir Input system.
251 * \param[in] mtop Complete system topology to check if an FE simulation perturbs charges.
252 * \param[out] error If non-null, the error message if the input is not supported on GPU.
254 * \returns true if PME can run on GPU with this input, false otherwise.
256 bool pme_gpu_supports_input(const t_inputrec& ir, const gmx_mtop_t& mtop, std::string* error);
259 * Returns the active PME codepath (CPU, GPU, mixed).
260 * \todo This is a rather static data that should be managed by the higher level task scheduler.
262 * \param[in] pme The PME data structure.
263 * \returns active PME codepath.
265 PmeRunMode pme_run_mode(const gmx_pme_t* pme);
267 /*! \libinternal \brief
268 * Return the pinning policy appropriate for this build configuration
269 * for relevant buffers used for PME task on this rank (e.g. running
271 gmx::PinningPolicy pme_get_pinning_policy();
274 * Tells if PME is enabled to run on GPU (not necessarily active at the moment).
275 * \todo This is a rather static data that should be managed by the hardware assignment manager.
276 * For now, it is synonymous with the active PME codepath (in the absence of dynamic switching).
278 * \param[in] pme The PME data structure.
279 * \returns true if PME can run on GPU, false otherwise.
281 inline bool pme_gpu_task_enabled(const gmx_pme_t* pme)
283 return (pme != nullptr) && (pme_run_mode(pme) != PmeRunMode::CPU);
286 /*! \brief Returns the size of the padding needed by GPU version of PME in the coordinates array.
288 * \param[in] pme The PME data structure.
290 GPU_FUNC_QUALIFIER int pme_gpu_get_padding_size(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
291 GPU_FUNC_TERM_WITH_RETURN(0);
293 // The following functions are all the PME GPU entry points,
294 // currently inlining to nothing on non-CUDA builds.
297 * Resets the PME GPU timings. To be called at the reset step.
299 * \param[in] pme The PME structure.
301 GPU_FUNC_QUALIFIER void pme_gpu_reset_timings(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM;
304 * Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.
306 * \param[in] pme The PME structure.
307 * \param[in] timings The gmx_wallclock_gpu_pme_t structure.
309 GPU_FUNC_QUALIFIER void pme_gpu_get_timings(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
310 gmx_wallclock_gpu_pme_t* GPU_FUNC_ARGUMENT(timings)) GPU_FUNC_TERM;
312 /* The main PME GPU functions */
315 * Prepares PME on GPU computation (updating the box if needed)
316 * \param[in] pme The PME data structure.
317 * \param[in] box The unit cell box.
318 * \param[in] wcycle The wallclock counter.
319 * \param[in] stepWork The required work for this simulation step
321 GPU_FUNC_QUALIFIER void pme_gpu_prepare_computation(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
322 const matrix GPU_FUNC_ARGUMENT(box),
323 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
324 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork)) GPU_FUNC_TERM;
327 * Launches first stage of PME on GPU - spreading kernel.
329 * \param[in] pme The PME data structure.
330 * \param[in] xReadyOnDevice Event synchronizer indicating that the coordinates are ready in the device memory; nullptr allowed only on separate PME ranks.
331 * \param[in] wcycle The wallclock counter.
333 GPU_FUNC_QUALIFIER void pme_gpu_launch_spread(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
334 GpuEventSynchronizer* GPU_FUNC_ARGUMENT(xReadyOnDevice),
335 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
338 * Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.
340 * \param[in] pme The PME data structure.
341 * \param[in] wcycle The wallclock counter.
342 * \param[in] stepWork The required work for this simulation step
344 GPU_FUNC_QUALIFIER void
345 pme_gpu_launch_complex_transforms(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
346 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
347 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork)) GPU_FUNC_TERM;
350 * Launches last stage of PME on GPU - force gathering and D2H force transfer.
352 * \param[in] pme The PME data structure.
353 * \param[in] wcycle The wallclock counter.
355 GPU_FUNC_QUALIFIER void pme_gpu_launch_gather(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
356 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
359 * Attempts to complete PME GPU tasks.
361 * The \p completionKind argument controls whether the function blocks until all
362 * PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only
363 * checks and returns immediately if they did not.
364 * When blocking or the tasks have completed it also gets the output forces
365 * by assigning the ArrayRef to the \p forces pointer passed in.
366 * Virial/energy are also outputs if they were to be computed.
368 * \param[in] pme The PME data structure.
369 * \param[in] stepWork The required work for this simulation step
370 * \param[in] wcycle The wallclock counter.
371 * \param[out] forceWithVirial The output force and virial
372 * \param[out] enerd The output energies
373 * \param[in] completionKind Indicates whether PME task completion should only be checked rather
375 * \returns True if the PME GPU tasks have completed
377 GPU_FUNC_QUALIFIER bool pme_gpu_try_finish_task(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
378 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork),
379 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
380 gmx::ForceWithVirial* GPU_FUNC_ARGUMENT(forceWithVirial),
381 gmx_enerdata_t* GPU_FUNC_ARGUMENT(enerd),
382 GpuTaskCompletion GPU_FUNC_ARGUMENT(completionKind))
383 GPU_FUNC_TERM_WITH_RETURN(false);
386 * Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy
387 * (if they were to be computed).
389 * \param[in] pme The PME data structure.
390 * \param[in] stepWork The required work for this simulation step
391 * \param[in] wcycle The wallclock counter.
392 * \param[out] forceWithVirial The output force and virial
393 * \param[out] enerd The output energies
395 GPU_FUNC_QUALIFIER void pme_gpu_wait_and_reduce(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
396 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork),
397 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
398 gmx::ForceWithVirial* GPU_FUNC_ARGUMENT(forceWithVirial),
399 gmx_enerdata_t* GPU_FUNC_ARGUMENT(enerd)) GPU_FUNC_TERM;
402 * The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.
404 * Clears the internal grid and energy/virial buffers; it is not safe to start
405 * the PME computation without calling this.
406 * Note that unlike in the nbnxn module, the force buffer does not need clearing.
408 * \todo Rename this function to *clear* -- it clearly only does output resetting
409 * and we should be clear about what the function does..
411 * \param[in] pme The PME data structure.
412 * \param[in] wcycle The wallclock counter.
414 GPU_FUNC_QUALIFIER void pme_gpu_reinit_computation(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
415 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
417 /*! \brief Set pointer to device copy of coordinate data.
418 * \param[in] pme The PME data structure.
419 * \param[in] d_x The pointer to the positions buffer to be set
421 GPU_FUNC_QUALIFIER void pme_gpu_set_device_x(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
422 DeviceBuffer<gmx::RVec> GPU_FUNC_ARGUMENT(d_x)) GPU_FUNC_TERM;
424 /*! \brief Get pointer to device copy of force data.
425 * \param[in] pme The PME data structure.
426 * \returns Pointer to force data
428 GPU_FUNC_QUALIFIER void* pme_gpu_get_device_f(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
429 GPU_FUNC_TERM_WITH_RETURN(nullptr);
431 /*! \brief Returns the pointer to the GPU stream.
432 * \param[in] pme The PME data structure.
433 * \returns Pointer to GPU stream object.
435 GPU_FUNC_QUALIFIER void* pme_gpu_get_device_stream(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
436 GPU_FUNC_TERM_WITH_RETURN(nullptr);
438 /*! \brief Returns the pointer to the GPU context.
439 * \param[in] pme The PME data structure.
440 * \returns Pointer to GPU context object.
442 GPU_FUNC_QUALIFIER void* pme_gpu_get_device_context(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
443 GPU_FUNC_TERM_WITH_RETURN(nullptr);
445 /*! \brief Get pointer to the device synchronizer object that allows syncing on PME force calculation completion
446 * \param[in] pme The PME data structure.
447 * \returns Pointer to sychronizer
449 GPU_FUNC_QUALIFIER GpuEventSynchronizer* pme_gpu_get_f_ready_synchronizer(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
450 GPU_FUNC_TERM_WITH_RETURN(nullptr);