6.4. Device Management [DEPRECATED]

This section describes the deprecated device management functions of the CUDA runtime application programming interface.

Functions

__host__ cudaError_t cudaDeviceGetSharedMemConfig(enum cudaSharedMemConfig *pConfig)

Returns the shared memory configuration for the current device.

__host__ cudaError_t cudaDeviceSetSharedMemConfig(enum cudaSharedMemConfig config)

Sets the shared memory configuration for the current device.

6.4.1. Functions

__host__ cudaError_t cudaDeviceGetSharedMemConfig(enum cudaSharedMemConfig *pConfig)

Returns the shared memory configuration for the current device.

Deprecated:

This function will return in pConfig the current size of shared memory banks on the current device. On devices with configurable shared memory banks, cudaDeviceSetSharedMemConfig can be used to change this setting, so that all subsequent kernel launches will by default use the new bank size. When cudaDeviceGetSharedMemConfig is called on devices without configurable shared memory, it will return the fixed bank size of the hardware.

The returned bank configurations can be either:

  • cudaSharedMemBankSizeFourByte - shared memory bank width is four bytes.

  • cudaSharedMemBankSizeEightByte - shared memory bank width is eight bytes.

See also

cudaDeviceSetCacheConfig, cudaDeviceGetCacheConfig, cudaDeviceSetSharedMemConfig, cudaFuncSetCacheConfig, ::cuCtxGetSharedMemConfig

Note

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

Note

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

Note

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.

Parameters

pConfig – - Returned cache configuration

Returns

cudaSuccess, cudaErrorInvalidValue

__host__ cudaError_t cudaDeviceSetSharedMemConfig(enum cudaSharedMemConfig config)

Sets the shared memory configuration for the current device.

Deprecated:

On devices with configurable shared memory banks, this function will set the shared memory bank size which is used for all subsequent kernel launches. Any per-function setting of shared memory set via cudaFuncSetSharedMemConfig will override the device wide setting.

Changing the shared memory configuration between launches may introduce a device side synchronization point.

Changing the shared memory bank size will not increase shared memory usage or affect occupancy of kernels, but may have major effects on performance. Larger bank sizes will allow for greater potential bandwidth to shared memory, but will change what kinds of accesses to shared memory will result in bank conflicts.

This function will do nothing on devices with fixed shared memory bank size.

The supported bank configurations are:

  • cudaSharedMemBankSizeDefault: set bank width the device default (currently, four bytes)

  • cudaSharedMemBankSizeFourByte: set shared memory bank width to be four bytes natively.

  • cudaSharedMemBankSizeEightByte: set shared memory bank width to be eight bytes natively.

See also

cudaDeviceSetCacheConfig, cudaDeviceGetCacheConfig, cudaDeviceGetSharedMemConfig, cudaFuncSetCacheConfig, ::cuCtxSetSharedMemConfig

Note

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

Note

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

Note

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.

Parameters

config – - Requested cache configuration

Returns

cudaSuccess, cudaErrorInvalidValue