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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;
68 struct gmx_wallclock_gpu_pme_t;
69 struct gmx_device_info_t;
70 struct gmx_enerdata_t;
76 enum class GpuTaskCompletion;
78 class GpuEventSynchronizer;
80 using PmeGpuProgramHandle = const PmeGpuProgram *;
85 class ForceWithVirial;
87 enum class PinningPolicy : int;
91 GMX_SUM_GRID_FORWARD, GMX_SUM_GRID_BACKWARD
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 //! PME gathering output forces treatment
106 enum class PmeForceOutputHandling
108 Set, /**< Gather simply writes into provided force buffer */
109 ReduceWithInput, /**< Gather adds its output to the buffer.
110 On GPU, that means additional H2D copy before the kernel launch. */
113 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
114 int minimalPmeGridSize(int pmeOrder);
116 /*! \brief Check restrictions on pme_order and the PME grid nkx,nky,nkz.
118 * With errorsAreFatal=true, an exception or fatal error is generated
119 * on violation of restrictions.
120 * With errorsAreFatal=false, false is returned on violation of restrictions.
121 * When all restrictions are obeyed, true is returned.
122 * Argument useThreads tells if any MPI rank doing PME uses more than 1 threads.
123 * If at calling useThreads is unknown, pass true for conservative checking.
125 * The PME GPU restrictions are checked separately during pme_gpu_init().
127 bool gmx_pme_check_restrictions(int pme_order,
128 int nkx, int nky, int nkz,
129 int numPmeDomainsAlongX,
131 bool errorsAreFatal);
133 /*! \brief Construct PME data
135 * \throws gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
136 * \returns Pointer to newly allocated and initialized PME data.
138 * \todo We should evolve something like a \c GpuManager that holds \c
139 * gmx_device_info_t * and \c PmeGpuProgramHandle and perhaps other
140 * related things whose lifetime can/should exceed that of a task (or
141 * perhaps task manager). See Redmine #2522.
143 gmx_pme_t *gmx_pme_init(const t_commrec *cr,
144 const NumPmeDomains &numPmeDomains,
145 const t_inputrec *ir,
146 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
147 gmx_bool bReproducible,
148 real ewaldcoeff_q, real ewaldcoeff_lj,
152 const gmx_device_info_t *gpuInfo,
153 PmeGpuProgramHandle pmeGpuProgram,
154 const gmx::MDLogger &mdlog);
156 /*! \brief Destroys the PME data structure.*/
157 void gmx_pme_destroy(gmx_pme_t *pme);
160 /*! \brief Flag values that control what gmx_pme_do() will calculate
162 * These can be combined with bitwise-OR if more than one thing is required.
164 #define GMX_PME_SPREAD (1<<0)
165 #define GMX_PME_SOLVE (1<<1)
166 #define GMX_PME_CALC_F (1<<2)
167 #define GMX_PME_CALC_ENER_VIR (1<<3)
168 /* This forces the grid to be backtransformed even without GMX_PME_CALC_F */
169 #define GMX_PME_CALC_POT (1<<4)
171 #define GMX_PME_DO_ALL_F (GMX_PME_SPREAD | GMX_PME_SOLVE | GMX_PME_CALC_F)
174 /*! \brief Do a PME calculation on a CPU for the long range electrostatics and/or LJ.
176 * Computes the PME forces and the energy and viral, when requested,
177 * for all atoms in \p coordinates. Forces, when requested, are added
178 * to the buffer \p forces, which is allowed to contain more elements
179 * than the number of elements in \p coordinates.
180 * The meaning of \p flags is defined above, and determines which
181 * parts of the calculation are performed.
183 * \return 0 indicates all well, non zero is an error code.
185 int gmx_pme_do(struct gmx_pme_t *pme,
186 gmx::ArrayRef<const gmx::RVec> coordinates,
187 gmx::ArrayRef<gmx::RVec> forces,
188 real chargeA[], real chargeB[],
189 real c6A[], real c6B[],
190 real sigmaA[], real sigmaB[],
191 const matrix box, const t_commrec *cr,
192 int maxshift_x, int maxshift_y,
193 t_nrnb *nrnb, gmx_wallcycle *wcycle,
194 matrix vir_q, matrix vir_lj,
195 real *energy_q, real *energy_lj,
196 real lambda_q, real lambda_lj,
197 real *dvdlambda_q, real *dvdlambda_lj,
200 /*! \brief Called on the nodes that do PME exclusively */
201 int gmx_pmeonly(struct gmx_pme_t *pme,
202 const t_commrec *cr, t_nrnb *mynrnb,
203 gmx_wallcycle *wcycle,
204 gmx_walltime_accounting_t walltime_accounting,
205 t_inputrec *ir, PmeRunMode runMode);
207 /*! \brief Calculate the PME grid energy V for n charges.
209 * The potential (found in \p pme) must have been found already with a
210 * call to gmx_pme_do() with at least GMX_PME_SPREAD and GMX_PME_SOLVE
211 * specified. Note that the charges are not spread on the grid in the
212 * pme struct. Currently does not work in parallel or with free
215 void gmx_pme_calc_energy(gmx_pme_t *pme,
216 gmx::ArrayRef<const gmx::RVec> x,
217 gmx::ArrayRef<const real> q,
220 /*! \brief Send the charges and maxshift to out PME-only node. */
221 void gmx_pme_send_parameters(const t_commrec *cr,
222 const interaction_const_t *ic,
223 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
224 real *chargeA, real *chargeB,
225 real *sqrt_c6A, real *sqrt_c6B,
226 real *sigmaA, real *sigmaB,
227 int maxshift_x, int maxshift_y);
229 /*! \brief Send the coordinates to our PME-only node and request a PME calculation */
230 void gmx_pme_send_coordinates(t_forcerec *fr, const t_commrec *cr, const matrix box, const rvec *x,
231 real lambda_q, real lambda_lj,
233 int64_t step, bool useGpuPmePpComms,
234 bool reinitGpuPmePpComms,
235 bool sendCoordinatesFromGpu, gmx_wallcycle *wcycle);
237 /*! \brief Tell our PME-only node to finish */
238 void gmx_pme_send_finish(const t_commrec *cr);
240 /*! \brief Tell our PME-only node to reset all cycle and flop counters */
241 void gmx_pme_send_resetcounters(const t_commrec *cr, int64_t step);
243 /*! \brief PP nodes receive the long range forces from the PME nodes */
244 void gmx_pme_receive_f(gmx::PmePpCommGpu *pmePpCommGpu,
246 gmx::ForceWithVirial *forceWithVirial,
247 real *energy_q, real *energy_lj,
248 real *dvdlambda_q, real *dvdlambda_lj,
249 bool useGpuPmePpComms, bool receivePmeForceToGpu,
253 * This function updates the local atom data on GPU after DD (charges, coordinates, etc.).
254 * TODO: it should update the PME CPU atom data as well.
255 * (currently PME CPU call gmx_pme_do() gets passed the input pointers for each computation).
257 * \param[in,out] pme The PME structure.
258 * \param[in] numAtoms The number of particles.
259 * \param[in] charges The pointer to the array of particle charges.
261 void gmx_pme_reinit_atoms(gmx_pme_t *pme,
263 const real *charges);
265 /* A block of PME GPU functions */
267 /*! \brief Checks whether the GROMACS build allows to run PME on GPU.
268 * TODO: this partly duplicates an internal PME assert function
269 * pme_gpu_check_restrictions(), except that works with a
270 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
272 * \param[out] error If non-null, the error message when PME is not supported on GPU.
274 * \returns true if PME can run on GPU on this build, false otherwise.
276 bool pme_gpu_supports_build(std::string *error);
278 /*! \brief Checks whether the detected (GPU) hardware allows to run PME on GPU.
280 * \param[in] hwinfo Information about the detected hardware
281 * \param[out] error If non-null, the error message when PME is not supported on GPU.
283 * \returns true if PME can run on GPU on this build, false otherwise.
285 bool pme_gpu_supports_hardware(const gmx_hw_info_t &hwinfo,
288 /*! \brief Checks whether the input system allows to run PME on GPU.
289 * TODO: this partly duplicates an internal PME assert function
290 * pme_gpu_check_restrictions(), except that works with a
291 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
293 * \param[in] ir Input system.
294 * \param[in] mtop Complete system topology to check if an FE simulation perturbs charges.
295 * \param[out] error If non-null, the error message if the input is not supported on GPU.
297 * \returns true if PME can run on GPU with this input, false otherwise.
299 bool pme_gpu_supports_input(const t_inputrec &ir, const gmx_mtop_t &mtop, std::string *error);
302 * Returns the active PME codepath (CPU, GPU, mixed).
303 * \todo This is a rather static data that should be managed by the higher level task scheduler.
305 * \param[in] pme The PME data structure.
306 * \returns active PME codepath.
308 PmeRunMode pme_run_mode(const gmx_pme_t *pme);
310 /*! \libinternal \brief
311 * Return the pinning policy appropriate for this build configuration
312 * for relevant buffers used for PME task on this rank (e.g. running
314 gmx::PinningPolicy pme_get_pinning_policy();
317 * Tells if PME is enabled to run on GPU (not necessarily active at the moment).
318 * \todo This is a rather static data that should be managed by the hardware assignment manager.
319 * For now, it is synonymous with the active PME codepath (in the absence of dynamic switching).
321 * \param[in] pme The PME data structure.
322 * \returns true if PME can run on GPU, false otherwise.
324 inline bool pme_gpu_task_enabled(const gmx_pme_t *pme)
326 return (pme != nullptr) && (pme_run_mode(pme) != PmeRunMode::CPU);
329 /*! \brief Returns the size of the padding needed by GPU version of PME in the coordinates array.
331 * \param[in] pme The PME data structure.
333 GPU_FUNC_QUALIFIER int pme_gpu_get_padding_size(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(0);
335 // The following functions are all the PME GPU entry points,
336 // currently inlining to nothing on non-CUDA builds.
339 * Resets the PME GPU timings. To be called at the reset step.
341 * \param[in] pme The PME structure.
343 GPU_FUNC_QUALIFIER void pme_gpu_reset_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM;
346 * Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.
348 * \param[in] pme The PME structure.
349 * \param[in] timings The gmx_wallclock_gpu_pme_t structure.
351 GPU_FUNC_QUALIFIER void pme_gpu_get_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
352 gmx_wallclock_gpu_pme_t *GPU_FUNC_ARGUMENT(timings)) GPU_FUNC_TERM;
354 /* The main PME GPU functions */
357 * Prepares PME on GPU computation (updating the box if needed)
358 * \param[in] pme The PME data structure.
359 * \param[in] needToUpdateBox Tells if the stored unit cell parameters should be updated from \p box.
360 * \param[in] box The unit cell box.
361 * \param[in] wcycle The wallclock counter.
362 * \param[in] flags The combination of flags to affect this PME computation.
363 * The flags are the GMX_PME_ flags from pme.h.
364 * \param[in] useGpuForceReduction Whether PME forces are reduced on GPU this step or should be downloaded for CPU reduction
366 GPU_FUNC_QUALIFIER void pme_gpu_prepare_computation(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
367 bool GPU_FUNC_ARGUMENT(needToUpdateBox),
368 const matrix GPU_FUNC_ARGUMENT(box),
369 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
370 int GPU_FUNC_ARGUMENT(flags),
371 bool GPU_FUNC_ARGUMENT(useGpuForceReduction)) GPU_FUNC_TERM;
374 * Launches first stage of PME on GPU - spreading kernel.
376 * \param[in] pme The PME data structure.
377 * \param[in] xReadyOnDevice Event synchronizer indicating that the coordinates are ready in the device memory; nullptr allowed only on separate PME ranks.
378 * \param[in] wcycle The wallclock counter.
380 GPU_FUNC_QUALIFIER void pme_gpu_launch_spread(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
381 GpuEventSynchronizer *GPU_FUNC_ARGUMENT(xReadyOnDevice),
382 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
385 * Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.
387 * \param[in] pme The PME data structure.
388 * \param[in] wcycle The wallclock counter.
390 GPU_FUNC_QUALIFIER void pme_gpu_launch_complex_transforms(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
391 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
394 * Launches last stage of PME on GPU - force gathering and D2H force transfer.
396 * \param[in] pme The PME data structure.
397 * \param[in] wcycle The wallclock counter.
398 * \param[in] forceTreatment Tells how data should be treated. The gathering kernel either stores
399 * the output reciprocal forces into the host array, or copies its contents to the GPU first
400 * and accumulates. The reduction is non-atomic.
402 GPU_FUNC_QUALIFIER void pme_gpu_launch_gather(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
403 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
404 PmeForceOutputHandling GPU_FUNC_ARGUMENT(forceTreatment)) GPU_FUNC_TERM;
407 * Attempts to complete PME GPU tasks.
409 * The \p completionKind argument controls whether the function blocks until all
410 * PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only
411 * checks and returns immediately if they did not.
412 * When blocking or the tasks have completed it also gets the output forces
413 * by assigning the ArrayRef to the \p forces pointer passed in.
414 * Virial/energy are also outputs if they were to be computed.
416 * \param[in] pme The PME data structure.
417 * \param[in] flags The combination of flags to affect this PME computation.
418 * The flags are the GMX_PME_ flags from pme.h.
419 * \param[in] wcycle The wallclock counter.
420 * \param[out] forceWithVirial The output force and virial
421 * \param[out] enerd The output energies
422 * \param[in] flags The combination of flags to affect this PME computation.
423 * The flags are the GMX_PME_ flags from pme.h.
424 * \param[in] completionKind Indicates whether PME task completion should only be checked rather than waited for
425 * \returns True if the PME GPU tasks have completed
427 GPU_FUNC_QUALIFIER bool
428 pme_gpu_try_finish_task(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
429 int GPU_FUNC_ARGUMENT(flags),
430 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
431 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
432 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd),
433 GpuTaskCompletion GPU_FUNC_ARGUMENT(completionKind)) GPU_FUNC_TERM_WITH_RETURN(false);
436 * Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy
437 * (if they were to be computed).
439 * \param[in] pme The PME data structure.
440 * \param[in] flags The combination of flags to affect this PME computation.
441 * The flags are the GMX_PME_ flags from pme.h.
442 * \param[in] wcycle The wallclock counter.
443 * \param[out] forceWithVirial The output force and virial
444 * \param[out] enerd The output energies
446 GPU_FUNC_QUALIFIER void
447 pme_gpu_wait_and_reduce(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
448 int GPU_FUNC_ARGUMENT(flags),
449 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
450 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
451 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd)) GPU_FUNC_TERM;
454 * The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.
456 * Clears the internal grid and energy/virial buffers; it is not safe to start
457 * the PME computation without calling this.
458 * Note that unlike in the nbnxn module, the force buffer does not need clearing.
460 * \todo Rename this function to *clear* -- it clearly only does output resetting
461 * and we should be clear about what the function does..
463 * \param[in] pme The PME data structure.
464 * \param[in] wcycle The wallclock counter.
466 GPU_FUNC_QUALIFIER void pme_gpu_reinit_computation(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
467 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM;
470 /*! \brief Get pointer to device copy of coordinate data.
471 * \param[in] pme The PME data structure.
472 * \returns Pointer to coordinate data
474 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> {});
476 /*! \brief Set pointer to device copy of coordinate data.
477 * \param[in] pme The PME data structure.
478 * \param[in] d_x The pointer to the positions buffer to be set
480 GPU_FUNC_QUALIFIER void pme_gpu_set_device_x(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
481 DeviceBuffer<float> GPU_FUNC_ARGUMENT(d_x)) GPU_FUNC_TERM;
483 /*! \brief Get pointer to device copy of force data.
484 * \param[in] pme The PME data structure.
485 * \returns Pointer to force data
487 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_f(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
489 /*! \brief Returns the pointer to the GPU stream.
490 * \param[in] pme The PME data structure.
491 * \returns Pointer to GPU stream object.
493 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_stream(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
495 /*! \brief Returns the pointer to the GPU context.
496 * \param[in] pme The PME data structure.
497 * \returns Pointer to GPU context object.
499 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_context(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);
501 /*! \brief Get pointer to the device synchronizer object that allows syncing on PME force calculation completion
502 * \param[in] pme The PME data structure.
503 * \returns Pointer to sychronizer
505 GPU_FUNC_QUALIFIER GpuEventSynchronizer *pme_gpu_get_f_ready_synchronizer(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr);