Occupancy

Functions

Occupancy

HIP API

Collaboration diagram for Occupancy:

Functions
hipError_t	hipModuleOccupancyMaxPotentialBlockSize (int *gridSize, int *blockSize, hipFunction_t f, size_t dynSharedMemPerBlk, int blockSizeLimit)
	determine the grid and block sizes to achieves maximum occupancy for a kernel More...
hipError_t	hipModuleOccupancyMaxPotentialBlockSizeWithFlags (int *gridSize, int *blockSize, hipFunction_t f, size_t dynSharedMemPerBlk, int blockSizeLimit, unsigned int flags)
	determine the grid and block sizes to achieves maximum occupancy for a kernel More...
hipError_t	hipModuleOccupancyMaxActiveBlocksPerMultiprocessor (int *numBlocks, hipFunction_t f, int blockSize, size_t dynSharedMemPerBlk)
	Returns occupancy for a device function. More...
hipError_t	hipModuleOccupancyMaxActiveBlocksPerMultiprocessorWithFlags (int *numBlocks, hipFunction_t f, int blockSize, size_t dynSharedMemPerBlk, unsigned int flags)
	Returns occupancy for a device function. More...
hipError_t	hipOccupancyMaxActiveBlocksPerMultiprocessor (int *numBlocks, const void *f, int blockSize, size_t dynSharedMemPerBlk)
	Returns occupancy for a device function. More...
hipError_t	hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags (int *numBlocks, const void *f, int blockSize, size_t dynSharedMemPerBlk, unsigned int flags __dparm(hipOccupancyDefault))
	Returns occupancy for a device function. More...
hipError_t	hipOccupancyMaxPotentialBlockSize (int *gridSize, int *blockSize, const void *f, size_t dynSharedMemPerBlk, int blockSizeLimit)
	determine the grid and block sizes to achieves maximum occupancy for a kernel More...

Detailed Description

This section describes the occupancy functions of HIP runtime API.

Function Documentation

◆ hipModuleOccupancyMaxActiveBlocksPerMultiprocessor()

hipError_t hipModuleOccupancyMaxActiveBlocksPerMultiprocessor	(	int *	numBlocks,
		hipFunction_t	f,
		int	blockSize,
		size_t	dynSharedMemPerBlk
	)

Returns occupancy for a device function.

Parameters

[out]	numBlocks	Returned occupancy
[in]	func	Kernel function (hipFunction) for which occupancy is calulated
[in]	blockSize	Block size the kernel is intended to be launched with
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block

◆ hipModuleOccupancyMaxActiveBlocksPerMultiprocessorWithFlags()

hipError_t hipModuleOccupancyMaxActiveBlocksPerMultiprocessorWithFlags	(	int *	numBlocks,
		hipFunction_t	f,
		int	blockSize,
		size_t	dynSharedMemPerBlk,
		unsigned int	flags
	)

Returns occupancy for a device function.

Parameters

[out]	numBlocks	Returned occupancy
[in]	f	Kernel function(hipFunction_t) for which occupancy is calulated
[in]	blockSize	Block size the kernel is intended to be launched with
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block
[in]	flags	Extra flags for occupancy calculation (only default supported)

◆ hipModuleOccupancyMaxPotentialBlockSize()

hipError_t hipModuleOccupancyMaxPotentialBlockSize	(	int *	gridSize,
		int *	blockSize,
		hipFunction_t	f,
		size_t	dynSharedMemPerBlk,
		int	blockSizeLimit
	)

determine the grid and block sizes to achieves maximum occupancy for a kernel

Parameters

[out]	gridSize	minimum grid size for maximum potential occupancy
[out]	blockSize	block size for maximum potential occupancy
[in]	f	kernel function for which occupancy is calulated
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block
[in]	blockSizeLimit	the maximum block size for the kernel, use 0 for no limit

Please note, HIP does not support kernel launch with total work items defined in dimension with size gridDim x blockDim >= 2^32.

Returns

hipSuccess, hipInvalidDevice, hipErrorInvalidValue

◆ hipModuleOccupancyMaxPotentialBlockSizeWithFlags()

hipError_t hipModuleOccupancyMaxPotentialBlockSizeWithFlags	(	int *	gridSize,
		int *	blockSize,
		hipFunction_t	f,
		size_t	dynSharedMemPerBlk,
		int	blockSizeLimit,
		unsigned int	flags
	)

determine the grid and block sizes to achieves maximum occupancy for a kernel

Parameters

[out]	gridSize	minimum grid size for maximum potential occupancy
[out]	blockSize	block size for maximum potential occupancy
[in]	f	kernel function for which occupancy is calulated
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block
[in]	blockSizeLimit	the maximum block size for the kernel, use 0 for no limit
[in]	flags	Extra flags for occupancy calculation (only default supported)

Please note, HIP does not support kernel launch with total work items defined in dimension with size gridDim x blockDim >= 2^32.

Returns

hipSuccess, hipInvalidDevice, hipErrorInvalidValue

◆ hipOccupancyMaxActiveBlocksPerMultiprocessor()

hipError_t hipOccupancyMaxActiveBlocksPerMultiprocessor	(	int *	numBlocks,
		const void *	f,
		int	blockSize,
		size_t	dynSharedMemPerBlk
	)

Returns occupancy for a device function.

Parameters

[out]	numBlocks	Returned occupancy
[in]	func	Kernel function for which occupancy is calulated
[in]	blockSize	Block size the kernel is intended to be launched with
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block

◆ hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags()

hipError_t hipOccupancyMaxActiveBlocksPerMultiprocessorWithFlags	(	int *	numBlocks,
		const void *	f,
		int	blockSize,
		size_t	dynSharedMemPerBlk,
		unsigned int flags	__dparmhipOccupancyDefault
	)

Returns occupancy for a device function.

Parameters

[out]	numBlocks	Returned occupancy
[in]	f	Kernel function for which occupancy is calulated
[in]	blockSize	Block size the kernel is intended to be launched with
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block
[in]	flags	Extra flags for occupancy calculation (currently ignored)

◆ hipOccupancyMaxPotentialBlockSize()

hipError_t hipOccupancyMaxPotentialBlockSize	(	int *	gridSize,
		int *	blockSize,
		const void *	f,
		size_t	dynSharedMemPerBlk,
		int	blockSizeLimit
	)

determine the grid and block sizes to achieves maximum occupancy for a kernel

Parameters

[out]	gridSize	minimum grid size for maximum potential occupancy
[out]	blockSize	block size for maximum potential occupancy
[in]	f	kernel function for which occupancy is calulated
[in]	dynSharedMemPerBlk	dynamic shared memory usage (in bytes) intended for each block
[in]	blockSizeLimit	the maximum block size for the kernel, use 0 for no limit

Please note, HIP does not support kernel launch with total work items defined in dimension with size gridDim x blockDim >= 2^32.

Returns

hipSuccess, hipInvalidDevice, hipErrorInvalidValue