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37 /*! \libinternal \file
39 * \brief This file contains function declarations necessary for
40 * computing energies and forces for the PME long-ranged part (Coulomb
43 * \author Berk Hess <hess@kth.se>
45 * \ingroup module_ewald
48 #ifndef GMX_EWALD_PME_H
49 #define GMX_EWALD_PME_H
53 #include "gromacs/gpu_utils/devicebuffer_datatype.h"
54 #include "gromacs/gpu_utils/gpu_macros.h"
55 #include "gromacs/math/vectypes.h"
56 #include "gromacs/timing/walltime_accounting.h"
57 #include "gromacs/utility/arrayref.h"
58 #include "gromacs/utility/basedefinitions.h"
59 #include "gromacs/utility/real.h"
62 struct interaction_const_t;
67 struct gmx_wallclock_gpu_pme_t;
68 struct gmx_device_info_t;
69 struct gmx_enerdata_t;
75 enum class GpuTaskCompletion;
77 class GpuEventSynchronizer;
79 using PmeGpuProgramHandle = const PmeGpuProgram *;
83 class ForceWithVirial;
85 enum class PinningPolicy : int;
89 GMX_SUM_GRID_FORWARD, GMX_SUM_GRID_BACKWARD
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 //! PME gathering output forces treatment
104 enum class PmeForceOutputHandling
106 Set, /**< Gather simply writes into provided force buffer */
107 ReduceWithInput, /**< Gather adds its output to the buffer.
108 On GPU, that means additional H2D copy before the kernel launch. */
111 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
112 int minimalPmeGridSize(int pmeOrder);
114 /*! \brief Check restrictions on pme_order and the PME grid nkx,nky,nkz.
116 * With errorsAreFatal=true, an exception or fatal error is generated
117 * on violation of restrictions.
118 * With errorsAreFatal=false, false is returned on violation of restrictions.
119 * When all restrictions are obeyed, true is returned.
120 * Argument useThreads tells if any MPI rank doing PME uses more than 1 threads.
121 * If at calling useThreads is unknown, pass true for conservative checking.
123 * The PME GPU restrictions are checked separately during pme_gpu_init().
125 bool gmx_pme_check_restrictions(int pme_order,
126 int nkx, int nky, int nkz,
127 int numPmeDomainsAlongX,
129 bool errorsAreFatal);
131 /*! \brief Construct PME data
133 * \throws gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
134 * \returns Pointer to newly allocated and initialized PME data.
136 * \todo We should evolve something like a \c GpuManager that holds \c
137 * gmx_device_info_t * and \c PmeGpuProgramHandle and perhaps other
138 * related things whose lifetime can/should exceed that of a task (or
139 * perhaps task manager). See Redmine #2522.
141 gmx_pme_t *gmx_pme_init(const t_commrec *cr,
142 const NumPmeDomains &numPmeDomains,
143 const t_inputrec *ir,
144 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
145 gmx_bool bReproducible,
146 real ewaldcoeff_q, real ewaldcoeff_lj,
150 const gmx_device_info_t *gpuInfo,
151 PmeGpuProgramHandle pmeGpuProgram,
152 const gmx::MDLogger &mdlog);
154 /*! \brief Destroys the PME data structure.*/
155 void gmx_pme_destroy(gmx_pme_t *pme);
158 /*! \brief Flag values that control what gmx_pme_do() will calculate
160 * These can be combined with bitwise-OR if more than one thing is required.
162 #define GMX_PME_SPREAD (1<<0)
163 #define GMX_PME_SOLVE (1<<1)
164 #define GMX_PME_CALC_F (1<<2)
165 #define GMX_PME_CALC_ENER_VIR (1<<3)
166 /* This forces the grid to be backtransformed even without GMX_PME_CALC_F */
167 #define GMX_PME_CALC_POT (1<<4)
169 #define GMX_PME_DO_ALL_F (GMX_PME_SPREAD | GMX_PME_SOLVE | GMX_PME_CALC_F)
172 /*! \brief Do a PME calculation on a CPU for the long range electrostatics and/or LJ.
174 * Computes the PME forces and the energy and viral, when requested,
175 * for all atoms in \p coordinates. Forces, when requested, are added
176 * to the buffer \p forces, which is allowed to contain more elements
177 * than the number of elements in \p coordinates.
178 * The meaning of \p flags is defined above, and determines which
179 * parts of the calculation are performed.
181 * \return 0 indicates all well, non zero is an error code.
183 int gmx_pme_do(struct gmx_pme_t *pme,
184 gmx::ArrayRef<const gmx::RVec> coordinates,
185 gmx::ArrayRef<gmx::RVec> forces,
186 real chargeA[], real chargeB[],
187 real c6A[], real c6B[],
188 real sigmaA[], real sigmaB[],
189 const matrix box, const t_commrec *cr,
190 int maxshift_x, int maxshift_y,
191 t_nrnb *nrnb, gmx_wallcycle *wcycle,
192 matrix vir_q, matrix vir_lj,
193 real *energy_q, real *energy_lj,
194 real lambda_q, real lambda_lj,
195 real *dvdlambda_q, real *dvdlambda_lj,
198 /*! \brief Called on the nodes that do PME exclusively */
199 int gmx_pmeonly(struct gmx_pme_t *pme,
200 const t_commrec *cr, t_nrnb *mynrnb,
201 gmx_wallcycle *wcycle,
202 gmx_walltime_accounting_t walltime_accounting,
203 t_inputrec *ir, PmeRunMode runMode);
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() with at least GMX_PME_SPREAD and GMX_PME_SOLVE
209 * specified. Note that the charges are not spread on the grid in the
210 * pme struct. Currently does not work in parallel or with free
213 void gmx_pme_calc_energy(gmx_pme_t *pme,
214 gmx::ArrayRef<const gmx::RVec> x,
215 gmx::ArrayRef<const real> q,
218 /*! \brief Send the charges and maxshift to out PME-only node. */
219 void gmx_pme_send_parameters(const t_commrec *cr,
220 const interaction_const_t *ic,
221 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
222 real *chargeA, real *chargeB,
223 real *sqrt_c6A, real *sqrt_c6B,
224 real *sigmaA, real *sigmaB,
225 int maxshift_x, int maxshift_y);
227 /*! \brief Send the coordinates to our PME-only node and request a PME calculation */
228 void gmx_pme_send_coordinates(const t_commrec *cr, const matrix box, const rvec *x,
229 real lambda_q, real lambda_lj,
231 int64_t step, gmx_wallcycle *wcycle);
233 /*! \brief Tell our PME-only node to finish */
234 void gmx_pme_send_finish(const t_commrec *cr);
236 /*! \brief Tell our PME-only node to reset all cycle and flop counters */
237 void gmx_pme_send_resetcounters(const t_commrec *cr, int64_t step);
239 /*! \brief PP nodes receive the long range forces from the PME nodes */
240 void gmx_pme_receive_f(const t_commrec *cr,
241 gmx::ForceWithVirial *forceWithVirial,
242 real *energy_q, real *energy_lj,
243 real *dvdlambda_q, real *dvdlambda_lj,
247 * This function updates the local atom data on GPU after DD (charges, coordinates, etc.).
248 * TODO: it should update the PME CPU atom data as well.
249 * (currently PME CPU call gmx_pme_do() gets passed the input pointers for each computation).
251 * \param[in,out] pme The PME structure.
252 * \param[in] numAtoms The number of particles.
253 * \param[in] charges The pointer to the array of particle charges.
255 void gmx_pme_reinit_atoms(gmx_pme_t *pme,
257 const real *charges);
259 /* A block of PME GPU functions */
261 /*! \brief Checks whether the GROMACS build allows to run PME on GPU.
262 * TODO: this partly duplicates an internal PME assert function
263 * pme_gpu_check_restrictions(), except that works with a
264 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
266 * \param[out] error If non-null, the error message when PME is not supported on GPU.
268 * \returns true if PME can run on GPU on this build, false otherwise.
270 bool pme_gpu_supports_build(std::string *error);
272 /*! \brief Checks whether the detected (GPU) hardware allows to run PME on GPU.
274 * \param[in] hwinfo Information about the detected hardware
275 * \param[out] error If non-null, the error message when PME is not supported on GPU.
277 * \returns true if PME can run on GPU on this build, false otherwise.
279 bool pme_gpu_supports_hardware(const gmx_hw_info_t &hwinfo,
282 /*! \brief Checks whether the input system allows to run PME on GPU.
283 * TODO: this partly duplicates an internal PME assert function
284 * pme_gpu_check_restrictions(), except that works with a
285 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
287 * \param[in] ir Input system.
288 * \param[in] mtop Complete system topology to check if an FE simulation perturbs charges.
289 * \param[out] error If non-null, the error message if the input is not supported on GPU.
291 * \returns true if PME can run on GPU with this input, false otherwise.
293 bool pme_gpu_supports_input(const t_inputrec &ir, const gmx_mtop_t &mtop, std::string *error);
296 * Returns the active PME codepath (CPU, GPU, mixed).
297 * \todo This is a rather static data that should be managed by the higher level task scheduler.
299 * \param[in] pme The PME data structure.
300 * \returns active PME codepath.
302 PmeRunMode pme_run_mode(const gmx_pme_t *pme);
304 /*! \libinternal \brief
305 * Return the pinning policy appropriate for this build configuration
306 * for relevant buffers used for PME task on this rank (e.g. running
308 gmx::PinningPolicy pme_get_pinning_policy();
311 * Tells if PME is enabled to run on GPU (not necessarily active at the moment).
312 * \todo This is a rather static data that should be managed by the hardware assignment manager.
313 * For now, it is synonymous with the active PME codepath (in the absence of dynamic switching).
315 * \param[in] pme The PME data structure.
316 * \returns true if PME can run on GPU, false otherwise.
318 inline bool pme_gpu_task_enabled(const gmx_pme_t *pme)
320 return (pme != nullptr) && (pme_run_mode(pme) != PmeRunMode::CPU);
323 /*! \brief Returns the size of the padding needed by GPU version of PME in the coordinates array.
325 * \param[in] pme The PME data structure.
327 GPU_FUNC_QUALIFIER int pme_gpu_get_padding_size(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(0);
329 // The following functions are all the PME GPU entry points,
330 // currently inlining to nothing on non-CUDA builds.
333 * Resets the PME GPU timings. To be called at the reset step.
335 * \param[in] pme The PME structure.
337 GPU_FUNC_QUALIFIER void pme_gpu_reset_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM;
340 * Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.
342 * \param[in] pme The PME structure.
343 * \param[in] timings The gmx_wallclock_gpu_pme_t structure.
345 GPU_FUNC_QUALIFIER void pme_gpu_get_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
346 gmx_wallclock_gpu_pme_t *GPU_FUNC_ARGUMENT(timings)) GPU_FUNC_TERM;
348 /* The main PME GPU functions */
351 * Prepares PME on GPU computation (updating the box if needed)
352 * \param[in] pme The PME data structure.
353 * \param[in] needToUpdateBox Tells if the stored unit cell parameters should be updated from \p box.
354 * \param[in] box The unit cell box.
355 * \param[in] wcycle The wallclock counter.
356 * \param[in] flags The combination of flags to affect this PME computation.
357 * The flags are the GMX_PME_ flags from pme.h.
358 * \param[in] useGpuForceReduction Whether PME forces are reduced on GPU this step or should be downloaded for CPU reduction
360 GPU_FUNC_QUALIFIER void pme_gpu_prepare_computation(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
361 bool GPU_FUNC_ARGUMENT(needToUpdateBox),
362 const matrix GPU_FUNC_ARGUMENT(box),
363 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
364 int GPU_FUNC_ARGUMENT(flags),
365 bool GPU_FUNC_ARGUMENT(useGpuForceReduction)) GPU_FUNC_TERM;
368 * Launches first stage of PME on GPU - spreading kernel.
370 * \param[in] pme The PME data structure.
371 * \param[in] wcycle The wallclock counter.
373 GPU_FUNC_QUALIFIER void pme_gpu_launch_spread(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
374 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
377 * Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.
379 * \param[in] pme The PME data structure.
380 * \param[in] wcycle The wallclock counter.
382 GPU_FUNC_QUALIFIER void pme_gpu_launch_complex_transforms(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
383 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
386 * Launches last stage of PME on GPU - force gathering and D2H force transfer.
388 * \param[in] pme The PME data structure.
389 * \param[in] wcycle The wallclock counter.
390 * \param[in] forceTreatment Tells how data should be treated. The gathering kernel either stores
391 * the output reciprocal forces into the host array, or copies its contents to the GPU first
392 * and accumulates. The reduction is non-atomic.
394 GPU_FUNC_QUALIFIER void pme_gpu_launch_gather(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
395 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
396 PmeForceOutputHandling GPU_FUNC_ARGUMENT(forceTreatment)) GPU_FUNC_TERM;
399 * Attempts to complete PME GPU tasks.
401 * The \p completionKind argument controls whether the function blocks until all
402 * PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only
403 * checks and returns immediately if they did not.
404 * When blocking or the tasks have completed it also gets the output forces
405 * by assigning the ArrayRef to the \p forces pointer passed in.
406 * Virial/energy are also outputs if they were to be computed.
408 * \param[in] pme The PME data structure.
409 * \param[in] flags The combination of flags to affect this PME computation.
410 * The flags are the GMX_PME_ flags from pme.h.
411 * \param[in] wcycle The wallclock counter.
412 * \param[out] forceWithVirial The output force and virial
413 * \param[out] enerd The output energies
414 * \param[in] flags The combination of flags to affect this PME computation.
415 * The flags are the GMX_PME_ flags from pme.h.
416 * \param[in] completionKind Indicates whether PME task completion should only be checked rather than waited for
417 * \returns True if the PME GPU tasks have completed
419 GPU_FUNC_QUALIFIER bool
420 pme_gpu_try_finish_task(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
421 int GPU_FUNC_ARGUMENT(flags),
422 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
423 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
424 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd),
425 GpuTaskCompletion GPU_FUNC_ARGUMENT(completionKind)) GPU_FUNC_TERM_WITH_RETURN(false);
428 * Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy
429 * (if they were to be computed).
431 * \param[in] pme The PME data structure.
432 * \param[in] flags The combination of flags to affect this PME computation.
433 * The flags are the GMX_PME_ flags from pme.h.
434 * \param[in] wcycle The wallclock counter.
435 * \param[out] forceWithVirial The output force and virial
436 * \param[out] enerd The output energies
438 GPU_FUNC_QUALIFIER void
439 pme_gpu_wait_and_reduce(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
440 int GPU_FUNC_ARGUMENT(flags),
441 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
442 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
443 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd)) GPU_FUNC_TERM;
446 * The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.
448 * Clears the internal grid and energy/virial buffers; it is not safe to start
449 * the PME computation without calling this.
450 * Note that unlike in the nbnxn module, the force buffer does not need clearing.
452 * \todo Rename this function to *clear* -- it clearly only does output resetting
453 * and we should be clear about what the function does..
455 * \param[in] pme The PME data structure.
456 * \param[in] wcycle The wallclock counter.
458 GPU_FUNC_QUALIFIER void pme_gpu_reinit_computation(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
459 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
462 /*! \brief Get pointer to device copy of coordinate data.
463 * \param[in] pme The PME data structure.
464 * \returns Pointer to coordinate data
466 GPU_FUNC_QUALIFIER DeviceBuffer<float> pme_gpu_get_device_x(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(DeviceBuffer<float> {});
468 /*! \brief Set pointer to device copy of coordinate data.
469 * \param[in] pme The PME data structure.
470 * \param[in] d_x The pointer to the positions buffer to be set
472 GPU_FUNC_QUALIFIER void pme_gpu_set_device_x(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
473 DeviceBuffer<float> GPU_FUNC_ARGUMENT(d_x)) GPU_FUNC_TERM;
475 /*! \brief Get pointer to device copy of force data.
476 * \param[in] pme The PME data structure.
477 * \returns Pointer to force data
479 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_f(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
481 /*! \brief Returns the pointer to the GPU stream.
482 * \param[in] pme The PME data structure.
483 * \returns Pointer to GPU stream object.
485 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_stream(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
487 /*! \brief Returns the pointer to the GPU context.
488 * \param[in] pme The PME data structure.
489 * \returns Pointer to GPU context object.
491 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_context(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
493 /*! \brief Get pointer to the device synchronizer object that allows syncing on PME force calculation completion
494 * \param[in] pme The PME data structure.
495 * \returns Pointer to sychronizer
497 GPU_FUNC_QUALIFIER GpuEventSynchronizer *pme_gpu_get_f_ready_synchronizer(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);