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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;
76 enum class GpuTaskCompletion;
78 class GpuEventSynchronizer;
82 class ForceWithVirial;
84 enum class PinningPolicy : int;
94 /*! \brief Possible PME codepaths on a rank.
95 * \todo: make this enum class with gmx_pme_t C++ refactoring
99 None, //!< No PME task is done
100 CPU, //!< Whole PME computation is done on CPU
101 GPU, //!< Whole PME computation is done on GPU
102 Mixed, //!< Mixed mode: only spread and gather run on GPU; FFT and solving are done on CPU.
105 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
106 int minimalPmeGridSize(int pmeOrder);
108 //! Return whether the grid of \c pme is identical to \c grid_size.
109 bool gmx_pme_grid_matches(const gmx_pme_t& pme, const ivec grid_size);
111 /*! \brief Check restrictions on pme_order and the PME grid nkx,nky,nkz.
113 * With errorsAreFatal=true, an exception or fatal error is generated
114 * on violation of restrictions.
115 * With errorsAreFatal=false, false is returned on violation of restrictions.
116 * When all restrictions are obeyed, true is returned.
117 * Argument useThreads tells if any MPI rank doing PME uses more than 1 threads.
118 * If at calling useThreads is unknown, pass true for conservative checking.
120 * The PME GPU restrictions are checked separately during pme_gpu_init().
122 bool gmx_pme_check_restrictions(int pme_order,
126 int numPmeDomainsAlongX,
128 bool errorsAreFatal);
130 /*! \brief Construct PME data
132 * \throws gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
133 * \returns Pointer to newly allocated and initialized PME data.
135 * \todo We should evolve something like a \c GpuManager that holds \c
136 * DeviceInformation* and \c PmeGpuProgram* and perhaps other
137 * related things whose lifetime can/should exceed that of a task (or
138 * perhaps task manager). See Redmine #2522.
140 gmx_pme_t* gmx_pme_init(const t_commrec* cr,
141 const NumPmeDomains& numPmeDomains,
142 const t_inputrec* ir,
143 gmx_bool bFreeEnergy_q,
144 gmx_bool bFreeEnergy_lj,
145 gmx_bool bReproducible,
151 const DeviceInformation* deviceInfo,
152 const PmeGpuProgram* pmeGpuProgram,
153 const gmx::MDLogger& mdlog);
155 /*! \brief As gmx_pme_init, but takes most settings, except the grid/Ewald coefficients, from
156 * pme_src. This is only called when the PME cut-off/grid size changes.
158 void gmx_pme_reinit(gmx_pme_t** pmedata,
161 const t_inputrec* ir,
162 const ivec grid_size,
166 /*! \brief Destroys the PME data structure.*/
167 void gmx_pme_destroy(gmx_pme_t* pme);
169 /*! \brief Do a PME calculation on a CPU for the long range electrostatics and/or LJ.
171 * Computes the PME forces and the energy and viral, when requested,
172 * for all atoms in \p coordinates. Forces, when requested, are added
173 * to the buffer \p forces, which is allowed to contain more elements
174 * than the number of elements in \p coordinates.
175 * The meaning of \p flags is defined above, and determines which
176 * parts of the calculation are performed.
178 * \return 0 indicates all well, non zero is an error code.
180 int gmx_pme_do(struct gmx_pme_t* pme,
181 gmx::ArrayRef<const gmx::RVec> coordinates,
182 gmx::ArrayRef<gmx::RVec> forces,
194 gmx_wallcycle* wcycle,
203 const gmx::StepWorkload& stepWork);
205 /*! \brief Calculate the PME grid energy V for n charges.
207 * The potential (found in \p pme) must have been found already with a
208 * call to gmx_pme_do(). Note that the charges are not spread on the grid in the
209 * pme struct. Currently does not work in parallel or with free
212 void gmx_pme_calc_energy(gmx_pme_t* pme, gmx::ArrayRef<const gmx::RVec> x, gmx::ArrayRef<const real> q, real* V);
215 * This function updates the local atom data on GPU after DD (charges, coordinates, etc.).
216 * TODO: it should update the PME CPU atom data as well.
217 * (currently PME CPU call gmx_pme_do() gets passed the input pointers for each computation).
219 * \param[in,out] pme The PME structure.
220 * \param[in] numAtoms The number of particles.
221 * \param[in] charges The pointer to the array of particle charges.
223 void gmx_pme_reinit_atoms(gmx_pme_t* pme, int numAtoms, const real* charges);
225 /* A block of PME GPU functions */
227 /*! \brief Checks whether the GROMACS build allows to run PME on GPU.
228 * TODO: this partly duplicates an internal PME assert function
229 * pme_gpu_check_restrictions(), except that works with a
230 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
232 * \param[out] error If non-null, the error message when PME is not supported on GPU.
234 * \returns true if PME can run on GPU on this build, false otherwise.
236 bool pme_gpu_supports_build(std::string* error);
238 /*! \brief Checks whether the detected (GPU) hardware allows to run PME on GPU.
240 * \param[in] hwinfo Information about the detected hardware
241 * \param[out] error If non-null, the error message when PME is not supported on GPU.
243 * \returns true if PME can run on GPU on this build, false otherwise.
245 bool pme_gpu_supports_hardware(const gmx_hw_info_t& hwinfo, std::string* error);
247 /*! \brief Checks whether the input system allows to run PME on GPU.
248 * TODO: this partly duplicates an internal PME assert function
249 * pme_gpu_check_restrictions(), except that works with a
250 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
252 * \param[in] ir Input system.
253 * \param[in] mtop Complete system topology to check if an FE simulation perturbs charges.
254 * \param[out] error If non-null, the error message if the input is not supported on GPU.
256 * \returns true if PME can run on GPU with this input, false otherwise.
258 bool pme_gpu_supports_input(const t_inputrec& ir, const gmx_mtop_t& mtop, std::string* error);
261 * Returns the active PME codepath (CPU, GPU, mixed).
262 * \todo This is a rather static data that should be managed by the higher level task scheduler.
264 * \param[in] pme The PME data structure.
265 * \returns active PME codepath.
267 PmeRunMode pme_run_mode(const gmx_pme_t* pme);
269 /*! \libinternal \brief
270 * Return the pinning policy appropriate for this build configuration
271 * for relevant buffers used for PME task on this rank (e.g. running
273 gmx::PinningPolicy pme_get_pinning_policy();
276 * Tells if PME is enabled to run on GPU (not necessarily active at the moment).
277 * \todo This is a rather static data that should be managed by the hardware assignment manager.
278 * For now, it is synonymous with the active PME codepath (in the absence of dynamic switching).
280 * \param[in] pme The PME data structure.
281 * \returns true if PME can run on GPU, false otherwise.
283 inline bool pme_gpu_task_enabled(const gmx_pme_t* pme)
285 return (pme != nullptr) && (pme_run_mode(pme) != PmeRunMode::CPU);
288 /*! \brief Returns the size of the padding needed by GPU version of PME in the coordinates array.
290 * \param[in] pme The PME data structure.
292 GPU_FUNC_QUALIFIER int pme_gpu_get_padding_size(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
293 GPU_FUNC_TERM_WITH_RETURN(0);
295 // The following functions are all the PME GPU entry points,
296 // currently inlining to nothing on non-CUDA builds.
299 * Resets the PME GPU timings. To be called at the reset step.
301 * \param[in] pme The PME structure.
303 GPU_FUNC_QUALIFIER void pme_gpu_reset_timings(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM;
306 * Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.
308 * \param[in] pme The PME structure.
309 * \param[in] timings The gmx_wallclock_gpu_pme_t structure.
311 GPU_FUNC_QUALIFIER void pme_gpu_get_timings(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
312 gmx_wallclock_gpu_pme_t* GPU_FUNC_ARGUMENT(timings)) GPU_FUNC_TERM;
314 /* The main PME GPU functions */
317 * Prepares PME on GPU computation (updating the box if needed)
318 * \param[in] pme The PME data structure.
319 * \param[in] box The unit cell box.
320 * \param[in] wcycle The wallclock counter.
321 * \param[in] stepWork The required work for this simulation step
323 GPU_FUNC_QUALIFIER void pme_gpu_prepare_computation(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
324 const matrix GPU_FUNC_ARGUMENT(box),
325 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
326 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork)) GPU_FUNC_TERM;
329 * Launches first stage of PME on GPU - spreading kernel.
331 * \param[in] pme The PME data structure.
332 * \param[in] xReadyOnDevice Event synchronizer indicating that the coordinates are ready in the device memory; nullptr allowed only on separate PME ranks.
333 * \param[in] wcycle The wallclock counter.
335 GPU_FUNC_QUALIFIER void pme_gpu_launch_spread(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
336 GpuEventSynchronizer* GPU_FUNC_ARGUMENT(xReadyOnDevice),
337 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
340 * Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.
342 * \param[in] pme The PME data structure.
343 * \param[in] wcycle The wallclock counter.
344 * \param[in] stepWork The required work for this simulation step
346 GPU_FUNC_QUALIFIER void
347 pme_gpu_launch_complex_transforms(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
348 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
349 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork)) GPU_FUNC_TERM;
352 * Launches last stage of PME on GPU - force gathering and D2H force transfer.
354 * \param[in] pme The PME data structure.
355 * \param[in] wcycle The wallclock counter.
357 GPU_FUNC_QUALIFIER void pme_gpu_launch_gather(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
358 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
361 * Attempts to complete PME GPU tasks.
363 * The \p completionKind argument controls whether the function blocks until all
364 * PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only
365 * checks and returns immediately if they did not.
366 * When blocking or the tasks have completed it also gets the output forces
367 * by assigning the ArrayRef to the \p forces pointer passed in.
368 * Virial/energy are also outputs if they were to be computed.
370 * \param[in] pme The PME data structure.
371 * \param[in] stepWork The required work for this simulation step
372 * \param[in] wcycle The wallclock counter.
373 * \param[out] forceWithVirial The output force and virial
374 * \param[out] enerd The output energies
375 * \param[in] completionKind Indicates whether PME task completion should only be checked rather
377 * \returns True if the PME GPU tasks have completed
379 GPU_FUNC_QUALIFIER bool pme_gpu_try_finish_task(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
380 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork),
381 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
382 gmx::ForceWithVirial* GPU_FUNC_ARGUMENT(forceWithVirial),
383 gmx_enerdata_t* GPU_FUNC_ARGUMENT(enerd),
384 GpuTaskCompletion GPU_FUNC_ARGUMENT(completionKind))
385 GPU_FUNC_TERM_WITH_RETURN(false);
388 * Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy
389 * (if they were to be computed).
391 * \param[in] pme The PME data structure.
392 * \param[in] stepWork The required work for this simulation step
393 * \param[in] wcycle The wallclock counter.
394 * \param[out] forceWithVirial The output force and virial
395 * \param[out] enerd The output energies
397 GPU_FUNC_QUALIFIER void pme_gpu_wait_and_reduce(gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
398 const gmx::StepWorkload& GPU_FUNC_ARGUMENT(stepWork),
399 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle),
400 gmx::ForceWithVirial* GPU_FUNC_ARGUMENT(forceWithVirial),
401 gmx_enerdata_t* GPU_FUNC_ARGUMENT(enerd)) GPU_FUNC_TERM;
404 * The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.
406 * Clears the internal grid and energy/virial buffers; it is not safe to start
407 * the PME computation without calling this.
408 * Note that unlike in the nbnxn module, the force buffer does not need clearing.
410 * \todo Rename this function to *clear* -- it clearly only does output resetting
411 * and we should be clear about what the function does..
413 * \param[in] pme The PME data structure.
414 * \param[in] wcycle The wallclock counter.
416 GPU_FUNC_QUALIFIER void pme_gpu_reinit_computation(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
417 gmx_wallcycle* GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
419 /*! \brief Set pointer to device copy of coordinate data.
420 * \param[in] pme The PME data structure.
421 * \param[in] d_x The pointer to the positions buffer to be set
423 GPU_FUNC_QUALIFIER void pme_gpu_set_device_x(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme),
424 DeviceBuffer<gmx::RVec> GPU_FUNC_ARGUMENT(d_x)) GPU_FUNC_TERM;
426 /*! \brief Get pointer to device copy of force data.
427 * \param[in] pme The PME data structure.
428 * \returns Pointer to force data
430 GPU_FUNC_QUALIFIER void* pme_gpu_get_device_f(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
431 GPU_FUNC_TERM_WITH_RETURN(nullptr);
433 /*! \brief Returns the pointer to the GPU stream.
434 * \param[in] pme The PME data structure.
435 * \returns Pointer to GPU stream object.
437 GPU_FUNC_QUALIFIER const DeviceStream* pme_gpu_get_device_stream(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
438 GPU_FUNC_TERM_WITH_RETURN(nullptr);
440 /*! \brief Get pointer to the device synchronizer object that allows syncing on PME force calculation completion
441 * \param[in] pme The PME data structure.
442 * \returns Pointer to sychronizer
444 GPU_FUNC_QUALIFIER GpuEventSynchronizer* pme_gpu_get_f_ready_synchronizer(const gmx_pme_t* GPU_FUNC_ARGUMENT(pme))
445 GPU_FUNC_TERM_WITH_RETURN(nullptr);