6.10. Module Management

This section describes the module management functions of the low-level CUDA driver application programming interface.

Enumerations

enum CUmoduleLoadingMode

Functions

CUresult cuLinkAddData ( CUlinkState state, CUjitInputType type, void* data, size_t size, const char* name, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Add an input to a pending linker invocation.
CUresult cuLinkAddFile ( CUlinkState state, CUjitInputType type, const char* path, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Add a file input to a pending linker invocation.
CUresult cuLinkComplete ( CUlinkState state, void** cubinOut, size_t* sizeOut )
Complete a pending linker invocation.
CUresult cuLinkCreate ( unsigned int  numOptions, CUjit_option* options, void** optionValues, CUlinkState* stateOut )
Creates a pending JIT linker invocation.
CUresult cuLinkDestroy ( CUlinkState state )
Destroys state for a JIT linker invocation.
CUresult cuModuleEnumerateFunctions ( CUfunction* functions, unsigned int  numFunctions, CUmodule mod )
Returns the function handles within a module.
CUresult cuModuleGetFunction ( CUfunction* hfunc, CUmodule hmod, const char* name )
Returns a function handle.
CUresult cuModuleGetFunctionCount ( unsigned int* count, CUmodule mod )
Returns the number of functions within a module.
CUresult cuModuleGetGlobal ( CUdeviceptr* dptr, size_t* bytes, CUmodule hmod, const char* name )
Returns a global pointer from a module.
CUresult cuModuleGetLoadingMode ( CUmoduleLoadingMode* mode )
Query lazy loading mode.
CUresult cuModuleLoad ( CUmodule* module, const char* fname )
Loads a compute module.
CUresult cuModuleLoadData ( CUmodule* module, const void* image )
Load a module's data.
CUresult cuModuleLoadDataEx ( CUmodule* module, const void* image, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Load a module's data with options.
CUresult cuModuleLoadFatBinary ( CUmodule* module, const void* fatCubin )
Load a module's data.
CUresult cuModuleUnload ( CUmodule hmod )
Unloads a module.

Enumerations

enum CUmoduleLoadingMode

CUDA Lazy Loading status

Values
CU_MODULE_EAGER_LOADING = 0x1
Lazy Kernel Loading is not enabled
CU_MODULE_LAZY_LOADING = 0x2
Lazy Kernel Loading is enabled

Functions

CUresult cuLinkAddData ( CUlinkState state, CUjitInputType type, void* data, size_t size, const char* name, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Add an input to a pending linker invocation.
Parameters
state
A pending linker action.
type
The type of the input data.
data
The input data. PTX must be NULL-terminated.
size
The length of the input data.
name
An optional name for this input in log messages.
numOptions
Size of options.
options
Options to be applied only for this input (overrides options from cuLinkCreate).
optionValues
Array of option values, each cast to void *.
Description

Ownership of data is retained by the caller. No reference is retained to any inputs after this call returns.

This method accepts only compiler options, which are used if the data must be compiled from PTX, and does not accept any of CU_JIT_WALL_TIME, CU_JIT_INFO_LOG_BUFFER, CU_JIT_ERROR_LOG_BUFFER, CU_JIT_TARGET_FROM_CUCONTEXT, or CU_JIT_TARGET.

Note:

For LTO-IR input, only LTO-IR compiled with toolkits prior to CUDA 12.0 will be accepted

See also:

cuLinkCreate, cuLinkAddFile, cuLinkComplete, cuLinkDestroy

CUresult cuLinkAddFile ( CUlinkState state, CUjitInputType type, const char* path, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Add a file input to a pending linker invocation.
Parameters
state
A pending linker action
type
The type of the input data
path
Path to the input file
numOptions
Size of options
options
Options to be applied only for this input (overrides options from cuLinkCreate)
optionValues
Array of option values, each cast to void *
Description

No reference is retained to any inputs after this call returns.

This method accepts only compiler options, which are used if the input must be compiled from PTX, and does not accept any of CU_JIT_WALL_TIME, CU_JIT_INFO_LOG_BUFFER, CU_JIT_ERROR_LOG_BUFFER, CU_JIT_TARGET_FROM_CUCONTEXT, or CU_JIT_TARGET.

This method is equivalent to invoking cuLinkAddData on the contents of the file.

Note:

For LTO-IR input, only LTO-IR compiled with toolkits prior to CUDA 12.0 will be accepted

See also:

cuLinkCreate, cuLinkAddData, cuLinkComplete, cuLinkDestroy

CUresult cuLinkComplete ( CUlinkState state, void** cubinOut, size_t* sizeOut )
Complete a pending linker invocation.
Parameters
state
A pending linker invocation
cubinOut
On success, this will point to the output image
sizeOut
Optional parameter to receive the size of the generated image
Description

Completes the pending linker action and returns the cubin image for the linked device code, which can be used with cuModuleLoadData. The cubin is owned by state, so it should be loaded before state is destroyed via cuLinkDestroy. This call does not destroy state.

See also:

cuLinkCreate, cuLinkAddData, cuLinkAddFile, cuLinkDestroy, cuModuleLoadData

CUresult cuLinkCreate ( unsigned int  numOptions, CUjit_option* options, void** optionValues, CUlinkState* stateOut )
Creates a pending JIT linker invocation.
Parameters
numOptions
Size of options arrays
options
Array of linker and compiler options
optionValues
Array of option values, each cast to void *
stateOut
On success, this will contain a CUlinkState to specify and complete this action
Description

If the call is successful, the caller owns the returned CUlinkState, which should eventually be destroyed with cuLinkDestroy. The device code machine size (32 or 64 bit) will match the calling application.

Both linker and compiler options may be specified. Compiler options will be applied to inputs to this linker action which must be compiled from PTX. The options CU_JIT_WALL_TIME, CU_JIT_INFO_LOG_BUFFER_SIZE_BYTES, and CU_JIT_ERROR_LOG_BUFFER_SIZE_BYTES will accumulate data until the CUlinkState is destroyed.

optionValues must remain valid for the life of the CUlinkState if output options are used. No other references to inputs are maintained after this call returns.

Note:

For LTO-IR input, only LTO-IR compiled with toolkits prior to CUDA 12.0 will be accepted

Note:

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

See also:

cuLinkAddData, cuLinkAddFile, cuLinkComplete, cuLinkDestroy

CUresult cuLinkDestroy ( CUlinkState state )
Destroys state for a JIT linker invocation.
Parameters
state
State object for the linker invocation
Description

See also:

cuLinkCreate

CUresult cuModuleEnumerateFunctions ( CUfunction* functions, unsigned int  numFunctions, CUmodule mod )
Returns the function handles within a module.
Parameters
functions
- Buffer where the function handles are returned to
numFunctions
- Maximum number of function handles may be returned to the buffer
mod
- Module to query from
Description

Returns in functions a maximum number of numFunctions function handles within mod. When function loading mode is set to LAZY the function retrieved may be partially loaded. The loading state of a function can be queried using cuFunctionIsLoaded. CUDA APIs may load the function automatically when called with partially loaded function handle which may incur additional latency. Alternatively, cuFunctionLoad can be used to explicitly load a function. The returned function handles become invalid when the module is unloaded.

See also:

cuModuleGetFunction, cuModuleGetFunctionCount, cuFuncIsLoaded, cuFuncLoad

CUresult cuModuleGetFunction ( CUfunction* hfunc, CUmodule hmod, const char* name )
Returns a function handle.
Parameters
hfunc
- Returned function handle
hmod
- Module to retrieve function from
name
- Name of function to retrieve
Description

Returns in *hfunc the handle of the function of name name located in module hmod. If no function of that name exists, cuModuleGetFunction() returns CUDA_ERROR_NOT_FOUND.

Note:

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

See also:

cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx, cuModuleLoadFatBinary, cuModuleUnload

CUresult cuModuleGetFunctionCount ( unsigned int* count, CUmodule mod )
Returns the number of functions within a module.
Parameters
count
- Number of functions found within the module
mod
- Module to query
Description

Returns in count the number of functions in mod.

CUresult cuModuleGetGlobal ( CUdeviceptr* dptr, size_t* bytes, CUmodule hmod, const char* name )
Returns a global pointer from a module.
Parameters
dptr
- Returned global device pointer
bytes
- Returned global size in bytes
hmod
- Module to retrieve global from
name
- Name of global to retrieve
Description

Returns in *dptr and *bytes the base pointer and size of the global of name name located in module hmod. If no variable of that name exists, cuModuleGetGlobal() returns CUDA_ERROR_NOT_FOUND. One of the parameters dptr or bytes (not both) can be NULL in which case it is ignored.

Note:

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

See also:

cuModuleGetFunction, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx, cuModuleLoadFatBinary, cuModuleUnload, cudaGetSymbolAddress, cudaGetSymbolSize

CUresult cuModuleGetLoadingMode ( CUmoduleLoadingMode* mode )
Query lazy loading mode.
Parameters
mode
- Returns the lazy loading mode
Description

Returns lazy loading mode Module loading mode is controlled by CUDA_MODULE_LOADING env variable

Note:

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

See also:

cuModuleLoad,

CUresult cuModuleLoad ( CUmodule* module, const char* fname )
Loads a compute module.
Parameters
module
- Returned module
fname
- Filename of module to load
Description

Takes a filename fname and loads the corresponding module module into the current context. The CUDA driver API does not attempt to lazily allocate the resources needed by a module; if the memory for functions and data (constant and global) needed by the module cannot be allocated, cuModuleLoad() fails. 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 from toolchain 4.0 or later.

Note:

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

See also:

cuModuleGetFunction, cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoadData, cuModuleLoadDataEx, cuModuleLoadFatBinary, cuModuleUnload

CUresult cuModuleLoadData ( CUmodule* module, const void* image )
Load a module's data.
Parameters
module
- Returned module
image
- Module data to load
Description

Takes a pointer image and loads the corresponding module module into the current context. The image may be a cubin or fatbin as output by nvcc, or a NULL-terminated PTX, either as output by nvcc or hand-written.

Note:

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

See also:

cuModuleGetFunction, cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadDataEx, cuModuleLoadFatBinary, cuModuleUnload

CUresult cuModuleLoadDataEx ( CUmodule* module, const void* image, unsigned int  numOptions, CUjit_option* options, void** optionValues )
Load a module's data with options.
Parameters
module
- Returned module
image
- Module data to load
numOptions
- Number of options
options
- Options for JIT
optionValues
- Option values for JIT
Description

Takes a pointer image and loads the corresponding module module into the current context. The image may be a cubin or fatbin as output by nvcc, or a NULL-terminated PTX, either as output by nvcc or hand-written.

Note:

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

See also:

cuModuleGetFunction, cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadData, cuModuleLoadFatBinary, cuModuleUnload

CUresult cuModuleLoadFatBinary ( CUmodule* module, const void* fatCubin )
Load a module's data.
Parameters
module
- Returned module
fatCubin
- Fat binary to load
Description

Takes a pointer fatCubin and loads the corresponding module module into the current context. The pointer represents a fat binary object, which is a collection of different cubin and/or PTX files, all representing the same device code, but compiled and optimized for different architectures.

Prior to CUDA 4.0, there was no documented API for constructing and using fat binary objects by programmers. Starting with CUDA 4.0, fat binary objects can be constructed by providing the -fatbin option to nvcc. More information can be found in the nvcc document.

Note:

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

See also:

cuModuleGetFunction, cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx, cuModuleUnload

CUresult cuModuleUnload ( CUmodule hmod )
Unloads a module.
Parameters
hmod
- Module to unload
Description

Unloads a module hmod from the current context. Attempting to unload a module which was obtained from the Library Management API such as cuLibraryGetModule will return CUDA_ERROR_NOT_PERMITTED.

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

  • Use of the handle after this call is undefined behavior.

See also:

cuModuleGetFunction, cuModuleGetGlobal, cuModuleGetTexRef, cuModuleLoad, cuModuleLoadData, cuModuleLoadDataEx, cuModuleLoadFatBinary