#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/mdtypes/inputrec.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-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
PmeRunMode	pme_run_mode (const gmx_pme_t *pme)
	Returns the active PME codepath (CPU, GPU, mixed). More...

bool	pme_gpu_supports_input (const t_inputrec ir, std::string error)
	Checks whether the input system allows to run PME on GPU. TODO: this mostly duplicates an internal PME assert function pme_gpu_check_restrictions(), except that works with a formed gmx_pme_t structure. Should that one go away/work with inputrec? 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...

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, bool needToUpdateBox, const matrix box, gmx_wallcycle_t wcycle, int flags)
	Prepares PME on GPU computation (updating the box if needed) More...

void	pme_gpu_launch_spread (gmx_pme_t pme, const rvec x, gmx_wallcycle_t wcycle)
	Launches first stage of PME on GPU - H2D input transfers, spreading kernel, and D2H grid transfer if needed. More...

void	pme_gpu_launch_complex_transforms (gmx_pme_t *pme, gmx_wallcycle_t wcycle)
	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_t wcycle, PmeForceOutputHandling forceTreatment)
	Launches last stage of PME on GPU - force gathering and D2H force transfer. More...

static void	pme_gpu_get_staged_results (const gmx_pme_t pme, gmx::ArrayRef< const gmx::RVec > forces, matrix virial, real *energy)
	Reduce staged virial and energy outputs. More...

bool	pme_gpu_try_finish_task (const gmx_pme_t pme, gmx_wallcycle_t wcycle, gmx::ArrayRef< const gmx::RVec > forces, matrix virial, real *energy, GpuTaskCompletion completionKind)
	Attempts to complete PME GPU tasks. More...

void	pme_gpu_wait_finish_task (const gmx_pme_t pme, gmx_wallcycle_t wcycle, gmx::ArrayRef< const gmx::RVec > forces, matrix virial, real *energy)
	Blocks until PME GPU tasks are completed, and gets the output forces and virial/energy (if they were to be computed). 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]	pme	The PME structure.
[in]	gridIndex	The grid index - should currently always be 0.
[in]	dir	The FFT direction enum.
[in]	wcycle	The wallclock counter.

static void pme_gpu_get_staged_results	(	const gmx_pme_t *	pme,
		gmx::ArrayRef< const gmx::RVec > *	forces,
		matrix	virial,
		real *	energy
	)

static

Reduce staged virial and energy outputs.

Parameters

[in]	pme	The PME data structure.
[out]	forces	Output forces pointer, the internal ArrayRef pointers gets assigned to it.
[out]	virial	The output virial matrix.
[out]	energy	The output energy.

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]	pme	The PME structure.
[in]	timings	The gmx_wallclock_gpu_pme_t structure.

void pme_gpu_launch_complex_transforms	(	gmx_pme_t *	pme,
		gmx_wallcycle_t	wcycle
	)

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

Parameters

[in]	pme	The PME data structure.
[in]	wcycle	The wallclock counter.

void pme_gpu_launch_gather	(	const gmx_pme_t *	pme,
		gmx_wallcycle_t	wcycle,
		PmeForceOutputHandling	forceTreatment
	)

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

Parameters

[in]	pme	The PME data structure.
[in]	wcycle	The wallclock counter.
[in]	forceTreatment	Tells how data should be treated. The gathering kernel either stores the output reciprocal forces into the host array, or copies its contents to the GPU first and accumulates. The reduction is non-atomic.

void pme_gpu_launch_spread	(	gmx_pme_t *	pme,
		const rvec *	x,
		gmx_wallcycle_t	wcycle
	)

Launches first stage of PME on GPU - H2D input transfers, spreading kernel, and D2H grid transfer if needed.

Parameters

[in]	pme	The PME data structure.
[in]	x	The array of local atoms' coordinates.
[in]	wcycle	The wallclock counter.

void pme_gpu_prepare_computation	(	gmx_pme_t *	pme,
		bool	needToUpdateBox,
		const matrix	box,
		gmx_wallcycle_t	wcycle,
		int	flags
	)

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

Parameters

[in]	pme	The PME data structure.
[in]	needToUpdateBox	Tells if the stored unit cell parameters should be updated from `box`.
[in]	box	The unit cell box.
[in]	wcycle	The wallclock counter.
[in]	flags	The combination of flags to affect this PME computation. The flags are the GMX_PME_ flags from pme.h.

void pme_gpu_reset_timings ( const gmx_pme_t * pme )

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

Parameters

[in] pme The PME structure.

bool pme_gpu_supports_input	(	const t_inputrec *	ir,
		std::string *	error
	)

Checks whether the input system allows to run PME on GPU. TODO: this mostly duplicates an internal PME assert function pme_gpu_check_restrictions(), except that works with a formed gmx_pme_t structure. Should that one go away/work with inputrec?

Parameters

[in]	ir	Input system.
[out]	error	The error message if the input is not supported on GPU.

Returns: true if PME can run on GPU with this input, false otherwise.

bool pme_gpu_try_finish_task	(	const gmx_pme_t *	pme,
		gmx_wallcycle_t	wcycle,
		gmx::ArrayRef< const gmx::RVec > *	forces,
		matrix	virial,
		real *	energy,
		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.

Note: also launches the reinitalization of the PME output buffers. TODO: this should be moved out to avoid miscounting its wall-time (as wait iso launch).

Parameters

[in]	pme	The PME data structure.
[in]	wcycle	The wallclock counter.
[out]	forces	The output forces.
[out]	virial	The output virial matrix.
[out]	energy	The output energy.
[in]	completionKind	Indicates 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_finish_task	(	const gmx_pme_t *	pme,
		gmx_wallcycle_t	wcycle,
		gmx::ArrayRef< const gmx::RVec > *	forces,
		matrix	virial,
		real *	energy
	)

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

Parameters

[in]	pme	The PME data structure.
[out]	wcycle	The wallclock counter.
[out]	forces	The output forces.
[out]	virial	The output virial matrix.
[out]	energy	The output energy.

PmeRunMode pme_run_mode ( const gmx_pme_t * pme )

Returns the active PME codepath (CPU, GPU, mixed).

Todo:: This is a rather static data that should be managed by the higher level task scheduler.

Parameters

[in] pme The PME data structure.

Returns: active PME codepath.

Description

Functions

Function Documentation