Functions

__host__ ​ __device__ ​cudaError_t cudaOccupancyMaxActiveBlocksPerMultiprocessor ( int* numBlocks, const void* func, int  blockSize, size_t dynamicSMemSize )

Returns occupancy for a device function.

Parameters

numBlocks

- Returned occupancy

func

- Kernel function for which occupancy is calculated

blockSize

- Block size the kernel is intended to be launched with

dynamicSMemSize

- Per-block dynamic shared memory usage intended, in bytes

Returns

cudaSuccess, cudaErrorInvalidDevice, cudaErrorInvalidDeviceFunction, cudaErrorInvalidValue, cudaErrorUnknown,

Description

Returns in *numBlocks the maximum number of active blocks per streaming multiprocessor for the device function.

Note:

• Note that this function may also return error codes from previous, asynchronous launches.

• Note that this function may also return cudaErrorInitializationError, cudaErrorInsufficientDriver or cudaErrorNoDevice if this call tries to initialize internal CUDA RT state.

• Note that as specified by cudaStreamAddCallback no CUDA function may be called from callback. cudaErrorNotPermitted may, but is not guaranteed to, be returned as a diagnostic in such case.

See also:

cudaOccupancyMaxActiveBlocksPerMultiprocessorWithFlags, cudaOccupancyMaxPotentialBlockSize ( C++ API), cudaOccupancyMaxPotentialBlockSizeWithFlags ( C++ API), cudaOccupancyMaxPotentialBlockSizeVariableSMem ( C++ API), cudaOccupancyMaxPotentialBlockSizeVariableSMemWithFlags ( C++ API), cuOccupancyMaxActiveBlocksPerMultiprocessor

__host__ ​cudaError_t cudaOccupancyMaxActiveBlocksPerMultiprocessorWithFlags ( int* numBlocks, const void* func, int  blockSize, size_t dynamicSMemSize, unsigned int  flags )

Returns occupancy for a device function with the specified flags.

Parameters

numBlocks

- Returned occupancy

func

- Kernel function for which occupancy is calculated

blockSize

- Block size the kernel is intended to be launched with

dynamicSMemSize

- Per-block dynamic shared memory usage intended, in bytes

flags

- Requested behavior for the occupancy calculator

Returns

cudaSuccess, cudaErrorInvalidDevice, cudaErrorInvalidDeviceFunction, cudaErrorInvalidValue, cudaErrorUnknown,

Description

Returns in *numBlocks the maximum number of active blocks per streaming multiprocessor for the device function.

The flags parameter controls how special cases are handled. Valid flags include:

• cudaOccupancyDefault: keeps the default behavior as cudaOccupancyMaxActiveBlocksPerMultiprocessor

• cudaOccupancyDisableCachingOverride: This flag suppresses the default behavior on platform where global caching affects occupancy. On such platforms, if caching is enabled, but per-block SM resource usage would result in zero occupancy, the occupancy calculator will calculate the occupancy as if caching is disabled. Setting this flag makes the occupancy calculator to return 0 in such cases. More information can be found about this feature in the "Unified L1/Texture Cache" section of the Maxwell tuning guide.

Note:

• Note that this function may also return error codes from previous, asynchronous launches.

• Note that this function may also return cudaErrorInitializationError, cudaErrorInsufficientDriver or cudaErrorNoDevice if this call tries to initialize internal CUDA RT state.

• Note that as specified by cudaStreamAddCallback no CUDA function may be called from callback. cudaErrorNotPermitted may, but is not guaranteed to, be returned as a diagnostic in such case.

See also:

cudaOccupancyMaxActiveBlocksPerMultiprocessor, cudaOccupancyMaxPotentialBlockSize ( C++ API), cudaOccupancyMaxPotentialBlockSizeWithFlags ( C++ API), cudaOccupancyMaxPotentialBlockSizeVariableSMem ( C++ API), cudaOccupancyMaxPotentialBlockSizeVariableSMemWithFlags ( C++ API), cuOccupancyMaxActiveBlocksPerMultiprocessorWithFlags