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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/gpu_macros.h"
54 #include "gromacs/math/vectypes.h"
55 #include "gromacs/timing/walltime_accounting.h"
56 #include "gromacs/utility/arrayref.h"
57 #include "gromacs/utility/basedefinitions.h"
58 #include "gromacs/utility/real.h"
61 struct interaction_const_t;
66 struct gmx_wallclock_gpu_pme_t;
67 struct gmx_device_info_t;
68 struct gmx_enerdata_t;
74 enum class GpuTaskCompletion;
77 using PmeGpuProgramHandle = const PmeGpuProgram *;
81 class ForceWithVirial;
83 enum class PinningPolicy : int;
87 GMX_SUM_GRID_FORWARD, GMX_SUM_GRID_BACKWARD
90 /*! \brief Possible PME codepaths on a rank.
91 * \todo: make this enum class with gmx_pme_t C++ refactoring
95 None, //!< No PME task is done
96 CPU, //!< Whole PME computation is done on CPU
97 GPU, //!< Whole PME computation is done on GPU
98 Mixed, //!< Mixed mode: only spread and gather run on GPU; FFT and solving are done on CPU.
101 //! PME gathering output forces treatment
102 enum class PmeForceOutputHandling
104 Set, /**< Gather simply writes into provided force buffer */
105 ReduceWithInput, /**< Gather adds its output to the buffer.
106 On GPU, that means additional H2D copy before the kernel launch. */
109 /*! \brief Return the smallest allowed PME grid size for \p pmeOrder */
110 int minimalPmeGridSize(int pmeOrder);
112 /*! \brief Check restrictions on pme_order and the PME grid nkx,nky,nkz.
114 * With errorsAreFatal=true, an exception or fatal error is generated
115 * on violation of restrictions.
116 * With errorsAreFatal=false, false is returned on violation of restrictions.
117 * When all restrictions are obeyed, true is returned.
118 * Argument useThreads tells if any MPI rank doing PME uses more than 1 threads.
119 * If at calling useThreads is unknown, pass true for conservative checking.
121 * The PME GPU restrictions are checked separately during pme_gpu_init().
123 bool gmx_pme_check_restrictions(int pme_order,
124 int nkx, int nky, int nkz,
125 int numPmeDomainsAlongX,
127 bool errorsAreFatal);
129 /*! \brief Construct PME data
131 * \throws gmx::InconsistentInputError if input grid sizes/PME order are inconsistent.
132 * \returns Pointer to newly allocated and initialized PME data.
134 * \todo We should evolve something like a \c GpuManager that holds \c
135 * gmx_device_info_t * and \c PmeGpuProgramHandle and perhaps other
136 * related things whose lifetime can/should exceed that of a task (or
137 * perhaps task manager). See Redmine #2522.
139 gmx_pme_t *gmx_pme_init(const t_commrec *cr,
140 const NumPmeDomains &numPmeDomains,
141 const t_inputrec *ir,
142 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
143 gmx_bool bReproducible,
144 real ewaldcoeff_q, real ewaldcoeff_lj,
148 const gmx_device_info_t *gpuInfo,
149 PmeGpuProgramHandle pmeGpuProgram,
150 const gmx::MDLogger &mdlog);
152 /*! \brief Destroys the PME data structure.*/
153 void gmx_pme_destroy(gmx_pme_t *pme);
156 /*! \brief Flag values that control what gmx_pme_do() will calculate
158 * These can be combined with bitwise-OR if more than one thing is required.
160 #define GMX_PME_SPREAD (1<<0)
161 #define GMX_PME_SOLVE (1<<1)
162 #define GMX_PME_CALC_F (1<<2)
163 #define GMX_PME_CALC_ENER_VIR (1<<3)
164 /* This forces the grid to be backtransformed even without GMX_PME_CALC_F */
165 #define GMX_PME_CALC_POT (1<<4)
167 #define GMX_PME_DO_ALL_F (GMX_PME_SPREAD | GMX_PME_SOLVE | GMX_PME_CALC_F)
170 /*! \brief Do a PME calculation on a CPU for the long range electrostatics and/or LJ.
172 * Computes the PME forces and the energy and viral, when requested,
173 * for all atoms in \p coordinates. Forces, when requested, are added
174 * to the buffer \p forces, which is allowed to contain more elements
175 * than the number of elements in \p coordinates.
176 * The meaning of \p flags is defined above, and determines which
177 * parts of the calculation are performed.
179 * \return 0 indicates all well, non zero is an error code.
181 int gmx_pme_do(struct gmx_pme_t *pme,
182 gmx::ArrayRef<const gmx::RVec> coordinates,
183 gmx::ArrayRef<gmx::RVec> forces,
184 real chargeA[], real chargeB[],
185 real c6A[], real c6B[],
186 real sigmaA[], real sigmaB[],
187 const matrix box, const t_commrec *cr,
188 int maxshift_x, int maxshift_y,
189 t_nrnb *nrnb, gmx_wallcycle *wcycle,
190 matrix vir_q, matrix vir_lj,
191 real *energy_q, real *energy_lj,
192 real lambda_q, real lambda_lj,
193 real *dvdlambda_q, real *dvdlambda_lj,
196 /*! \brief Called on the nodes that do PME exclusively */
197 int gmx_pmeonly(struct gmx_pme_t *pme,
198 const t_commrec *cr, t_nrnb *mynrnb,
199 gmx_wallcycle *wcycle,
200 gmx_walltime_accounting_t walltime_accounting,
201 t_inputrec *ir, PmeRunMode runMode);
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() with at least GMX_PME_SPREAD and GMX_PME_SOLVE
207 * specified. Note that the charges are not spread on the grid in the
208 * pme struct. Currently does not work in parallel or with free
211 void gmx_pme_calc_energy(gmx_pme_t *pme,
212 gmx::ArrayRef<const gmx::RVec> x,
213 gmx::ArrayRef<const real> q,
216 /*! \brief Send the charges and maxshift to out PME-only node. */
217 void gmx_pme_send_parameters(const t_commrec *cr,
218 const interaction_const_t *ic,
219 gmx_bool bFreeEnergy_q, gmx_bool bFreeEnergy_lj,
220 real *chargeA, real *chargeB,
221 real *sqrt_c6A, real *sqrt_c6B,
222 real *sigmaA, real *sigmaB,
223 int maxshift_x, int maxshift_y);
225 /*! \brief Send the coordinates to our PME-only node and request a PME calculation */
226 void gmx_pme_send_coordinates(const t_commrec *cr, matrix box, rvec *x,
227 real lambda_q, real lambda_lj,
229 int64_t step, gmx_wallcycle *wcycle);
231 /*! \brief Tell our PME-only node to finish */
232 void gmx_pme_send_finish(const t_commrec *cr);
234 /*! \brief Tell our PME-only node to reset all cycle and flop counters */
235 void gmx_pme_send_resetcounters(const t_commrec *cr, int64_t step);
237 /*! \brief PP nodes receive the long range forces from the PME nodes */
238 void gmx_pme_receive_f(const t_commrec *cr,
239 gmx::ForceWithVirial *forceWithVirial,
240 real *energy_q, real *energy_lj,
241 real *dvdlambda_q, real *dvdlambda_lj,
245 * This function updates the local atom data on GPU after DD (charges, coordinates, etc.).
246 * TODO: it should update the PME CPU atom data as well.
247 * (currently PME CPU call gmx_pme_do() gets passed the input pointers for each computation).
249 * \param[in,out] pme The PME structure.
250 * \param[in] numAtoms The number of particles.
251 * \param[in] charges The pointer to the array of particle charges.
253 void gmx_pme_reinit_atoms(gmx_pme_t *pme,
255 const real *charges);
257 /* A block of PME GPU functions */
259 /*! \brief Checks whether the GROMACS build allows to run PME on GPU.
260 * TODO: this partly duplicates an internal PME assert function
261 * pme_gpu_check_restrictions(), except that works with a
262 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
264 * \param[out] error If non-null, the error message when PME is not supported on GPU.
266 * \returns true if PME can run on GPU on this build, false otherwise.
268 bool pme_gpu_supports_build(std::string *error);
270 /*! \brief Checks whether the detected (GPU) hardware allows to run PME on GPU.
272 * \param[in] hwinfo Information about the detected hardware
273 * \param[out] error If non-null, the error message when PME is not supported on GPU.
275 * \returns true if PME can run on GPU on this build, false otherwise.
277 bool pme_gpu_supports_hardware(const gmx_hw_info_t &hwinfo,
280 /*! \brief Checks whether the input system allows to run PME on GPU.
281 * TODO: this partly duplicates an internal PME assert function
282 * pme_gpu_check_restrictions(), except that works with a
283 * formed gmx_pme_t structure. Should that one go away/work with inputrec?
285 * \param[in] ir Input system.
286 * \param[in] mtop Complete system topology to check if an FE simulation perturbs charges.
287 * \param[out] error If non-null, the error message if the input is not supported on GPU.
289 * \returns true if PME can run on GPU with this input, false otherwise.
291 bool pme_gpu_supports_input(const t_inputrec &ir, const gmx_mtop_t &mtop, std::string *error);
294 * Returns the active PME codepath (CPU, GPU, mixed).
295 * \todo This is a rather static data that should be managed by the higher level task scheduler.
297 * \param[in] pme The PME data structure.
298 * \returns active PME codepath.
300 PmeRunMode pme_run_mode(const gmx_pme_t *pme);
302 /*! \libinternal \brief
303 * Return the pinning policy appropriate for this build configuration
304 * for relevant buffers used for PME task on this rank (e.g. running
306 gmx::PinningPolicy pme_get_pinning_policy();
309 * Tells if PME is enabled to run on GPU (not necessarily active at the moment).
310 * \todo This is a rather static data that should be managed by the hardware assignment manager.
311 * For now, it is synonymous with the active PME codepath (in the absence of dynamic switching).
313 * \param[in] pme The PME data structure.
314 * \returns true if PME can run on GPU, false otherwise.
316 inline bool pme_gpu_task_enabled(const gmx_pme_t *pme)
318 return (pme != nullptr) && (pme_run_mode(pme) != PmeRunMode::CPU);
321 // The following functions are all the PME GPU entry points,
322 // currently inlining to nothing on non-CUDA builds.
325 * Resets the PME GPU timings. To be called at the reset step.
327 * \param[in] pme The PME structure.
329 GPU_FUNC_QUALIFIER void pme_gpu_reset_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM
332 * Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.
334 * \param[in] pme The PME structure.
335 * \param[in] timings The gmx_wallclock_gpu_pme_t structure.
337 GPU_FUNC_QUALIFIER void pme_gpu_get_timings(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
338 gmx_wallclock_gpu_pme_t *GPU_FUNC_ARGUMENT(timings)) GPU_FUNC_TERM
340 /* The main PME GPU functions */
343 * Prepares PME on GPU computation (updating the box if needed)
344 * \param[in] pme The PME data structure.
345 * \param[in] needToUpdateBox Tells if the stored unit cell parameters should be updated from \p box.
346 * \param[in] box The unit cell box.
347 * \param[in] wcycle The wallclock counter.
348 * \param[in] flags The combination of flags to affect this PME computation.
349 * The flags are the GMX_PME_ flags from pme.h.
351 GPU_FUNC_QUALIFIER void pme_gpu_prepare_computation(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
352 bool GPU_FUNC_ARGUMENT(needToUpdateBox),
353 const matrix GPU_FUNC_ARGUMENT(box),
354 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
355 int GPU_FUNC_ARGUMENT(flags)) GPU_FUNC_TERM
358 * Launches first stage of PME on GPU - H2D input transfers, spreading kernel, and D2H grid transfer if needed.
360 * \param[in] pme The PME data structure.
361 * \param[in] x The array of local atoms' coordinates.
362 * \param[in] wcycle The wallclock counter.
364 GPU_FUNC_QUALIFIER void pme_gpu_launch_spread(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
365 const rvec *GPU_FUNC_ARGUMENT(x),
366 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM
369 * Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.
371 * \param[in] pme The PME data structure.
372 * \param[in] wcycle The wallclock counter.
374 GPU_FUNC_QUALIFIER void pme_gpu_launch_complex_transforms(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
375 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM
378 * Launches last stage of PME on GPU - force gathering and D2H force transfer.
380 * \param[in] pme The PME data structure.
381 * \param[in] wcycle The wallclock counter.
382 * \param[in] forceTreatment Tells how data should be treated. The gathering kernel either stores
383 * the output reciprocal forces into the host array, or copies its contents to the GPU first
384 * and accumulates. The reduction is non-atomic.
386 GPU_FUNC_QUALIFIER void pme_gpu_launch_gather(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
387 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
388 PmeForceOutputHandling GPU_FUNC_ARGUMENT(forceTreatment)) GPU_FUNC_TERM
391 * Attempts to complete PME GPU tasks.
393 * The \p completionKind argument controls whether the function blocks until all
394 * PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only
395 * checks and returns immediately if they did not.
396 * When blocking or the tasks have completed it also gets the output forces
397 * by assigning the ArrayRef to the \p forces pointer passed in.
398 * Virial/energy are also outputs if they were to be computed.
400 * \param[in] pme The PME data structure.
401 * \param[in] flags The combination of flags to affect this PME computation.
402 * The flags are the GMX_PME_ flags from pme.h.
403 * \param[in] wcycle The wallclock counter.
404 * \param[out] forceWithVirial The output force and virial
405 * \param[out] enerd The output energies
406 * \param[in] flags The combination of flags to affect this PME computation.
407 * The flags are the GMX_PME_ flags from pme.h.
408 * \param[in] completionKind Indicates whether PME task completion should only be checked rather than waited for
409 * \returns True if the PME GPU tasks have completed
411 GPU_FUNC_QUALIFIER bool
412 pme_gpu_try_finish_task(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
413 int GPU_FUNC_ARGUMENT(flags),
414 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
415 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
416 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd),
417 GpuTaskCompletion GPU_FUNC_ARGUMENT(completionKind)) GPU_FUNC_TERM_WITH_RETURN(false)
420 * Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy
421 * (if they were to be computed).
423 * \param[in] pme The PME data structure.
424 * \param[in] flags The combination of flags to affect this PME computation.
425 * The flags are the GMX_PME_ flags from pme.h.
426 * \param[in] wcycle The wallclock counter.
427 * \param[out] forceWithVirial The output force and virial
428 * \param[out] enerd The output energies
430 GPU_FUNC_QUALIFIER void
431 pme_gpu_wait_and_reduce(gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
432 int GPU_FUNC_ARGUMENT(flags),
433 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle),
434 gmx::ForceWithVirial *GPU_FUNC_ARGUMENT(forceWithVirial),
435 gmx_enerdata_t *GPU_FUNC_ARGUMENT(enerd)) GPU_FUNC_TERM
438 * The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.
440 * Clears the internal grid and energy/virial buffers; it is not safe to start
441 * the PME computation without calling this.
442 * Note that unlike in the nbnxn module, the force buffer does not need clearing.
444 * \todo Rename this function to *clear* -- it clearly only does output resetting
445 * and we should be clear about what the function does..
447 * \param[in] pme The PME data structure.
448 * \param[in] wcycle The wallclock counter.
450 GPU_FUNC_QUALIFIER void pme_gpu_reinit_computation(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme),
451 gmx_wallcycle *GPU_FUNC_ARGUMENT(wcycle)) GPU_FUNC_TERM
454 /*! \brief Get pointer to device copy of coordinate data. */
455 GPU_FUNC_QUALIFIER void *pme_gpu_get_device_x(const gmx_pme_t *GPU_FUNC_ARGUMENT(pme)) GPU_FUNC_TERM_WITH_RETURN(nullptr)