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#include "gmxpre.h"
#include "config.h"
#include <list>
#include "gromacs/ewald/ewald_utils.h"
#include "gromacs/ewald/pme.h"
#include "gromacs/fft/parallel_3dfft.h"
#include "gromacs/math/invertmatrix.h"
#include "gromacs/mdlib/gmx_omp_nthreads.h"
#include "gromacs/mdtypes/enerdata.h"
#include "gromacs/mdtypes/forceoutput.h"
#include "gromacs/mdtypes/inputrec.h"
#include "gromacs/mdtypes/simulation_workload.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/fatalerror.h"
#include "gromacs/utility/gmxassert.h"
#include "gromacs/utility/stringutil.h"
#include "pme_gpu_internal.h"
#include "pme_gpu_settings.h"
#include "pme_gpu_timings.h"
#include "pme_gpu_types_host.h"
#include "pme_grid.h"
#include "pme_internal.h"
#include "pme_solve.h"
+ Include dependency graph for pme_gpu.cpp:

Description

Implements high-level PME GPU functions which do not require GPU framework-specific code.

Author
Aleksei Iupinov a.yup.nosp@m.inov.nosp@m.@gmai.nosp@m.l.co.nosp@m.m

Functions

static bool pme_gpu_active (const gmx_pme_t *pme)
 Finds out if PME is currently running on GPU. More...
 
void pme_gpu_reset_timings (const gmx_pme_t *pme)
 Resets the PME GPU timings. To be called at the reset step. More...
 
void pme_gpu_get_timings (const gmx_pme_t *pme, gmx_wallclock_gpu_pme_t *timings)
 Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end. More...
 
int pme_gpu_get_block_size (const gmx_pme_t *pme)
 Returns the block size requirement. More...
 
void parallel_3dfft_execute_gpu_wrapper (gmx_pme_t *pme, const int gridIndex, enum gmx_fft_direction dir, gmx_wallcycle_t wcycle)
 A convenience wrapper for launching either the GPU or CPU FFT. More...
 
void pme_gpu_prepare_computation (gmx_pme_t *pme, const matrix box, gmx_wallcycle *wcycle, const gmx::StepWorkload &stepWork)
 Prepares PME on GPU computation (updating the box if needed) More...
 
void pme_gpu_launch_spread (gmx_pme_t *pme, GpuEventSynchronizer *xReadyOnDevice, gmx_wallcycle *wcycle, const real lambdaQ)
 Launches first stage of PME on GPU - spreading kernel. More...
 
void pme_gpu_launch_complex_transforms (gmx_pme_t *pme, gmx_wallcycle *wcycle, const gmx::StepWorkload &stepWork)
 Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode. More...
 
void pme_gpu_launch_gather (const gmx_pme_t *pme, gmx_wallcycle *wcycle, const real lambdaQ)
 Launches last stage of PME on GPU - force gathering and D2H force transfer. More...
 
static void sum_forces (gmx::ArrayRef< gmx::RVec > f, gmx::ArrayRef< const gmx::RVec > forceToAdd)
 Accumulate the forcesToAdd to f, using the available threads.
 
static void pme_gpu_reduce_outputs (const bool computeEnergyAndVirial, const PmeOutput &output, gmx_wallcycle *wcycle, gmx::ForceWithVirial *forceWithVirial, gmx_enerdata_t *enerd)
 Reduce quantities from output to forceWithVirial and enerd.
 
bool pme_gpu_try_finish_task (gmx_pme_t *pme, const gmx::StepWorkload &stepWork, gmx_wallcycle *wcycle, gmx::ForceWithVirial *forceWithVirial, gmx_enerdata_t *enerd, const real lambdaQ, GpuTaskCompletion completionKind)
 Attempts to complete PME GPU tasks. More...
 
PmeOutput pme_gpu_wait_finish_task (gmx_pme_t *pme, const bool computeEnergyAndVirial, const real lambdaQ, gmx_wallcycle *wcycle)
 Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy (if they were to be computed). More...
 
void pme_gpu_wait_and_reduce (gmx_pme_t *pme, const gmx::StepWorkload &stepWork, gmx_wallcycle *wcycle, gmx::ForceWithVirial *forceWithVirial, gmx_enerdata_t *enerd, const real lambdaQ)
 Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy (if they were to be computed). More...
 
void pme_gpu_reinit_computation (const gmx_pme_t *pme, gmx_wallcycle *wcycle)
 The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing. More...
 
void * pme_gpu_get_device_f (const gmx_pme_t *pme)
 Get pointer to device copy of force data. More...
 
void pme_gpu_set_device_x (const gmx_pme_t *pme, DeviceBuffer< gmx::RVec > d_x)
 Set pointer to device copy of coordinate data. More...
 
GpuEventSynchronizer * pme_gpu_get_f_ready_synchronizer (const gmx_pme_t *pme)
 Get pointer to the device synchronizer object that allows syncing on PME force calculation completion. More...
 

Function Documentation

void parallel_3dfft_execute_gpu_wrapper ( gmx_pme_t *  pme,
const int  gridIndex,
enum gmx_fft_direction  dir,
gmx_wallcycle_t  wcycle 
)
inline

A convenience wrapper for launching either the GPU or CPU FFT.

Parameters
[in]pmeThe PME structure.
[in]gridIndexThe grid index - should currently always be 0.
[in]dirThe FFT direction enum.
[in]wcycleThe wallclock counter.
static bool pme_gpu_active ( const gmx_pme_t *  pme)
inlinestatic

Finds out if PME is currently running on GPU.

Todo:
The GPU module should not be constructed (or at least called) when it is not active, so there should be no need to check whether it is active. An assertion that this is true makes sense.
Parameters
[in]pmeThe PME structure.
Returns
True if PME runs on GPU currently, false otherwise.
int pme_gpu_get_block_size ( const gmx_pme_t *  pme)

Returns the block size requirement.

The GPU version of PME requires that the coordinates array have a size divisible by the returned number.

Parameters
[in]pmeThe PME data structure.
void* pme_gpu_get_device_f ( const gmx_pme_t *  pme)

Get pointer to device copy of force data.

Parameters
[in]pmeThe PME data structure.
Returns
Pointer to force data
GpuEventSynchronizer* pme_gpu_get_f_ready_synchronizer ( const gmx_pme_t *  pme)

Get pointer to the device synchronizer object that allows syncing on PME force calculation completion.

Parameters
[in]pmeThe PME data structure.
Returns
Pointer to sychronizer
void pme_gpu_get_timings ( const gmx_pme_t *  pme,
gmx_wallclock_gpu_pme_t timings 
)

Copies the PME GPU timings to the gmx_wallclock_gpu_pme_t structure (for log output). To be called at the run end.

Parameters
[in]pmeThe PME structure.
[in]timingsThe gmx_wallclock_gpu_pme_t structure.
void pme_gpu_launch_complex_transforms ( gmx_pme_t *  pme,
gmx_wallcycle *  wcycle,
const gmx::StepWorkload stepWork 
)

Launches middle stages of PME (FFT R2C, solving, FFT C2R) either on GPU or on CPU, depending on the run mode.

Parameters
[in]pmeThe PME data structure.
[in]wcycleThe wallclock counter.
[in]stepWorkThe required work for this simulation step
void pme_gpu_launch_gather ( const gmx_pme_t *  pme,
gmx_wallcycle *  wcycle,
real  lambdaQ 
)

Launches last stage of PME on GPU - force gathering and D2H force transfer.

Parameters
[in]pmeThe PME data structure.
[in]wcycleThe wallclock counter.
[in]lambdaQThe Coulomb lambda to use when calculating the results.
void pme_gpu_launch_spread ( gmx_pme_t *  pme,
GpuEventSynchronizer *  xReadyOnDevice,
gmx_wallcycle *  wcycle,
real  lambdaQ 
)

Launches first stage of PME on GPU - spreading kernel.

Parameters
[in]pmeThe PME data structure.
[in]xReadyOnDeviceEvent synchronizer indicating that the coordinates are ready in the device memory; nullptr allowed only on separate PME ranks.
[in]wcycleThe wallclock counter.
[in]lambdaQThe Coulomb lambda of the current state of the system. Only used if FEP of Coulomb is active.
void pme_gpu_prepare_computation ( gmx_pme_t *  pme,
const matrix  box,
gmx_wallcycle *  wcycle,
const gmx::StepWorkload stepWork 
)

Prepares PME on GPU computation (updating the box if needed)

Parameters
[in]pmeThe PME data structure.
[in]boxThe unit cell box.
[in]wcycleThe wallclock counter.
[in]stepWorkThe required work for this simulation step
void pme_gpu_reinit_computation ( const gmx_pme_t *  pme,
gmx_wallcycle *  wcycle 
)

The PME GPU reinitialization function that is called both at the end of any PME computation and on any load balancing.

Clears the internal grid and energy/virial buffers; it is not safe to start the PME computation without calling this. Note that unlike in the nbnxn module, the force buffer does not need clearing.

Todo:
Rename this function to clear – it clearly only does output resetting and we should be clear about what the function does..
Parameters
[in]pmeThe PME data structure.
[in]wcycleThe wallclock counter.
void pme_gpu_reset_timings ( const gmx_pme_t *  pme)

Resets the PME GPU timings. To be called at the reset step.

Parameters
[in]pmeThe PME structure.
void pme_gpu_set_device_x ( const gmx_pme_t *  pme,
DeviceBuffer< gmx::RVec d_x 
)

Set pointer to device copy of coordinate data.

Parameters
[in]pmeThe PME data structure.
[in]d_xThe pointer to the positions buffer to be set
bool pme_gpu_try_finish_task ( gmx_pme_t *  pme,
const gmx::StepWorkload stepWork,
gmx_wallcycle *  wcycle,
gmx::ForceWithVirial forceWithVirial,
gmx_enerdata_t enerd,
real  lambdaQ,
GpuTaskCompletion  completionKind 
)

Attempts to complete PME GPU tasks.

The completionKind argument controls whether the function blocks until all PME GPU tasks enqueued completed (as pme_gpu_wait_finish_task() does) or only checks and returns immediately if they did not. When blocking or the tasks have completed it also gets the output forces by assigning the ArrayRef to the forces pointer passed in. Virial/energy are also outputs if they were to be computed.

Parameters
[in]pmeThe PME data structure.
[in]stepWorkThe required work for this simulation step
[in]wcycleThe wallclock counter.
[out]forceWithVirialThe output force and virial
[out]enerdThe output energies
[in]lambdaQThe Coulomb lambda to use when calculating the results.
[in]completionKindIndicates whether PME task completion should only be checked rather than waited for
Returns
True if the PME GPU tasks have completed
void pme_gpu_wait_and_reduce ( gmx_pme_t *  pme,
const gmx::StepWorkload stepWork,
gmx_wallcycle *  wcycle,
gmx::ForceWithVirial forceWithVirial,
gmx_enerdata_t enerd,
real  lambdaQ 
)

Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy (if they were to be computed).

Parameters
[in]pmeThe PME data structure.
[in]stepWorkThe required work for this simulation step
[in]wcycleThe wallclock counter.
[out]forceWithVirialThe output force and virial
[out]enerdThe output energies
[in]lambdaQThe Coulomb lambda to use when calculating the results.
PmeOutput pme_gpu_wait_finish_task ( gmx_pme_t *  pme,
bool  computeEnergyAndVirial,
real  lambdaQ,
gmx_wallcycle *  wcycle 
)

Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy (if they were to be computed).

Parameters
[in]pmeThe PME data structure.
[in]computeEnergyAndVirialTells if the energy and virial computation should be performed.
[in]lambdaQThe Coulomb lambda to use when calculating the results.
[out]wcycleThe wallclock counter.
Returns
The output forces, energy and virial