Provided by: nvidia-cuda-dev_9.1.85-3ubuntu1_amd64 
NAME
Memory Management -
Functions
cudaError_t cudaArrayGetInfo (struct cudaChannelFormatDesc *desc, struct cudaExtent
*extent, unsigned int *flags, cudaArray_t array)
Gets info about the specified cudaArray.
__cudart_builtin__ cudaError_t cudaFree (void *devPtr)
Frees memory on the device.
cudaError_t cudaFreeArray (cudaArray_t array)
Frees an array on the device.
cudaError_t cudaFreeHost (void *ptr)
Frees page-locked memory.
cudaError_t cudaFreeMipmappedArray (cudaMipmappedArray_t mipmappedArray)
Frees a mipmapped array on the device.
cudaError_t cudaGetMipmappedArrayLevel (cudaArray_t *levelArray,
cudaMipmappedArray_const_t mipmappedArray, unsigned int level)
Gets a mipmap level of a CUDA mipmapped array.
cudaError_t cudaGetSymbolAddress (void **devPtr, const void *symbol)
Finds the address associated with a CUDA symbol.
cudaError_t cudaGetSymbolSize (size_t *size, const void *symbol)
Finds the size of the object associated with a CUDA symbol.
cudaError_t cudaHostAlloc (void **pHost, size_t size, unsigned int flags)
Allocates page-locked memory on the host.
cudaError_t cudaHostGetDevicePointer (void **pDevice, void *pHost, unsigned int flags)
Passes back device pointer of mapped host memory allocated by cudaHostAlloc or
registered by cudaHostRegister.
cudaError_t cudaHostGetFlags (unsigned int *pFlags, void *pHost)
Passes back flags used to allocate pinned host memory allocated by cudaHostAlloc.
cudaError_t cudaHostRegister (void *ptr, size_t size, unsigned int flags)
Registers an existing host memory range for use by CUDA.
cudaError_t cudaHostUnregister (void *ptr)
Unregisters a memory range that was registered with cudaHostRegister.
__cudart_builtin__ cudaError_t cudaMalloc (void **devPtr, size_t size)
Allocate memory on the device.
cudaError_t cudaMalloc3D (struct cudaPitchedPtr *pitchedDevPtr, struct cudaExtent extent)
Allocates logical 1D, 2D, or 3D memory objects on the device.
cudaError_t cudaMalloc3DArray (cudaArray_t *array, const struct cudaChannelFormatDesc
*desc, struct cudaExtent extent, unsigned int flags=0)
Allocate an array on the device.
cudaError_t cudaMallocArray (cudaArray_t *array, const struct cudaChannelFormatDesc *desc,
size_t width, size_t height=0, unsigned int flags=0)
Allocate an array on the device.
cudaError_t cudaMallocHost (void **ptr, size_t size)
Allocates page-locked memory on the host.
__cudart_builtin__ cudaError_t cudaMallocManaged (void **devPtr, size_t size, unsigned int
flags=0x01)
Allocates memory that will be automatically managed by the Unified Memory system.
cudaError_t cudaMallocMipmappedArray (cudaMipmappedArray_t *mipmappedArray, const struct
cudaChannelFormatDesc *desc, struct cudaExtent extent, unsigned int numLevels,
unsigned int flags=0)
Allocate a mipmapped array on the device.
cudaError_t cudaMallocPitch (void **devPtr, size_t *pitch, size_t width, size_t height)
Allocates pitched memory on the device.
cudaError_t cudaMemAdvise (const void *devPtr, size_t count, enum cudaMemoryAdvise advice,
int device)
Advise about the usage of a given memory range.
cudaError_t cudaMemcpy (void *dst, const void *src, size_t count, enum cudaMemcpyKind
kind)
Copies data between host and device.
cudaError_t cudaMemcpy2D (void *dst, size_t dpitch, const void *src, size_t spitch, size_t
width, size_t height, enum cudaMemcpyKind kind)
Copies data between host and device.
cudaError_t cudaMemcpy2DArrayToArray (cudaArray_t dst, size_t wOffsetDst, size_t
hOffsetDst, cudaArray_const_t src, size_t wOffsetSrc, size_t hOffsetSrc, size_t width,
size_t height, enum cudaMemcpyKind kind=cudaMemcpyDeviceToDevice)
Copies data between host and device.
__cudart_builtin__ cudaError_t cudaMemcpy2DAsync (void *dst, size_t dpitch, const void
*src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind,
cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpy2DFromArray (void *dst, size_t dpitch, cudaArray_const_t src, size_t
wOffset, size_t hOffset, size_t width, size_t height, enum cudaMemcpyKind kind)
Copies data between host and device.
cudaError_t cudaMemcpy2DFromArrayAsync (void *dst, size_t dpitch, cudaArray_const_t src,
size_t wOffset, size_t hOffset, size_t width, size_t height, enum cudaMemcpyKind kind,
cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpy2DToArray (cudaArray_t dst, size_t wOffset, size_t hOffset, const
void *src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind)
Copies data between host and device.
cudaError_t cudaMemcpy2DToArrayAsync (cudaArray_t dst, size_t wOffset, size_t hOffset,
const void *src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind,
cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpy3D (const struct cudaMemcpy3DParms *p)
Copies data between 3D objects.
__cudart_builtin__ cudaError_t cudaMemcpy3DAsync (const struct cudaMemcpy3DParms *p,
cudaStream_t stream=0)
Copies data between 3D objects.
cudaError_t cudaMemcpy3DPeer (const struct cudaMemcpy3DPeerParms *p)
Copies memory between devices.
cudaError_t cudaMemcpy3DPeerAsync (const struct cudaMemcpy3DPeerParms *p, cudaStream_t
stream=0)
Copies memory between devices asynchronously.
cudaError_t cudaMemcpyArrayToArray (cudaArray_t dst, size_t wOffsetDst, size_t hOffsetDst,
cudaArray_const_t src, size_t wOffsetSrc, size_t hOffsetSrc, size_t count, enum
cudaMemcpyKind kind=cudaMemcpyDeviceToDevice)
Copies data between host and device.
__cudart_builtin__ cudaError_t cudaMemcpyAsync (void *dst, const void *src, size_t count,
enum cudaMemcpyKind kind, cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpyFromArray (void *dst, cudaArray_const_t src, size_t wOffset, size_t
hOffset, size_t count, enum cudaMemcpyKind kind)
Copies data between host and device.
cudaError_t cudaMemcpyFromArrayAsync (void *dst, cudaArray_const_t src, size_t wOffset,
size_t hOffset, size_t count, enum cudaMemcpyKind kind, cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpyFromSymbol (void *dst, const void *symbol, size_t count, size_t
offset=0, enum cudaMemcpyKind kind=cudaMemcpyDeviceToHost)
Copies data from the given symbol on the device.
cudaError_t cudaMemcpyFromSymbolAsync (void *dst, const void *symbol, size_t count, size_t
offset, enum cudaMemcpyKind kind, cudaStream_t stream=0)
Copies data from the given symbol on the device.
cudaError_t cudaMemcpyPeer (void *dst, int dstDevice, const void *src, int srcDevice,
size_t count)
Copies memory between two devices.
cudaError_t cudaMemcpyPeerAsync (void *dst, int dstDevice, const void *src, int srcDevice,
size_t count, cudaStream_t stream=0)
Copies memory between two devices asynchronously.
cudaError_t cudaMemcpyToArray (cudaArray_t dst, size_t wOffset, size_t hOffset, const void
*src, size_t count, enum cudaMemcpyKind kind)
Copies data between host and device.
cudaError_t cudaMemcpyToArrayAsync (cudaArray_t dst, size_t wOffset, size_t hOffset, const
void *src, size_t count, enum cudaMemcpyKind kind, cudaStream_t stream=0)
Copies data between host and device.
cudaError_t cudaMemcpyToSymbol (const void *symbol, const void *src, size_t count, size_t
offset=0, enum cudaMemcpyKind kind=cudaMemcpyHostToDevice)
Copies data to the given symbol on the device.
cudaError_t cudaMemcpyToSymbolAsync (const void *symbol, const void *src, size_t count,
size_t offset, enum cudaMemcpyKind kind, cudaStream_t stream=0)
Copies data to the given symbol on the device.
cudaError_t cudaMemGetInfo (size_t *free, size_t *total)
Gets free and total device memory.
cudaError_t cudaMemPrefetchAsync (const void *devPtr, size_t count, int dstDevice,
cudaStream_t stream=0)
Prefetches memory to the specified destination device.
cudaError_t cudaMemRangeGetAttribute (void *data, size_t dataSize, enum
cudaMemRangeAttribute attribute, const void *devPtr, size_t count)
Query an attribute of a given memory range.
cudaError_t cudaMemRangeGetAttributes (void **data, size_t *dataSizes, enum
cudaMemRangeAttribute *attributes, size_t numAttributes, const void *devPtr, size_t
count)
Query attributes of a given memory range.
cudaError_t cudaMemset (void *devPtr, int value, size_t count)
Initializes or sets device memory to a value.
cudaError_t cudaMemset2D (void *devPtr, size_t pitch, int value, size_t width, size_t
height)
Initializes or sets device memory to a value.
__cudart_builtin__ cudaError_t cudaMemset2DAsync (void *devPtr, size_t pitch, int value,
size_t width, size_t height, cudaStream_t stream=0)
Initializes or sets device memory to a value.
cudaError_t cudaMemset3D (struct cudaPitchedPtr pitchedDevPtr, int value, struct
cudaExtent extent)
Initializes or sets device memory to a value.
__cudart_builtin__ cudaError_t cudaMemset3DAsync (struct cudaPitchedPtr pitchedDevPtr, int
value, struct cudaExtent extent, cudaStream_t stream=0)
Initializes or sets device memory to a value.
__cudart_builtin__ cudaError_t cudaMemsetAsync (void *devPtr, int value, size_t count,
cudaStream_t stream=0)
Initializes or sets device memory to a value.
struct cudaExtent make_cudaExtent (size_t w, size_t h, size_t d)
Returns a cudaExtent based on input parameters.
struct cudaPitchedPtr make_cudaPitchedPtr (void *d, size_t p, size_t xsz, size_t ysz)
Returns a cudaPitchedPtr based on input parameters.
struct cudaPos make_cudaPos (size_t x, size_t y, size_t z)
Returns a cudaPos based on input parameters.
Detailed Description
\brief memory management functions of the CUDA runtime API (cuda_runtime_api.h)
This section describes the memory management functions of the CUDA runtime application
programming interface.
Some functions have overloaded C++ API template versions documented separately in the C++
API Routines module.
Function Documentation
cudaError_t cudaArrayGetInfo (struct cudaChannelFormatDesc * desc, struct cudaExtent * extent,
unsigned int * flags, cudaArray_t array)
Returns in *desc, *extent and *flags respectively, the type, shape and flags of array.
Any of *desc, *extent and *flags may be specified as NULL.
Parameters:
desc - Returned array type
extent - Returned array shape. 2D arrays will have depth of zero
flags - Returned array flags
array - The cudaArray to get info for
Returns:
cudaSuccess, cudaErrorInvalidValue
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cuArrayGetDescriptor, cuArray3DGetDescriptor
__cudart_builtin__ cudaError_t cudaFree (void * devPtr)
Frees the memory space pointed to by devPtr, which must have been returned by a previous
call to cudaMalloc() or cudaMallocPitch(). Otherwise, or if cudaFree(devPtr) has already
been called before, an error is returned. If devPtr is 0, no operation is performed.
cudaFree() returns cudaErrorInvalidDevicePointer in case of failure.
The device version of cudaFree cannot be used with a *devPtr allocated using the host API,
and vice versa.
Parameters:
devPtr - Device pointer to memory to free
Returns:
cudaSuccess, cudaErrorInvalidDevicePointer, cudaErrorInitializationError
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaMallocArray, cudaFreeArray, cudaMallocHost (C API),
cudaFreeHost, cudaMalloc3D, cudaMalloc3DArray, cudaHostAlloc, cuMemFree
cudaError_t cudaFreeArray (cudaArray_t array)
Frees the CUDA array array, which must have been * returned by a previous call to
cudaMallocArray(). If cudaFreeArray(array) has already been called before,
cudaErrorInvalidValue is returned. If devPtr is 0, no operation is performed.
Parameters:
array - Pointer to array to free
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInitializationError
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaFree, cudaMallocArray, cudaMallocHost (C API),
cudaFreeHost, cudaHostAlloc, cuArrayDestroy
cudaError_t cudaFreeHost (void * ptr)
Frees the memory space pointed to by hostPtr, which must have been returned by a previous
call to cudaMallocHost() or cudaHostAlloc().
Parameters:
ptr - Pointer to memory to free
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInitializationError
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaFree, cudaMallocArray, cudaFreeArray, cudaMallocHost
(C API), cudaMalloc3D, cudaMalloc3DArray, cudaHostAlloc, cuMemFreeHost
cudaError_t cudaFreeMipmappedArray (cudaMipmappedArray_t mipmappedArray)
Frees the CUDA mipmapped array mipmappedArray, which must have been returned by a previous
call to cudaMallocMipmappedArray(). If cudaFreeMipmappedArray(mipmappedArray) has already
been called before, cudaErrorInvalidValue is returned.
Parameters:
mipmappedArray - Pointer to mipmapped array to free
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInitializationError
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaFree, cudaMallocArray, cudaMallocHost (C API),
cudaFreeHost, cudaHostAlloc, cuMipmappedArrayDestroy
cudaError_t cudaGetMipmappedArrayLevel (cudaArray_t * levelArray, cudaMipmappedArray_const_t
mipmappedArray, unsigned int level)
Returns in *levelArray a CUDA array that represents a single mipmap level of the CUDA
mipmapped array mipmappedArray.
If level is greater than the maximum number of levels in this mipmapped array,
cudaErrorInvalidValue is returned.
Parameters:
levelArray - Returned mipmap level CUDA array
mipmappedArray - CUDA mipmapped array
level - Mipmap level
Returns:
cudaSuccess, cudaErrorInvalidValue
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc3D, cudaMalloc, cudaMallocPitch, cudaFree, cudaFreeArray, cudaMallocHost (C
API), cudaFreeHost, cudaHostAlloc, make_cudaExtent, cuMipmappedArrayGetLevel
cudaError_t cudaGetSymbolAddress (void ** devPtr, const void * symbol)
Returns in *devPtr the address of symbol symbol on the device. symbol is a variable that
resides in global or constant memory space. If symbol cannot be found, or if symbol is not
declared in the global or constant memory space, *devPtr is unchanged and the error
cudaErrorInvalidSymbol is returned.
Parameters:
devPtr - Return device pointer associated with symbol
symbol - Device symbol address
Returns:
cudaSuccess, cudaErrorInvalidSymbol, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaGetSymbolAddress (C++ API), cudaGetSymbolSize (C API), cuModuleGetGlobal
cudaError_t cudaGetSymbolSize (size_t * size, const void * symbol)
Returns in *size the size of symbol symbol. symbol is a variable that resides in global or
constant memory space. If symbol cannot be found, or if symbol is not declared in global
or constant memory space, *size is unchanged and the error cudaErrorInvalidSymbol is
returned.
Parameters:
size - Size of object associated with symbol
symbol - Device symbol address
Returns:
cudaSuccess, cudaErrorInvalidSymbol, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaGetSymbolAddress (C API), cudaGetSymbolSize (C++ API), cuModuleGetGlobal
cudaError_t cudaHostAlloc (void ** pHost, size_t size, unsigned int flags)
Allocates size bytes of host memory that is page-locked and accessible to the device. The
driver tracks the virtual memory ranges allocated with this function and automatically
accelerates calls to functions such as cudaMemcpy(). Since the memory can be accessed
directly by the device, it can be read or written with much higher bandwidth than pageable
memory obtained with functions such as malloc(). Allocating excessive amounts of pinned
memory may degrade system performance, since it reduces the amount of memory available to
the system for paging. As a result, this function is best used sparingly to allocate
staging areas for data exchange between host and device.
The flags parameter enables different options to be specified that affect the allocation,
as follows.
• cudaHostAllocDefault: This flag's value is defined to be 0 and causes cudaHostAlloc() to
emulate cudaMallocHost().
• cudaHostAllocPortable: The memory returned by this call will be considered as pinned
memory by all CUDA contexts, not just the one that performed the allocation.
• cudaHostAllocMapped: Maps the allocation into the CUDA address space. The device pointer
to the memory may be obtained by calling cudaHostGetDevicePointer().
• cudaHostAllocWriteCombined: Allocates the memory as write-combined (WC). WC memory can
be transferred across the PCI Express bus more quickly on some system configurations,
but cannot be read efficiently by most CPUs. WC memory is a good option for buffers that
will be written by the CPU and read by the device via mapped pinned memory or
host->device transfers.
All of these flags are orthogonal to one another: a developer may allocate memory that is
portable, mapped and/or write-combined with no restrictions.
In order for the cudaHostAllocMapped flag to have any effect, the CUDA context must
support the cudaDeviceMapHost flag, which can be checked via cudaGetDeviceFlags(). The
cudaDeviceMapHost flag is implicitly set for contexts created via the runtime API.
The cudaHostAllocMapped flag may be specified on CUDA contexts for devices that do not
support mapped pinned memory. The failure is deferred to cudaHostGetDevicePointer()
because the memory may be mapped into other CUDA contexts via the cudaHostAllocPortable
flag.
Memory allocated by this function must be freed with cudaFreeHost().
Parameters:
pHost - Device pointer to allocated memory
size - Requested allocation size in bytes
flags - Requested properties of allocated memory
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaSetDeviceFlags, cudaMallocHost (C API), cudaFreeHost, cudaGetDeviceFlags,
cuMemHostAlloc
cudaError_t cudaHostGetDevicePointer (void ** pDevice, void * pHost, unsigned int flags)
Passes back the device pointer corresponding to the mapped, pinned host buffer allocated
by cudaHostAlloc() or registered by cudaHostRegister().
cudaHostGetDevicePointer() will fail if the cudaDeviceMapHost flag was not specified
before deferred context creation occurred, or if called on a device that does not support
mapped, pinned memory.
For devices that have a non-zero value for the device attribute
cudaDevAttrCanUseHostPointerForRegisteredMem, the memory can also be accessed from the
device using the host pointer pHost. The device pointer returned by
cudaHostGetDevicePointer() may or may not match the original host pointer pHost and
depends on the devices visible to the application. If all devices visible to the
application have a non-zero value for the device attribute, the device pointer returned by
cudaHostGetDevicePointer() will match the original pointer pHost. If any device visible to
the application has a zero value for the device attribute, the device pointer returned by
cudaHostGetDevicePointer() will not match the original host pointer pHost, but it will be
suitable for use on all devices provided Unified Virtual Addressing is enabled. In such
systems, it is valid to access the memory using either pointer on devices that have a non-
zero value for the device attribute. Note however that such devices should access the
memory using only of the two pointers and not both.
flags provides for future releases. For now, it must be set to 0.
Parameters:
pDevice - Returned device pointer for mapped memory
pHost - Requested host pointer mapping
flags - Flags for extensions (must be 0 for now)
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaSetDeviceFlags, cudaHostAlloc, cuMemHostGetDevicePointer
cudaError_t cudaHostGetFlags (unsigned int * pFlags, void * pHost)
cudaHostGetFlags() will fail if the input pointer does not reside in an address range
allocated by cudaHostAlloc().
Parameters:
pFlags - Returned flags word
pHost - Host pointer
Returns:
cudaSuccess, cudaErrorInvalidValue
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaHostAlloc, cuMemHostGetFlags
cudaError_t cudaHostRegister (void * ptr, size_t size, unsigned int flags)
Page-locks the memory range specified by ptr and size and maps it for the device(s) as
specified by flags. This memory range also is added to the same tracking mechanism as
cudaHostAlloc() to automatically accelerate calls to functions such as cudaMemcpy(). Since
the memory can be accessed directly by the device, it can be read or written with much
higher bandwidth than pageable memory that has not been registered. Page-locking excessive
amounts of memory may degrade system performance, since it reduces the amount of memory
available to the system for paging. As a result, this function is best used sparingly to
register staging areas for data exchange between host and device.
cudaHostRegister is not supported on non I/O coherent devices.
The flags parameter enables different options to be specified that affect the allocation,
as follows.
• cudaHostRegisterDefault: On a system with unified virtual addressing, the memory will be
both mapped and portable. On a system with no unified virtual addressing, the memory
will be neither mapped nor portable.
• cudaHostRegisterPortable: The memory returned by this call will be considered as pinned
memory by all CUDA contexts, not just the one that performed the allocation.
• cudaHostRegisterMapped: Maps the allocation into the CUDA address space. The device
pointer to the memory may be obtained by calling cudaHostGetDevicePointer().
• cudaHostRegisterIoMemory: The passed memory pointer is treated as pointing to some
memory-mapped I/O space, e.g. belonging to a third-party PCIe device, and it will marked
as non cache-coherent and contiguous.
All of these flags are orthogonal to one another: a developer may page-lock memory that is
portable or mapped with no restrictions.
The CUDA context must have been created with the cudaMapHost flag in order for the
cudaHostRegisterMapped flag to have any effect.
The cudaHostRegisterMapped flag may be specified on CUDA contexts for devices that do not
support mapped pinned memory. The failure is deferred to cudaHostGetDevicePointer()
because the memory may be mapped into other CUDA contexts via the cudaHostRegisterPortable
flag.
For devices that have a non-zero value for the device attribute
cudaDevAttrCanUseHostPointerForRegisteredMem, the memory can also be accessed from the
device using the host pointer ptr. The device pointer returned by
cudaHostGetDevicePointer() may or may not match the original host pointer ptr and depends
on the devices visible to the application. If all devices visible to the application have
a non-zero value for the device attribute, the device pointer returned by
cudaHostGetDevicePointer() will match the original pointer ptr. If any device visible to
the application has a zero value for the device attribute, the device pointer returned by
cudaHostGetDevicePointer() will not match the original host pointer ptr, but it will be
suitable for use on all devices provided Unified Virtual Addressing is enabled. In such
systems, it is valid to access the memory using either pointer on devices that have a non-
zero value for the device attribute. Note however that such devices should access the
memory using only of the two pointers and not both.
The memory page-locked by this function must be unregistered with cudaHostUnregister().
Parameters:
ptr - Host pointer to memory to page-lock
size - Size in bytes of the address range to page-lock in bytes
flags - Flags for allocation request
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation,
cudaErrorHostMemoryAlreadyRegistered, cudaErrorNotSupported
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaHostUnregister, cudaHostGetFlags, cudaHostGetDevicePointer, cuMemHostRegister
cudaError_t cudaHostUnregister (void * ptr)
Unmaps the memory range whose base address is specified by ptr, and makes it pageable
again.
The base address must be the same one specified to cudaHostRegister().
Parameters:
ptr - Host pointer to memory to unregister
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorHostMemoryNotRegistered
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaHostUnregister, cuMemHostUnregister
__cudart_builtin__ cudaError_t cudaMalloc (void ** devPtr, size_t size)
Allocates size bytes of linear memory on the device and returns in *devPtr a pointer to
the allocated memory. The allocated memory is suitably aligned for any kind of variable.
The memory is not cleared. cudaMalloc() returns cudaErrorMemoryAllocation in case of
failure.
The device version of cudaFree cannot be used with a *devPtr allocated using the host API,
and vice versa.
Parameters:
devPtr - Pointer to allocated device memory
size - Requested allocation size in bytes
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
See also:
cudaMallocPitch, cudaFree, cudaMallocArray, cudaFreeArray, cudaMalloc3D,
cudaMalloc3DArray, cudaMallocHost (C API), cudaFreeHost, cudaHostAlloc, cuMemAlloc
cudaError_t cudaMalloc3D (struct cudaPitchedPtr * pitchedDevPtr, struct cudaExtent extent)
Allocates at least width * height * depth bytes of linear memory on the device and returns
a cudaPitchedPtr in which ptr is a pointer to the allocated memory. The function may pad
the allocation to ensure hardware alignment requirements are met. The pitch returned in
the pitch field of pitchedDevPtr is the width in bytes of the allocation.
The returned cudaPitchedPtr contains additional fields xsize and ysize, the logical width
and height of the allocation, which are equivalent to the width and height extent
parameters provided by the programmer during allocation.
For allocations of 2D and 3D objects, it is highly recommended that programmers perform
allocations using cudaMalloc3D() or cudaMallocPitch(). Due to alignment restrictions in
the hardware, this is especially true if the application will be performing memory copies
involving 2D or 3D objects (whether linear memory or CUDA arrays).
Parameters:
pitchedDevPtr - Pointer to allocated pitched device memory
extent - Requested allocation size (width field in bytes)
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMallocPitch, cudaFree, cudaMemcpy3D, cudaMemset3D, cudaMalloc3DArray,
cudaMallocArray, cudaFreeArray, cudaMallocHost (C API), cudaFreeHost, cudaHostAlloc,
make_cudaPitchedPtr, make_cudaExtent, cuMemAllocPitch
cudaError_t cudaMalloc3DArray (cudaArray_t * array, const struct cudaChannelFormatDesc * desc,
struct cudaExtent extent, unsigned int flags = 0)
Allocates a CUDA array according to the cudaChannelFormatDesc structure desc and returns a
handle to the new CUDA array in *array.
The cudaChannelFormatDesc is defined as:
struct cudaChannelFormatDesc {
int x, y, z, w;
enum cudaChannelFormatKind f;
};
where cudaChannelFormatKind is one of cudaChannelFormatKindSigned,
cudaChannelFormatKindUnsigned, or cudaChannelFormatKindFloat.
cudaMalloc3DArray() can allocate the following:
• A 1D array is allocated if the height and depth extents are both zero.
• A 2D array is allocated if only the depth extent is zero.
• A 3D array is allocated if all three extents are non-zero.
• A 1D layered CUDA array is allocated if only the height extent is zero and the
cudaArrayLayered flag is set. Each layer is a 1D array. The number of layers is
determined by the depth extent.
• A 2D layered CUDA array is allocated if all three extents are non-zero and the
cudaArrayLayered flag is set. Each layer is a 2D array. The number of layers is
determined by the depth extent.
• A cubemap CUDA array is allocated if all three extents are non-zero and the
cudaArrayCubemap flag is set. Width must be equal to height, and depth must be six. A
cubemap is a special type of 2D layered CUDA array, where the six layers represent the
six faces of a cube. The order of the six layers in memory is the same as that listed in
cudaGraphicsCubeFace.
• A cubemap layered CUDA array is allocated if all three extents are non-zero, and both,
cudaArrayCubemap and cudaArrayLayered flags are set. Width must be equal to height, and
depth must be a multiple of six. A cubemap layered CUDA array is a special type of 2D
layered CUDA array that consists of a collection of cubemaps. The first six layers
represent the first cubemap, the next six layers form the second cubemap, and so on.
The flags parameter enables different options to be specified that affect the allocation,
as follows.
• cudaArrayDefault: This flag's value is defined to be 0 and provides default array
allocation
• cudaArrayLayered: Allocates a layered CUDA array, with the depth extent indicating the
number of layers
• cudaArrayCubemap: Allocates a cubemap CUDA array. Width must be equal to height, and
depth must be six. If the cudaArrayLayered flag is also set, depth must be a multiple of
six.
• cudaArraySurfaceLoadStore: Allocates a CUDA array that could be read from or written to
using a surface reference.
• cudaArrayTextureGather: This flag indicates that texture gather operations will be
performed on the CUDA array. Texture gather can only be performed on 2D CUDA arrays.
The width, height and depth extents must meet certain size requirements as listed in the
following table. All values are specified in elements.
Note that 2D CUDA arrays have different size requirements if the cudaArrayTextureGather
flag is set. In that case, the valid range for (width, height, depth) is
((1,maxTexture2DGather[0]), (1,maxTexture2DGather[1]), 0).
Parameters:
array - Pointer to allocated array in device memory
desc - Requested channel format
extent - Requested allocation size (width field in elements)
flags - Flags for extensions
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc3D, cudaMalloc, cudaMallocPitch, cudaFree, cudaFreeArray, cudaMallocHost (C
API), cudaFreeHost, cudaHostAlloc, make_cudaExtent, cuArray3DCreate
cudaError_t cudaMallocArray (cudaArray_t * array, const struct cudaChannelFormatDesc * desc,
size_t width, size_t height = 0, unsigned int flags = 0)
Allocates a CUDA array according to the cudaChannelFormatDesc structure desc and returns a
handle to the new CUDA array in *array.
The cudaChannelFormatDesc is defined as:
struct cudaChannelFormatDesc {
int x, y, z, w;
enum cudaChannelFormatKind f;
};
where cudaChannelFormatKind is one of cudaChannelFormatKindSigned,
cudaChannelFormatKindUnsigned, or cudaChannelFormatKindFloat.
The flags parameter enables different options to be specified that affect the allocation,
as follows.
• cudaArrayDefault: This flag's value is defined to be 0 and provides default array
allocation
• cudaArraySurfaceLoadStore: Allocates an array that can be read from or written to using
a surface reference
• cudaArrayTextureGather: This flag indicates that texture gather operations will be
performed on the array.
width and height must meet certain size requirements. See cudaMalloc3DArray() for more
details.
Parameters:
array - Pointer to allocated array in device memory
desc - Requested channel format
width - Requested array allocation width
height - Requested array allocation height
flags - Requested properties of allocated array
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaFree, cudaFreeArray, cudaMallocHost (C API),
cudaFreeHost, cudaMalloc3D, cudaMalloc3DArray, cudaHostAlloc, cuArrayCreate
cudaError_t cudaMallocHost (void ** ptr, size_t size)
Allocates size bytes of host memory that is page-locked and accessible to the device. The
driver tracks the virtual memory ranges allocated with this function and automatically
accelerates calls to functions such as cudaMemcpy*(). Since the memory can be accessed
directly by the device, it can be read or written with much higher bandwidth than pageable
memory obtained with functions such as malloc(). Allocating excessive amounts of memory
with cudaMallocHost() may degrade system performance, since it reduces the amount of
memory available to the system for paging. As a result, this function is best used
sparingly to allocate staging areas for data exchange between host and device.
Parameters:
ptr - Pointer to allocated host memory
size - Requested allocation size in bytes
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaMallocPitch, cudaMallocArray, cudaMalloc3D, cudaMalloc3DArray,
cudaHostAlloc, cudaFree, cudaFreeArray, cudaMallocHost (C++ API), cudaFreeHost,
cudaHostAlloc, cuMemAllocHost
__cudart_builtin__ cudaError_t cudaMallocManaged (void ** devPtr, size_t size, unsigned int
flags = 0x01)
Allocates size bytes of managed memory on the device and returns in *devPtr a pointer to
the allocated memory. If the device doesn't support allocating managed memory,
cudaErrorNotSupported is returned. Support for managed memory can be queried using the
device attribute cudaDevAttrManagedMemory. The allocated memory is suitably aligned for
any kind of variable. The memory is not cleared. If size is 0, cudaMallocManaged returns
cudaErrorInvalidValue. The pointer is valid on the CPU and on all GPUs in the system that
support managed memory. All accesses to this pointer must obey the Unified Memory
programming model.
flags specifies the default stream association for this allocation. flags must be one of
cudaMemAttachGlobal or cudaMemAttachHost. The default value for flags is
cudaMemAttachGlobal. If cudaMemAttachGlobal is specified, then this memory is accessible
from any stream on any device. If cudaMemAttachHost is specified, then the allocation
should not be accessed from devices that have a zero value for the device attribute
cudaDevAttrConcurrentManagedAccess; an explicit call to cudaStreamAttachMemAsync will be
required to enable access on such devices.
If the association is later changed via cudaStreamAttachMemAsync to a single stream, the
default association, as specified during cudaMallocManaged, is restored when that stream
is destroyed. For __managed__ variables, the default association is always
cudaMemAttachGlobal. Note that destroying a stream is an asynchronous operation, and as a
result, the change to default association won't happen until all work in the stream has
completed.
Memory allocated with cudaMallocManaged should be released with cudaFree.
Device memory oversubscription is possible for GPUs that have a non-zero value for the
device attribute cudaDevAttrConcurrentManagedAccess. Managed memory on such GPUs may be
evicted from device memory to host memory at any time by the Unified Memory driver in
order to make room for other allocations.
In a multi-GPU system where all GPUs have a non-zero value for the device attribute
cudaDevAttrConcurrentManagedAccess, managed memory may not be populated when this API
returns and instead may be populated on access. In such systems, managed memory can
migrate to any processor's memory at any time. The Unified Memory driver will employ
heuristics to maintain data locality and prevent excessive page faults to the extent
possible. The application can also guide the driver about memory usage patterns via
cudaMemAdvise. The application can also explicitly migrate memory to a desired processor's
memory via cudaMemPrefetchAsync.
In a multi-GPU system where all of the GPUs have a zero value for the device attribute
cudaDevAttrConcurrentManagedAccess and all the GPUs have peer-to-peer support with each
other, the physical storage for managed memory is created on the GPU which is active at
the time cudaMallocManaged is called. All other GPUs will reference the data at reduced
bandwidth via peer mappings over the PCIe bus. The Unified Memory driver does not migrate
memory among such GPUs.
In a multi-GPU system where not all GPUs have peer-to-peer support with each other and
where the value of the device attribute cudaDevAttrConcurrentManagedAccess is zero for at
least one of those GPUs, the location chosen for physical storage of managed memory is
system-dependent.
• On Linux, the location chosen will be device memory as long as the current set of active
contexts are on devices that either have peer-to-peer support with each other or have a
non-zero value for the device attribute cudaDevAttrConcurrentManagedAccess. If there is
an active context on a GPU that does not have a non-zero value for that device attribute
and it does not have peer-to-peer support with the other devices that have active
contexts on them, then the location for physical storage will be 'zero-copy' or host
memory. Note that this means that managed memory that is located in device memory is
migrated to host memory if a new context is created on a GPU that doesn't have a non-
zero value for the device attribute and does not support peer-to-peer with at least one
of the other devices that has an active context. This in turn implies that context
creation may fail if there is insufficient host memory to migrate all managed
allocations.
• On Windows, the physical storage is always created in 'zero-copy' or host memory. All
GPUs will reference the data at reduced bandwidth over the PCIe bus. In these
circumstances, use of the environment variable CUDA_VISIBLE_DEVICES is recommended to
restrict CUDA to only use those GPUs that have peer-to-peer support. Alternatively,
users can also set CUDA_MANAGED_FORCE_DEVICE_ALLOC to a non-zero value to force the
driver to always use device memory for physical storage. When this environment variable
is set to a non-zero value, all devices used in that process that support managed memory
have to be peer-to-peer compatible with each other. The error cudaErrorInvalidDevice
will be returned if a device that supports managed memory is used and it is not peer-to-
peer compatible with any of the other managed memory supporting devices that were
previously used in that process, even if cudaDeviceReset has been called on those
devices. These environment variables are described in the CUDA programming guide under
the 'CUDA environment variables' section.
Parameters:
devPtr - Pointer to allocated device memory
size - Requested allocation size in bytes
flags - Must be either cudaMemAttachGlobal or cudaMemAttachHost (defaults to
cudaMemAttachGlobal)
Returns:
cudaSuccess, cudaErrorMemoryAllocation, cudaErrorNotSupported, cudaErrorInvalidValue
See also:
cudaMallocPitch, cudaFree, cudaMallocArray, cudaFreeArray, cudaMalloc3D,
cudaMalloc3DArray, cudaMallocHost (C API), cudaFreeHost, cudaHostAlloc,
cudaDeviceGetAttribute, cudaStreamAttachMemAsync, cuMemAllocManaged
Parameters:
flags Memory can be accessed by any stream on any device
cudaError_t cudaMallocMipmappedArray (cudaMipmappedArray_t * mipmappedArray, const struct
cudaChannelFormatDesc * desc, struct cudaExtent extent, unsigned int numLevels, unsigned
int flags = 0)
Allocates a CUDA mipmapped array according to the cudaChannelFormatDesc structure desc and
returns a handle to the new CUDA mipmapped array in *mipmappedArray. numLevels specifies
the number of mipmap levels to be allocated. This value is clamped to the range [1, 1 +
floor(log2(max(width, height, depth)))].
The cudaChannelFormatDesc is defined as:
struct cudaChannelFormatDesc {
int x, y, z, w;
enum cudaChannelFormatKind f;
};
where cudaChannelFormatKind is one of cudaChannelFormatKindSigned,
cudaChannelFormatKindUnsigned, or cudaChannelFormatKindFloat.
cudaMallocMipmappedArray() can allocate the following:
• A 1D mipmapped array is allocated if the height and depth extents are both zero.
• A 2D mipmapped array is allocated if only the depth extent is zero.
• A 3D mipmapped array is allocated if all three extents are non-zero.
• A 1D layered CUDA mipmapped array is allocated if only the height extent is zero and the
cudaArrayLayered flag is set. Each layer is a 1D mipmapped array. The number of layers
is determined by the depth extent.
• A 2D layered CUDA mipmapped array is allocated if all three extents are non-zero and the
cudaArrayLayered flag is set. Each layer is a 2D mipmapped array. The number of layers
is determined by the depth extent.
• A cubemap CUDA mipmapped array is allocated if all three extents are non-zero and the
cudaArrayCubemap flag is set. Width must be equal to height, and depth must be six. The
order of the six layers in memory is the same as that listed in cudaGraphicsCubeFace.
• A cubemap layered CUDA mipmapped array is allocated if all three extents are non-zero,
and both, cudaArrayCubemap and cudaArrayLayered flags are set. Width must be equal to
height, and depth must be a multiple of six. A cubemap layered CUDA mipmapped array is a
special type of 2D layered CUDA mipmapped array that consists of a collection of cubemap
mipmapped arrays. The first six layers represent the first cubemap mipmapped array, the
next six layers form the second cubemap mipmapped array, and so on.
The flags parameter enables different options to be specified that affect the allocation,
as follows.
• cudaArrayDefault: This flag's value is defined to be 0 and provides default mipmapped
array allocation
• cudaArrayLayered: Allocates a layered CUDA mipmapped array, with the depth extent
indicating the number of layers
• cudaArrayCubemap: Allocates a cubemap CUDA mipmapped array. Width must be equal to
height, and depth must be six. If the cudaArrayLayered flag is also set, depth must be a
multiple of six.
• cudaArraySurfaceLoadStore: This flag indicates that individual mipmap levels of the CUDA
mipmapped array will be read from or written to using a surface reference.
• cudaArrayTextureGather: This flag indicates that texture gather operations will be
performed on the CUDA array. Texture gather can only be performed on 2D CUDA mipmapped
arrays, and the gather operations are performed only on the most detailed mipmap level.
The width, height and depth extents must meet certain size requirements as listed in the
following table. All values are specified in elements.
Parameters:
mipmappedArray - Pointer to allocated mipmapped array in device memory
desc - Requested channel format
extent - Requested allocation size (width field in elements)
numLevels - Number of mipmap levels to allocate
flags - Flags for extensions
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc3D, cudaMalloc, cudaMallocPitch, cudaFree, cudaFreeArray, cudaMallocHost (C
API), cudaFreeHost, cudaHostAlloc, make_cudaExtent, cuMipmappedArrayCreate
cudaError_t cudaMallocPitch (void ** devPtr, size_t * pitch, size_t width, size_t height)
Allocates at least width (in bytes) * height bytes of linear memory on the device and
returns in *devPtr a pointer to the allocated memory. The function may pad the allocation
to ensure that corresponding pointers in any given row will continue to meet the alignment
requirements for coalescing as the address is updated from row to row. The pitch returned
in *pitch by cudaMallocPitch() is the width in bytes of the allocation. The intended usage
of pitch is as a separate parameter of the allocation, used to compute addresses within
the 2D array. Given the row and column of an array element of type T, the address is
computed as:
T* pElement = (T*)((char*)BaseAddress + Row * pitch) + Column;
For allocations of 2D arrays, it is recommended that programmers consider performing pitch
allocations using cudaMallocPitch(). Due to pitch alignment restrictions in the hardware,
this is especially true if the application will be performing 2D memory copies between
different regions of device memory (whether linear memory or CUDA arrays).
Parameters:
devPtr - Pointer to allocated pitched device memory
pitch - Pitch for allocation
width - Requested pitched allocation width (in bytes)
height - Requested pitched allocation height
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorMemoryAllocation
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMalloc, cudaFree, cudaMallocArray, cudaFreeArray, cudaMallocHost (C API),
cudaFreeHost, cudaMalloc3D, cudaMalloc3DArray, cudaHostAlloc, cuMemAllocPitch
cudaError_t cudaMemAdvise (const void * devPtr, size_t count, enum cudaMemoryAdvise advice,
int device)
Advise the Unified Memory subsystem about the usage pattern for the memory range starting
at devPtr with a size of count bytes. The start address and end address of the memory
range will be rounded down and rounded up respectively to be aligned to CPU page size
before the advice is applied. The memory range must refer to managed memory allocated via
cudaMallocManaged or declared via __managed__ variables.
The advice parameter can take the following values:
• cudaMemAdviseSetReadMostly: This implies that the data is mostly going to be read from
and only occasionally written to. Any read accesses from any processor to this region
will create a read-only copy of at least the accessed pages in that processor's memory.
Additionally, if cudaMemPrefetchAsync is called on this region, it will create a read-
only copy of the data on the destination processor. If any processor writes to this
region, all copies of the corresponding page will be invalidated except for the one
where the write occurred. The device argument is ignored for this advice. Note that for
a page to be read-duplicated, the accessing processor must either be the CPU or a GPU
that has a non-zero value for the device attribute cudaDevAttrConcurrentManagedAccess.
Also, if a context is created on a device that does not have the device attribute
cudaDevAttrConcurrentManagedAccess set, then read-duplication will not occur until all
such contexts are destroyed.
• cudaMemAdviceUnsetReadMostly: Undoes the effect of cudaMemAdviceReadMostly and also
prevents the Unified Memory driver from attempting heuristic read-duplication on the
memory range. Any read-duplicated copies of the data will be collapsed into a single
copy. The location for the collapsed copy will be the preferred location if the page has
a preferred location and one of the read-duplicated copies was resident at that
location. Otherwise, the location chosen is arbitrary.
• cudaMemAdviseSetPreferredLocation: This advice sets the preferred location for the data
to be the memory belonging to device. Passing in cudaCpuDeviceId for device sets the
preferred location as host memory. If device is a GPU, then it must have a non-zero
value for the device attribute cudaDevAttrConcurrentManagedAccess. Setting the preferred
location does not cause data to migrate to that location immediately. Instead, it guides
the migration policy when a fault occurs on that memory region. If the data is already
in its preferred location and the faulting processor can establish a mapping without
requiring the data to be migrated, then data migration will be avoided. On the other
hand, if the data is not in its preferred location or if a direct mapping cannot be
established, then it will be migrated to the processor accessing it. It is important to
note that setting the preferred location does not prevent data prefetching done using
cudaMemPrefetchAsync. Having a preferred location can override the page thrash detection
and resolution logic in the Unified Memory driver. Normally, if a page is detected to be
constantly thrashing between for example host and device memory, the page may eventually
be pinned to host memory by the Unified Memory driver. But if the preferred location is
set as device memory, then the page will continue to thrash indefinitely. If
cudaMemAdviseSetReadMostly is also set on this memory region or any subset of it, then
the policies associated with that advice will override the policies of this advice.
• cudaMemAdviseUnsetPreferredLocation: Undoes the effect of
cudaMemAdviseSetPreferredLocation and changes the preferred location to none.
• cudaMemAdviseSetAccessedBy: This advice implies that the data will be accessed by
device. Passing in cudaCpuDeviceId for device will set the advice for the CPU. If device
is a GPU, then the device attribute cudaDevAttrConcurrentManagedAccess must be non-zero.
This advice does not cause data migration and has no impact on the location of the data
per se. Instead, it causes the data to always be mapped in the specified processor's
page tables, as long as the location of the data permits a mapping to be established. If
the data gets migrated for any reason, the mappings are updated accordingly. This advice
is recommended in scenarios where data locality is not important, but avoiding faults
is. Consider for example a system containing multiple GPUs with peer-to-peer access
enabled, where the data located on one GPU is occasionally accessed by peer GPUs. In
such scenarios, migrating data over to the other GPUs is not as important because the
accesses are infrequent and the overhead of migration may be too high. But preventing
faults can still help improve performance, and so having a mapping set up in advance is
useful. Note that on CPU access of this data, the data may be migrated to host memory
because the CPU typically cannot access device memory directly. Any GPU that had the
cudaMemAdviceSetAccessedBy flag set for this data will now have its mapping updated to
point to the page in host memory. If cudaMemAdviseSetReadMostly is also set on this
memory region or any subset of it, then the policies associated with that advice will
override the policies of this advice. Additionally, if the preferred location of this
memory region or any subset of it is also device, then the policies associated with
cudaMemAdviseSetPreferredLocation will override the policies of this advice.
• cudaMemAdviseUnsetAccessedBy: Undoes the effect of cudaMemAdviseSetAccessedBy. Any
mappings to the data from device may be removed at any time causing accesses to result
in non-fatal page faults.
Parameters:
devPtr - Pointer to memory to set the advice for
count - Size in bytes of the memory range
advice - Advice to be applied for the specified memory range
device - Device to apply the advice for
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpyPeer, cudaMemcpyAsync, cudaMemcpy3DPeerAsync,
cudaMemPrefetchAsync, cuMemAdvise
cudaError_t cudaMemcpy (void * dst, const void * src, size_t count, enum cudaMemcpyKind kind)
Copies count bytes from the memory area pointed to by src to the memory area pointed to by
dst, where kind specifies the direction of the copy, and must be one of
cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
Calling cudaMemcpy() with dst and src pointers that do not match the direction of the copy
results in an undefined behavior.
Parameters:
dst - Destination memory address
src - Source memory address
count - Size in bytes to copy
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
cuMemcpyDtoH, cuMemcpyHtoD, cuMemcpyDtoD, cuMemcpy
cudaError_t cudaMemcpy2D (void * dst, size_t dpitch, const void * src, size_t spitch, size_t
width, size_t height, enum cudaMemcpyKind kind)
Copies a matrix (height rows of width bytes each) from the memory area pointed to by src
to the memory area pointed to by dst, where kind specifies the direction of the copy, and
must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
dpitch and spitch are the widths in memory in bytes of the 2D arrays pointed to by dst and
src, including any padding added to the end of each row. The memory areas may not overlap.
width must not exceed either dpitch or spitch. Calling cudaMemcpy2D() with dst and src
pointers that do not match the direction of the copy results in an undefined behavior.
cudaMemcpy2D() returns an error if dpitch or spitch exceeds the maximum allowed.
Parameters:
dst - Destination memory address
dpitch - Pitch of destination memory
src - Source memory address
spitch - Pitch of source memory
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMemcpy, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
cuMemcpy2D, cuMemcpy2DUnaligned
cudaError_t cudaMemcpy2DArrayToArray (cudaArray_t dst, size_t wOffsetDst, size_t hOffsetDst,
cudaArray_const_t src, size_t wOffsetSrc, size_t hOffsetSrc, size_t width, size_t height,
enum cudaMemcpyKind kind = cudaMemcpyDeviceToDevice)
Copies a matrix (height rows of width bytes each) from the CUDA array srcArray starting at
the upper left corner (wOffsetSrc, hOffsetSrc) to the CUDA array dst starting at the upper
left corner (wOffsetDst, hOffsetDst), where kind specifies the direction of the copy, and
must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
wOffsetDst + width must not exceed the width of the CUDA array dst. wOffsetSrc + width
must not exceed the width of the CUDA array src.
Parameters:
dst - Destination memory address
wOffsetDst - Destination starting X offset
hOffsetDst - Destination starting Y offset
src - Source memory address
wOffsetSrc - Source starting X offset
hOffsetSrc - Source starting Y offset
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpyToSymbol,
cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy2D, cuMemcpy2DUnaligned
__cudart_builtin__ cudaError_t cudaMemcpy2DAsync (void * dst, size_t dpitch, const void * src,
size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind, cudaStream_t stream
= 0)
Copies a matrix (height rows of width bytes each) from the memory area pointed to by src
to the memory area pointed to by dst, where kind specifies the direction of the copy, and
must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
dpitch and spitch are the widths in memory in bytes of the 2D arrays pointed to by dst and
src, including any padding added to the end of each row. The memory areas may not overlap.
width must not exceed either dpitch or spitch.
Calling cudaMemcpy2DAsync() with dst and src pointers that do not match the direction of
the copy results in an undefined behavior. cudaMemcpy2DAsync() returns an error if dpitch
or spitch is greater than the maximum allowed.
cudaMemcpy2DAsync() is asynchronous with respect to the host, so the call may return
before the copy is complete. The copy can optionally be associated to a stream by passing
a non-zero stream argument. If kind is cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost
and stream is non-zero, the copy may overlap with operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
dst - Destination memory address
dpitch - Pitch of destination memory
src - Source memory address
spitch - Pitch of source memory
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy2DAsync
cudaError_t cudaMemcpy2DFromArray (void * dst, size_t dpitch, cudaArray_const_t src, size_t
wOffset, size_t hOffset, size_t width, size_t height, enum cudaMemcpyKind kind)
Copies a matrix (height rows of width bytes each) from the CUDA array srcArray starting at
the upper left corner (wOffset, hOffset) to the memory area pointed to by dst, where kind
specifies the direction of the copy, and must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. dpitch is the width in memory in bytes
of the 2D array pointed to by dst, including any padding added to the end of each row.
wOffset + width must not exceed the width of the CUDA array src. width must not exceed
dpitch. cudaMemcpy2DFromArray() returns an error if dpitch exceeds the maximum allowed.
Parameters:
dst - Destination memory address
dpitch - Pitch of destination memory
src - Source memory address
wOffset - Source starting X offset
hOffset - Source starting Y offset
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray, cudaMemcpyToSymbol,
cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy2D, cuMemcpy2DUnaligned
cudaError_t cudaMemcpy2DFromArrayAsync (void * dst, size_t dpitch, cudaArray_const_t src,
size_t wOffset, size_t hOffset, size_t width, size_t height, enum cudaMemcpyKind kind,
cudaStream_t stream = 0)
Copies a matrix (height rows of width bytes each) from the CUDA array srcArray starting at
the upper left corner (wOffset, hOffset) to the memory area pointed to by dst, where kind
specifies the direction of the copy, and must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. dpitch is the width in memory in bytes
of the 2D array pointed to by dst, including any padding added to the end of each row.
wOffset + width must not exceed the width of the CUDA array src. width must not exceed
dpitch. cudaMemcpy2DFromArrayAsync() returns an error if dpitch exceeds the maximum
allowed.
cudaMemcpy2DFromArrayAsync() is asynchronous with respect to the host, so the call may
return before the copy is complete. The copy can optionally be associated to a stream by
passing a non-zero stream argument. If kind is cudaMemcpyHostToDevice or
cudaMemcpyDeviceToHost and stream is non-zero, the copy may overlap with operations in
other streams.
Parameters:
dst - Destination memory address
dpitch - Pitch of destination memory
src - Source memory address
wOffset - Source starting X offset
hOffset - Source starting Y offset
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy2DAsync
cudaError_t cudaMemcpy2DToArray (cudaArray_t dst, size_t wOffset, size_t hOffset, const void *
src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind)
Copies a matrix (height rows of width bytes each) from the memory area pointed to by src
to the CUDA array dst starting at the upper left corner (wOffset, hOffset) where kind
specifies the direction of the copy, and must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. spitch is the width in memory in bytes
of the 2D array pointed to by src, including any padding added to the end of each row.
wOffset + width must not exceed the width of the CUDA array dst. width must not exceed
spitch. cudaMemcpy2DToArray() returns an error if spitch exceeds the maximum allowed.
Parameters:
dst - Destination memory address
wOffset - Destination starting X offset
hOffset - Destination starting Y offset
src - Source memory address
spitch - Pitch of source memory
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
cuMemcpy2D, cuMemcpy2DUnaligned
cudaError_t cudaMemcpy2DToArrayAsync (cudaArray_t dst, size_t wOffset, size_t hOffset, const
void * src, size_t spitch, size_t width, size_t height, enum cudaMemcpyKind kind,
cudaStream_t stream = 0)
Copies a matrix (height rows of width bytes each) from the memory area pointed to by src
to the CUDA array dst starting at the upper left corner (wOffset, hOffset) where kind
specifies the direction of the copy, and must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. spitch is the width in memory in bytes
of the 2D array pointed to by src, including any padding added to the end of each row.
wOffset + width must not exceed the width of the CUDA array dst. width must not exceed
spitch. cudaMemcpy2DToArrayAsync() returns an error if spitch exceeds the maximum allowed.
cudaMemcpy2DToArrayAsync() is asynchronous with respect to the host, so the call may
return before the copy is complete. The copy can optionally be associated to a stream by
passing a non-zero stream argument. If kind is cudaMemcpyHostToDevice or
cudaMemcpyDeviceToHost and stream is non-zero, the copy may overlap with operations in
other streams.
Parameters:
dst - Destination memory address
wOffset - Destination starting X offset
hOffset - Destination starting Y offset
src - Source memory address
spitch - Pitch of source memory
width - Width of matrix transfer (columns in bytes)
height - Height of matrix transfer (rows)
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy2DAsync
cudaError_t cudaMemcpy3D (const struct cudaMemcpy3DParms * p)
struct cudaExtent {
size_t width;
size_t height;
size_t depth;
};
struct cudaExtent make_cudaExtent(size_t w, size_t h, size_t d);
struct cudaPos {
size_t x;
size_t y;
size_t z;
};
struct cudaPos make_cudaPos(size_t x, size_t y, size_t z);
struct cudaMemcpy3DParms {
cudaArray_t srcArray;
struct cudaPos srcPos;
struct cudaPitchedPtr srcPtr;
cudaArray_t dstArray;
struct cudaPos dstPos;
struct cudaPitchedPtr dstPtr;
struct cudaExtent extent;
enum cudaMemcpyKind kind;
};
cudaMemcpy3D() copies data between two 3D objects. The source and destination objects may
be in either host memory, device memory, or a CUDA array. The source, destination, extent,
and kind of copy performed is specified by the cudaMemcpy3DParms struct which should be
initialized to zero before use:
cudaMemcpy3DParms myParms = {0};
The struct passed to cudaMemcpy3D() must specify one of srcArray or srcPtr and one of
dstArray or dstPtr. Passing more than one non-zero source or destination will cause
cudaMemcpy3D() to return an error.
The srcPos and dstPos fields are optional offsets into the source and destination objects
and are defined in units of each object's elements. The element for a host or device
pointer is assumed to be unsigned char.
The extent field defines the dimensions of the transferred area in elements. If a CUDA
array is participating in the copy, the extent is defined in terms of that array's
elements. If no CUDA array is participating in the copy then the extents are defined in
elements of unsigned char.
The kind field defines the direction of the copy. It must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. For cudaMemcpyHostToHost or
cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost passed as kind and cudaArray type passed
as source or destination, if the kind implies cudaArray type to be present on the host,
cudaMemcpy3D() will disregard that implication and silently correct the kind based on the
fact that cudaArray type can only be present on the device.
If the source and destination are both arrays, cudaMemcpy3D() will return an error if they
do not have the same element size.
The source and destination object may not overlap. If overlapping source and destination
objects are specified, undefined behavior will result.
The source object must lie entirely within the region defined by srcPos and extent. The
destination object must lie entirely within the region defined by dstPos and extent.
cudaMemcpy3D() returns an error if the pitch of srcPtr or dstPtr exceeds the maximum
allowed. The pitch of a cudaPitchedPtr allocated with cudaMalloc3D() will always be valid.
Parameters:
p - 3D memory copy parameters
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMalloc3D, cudaMalloc3DArray, cudaMemset3D, cudaMemcpy3DAsync, cudaMemcpy,
cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
make_cudaExtent, make_cudaPos, cuMemcpy3D
__cudart_builtin__ cudaError_t cudaMemcpy3DAsync (const struct cudaMemcpy3DParms * p,
cudaStream_t stream = 0)
struct cudaExtent {
size_t width;
size_t height;
size_t depth;
};
struct cudaExtent make_cudaExtent(size_t w, size_t h, size_t d);
struct cudaPos {
size_t x;
size_t y;
size_t z;
};
struct cudaPos make_cudaPos(size_t x, size_t y, size_t z);
struct cudaMemcpy3DParms {
cudaArray_t srcArray;
struct cudaPos srcPos;
struct cudaPitchedPtr srcPtr;
cudaArray_t dstArray;
struct cudaPos dstPos;
struct cudaPitchedPtr dstPtr;
struct cudaExtent extent;
enum cudaMemcpyKind kind;
};
cudaMemcpy3DAsync() copies data between two 3D objects. The source and destination objects
may be in either host memory, device memory, or a CUDA array. The source, destination,
extent, and kind of copy performed is specified by the cudaMemcpy3DParms struct which
should be initialized to zero before use:
cudaMemcpy3DParms myParms = {0};
The struct passed to cudaMemcpy3DAsync() must specify one of srcArray or srcPtr and one of
dstArray or dstPtr. Passing more than one non-zero source or destination will cause
cudaMemcpy3DAsync() to return an error.
The srcPos and dstPos fields are optional offsets into the source and destination objects
and are defined in units of each object's elements. The element for a host or device
pointer is assumed to be unsigned char. For CUDA arrays, positions must be in the range
[0, 2048) for any dimension.
The extent field defines the dimensions of the transferred area in elements. If a CUDA
array is participating in the copy, the extent is defined in terms of that array's
elements. If no CUDA array is participating in the copy then the extents are defined in
elements of unsigned char.
The kind field defines the direction of the copy. It must be one of cudaMemcpyHostToHost,
cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or
cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended, in which case the type of
transfer is inferred from the pointer values. However, cudaMemcpyDefault is only allowed
on systems that support unified virtual addressing. For cudaMemcpyHostToHost or
cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost passed as kind and cudaArray type passed
as source or destination, if the kind implies cudaArray type to be present on the host,
cudaMemcpy3DAsync() will disregard that implication and silently correct the kind based on
the fact that cudaArray type can only be present on the device.
If the source and destination are both arrays, cudaMemcpy3DAsync() will return an error if
they do not have the same element size.
The source and destination object may not overlap. If overlapping source and destination
objects are specified, undefined behavior will result.
The source object must lie entirely within the region defined by srcPos and extent. The
destination object must lie entirely within the region defined by dstPos and extent.
cudaMemcpy3DAsync() returns an error if the pitch of srcPtr or dstPtr exceeds the maximum
allowed. The pitch of a cudaPitchedPtr allocated with cudaMalloc3D() will always be valid.
cudaMemcpy3DAsync() is asynchronous with respect to the host, so the call may return
before the copy is complete. The copy can optionally be associated to a stream by passing
a non-zero stream argument. If kind is cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost
and stream is non-zero, the copy may overlap with operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
p - 3D memory copy parameters
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidPitchValue,
cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMalloc3D, cudaMalloc3DArray, cudaMemset3D, cudaMemcpy3D, cudaMemcpy, cudaMemcpy2D,
cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray, cudaMemcpy2DFromArray,
cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray, cudaMemcpyToSymbol,
cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, make_cudaExtent, make_cudaPos,
cuMemcpy3DAsync
cudaError_t cudaMemcpy3DPeer (const struct cudaMemcpy3DPeerParms * p)
Perform a 3D memory copy according to the parameters specified in p. See the definition of
the cudaMemcpy3DPeerParms structure for documentation of its parameters.
Note that this function is synchronous with respect to the host only if the source or
destination of the transfer is host memory. Note also that this copy is serialized with
respect to all pending and future asynchronous work in to the current device, the copy's
source device, and the copy's destination device (use cudaMemcpy3DPeerAsync to avoid this
synchronization).
Parameters:
p - Parameters for the memory copy
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpyPeer, cudaMemcpyAsync, cudaMemcpyPeerAsync,
cudaMemcpy3DPeerAsync, cuMemcpy3DPeer
cudaError_t cudaMemcpy3DPeerAsync (const struct cudaMemcpy3DPeerParms * p, cudaStream_t stream
= 0)
Perform a 3D memory copy according to the parameters specified in p. See the definition of
the cudaMemcpy3DPeerParms structure for documentation of its parameters.
Parameters:
p - Parameters for the memory copy
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpyPeer, cudaMemcpyAsync, cudaMemcpyPeerAsync,
cudaMemcpy3DPeerAsync, cuMemcpy3DPeerAsync
cudaError_t cudaMemcpyArrayToArray (cudaArray_t dst, size_t wOffsetDst, size_t hOffsetDst,
cudaArray_const_t src, size_t wOffsetSrc, size_t hOffsetSrc, size_t count, enum
cudaMemcpyKind kind = cudaMemcpyDeviceToDevice)
Copies count bytes from the CUDA array src starting at the upper left corner (wOffsetSrc,
hOffsetSrc) to the CUDA array dst starting at the upper left corner (wOffsetDst,
hOffsetDst) where kind specifies the direction of the copy, and must be one of
cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
Parameters:
dst - Destination memory address
wOffsetDst - Destination starting X offset
hOffsetDst - Destination starting Y offset
src - Source memory address
wOffsetSrc - Source starting X offset
hOffsetSrc - Source starting Y offset
count - Size in bytes to copy
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpy2DArrayToArray, cudaMemcpyToSymbol,
cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpyAtoA
__cudart_builtin__ cudaError_t cudaMemcpyAsync (void * dst, const void * src, size_t count,
enum cudaMemcpyKind kind, cudaStream_t stream = 0)
Copies count bytes from the memory area pointed to by src to the memory area pointed to by
dst, where kind specifies the direction of the copy, and must be one of
cudaMemcpyHostToHost, cudaMemcpyHostToDevice, cudaMemcpyDeviceToHost,
cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing cudaMemcpyDefault is recommended,
in which case the type of transfer is inferred from the pointer values. However,
cudaMemcpyDefault is only allowed on systems that support unified virtual addressing.
The memory areas may not overlap. Calling cudaMemcpyAsync() with dst and src pointers that
do not match the direction of the copy results in an undefined behavior.
cudaMemcpyAsync() is asynchronous with respect to the host, so the call may return before
the copy is complete. The copy can optionally be associated to a stream by passing a non-
zero stream argument. If kind is cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost and the
stream is non-zero, the copy may overlap with operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
dst - Destination memory address
src - Source memory address
count - Size in bytes to copy
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync cuMemcpyAsync, cuMemcpyDtoHAsync,
cuMemcpyHtoDAsync, cuMemcpyDtoDAsync
cudaError_t cudaMemcpyFromArray (void * dst, cudaArray_const_t src, size_t wOffset, size_t
hOffset, size_t count, enum cudaMemcpyKind kind)
Copies count bytes from the CUDA array src starting at the upper left corner (wOffset,
hOffset) to the memory area pointed to by dst, where kind specifies the direction of the
copy, and must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice,
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
Parameters:
dst - Destination memory address
src - Source memory address
wOffset - Source starting X offset
hOffset - Source starting Y offset
count - Size in bytes to copy
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
cuMemcpyAtoH, cuMemcpyAtoD
cudaError_t cudaMemcpyFromArrayAsync (void * dst, cudaArray_const_t src, size_t wOffset,
size_t hOffset, size_t count, enum cudaMemcpyKind kind, cudaStream_t stream = 0)
Copies count bytes from the CUDA array src starting at the upper left corner (wOffset,
hOffset) to the memory area pointed to by dst, where kind specifies the direction of the
copy, and must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice,
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
cudaMemcpyFromArrayAsync() is asynchronous with respect to the host, so the call may
return before the copy is complete. The copy can optionally be associated to a stream by
passing a non-zero stream argument. If kind is cudaMemcpyHostToDevice or
cudaMemcpyDeviceToHost and stream is non-zero, the copy may overlap with operations in
other streams.
Parameters:
dst - Destination memory address
src - Source memory address
wOffset - Source starting X offset
hOffset - Source starting Y offset
count - Size in bytes to copy
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpyAtoHAsync, cuMemcpy2DAsync
cudaError_t cudaMemcpyFromSymbol (void * dst, const void * symbol, size_t count, size_t offset
= 0, enum cudaMemcpyKind kind = cudaMemcpyDeviceToHost)
Copies count bytes from the memory area pointed to by offset bytes from the start of
symbol symbol to the memory area pointed to by dst. The memory areas may not overlap.
symbol is a variable that resides in global or constant memory space. kind can be either
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
Parameters:
dst - Destination memory address
symbol - Device symbol address
count - Size in bytes to copy
offset - Offset from start of symbol in bytes
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidSymbol,
cudaErrorInvalidMemcpyDirection, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy, cuMemcpyDtoH,
cuMemcpyDtoD
cudaError_t cudaMemcpyFromSymbolAsync (void * dst, const void * symbol, size_t count, size_t
offset, enum cudaMemcpyKind kind, cudaStream_t stream = 0)
Copies count bytes from the memory area pointed to by offset bytes from the start of
symbol symbol to the memory area pointed to by dst. The memory areas may not overlap.
symbol is a variable that resides in global or constant memory space. kind can be either
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
cudaMemcpyFromSymbolAsync() is asynchronous with respect to the host, so the call may
return before the copy is complete. The copy can optionally be associated to a stream by
passing a non-zero stream argument. If kind is cudaMemcpyDeviceToHost and stream is non-
zero, the copy may overlap with operations in other streams.
Parameters:
dst - Destination memory address
symbol - Device symbol address
count - Size in bytes to copy
offset - Offset from start of symbol in bytes
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidSymbol,
cudaErrorInvalidMemcpyDirection, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cuMemcpyAsync, cuMemcpyDtoHAsync,
cuMemcpyDtoDAsync
cudaError_t cudaMemcpyPeer (void * dst, int dstDevice, const void * src, int srcDevice, size_t
count)
Copies memory from one device to memory on another device. dst is the base device pointer
of the destination memory and dstDevice is the destination device. src is the base device
pointer of the source memory and srcDevice is the source device. count specifies the
number of bytes to copy.
Note that this function is asynchronous with respect to the host, but serialized with
respect all pending and future asynchronous work in to the current device, srcDevice, and
dstDevice (use cudaMemcpyPeerAsync to avoid this synchronization).
Parameters:
dst - Destination device pointer
dstDevice - Destination device
src - Source device pointer
srcDevice - Source device
count - Size of memory copy in bytes
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpyAsync, cudaMemcpyPeerAsync, cudaMemcpy3DPeerAsync, cuMemcpyPeer
cudaError_t cudaMemcpyPeerAsync (void * dst, int dstDevice, const void * src, int srcDevice,
size_t count, cudaStream_t stream = 0)
Copies memory from one device to memory on another device. dst is the base device pointer
of the destination memory and dstDevice is the destination device. src is the base device
pointer of the source memory and srcDevice is the source device. count specifies the
number of bytes to copy.
Note that this function is asynchronous with respect to the host and all work on other
devices.
Parameters:
dst - Destination device pointer
dstDevice - Destination device
src - Source device pointer
srcDevice - Source device
count - Size of memory copy in bytes
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpyPeer, cudaMemcpyAsync, cudaMemcpy3DPeerAsync, cuMemcpyPeerAsync
cudaError_t cudaMemcpyToArray (cudaArray_t dst, size_t wOffset, size_t hOffset, const void *
src, size_t count, enum cudaMemcpyKind kind)
Copies count bytes from the memory area pointed to by src to the CUDA array dst starting
at the upper left corner (wOffset, hOffset), where kind specifies the direction of the
copy, and must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice,
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
Parameters:
dst - Destination memory address
wOffset - Destination starting X offset
hOffset - Destination starting Y offset
src - Source memory address
count - Size in bytes to copy
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync,
cuMemcpyHtoA, cuMemcpyDtoA
cudaError_t cudaMemcpyToArrayAsync (cudaArray_t dst, size_t wOffset, size_t hOffset, const
void * src, size_t count, enum cudaMemcpyKind kind, cudaStream_t stream = 0)
Copies count bytes from the memory area pointed to by src to the CUDA array dst starting
at the upper left corner (wOffset, hOffset), where kind specifies the direction of the
copy, and must be one of cudaMemcpyHostToHost, cudaMemcpyHostToDevice,
cudaMemcpyDeviceToHost, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
cudaMemcpyToArrayAsync() is asynchronous with respect to the host, so the call may return
before the copy is complete. The copy can optionally be associated to a stream by passing
a non-zero stream argument. If kind is cudaMemcpyHostToDevice or cudaMemcpyDeviceToHost
and stream is non-zero, the copy may overlap with operations in other streams.
Parameters:
dst - Destination memory address
wOffset - Destination starting X offset
hOffset - Destination starting Y offset
src - Source memory address
count - Size in bytes to copy
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidMemcpyDirection
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpyHtoAAsync, cuMemcpy2DAsync
cudaError_t cudaMemcpyToSymbol (const void * symbol, const void * src, size_t count, size_t
offset = 0, enum cudaMemcpyKind kind = cudaMemcpyHostToDevice)
Copies count bytes from the memory area pointed to by src to the memory area pointed to by
offset bytes from the start of symbol symbol. The memory areas may not overlap. symbol is
a variable that resides in global or constant memory space. kind can be either
cudaMemcpyHostToDevice, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
Parameters:
symbol - Device symbol address
src - Source memory address
count - Size in bytes to copy
offset - Offset from start of symbol in bytes
kind - Type of transfer
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidSymbol,
cudaErrorInvalidMemcpyDirection, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync, cudaMemcpyToArrayAsync,
cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync, cudaMemcpy2DFromArrayAsync,
cudaMemcpyToSymbolAsync, cudaMemcpyFromSymbolAsync, cuMemcpy, cuMemcpyHtoD,
cuMemcpyDtoD
cudaError_t cudaMemcpyToSymbolAsync (const void * symbol, const void * src, size_t count,
size_t offset, enum cudaMemcpyKind kind, cudaStream_t stream = 0)
Copies count bytes from the memory area pointed to by src to the memory area pointed to by
offset bytes from the start of symbol symbol. The memory areas may not overlap. symbol is
a variable that resides in global or constant memory space. kind can be either
cudaMemcpyHostToDevice, cudaMemcpyDeviceToDevice, or cudaMemcpyDefault. Passing
cudaMemcpyDefault is recommended, in which case the type of transfer is inferred from the
pointer values. However, cudaMemcpyDefault is only allowed on systems that support unified
virtual addressing.
cudaMemcpyToSymbolAsync() is asynchronous with respect to the host, so the call may return
before the copy is complete. The copy can optionally be associated to a stream by passing
a non-zero stream argument. If kind is cudaMemcpyHostToDevice and stream is non-zero, the
copy may overlap with operations in other streams.
Parameters:
symbol - Device symbol address
src - Source memory address
count - Size in bytes to copy
offset - Offset from start of symbol in bytes
kind - Type of transfer
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidSymbol,
cudaErrorInvalidMemcpyDirection, cudaErrorNoKernelImageForDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
Use of a string naming a variable as the symbol parameter was deprecated in CUDA 4.1
and removed in CUDA 5.0.
See also:
cudaMemcpy, cudaMemcpy2D, cudaMemcpyToArray, cudaMemcpy2DToArray, cudaMemcpyFromArray,
cudaMemcpy2DFromArray, cudaMemcpyArrayToArray, cudaMemcpy2DArrayToArray,
cudaMemcpyToSymbol, cudaMemcpyFromSymbol, cudaMemcpyAsync, cudaMemcpy2DAsync,
cudaMemcpyToArrayAsync, cudaMemcpy2DToArrayAsync, cudaMemcpyFromArrayAsync,
cudaMemcpy2DFromArrayAsync, cudaMemcpyFromSymbolAsync, cuMemcpyAsync,
cuMemcpyHtoDAsync, cuMemcpyDtoDAsync
cudaError_t cudaMemGetInfo (size_t * free, size_t * total)
Returns in *free and *total respectively, the free and total amount of memory available
for allocation by the device in bytes.
Parameters:
free - Returned free memory in bytes
total - Returned total memory in bytes
Returns:
cudaSuccess, cudaErrorInitializationError, cudaErrorInvalidValue,
cudaErrorLaunchFailure
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cuMemGetInfo
cudaError_t cudaMemPrefetchAsync (const void * devPtr, size_t count, int dstDevice,
cudaStream_t stream = 0)
Prefetches memory to the specified destination device. devPtr is the base device pointer
of the memory to be prefetched and dstDevice is the destination device. count specifies
the number of bytes to copy. stream is the stream in which the operation is enqueued. The
memory range must refer to managed memory allocated via cudaMallocManaged or declared via
__managed__ variables.
Passing in cudaCpuDeviceId for dstDevice will prefetch the data to host memory. If
dstDevice is a GPU, then the device attribute cudaDevAttrConcurrentManagedAccess must be
non-zero. Additionally, stream must be associated with a device that has a non-zero value
for the device attribute cudaDevAttrConcurrentManagedAccess.
The start address and end address of the memory range will be rounded down and rounded up
respectively to be aligned to CPU page size before the prefetch operation is enqueued in
the stream.
If no physical memory has been allocated for this region, then this memory region will be
populated and mapped on the destination device. If there's insufficient memory to prefetch
the desired region, the Unified Memory driver may evict pages from other cudaMallocManaged
allocations to host memory in order to make room. Device memory allocated using cudaMalloc
or cudaMallocArray will not be evicted.
By default, any mappings to the previous location of the migrated pages are removed and
mappings for the new location are only setup on dstDevice. The exact behavior however also
depends on the settings applied to this memory range via cudaMemAdvise as described below:
If cudaMemAdviseSetReadMostly was set on any subset of this memory range, then that subset
will create a read-only copy of the pages on dstDevice.
If cudaMemAdviseSetPreferredLocation was called on any subset of this memory range, then
the pages will be migrated to dstDevice even if dstDevice is not the preferred location of
any pages in the memory range.
If cudaMemAdviseSetAccessedBy was called on any subset of this memory range, then mappings
to those pages from all the appropriate processors are updated to refer to the new
location if establishing such a mapping is possible. Otherwise, those mappings are
cleared.
Note that this API is not required for functionality and only serves to improve
performance by allowing the application to migrate data to a suitable location before it
is accessed. Memory accesses to this range are always coherent and are allowed even when
the data is actively being migrated.
Note that this function is asynchronous with respect to the host and all work on other
devices.
Parameters:
devPtr - Pointer to be prefetched
count - Size in bytes
dstDevice - Destination device to prefetch to
stream - Stream to enqueue prefetch operation
Returns:
cudaSuccess, cudaErrorInvalidValue, cudaErrorInvalidDevice
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemcpy, cudaMemcpyPeer, cudaMemcpyAsync, cudaMemcpy3DPeerAsync, cudaMemAdvise,
cuMemPrefetchAsync
cudaError_t cudaMemRangeGetAttribute (void * data, size_t dataSize, enum cudaMemRangeAttribute
attribute, const void * devPtr, size_t count)
Query an attribute about the memory range starting at devPtr with a size of count bytes.
The memory range must refer to managed memory allocated via cudaMallocManaged or declared
via __managed__ variables.
The attribute parameter can take the following values:
• cudaMemRangeAttributeReadMostly: If this attribute is specified, data will be
interpreted as a 32-bit integer, and dataSize must be 4. The result returned will be 1
if all pages in the given memory range have read-duplication enabled, or 0 otherwise.
• cudaMemRangeAttributePreferredLocation: If this attribute is specified, data will be
interpreted as a 32-bit integer, and dataSize must be 4. The result returned will be a
GPU device id if all pages in the memory range have that GPU as their preferred
location, or it will be cudaCpuDeviceId if all pages in the memory range have the CPU as
their preferred location, or it will be cudaInvalidDeviceId if either all the pages
don't have the same preferred location or some of the pages don't have a preferred
location at all. Note that the actual location of the pages in the memory range at the
time of the query may be different from the preferred location.
• cudaMemRangeAttributeAccessedBy: If this attribute is specified, data will be
interpreted as an array of 32-bit integers, and dataSize must be a non-zero multiple of
4. The result returned will be a list of device ids that had cudaMemAdviceSetAccessedBy
set for that entire memory range. If any device does not have that advice set for the
entire memory range, that device will not be included. If data is larger than the number
of devices that have that advice set for that memory range, cudaInvalidDeviceId will be
returned in all the extra space provided. For ex., if dataSize is 12 (i.e. data has 3
elements) and only device 0 has the advice set, then the result returned will be { 0,
cudaInvalidDeviceId, cudaInvalidDeviceId }. If data is smaller than the number of
devices that have that advice set, then only as many devices will be returned as can fit
in the array. There is no guarantee on which specific devices will be returned, however.
• cudaMemRangeAttributeLastPrefetchLocation: If this attribute is specified, data will be
interpreted as a 32-bit integer, and dataSize must be 4. The result returned will be the
last location to which all pages in the memory range were prefetched explicitly via
cudaMemPrefetchAsync. This will either be a GPU id or cudaCpuDeviceId depending on
whether the last location for prefetch was a GPU or the CPU respectively. If any page in
the memory range was never explicitly prefetched or if all pages were not prefetched to
the same location, cudaInvalidDeviceId will be returned. Note that this simply returns
the last location that the applicaton requested to prefetch the memory range to. It
gives no indication as to whether the prefetch operation to that location has completed
or even begun.
Parameters:
data - A pointers to a memory location where the result of each attribute query will
be written to.
dataSize - Array containing the size of data
attribute - The attribute to query
devPtr - Start of the range to query
count - Size of the range to query
Returns:
cudaSuccess, cudaErrorInvalidValue
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
This function exhibits behavior for most use cases.
This function uses standard semantics.
See also:
cudaMemRangeGetAttributes, cudaMemPrefetchAsync, cudaMemAdvise, cuMemRangeGetAttribute
cudaError_t cudaMemRangeGetAttributes (void ** data, size_t * dataSizes, enum
cudaMemRangeAttribute * attributes, size_t numAttributes, const void * devPtr, size_t
count)
Query attributes of the memory range starting at devPtr with a size of count bytes. The
memory range must refer to managed memory allocated via cudaMallocManaged or declared via
__managed__ variables. The attributes array will be interpreted to have numAttributes
entries. The dataSizes array will also be interpreted to have numAttributes entries. The
results of the query will be stored in data.
The list of supported attributes are given below. Please refer to cudaMemRangeGetAttribute
for attribute descriptions and restrictions.
• cudaMemRangeAttributeReadMostly
• cudaMemRangeAttributePreferredLocation
• cudaMemRangeAttributeAccessedBy
• cudaMemRangeAttributeLastPrefetchLocation
Parameters:
data - A two-dimensional array containing pointers to memory locations where the
result of each attribute query will be written to.
dataSizes - Array containing the sizes of each result
attributes - An array of attributes to query (numAttributes and the number of
attributes in this array should match)
numAttributes - Number of attributes to query
devPtr - Start of the range to query
count - Size of the range to query
Returns:
cudaSuccess, cudaErrorInvalidValue
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also:
cudaMemRangeGetAttribute, cudaMemAdvise cudaMemPrefetchAsync, cuMemRangeGetAttributes
cudaError_t cudaMemset (void * devPtr, int value, size_t count)
Fills the first count bytes of the memory area pointed to by devPtr with the constant byte
value value.
Note that this function is asynchronous with respect to the host unless devPtr refers to
pinned host memory.
Parameters:
devPtr - Pointer to device memory
value - Value to set for each byte of specified memory
count - Size in bytes to set
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
See also:
cuMemsetD8, cuMemsetD16, cuMemsetD32
cudaError_t cudaMemset2D (void * devPtr, size_t pitch, int value, size_t width, size_t height)
Sets to the specified value value a matrix (height rows of width bytes each) pointed to by
dstPtr. pitch is the width in bytes of the 2D array pointed to by dstPtr, including any
padding added to the end of each row. This function performs fastest when the pitch is one
that has been passed back by cudaMallocPitch().
Note that this function is asynchronous with respect to the host unless devPtr refers to
pinned host memory.
Parameters:
devPtr - Pointer to 2D device memory
pitch - Pitch in bytes of 2D device memory
value - Value to set for each byte of specified memory
width - Width of matrix set (columns in bytes)
height - Height of matrix set (rows)
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
See also:
cudaMemset, cudaMemset3D, cudaMemsetAsync, cudaMemset2DAsync, cudaMemset3DAsync,
cuMemsetD2D8, cuMemsetD2D16, cuMemsetD2D32
__cudart_builtin__ cudaError_t cudaMemset2DAsync (void * devPtr, size_t pitch, int value,
size_t width, size_t height, cudaStream_t stream = 0)
Sets to the specified value value a matrix (height rows of width bytes each) pointed to by
dstPtr. pitch is the width in bytes of the 2D array pointed to by dstPtr, including any
padding added to the end of each row. This function performs fastest when the pitch is one
that has been passed back by cudaMallocPitch().
cudaMemset2DAsync() is asynchronous with respect to the host, so the call may return
before the memset is complete. The operation can optionally be associated to a stream by
passing a non-zero stream argument. If stream is non-zero, the operation may overlap with
operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
devPtr - Pointer to 2D device memory
pitch - Pitch in bytes of 2D device memory
value - Value to set for each byte of specified memory
width - Width of matrix set (columns in bytes)
height - Height of matrix set (rows)
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
This function uses standard semantics.
See also:
cudaMemset, cudaMemset2D, cudaMemset3D, cudaMemsetAsync, cudaMemset3DAsync,
cuMemsetD2D8Async, cuMemsetD2D16Async, cuMemsetD2D32Async
cudaError_t cudaMemset3D (struct cudaPitchedPtr pitchedDevPtr, int value, struct cudaExtent
extent)
Initializes each element of a 3D array to the specified value value. The object to
initialize is defined by pitchedDevPtr. The pitch field of pitchedDevPtr is the width in
memory in bytes of the 3D array pointed to by pitchedDevPtr, including any padding added
to the end of each row. The xsize field specifies the logical width of each row in bytes,
while the ysize field specifies the height of each 2D slice in rows.
The extents of the initialized region are specified as a width in bytes, a height in rows,
and a depth in slices.
Extents with width greater than or equal to the xsize of pitchedDevPtr may perform
significantly faster than extents narrower than the xsize. Secondarily, extents with
height equal to the ysize of pitchedDevPtr will perform faster than when the height is
shorter than the ysize.
This function performs fastest when the pitchedDevPtr has been allocated by
cudaMalloc3D().
Note that this function is asynchronous with respect to the host unless pitchedDevPtr
refers to pinned host memory.
Parameters:
pitchedDevPtr - Pointer to pitched device memory
value - Value to set for each byte of specified memory
extent - Size parameters for where to set device memory (width field in bytes)
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
See also:
cudaMemset, cudaMemset2D, cudaMemsetAsync, cudaMemset2DAsync, cudaMemset3DAsync,
cudaMalloc3D, make_cudaPitchedPtr, make_cudaExtent
__cudart_builtin__ cudaError_t cudaMemset3DAsync (struct cudaPitchedPtr pitchedDevPtr, int
value, struct cudaExtent extent, cudaStream_t stream = 0)
Initializes each element of a 3D array to the specified value value. The object to
initialize is defined by pitchedDevPtr. The pitch field of pitchedDevPtr is the width in
memory in bytes of the 3D array pointed to by pitchedDevPtr, including any padding added
to the end of each row. The xsize field specifies the logical width of each row in bytes,
while the ysize field specifies the height of each 2D slice in rows.
The extents of the initialized region are specified as a width in bytes, a height in rows,
and a depth in slices.
Extents with width greater than or equal to the xsize of pitchedDevPtr may perform
significantly faster than extents narrower than the xsize. Secondarily, extents with
height equal to the ysize of pitchedDevPtr will perform faster than when the height is
shorter than the ysize.
This function performs fastest when the pitchedDevPtr has been allocated by
cudaMalloc3D().
cudaMemset3DAsync() is asynchronous with respect to the host, so the call may return
before the memset is complete. The operation can optionally be associated to a stream by
passing a non-zero stream argument. If stream is non-zero, the operation may overlap with
operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
pitchedDevPtr - Pointer to pitched device memory
value - Value to set for each byte of specified memory
extent - Size parameters for where to set device memory (width field in bytes)
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
This function uses standard semantics.
See also:
cudaMemset, cudaMemset2D, cudaMemset3D, cudaMemsetAsync, cudaMemset2DAsync,
cudaMalloc3D, make_cudaPitchedPtr, make_cudaExtent
__cudart_builtin__ cudaError_t cudaMemsetAsync (void * devPtr, int value, size_t count,
cudaStream_t stream = 0)
Fills the first count bytes of the memory area pointed to by devPtr with the constant byte
value value.
cudaMemsetAsync() is asynchronous with respect to the host, so the call may return before
the memset is complete. The operation can optionally be associated to a stream by passing
a non-zero stream argument. If stream is non-zero, the operation may overlap with
operations in other streams.
The device version of this function only handles device to device copies and cannot be
given local or shared pointers.
Parameters:
devPtr - Pointer to device memory
value - Value to set for each byte of specified memory
count - Size in bytes to set
stream - Stream identifier
Returns:
cudaSuccess, cudaErrorInvalidValue,
Note:
Note that this function may also return error codes from previous, asynchronous
launches.
See also .
This function uses standard semantics.
See also:
cudaMemset, cudaMemset2D, cudaMemset3D, cudaMemset2DAsync, cudaMemset3DAsync,
cuMemsetD8Async, cuMemsetD16Async, cuMemsetD32Async
struct cudaExtent make_cudaExtent (size_t w, size_t h, size_t d) [read]
Returns a cudaExtent based on the specified input parameters w, h, and d.
Parameters:
w - Width in elements when referring to array memory, in bytes when referring to
linear memory
h - Height in elements
d - Depth in elements
Returns:
cudaExtent specified by w, h, and d
See also:
make_cudaPitchedPtr, make_cudaPos
struct cudaPitchedPtr make_cudaPitchedPtr (void * d, size_t p, size_t xsz, size_t ysz) [read]
Returns a cudaPitchedPtr based on the specified input parameters d, p, xsz, and ysz.
Parameters:
d - Pointer to allocated memory
p - Pitch of allocated memory in bytes
xsz - Logical width of allocation in elements
ysz - Logical height of allocation in elements
Returns:
cudaPitchedPtr specified by d, p, xsz, and ysz
See also:
make_cudaExtent, make_cudaPos
struct cudaPos make_cudaPos (size_t x, size_t y, size_t z) [read]
Returns a cudaPos based on the specified input parameters x, y, and z.
Parameters:
x - X position
y - Y position
z - Z position
Returns:
cudaPos specified by x, y, and z
See also:
make_cudaExtent, make_cudaPitchedPtr
Author
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