Functions

CUresult cuKernelGetAttribute ( int* pi, CUfunction_attribute attrib, CUkernel kernel, CUdevice dev )

Returns information about a kernel.

Parameters

pi

- Returned attribute value

attrib

- Attribute requested

kernel

- Kernel to query attribute of

dev

- Device to query attribute of

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_DEVICE

Description

Returns in *pi the integer value of the attribute attrib for the kernel kernel for the requested device dev. The supported attributes are:

• CU_FUNC_ATTRIBUTE_MAX_THREADS_PER_BLOCK: The maximum number of threads per block, beyond which a launch of the kernel would fail. This number depends on both the kernel and the requested device.

• CU_FUNC_ATTRIBUTE_SHARED_SIZE_BYTES: The size in bytes of statically-allocated shared memory per block required by this kernel. This does not include dynamically-allocated shared memory requested by the user at runtime.

• CU_FUNC_ATTRIBUTE_CONST_SIZE_BYTES: The size in bytes of user-allocated constant memory required by this kernel.

• CU_FUNC_ATTRIBUTE_LOCAL_SIZE_BYTES: The size in bytes of local memory used by each thread of this kernel.

• CU_FUNC_ATTRIBUTE_NUM_REGS: The number of registers used by each thread of this kernel.

• CU_FUNC_ATTRIBUTE_PTX_VERSION: The PTX virtual architecture version for which the kernel was compiled. This value is the major PTX version * 10 + the minor PTX version, so a PTX version 1.3 function would return the value 13. Note that this may return the undefined value of 0 for cubins compiled prior to CUDA 3.0.

• CU_FUNC_ATTRIBUTE_BINARY_VERSION: The binary architecture version for which the kernel was compiled. This value is the major binary version * 10 + the minor binary version, so a binary version 1.3 function would return the value 13. Note that this will return a value of 10 for legacy cubins that do not have a properly-encoded binary architecture version.

• CU_FUNC_CACHE_MODE_CA: The attribute to indicate whether the kernel has been compiled with user specified option "-Xptxas --dlcm=ca" set.

• CU_FUNC_ATTRIBUTE_MAX_DYNAMIC_SHARED_SIZE_BYTES: The maximum size in bytes of dynamically-allocated shared memory.

• CU_FUNC_ATTRIBUTE_PREFERRED_SHARED_MEMORY_CARVEOUT: Preferred shared memory-L1 cache split ratio in percent of total shared memory.

• CU_FUNC_ATTRIBUTE_CLUSTER_SIZE_MUST_BE_SET: If this attribute is set, the kernel must launch with a valid cluster size specified.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_WIDTH: The required cluster width in blocks.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_HEIGHT: The required cluster height in blocks.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_DEPTH: The required cluster depth in blocks.

• CU_FUNC_ATTRIBUTE_NON_PORTABLE_CLUSTER_SIZE_ALLOWED: Indicates whether the function can be launched with non-portable cluster size. 1 is allowed, 0 is disallowed. A non-portable cluster size may only function on the specific SKUs the program is tested on. The launch might fail if the program is run on a different hardware platform. CUDA API provides cudaOccupancyMaxActiveClusters to assist with checking whether the desired size can be launched on the current device. A portable cluster size is guaranteed to be functional on all compute capabilities higher than the target compute capability. The portable cluster size for sm_90 is 8 blocks per cluster. This value may increase for future compute capabilities. The specific hardware unit may support higher cluster sizes that’s not guaranteed to be portable.

• CU_FUNC_ATTRIBUTE_CLUSTER_SCHEDULING_POLICY_PREFERENCE: The block scheduling policy of a function. The value type is CUclusterSchedulingPolicy.

Note:

If another thread is trying to set the same attribute on the same device using cuKernelSetAttribute() simultaneously, the attribute query will give the old or new value depending on the interleavings chosen by the OS scheduler and memory consistency.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuKernelSetAttribute, cuLibraryGetKernel, cuLaunchKernel, cuKernelGetFunction, cuLibraryGetModule, cuModuleGetFunction, cuFuncGetAttribute

CUresult cuKernelGetFunction ( CUfunction* pFunc, CUkernel kernel )

Returns a function handle.

Parameters

pFunc

- Returned function handle

kernel

- Kernel to retrieve function for the requested context

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND, CUDA_ERROR_INVALID_CONTEXT, CUDA_ERROR_CONTEXT_IS_DESTROYED

Description

Returns in pFunc the handle of the function for the requested kernel kernel and the current context. If function handle is not found, the call returns CUDA_ERROR_NOT_FOUND.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuLibraryGetKernel, cuLibraryGetModule, cuModuleGetFunction

CUresult cuKernelGetName ( const char** name, CUkernel hfunc )

Returns the function name for a CUkernel handle.

Parameters

name

- The returned name of the function

hfunc

- The function handle to retrieve the name for

Returns

CUDA_SUCCESS, CUDA_ERROR_INVALID_VALUE

Description

Returns in **name the function name associated with the kernel handle hfunc . The function name is returned as a null-terminated string. The returned name is only valid when the kernel handle is valid. If the library is unloaded or reloaded, one must call the API again to get the updated name. This API may return a mangled name if the function is not declared as having C linkage. If either **name or hfunc is NULL, CUDA_ERROR_INVALID_VALUE is returned.

Note:

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

CUresult cuKernelGetParamInfo ( CUkernel kernel, size_t paramIndex, size_t* paramOffset, size_t* paramSize )

Returns the offset and size of a kernel parameter in the device-side parameter layout.

Parameters

kernel

- The kernel to query

paramIndex

- The parameter index to query

paramOffset

- Returns the offset into the device-side parameter layout at which the parameter resides

paramSize

- Optionally returns the size of the parameter in the device-side parameter layout

Returns

CUDA_SUCCESS, CUDA_ERROR_INVALID_VALUE,

Description

Queries the kernel parameter at paramIndex into kernel's list of parameters, and returns in paramOffset and paramSize the offset and size, respectively, where the parameter will reside in the device-side parameter layout. This information can be used to update kernel node parameters from the device via cudaGraphKernelNodeSetParam() and cudaGraphKernelNodeUpdatesApply(). paramIndex must be less than the number of parameters that kernel takes. paramSize can be set to NULL if only the parameter offset is desired.

Note:

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

See also:

cuFuncGetParamInfo

CUresult cuKernelSetAttribute ( CUfunction_attribute attrib, int  val, CUkernel kernel, CUdevice dev )

Sets information about a kernel.

Parameters

attrib

- Attribute requested

val

- Value to set

kernel

- Kernel to set attribute of

dev

- Device to set attribute of

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_DEVICE, CUDA_ERROR_OUT_OF_MEMORY

Description

This call sets the value of a specified attribute attrib on the kernel kernel for the requested device dev to an integer value specified by val. This function returns CUDA_SUCCESS if the new value of the attribute could be successfully set. If the set fails, this call will return an error. Not all attributes can have values set. Attempting to set a value on a read-only attribute will result in an error (CUDA_ERROR_INVALID_VALUE)

Note that attributes set using cuFuncSetAttribute() will override the attribute set by this API irrespective of whether the call to cuFuncSetAttribute() is made before or after this API call. However, cuKernelGetAttribute() will always return the attribute value set by this API.

Supported attributes are:

• CU_FUNC_ATTRIBUTE_MAX_DYNAMIC_SHARED_SIZE_BYTES: This is the maximum size in bytes of dynamically-allocated shared memory. The value should contain the requested maximum size of dynamically-allocated shared memory. The sum of this value and the function attribute CU_FUNC_ATTRIBUTE_SHARED_SIZE_BYTES cannot exceed the device attribute CU_DEVICE_ATTRIBUTE_MAX_SHARED_MEMORY_PER_BLOCK_OPTIN. The maximal size of requestable dynamic shared memory may differ by GPU architecture.

• CU_FUNC_ATTRIBUTE_PREFERRED_SHARED_MEMORY_CARVEOUT: On devices where the L1 cache and shared memory use the same hardware resources, this sets the shared memory carveout preference, in percent of the total shared memory. See CU_DEVICE_ATTRIBUTE_MAX_SHARED_MEMORY_PER_MULTIPROCESSOR This is only a hint, and the driver can choose a different ratio if required to execute the function.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_WIDTH: The required cluster width in blocks. The width, height, and depth values must either all be 0 or all be positive. The validity of the cluster dimensions is checked at launch time. If the value is set during compile time, it cannot be set at runtime. Setting it at runtime will return CUDA_ERROR_NOT_PERMITTED.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_HEIGHT: The required cluster height in blocks. The width, height, and depth values must either all be 0 or all be positive. The validity of the cluster dimensions is checked at launch time. If the value is set during compile time, it cannot be set at runtime. Setting it at runtime will return CUDA_ERROR_NOT_PERMITTED.

• CU_FUNC_ATTRIBUTE_REQUIRED_CLUSTER_DEPTH: The required cluster depth in blocks. The width, height, and depth values must either all be 0 or all be positive. The validity of the cluster dimensions is checked at launch time. If the value is set during compile time, it cannot be set at runtime. Setting it at runtime will return CUDA_ERROR_NOT_PERMITTED.

• CU_FUNC_ATTRIBUTE_CLUSTER_SCHEDULING_POLICY_PREFERENCE: The block scheduling policy of a function. The value type is CUclusterSchedulingPolicy.

Note:

The API has stricter locking requirements in comparison to its legacy counterpart cuFuncSetAttribute() due to device-wide semantics. If multiple threads are trying to set the same attribute on the same device simultaneously, the attribute setting will depend on the interleavings chosen by the OS scheduler and memory consistency.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuKernelGetAttribute, cuLibraryGetKernel, cuLaunchKernel, cuKernelGetFunction, cuLibraryGetModule, cuModuleGetFunction, cuFuncSetAttribute

CUresult cuKernelSetCacheConfig ( CUkernel kernel, CUfunc_cache config, CUdevice dev )

Sets the preferred cache configuration for a device kernel.

Parameters

kernel

- Kernel to configure cache for

config

- Requested cache configuration

dev

- Device to set attribute of

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_DEVICE, CUDA_ERROR_OUT_OF_MEMORY

Description

On devices where the L1 cache and shared memory use the same hardware resources, this sets through config the preferred cache configuration for the device kernel kernel on the requested device dev. This is only a preference. The driver will use the requested configuration if possible, but it is free to choose a different configuration if required to execute kernel. Any context-wide preference set via cuCtxSetCacheConfig() will be overridden by this per-kernel setting.

Note that attributes set using cuFuncSetCacheConfig() will override the attribute set by this API irrespective of whether the call to cuFuncSetCacheConfig() is made before or after this API call.

This setting does nothing on devices where the size of the L1 cache and shared memory are fixed.

Launching a kernel with a different preference than the most recent preference setting may insert a device-side synchronization point.

The supported cache configurations are:

• CU_FUNC_CACHE_PREFER_NONE: no preference for shared memory or L1 (default)

• CU_FUNC_CACHE_PREFER_SHARED: prefer larger shared memory and smaller L1 cache

• CU_FUNC_CACHE_PREFER_L1: prefer larger L1 cache and smaller shared memory

• CU_FUNC_CACHE_PREFER_EQUAL: prefer equal sized L1 cache and shared memory

Note:

The API has stricter locking requirements in comparison to its legacy counterpart cuFuncSetCacheConfig() due to device-wide semantics. If multiple threads are trying to set a config on the same device simultaneously, the cache config setting will depend on the interleavings chosen by the OS scheduler and memory consistency.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuLibraryGetKernel, cuKernelGetFunction, cuLibraryGetModule, cuModuleGetFunction, cuFuncSetCacheConfig, cuCtxSetCacheConfig, cuLaunchKernel

CUresult cuLibraryEnumerateKernels ( CUkernel* kernels, unsigned int  numKernels, CUlibrary lib )

Retrieve the kernel handles within a library.

Parameters

kernels

- Buffer where the kernel handles are returned to

numKernels

- Maximum number of kernel handles may be returned to the buffer

lib

- Library to query from

Returns

CUDA_SUCCESS, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE

Description

Returns in kernels a maximum number of numKernels kernel handles within lib. The returned kernel handle becomes invalid when the library is unloaded.

See also:

cuLibraryGetKernelCount

CUresult cuLibraryGetGlobal ( CUdeviceptr* dptr, size_t* bytes, CUlibrary library, const char* name )

Returns a global device pointer.

Parameters

dptr

- Returned global device pointer for the requested context

bytes

- Returned global size in bytes

library

- Library to retrieve global from

name

- Name of global to retrieve

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND, CUDA_ERROR_INVALID_CONTEXT, CUDA_ERROR_CONTEXT_IS_DESTROYED

Description

Returns in *dptr and *bytes the base pointer and size of the global with name name for the requested library library and the current context. If no global for the requested name name exists, the call returns CUDA_ERROR_NOT_FOUND. One of the parameters dptr or bytes (not both) can be NULL in which case it is ignored.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuLibraryGetModule, cuModuleGetGlobal

CUresult cuLibraryGetKernel ( CUkernel* pKernel, CUlibrary library, const char* name )

Returns a kernel handle.

Parameters

pKernel

- Returned kernel handle

library

- Library to retrieve kernel from

name

- Name of kernel to retrieve

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND

Description

Returns in pKernel the handle of the kernel with name name located in library library. If kernel handle is not found, the call returns CUDA_ERROR_NOT_FOUND.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuKernelGetFunction, cuLibraryGetModule, cuModuleGetFunction

CUresult cuLibraryGetKernelCount ( unsigned int* count, CUlibrary lib )

Returns the number of kernels within a library.

Parameters

count

- Number of kernels found within the library

lib

- Library to query

Returns

CUDA_SUCCESS, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_INVALID_VALUE

Description

Returns in count the number of kernels in lib.

CUresult cuLibraryGetManaged ( CUdeviceptr* dptr, size_t* bytes, CUlibrary library, const char* name )

Returns a pointer to managed memory.

Parameters

dptr

- Returned pointer to the managed memory

bytes

- Returned memory size in bytes

library

- Library to retrieve managed memory from

name

- Name of managed memory to retrieve

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND

Description

Returns in *dptr and *bytes the base pointer and size of the managed memory with name name for the requested library library. If no managed memory with the requested name name exists, the call returns CUDA_ERROR_NOT_FOUND. One of the parameters dptr or bytes (not both) can be NULL in which case it is ignored. Note that managed memory for library library is shared across devices and is registered when the library is loaded into atleast one context.

Note:

The API requires a CUDA context to be present and initialized on at least one device. If no context is present, the call returns CUDA_ERROR_NOT_FOUND.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload

CUresult cuLibraryGetModule ( CUmodule* pMod, CUlibrary library )

Returns a module handle.

Parameters

pMod

- Returned module handle

library

- Library to retrieve module from

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND, CUDA_ERROR_INVALID_CONTEXT, CUDA_ERROR_CONTEXT_IS_DESTROYED

Description

Returns in pMod the module handle associated with the current context located in library library. If module handle is not found, the call returns CUDA_ERROR_NOT_FOUND.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload, cuModuleGetFunction

CUresult cuLibraryGetUnifiedFunction ( void** fptr, CUlibrary library, const char* symbol )

Returns a pointer to a unified function.

Parameters

fptr

- Returned pointer to a unified function

library

- Library to retrieve function pointer memory from

symbol

- Name of function pointer to retrieve

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_HANDLE, CUDA_ERROR_NOT_FOUND

Description

Returns in *fptr the function pointer to a unified function denoted by symbol. If no unified function with name symbol exists, the call returns CUDA_ERROR_NOT_FOUND. If there is no device with attribute CU_DEVICE_ATTRIBUTE_UNIFIED_FUNCTION_POINTERS present in the system, the call may return CUDA_ERROR_NOT_FOUND.

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuLibraryUnload

CUresult cuLibraryLoadData ( CUlibrary* library, const void* code, CUjit_option* jitOptions, void** jitOptionsValues, unsigned int  numJitOptions, CUlibraryOption* libraryOptions, void** libraryOptionValues, unsigned int  numLibraryOptions )

Load a library with specified code and options.

Parameters

library

- Returned library

code

- Code to load

jitOptions

- Options for JIT

jitOptionsValues

- Option values for JIT

numJitOptions

- Number of options

libraryOptions

- Options for loading

libraryOptionValues

- Option values for loading

numLibraryOptions

- Number of options for loading

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_PTX, CUDA_ERROR_UNSUPPORTED_PTX_VERSION, CUDA_ERROR_OUT_OF_MEMORY, CUDA_ERROR_NO_BINARY_FOR_GPU, CUDA_ERROR_SHARED_OBJECT_SYMBOL_NOT_FOUND, CUDA_ERROR_SHARED_OBJECT_INIT_FAILED, CUDA_ERROR_JIT_COMPILER_NOT_FOUND

Description

Takes a pointer code and loads the corresponding library library based on the application defined library loading mode:

• If module loading is set to EAGER, via the environment variables described in "Module loading", library is loaded eagerly into all contexts at the time of the call and future contexts at the time of creation until the library is unloaded with cuLibraryUnload().

• If the environment variables are set to LAZY, library is not immediately loaded onto all existent contexts and will only be loaded when a function is needed for that context, such as a kernel launch.

These environment variables are described in the CUDA programming guide under the "CUDA environment variables" section.

The code may be a cubin or fatbin as output by nvcc, or a NULL-terminated PTX, either as output by nvcc or hand-written.

Options are passed as an array via jitOptions and any corresponding parameters are passed in jitOptionsValues. The number of total JIT options is supplied via numJitOptions. Any outputs will be returned via jitOptionsValues.

Library load options are passed as an array via libraryOptions and any corresponding parameters are passed in libraryOptionValues. The number of total library load options is supplied via numLibraryOptions.

See also:

cuLibraryLoadFromFile, cuLibraryUnload, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx

CUresult cuLibraryLoadFromFile ( CUlibrary* library, const char* fileName, CUjit_option* jitOptions, void** jitOptionsValues, unsigned int  numJitOptions, CUlibraryOption* libraryOptions, void** libraryOptionValues, unsigned int  numLibraryOptions )

Load a library with specified file and options.

Parameters

library

- Returned library

fileName

- File to load from

jitOptions

- Options for JIT

jitOptionsValues

- Option values for JIT

numJitOptions

- Number of options

libraryOptions

- Options for loading

libraryOptionValues

- Option values for loading

numLibraryOptions

- Number of options for loading

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE, CUDA_ERROR_INVALID_PTX, CUDA_ERROR_UNSUPPORTED_PTX_VERSION, CUDA_ERROR_OUT_OF_MEMORY, CUDA_ERROR_NO_BINARY_FOR_GPU, CUDA_ERROR_SHARED_OBJECT_SYMBOL_NOT_FOUND, CUDA_ERROR_SHARED_OBJECT_INIT_FAILED, CUDA_ERROR_JIT_COMPILER_NOT_FOUND

Description

Takes a pointer code and loads the corresponding library library based on the application defined library loading mode:

• If module loading is set to EAGER, via the environment variables described in "Module loading", library is loaded eagerly into all contexts at the time of the call and future contexts at the time of creation until the library is unloaded with cuLibraryUnload().

• If the environment variables are set to LAZY, library is not immediately loaded onto all existent contexts and will only be loaded when a function is needed for that context, such as a kernel launch.

These environment variables are described in the CUDA programming guide under the "CUDA environment variables" section.

The file should be a cubin file as output by nvcc, or a PTX file either as output by nvcc or handwritten, or a fatbin file as output by nvcc.

Options are passed as an array via jitOptions and any corresponding parameters are passed in jitOptionsValues. The number of total options is supplied via numJitOptions. Any outputs will be returned via jitOptionsValues.

Library load options are passed as an array via libraryOptions and any corresponding parameters are passed in libraryOptionValues. The number of total library load options is supplied via numLibraryOptions.

See also:

cuLibraryLoadData, cuLibraryUnload, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx

CUresult cuLibraryUnload ( CUlibrary library )

Unloads a library.

Parameters

library

- Library to unload

Returns

CUDA_SUCCESS, CUDA_ERROR_DEINITIALIZED, CUDA_ERROR_NOT_INITIALIZED, CUDA_ERROR_INVALID_VALUE

Description

Unloads the library specified with library

See also:

cuLibraryLoadData, cuLibraryLoadFromFile, cuModuleUnload