cufile.h(3)

NAME
cufile.h - cuFile C APIs

SYNOPSIS

  Data Structures
struct CUfileDescr_t
struct CUfileDrvProps
struct CUfileError
cufileop status string
struct CUfileFSOps
struct CUfileIOEvents
struct CUfileIOParams
struct cufileRDMAInfo

  Macros
#define CU_FILE_CUDA_ERR(status) ((status).cu_err)
#define CU_FILE_RDMA_REGISTER 1
#define CU_FILE_RDMA_RELAXED_ORDERING (1<<1)
#define CU_FILE_STREAM_FIXED_BUF_OFFSET 1
#define CU_FILE_STREAM_FIXED_FILE_OFFSET 2
#define CU_FILE_STREAM_FIXED_FILE_SIZE 4
#define CU_FILE_STREAM_PAGE_ALIGNED_INPUTS 8
#define CUFILE_ERRSTR(err) cufileop_status_error((CUfileOpError)abs((err)))
#define cuFileDriverClose cuFileDriverClose_v2
#define IS_CUDA_ERR(status) ((status).err == CU_FILE_CUDA_DRIVER_ERROR)
#define IS_CUFILE_ERR(err) (abs((err)) > CUFILEOP_BASE_ERR)
error macros to inspect error status of type CUfileOpError

  Typedefs
typedef void * CUfileBatchHandle_t
typedef enum cufileBatchMode CUfileBatchMode_t
typedef struct CUfileDescr_t CUfileDescr_t
typedef enum CUfileDriverControlFlags CUfileDriverControlFlags_t
typedef enum CUfileDriverStatusFlags CUfileDriverStatusFlags_t
typedef struct CUfileDrvProps CUfileDrvProps_t
typedef struct CUfileError CUfileError_t
cufileop status string
typedef enum CUfileFeatureFlags CUfileFeatureFlags_t
typedef struct CUfileFSOps CUfileFSOps_t
typedef void * CUfileHandle_t
File handle type.
typedef struct CUfileIOEvents CUfileIOEvents_t
typedef struct CUfileIOParams CUfileIOParams_t
typedef enum CUfileOpcode CUfileOpcode_t
typedef struct cufileRDMAInfo cufileRDMAInfo_t
typedef enum CUFILEStatus_enum CUfileStatus_t
typedef struct sockaddr sockaddr_t

  Enumerations
enum cufileBatchMode { CUFILE_BATCH = 1 }
enum CUfileDriverControlFlags { CU_FILE_USE_POLL_MODE = 0, CU_FILE_ALLOW_COMPAT_MODE = 1 }
enum CUfileDriverStatusFlags { CU_FILE_LUSTRE_SUPPORTED = 0, CU_FILE_WEKAFS_SUPPORTED = 1, CU_FILE_NFS_SUPPORTED = 2, CU_FILE_GPFS_SUPPORTED = 3, CU_FILE_NVME_SUPPORTED = 4, CU_FILE_NVMEOF_SUPPORTED = 5, CU_FILE_SCSI_SUPPORTED = 6, CU_FILE_SCALEFLUX_CSD_SUPPORTED = 7, CU_FILE_NVMESH_SUPPORTED = 8, CU_FILE_BEEGFS_SUPPORTED = 9 }
enum CUfileFeatureFlags { CU_FILE_DYN_ROUTING_SUPPORTED = 0, CU_FILE_BATCH_IO_SUPPORTED = 1, CU_FILE_STREAMS_SUPPORTED = 2, CU_FILE_PARALLEL_IO_SUPPORTED = 3 }
enum CUfileFileHandleType { CU_FILE_HANDLE_TYPE_OPAQUE_FD = 1, CU_FILE_HANDLE_TYPE_OPAQUE_WIN32 = 2, CU_FILE_HANDLE_TYPE_USERSPACE_FS = 3 }
enum CUfileOpcode { CUFILE_READ = 0, CUFILE_WRITE }
enum CUFILEStatus_enum { CUFILE_WAITING = 0x000001, CUFILE_PENDING = 0x000002, CUFILE_INVALID = 0x000004, CUFILE_CANCELED = 0x000008, CUFILE_COMPLETE = 0x0000010, CUFILE_TIMEOUT = 0x0000020, CUFILE_FAILED = 0x0000040 }

  Functions
CUfileError_t cuFileBatchIOCancel (CUfileBatchHandle_t batch_idp)
void cuFileBatchIODestroy (CUfileBatchHandle_t batch_idp)
CUfileError_t cuFileBatchIOGetStatus (CUfileBatchHandle_t batch_idp, unsigned min_nr, unsigned *nr, CUfileIOEvents_t *iocbp, struct timespec *timeout)
CUfileError_t cuFileBatchIOSetUp (CUfileBatchHandle_t *batch_idp, unsigned nr)
CUfileError_t cuFileBatchIOSubmit (CUfileBatchHandle_t batch_idp, unsigned nr, CUfileIOParams_t *iocbp, unsigned int flags)
CUfileError_t cuFileBufDeregister (const void *bufPtr_base)
deregister an already registered device or host memory from cuFile
CUfileError_t cuFileBufRegister (const void *bufPtr_base, size_t length, int flags)
register an existing cudaMalloced memory with cuFile to pin for GPUDirect Storage access or register host allocated memory with cuFile.
CUfileError_t cuFileDriverClose (void)
CUfileError_t cuFileDriverClose_v2 (void)
reset the cuFile library and release the nvidia-fs driver
CUfileError_t cuFileDriverGetProperties (CUfileDrvProps_t *props)
Gets the Driver session properties.
CUfileError_t cuFileDriverOpen (void)
Initialize the cuFile library and open the nvidia-fs driver.
CUfileError_t cuFileDriverSetMaxCacheSize (size_t max_cache_size)
Control parameter to set maximum GPU memory reserved per device by the library for internal buffering.
CUfileError_t cuFileDriverSetMaxDirectIOSize (size_t max_direct_io_size)
Control parameter to set max IO size(KB) used by the library to talk to nvidia-fs driver.
CUfileError_t cuFileDriverSetMaxPinnedMemSize (size_t max_pinned_size)
Sets maximum buffer space that is pinned in KB for use by cuFileBufRegister.
CUfileError_t cuFileDriverSetPollMode (bool poll, size_t poll_threshold_size)
Sets whether the Read/Write APIs use polling to do IO operations.
CUfileError_t cuFileGetVersion (int *version)
void cuFileHandleDeregister (CUfileHandle_t fh)
releases a registered filehandle from cuFile
CUfileError_t cuFileHandleRegister (CUfileHandle_t *fh, CUfileDescr_t *descr)
cuFileHandleRegister is required, and performs extra checking that is memoized to provide increased performance on later cuFile operations.
ssize_t cuFileRead (CUfileHandle_t fh, void *bufPtr_base, size_t size, off_t file_offset, off_t bufPtr_offset)
read data from a registered file handle to a specified device or host memory
CUfileError_t cuFileReadAsync (CUfileHandle_t fh, void *bufPtr_base, size_t *size_p, off_t *file_offset_p, off_t *bufPtr_offset_p, ssize_t *bytes_read_p, CUstream stream)
CUfileError_t cuFileStreamDeregister (CUstream stream)
CUfileError_t cuFileStreamRegister (CUstream stream, unsigned flags)
long cuFileUseCount (void)
returns use count of cufile drivers at that moment by the process.
ssize_t cuFileWrite (CUfileHandle_t fh, const void *bufPtr_base, size_t size, off_t file_offset, off_t bufPtr_offset)
write data from a specified device or host memory to a registered file handle
CUfileError_t cuFileWriteAsync (CUfileHandle_t fh, void *bufPtr_base, size_t *size_p, off_t *file_offset_p, off_t *bufPtr_offset_p, ssize_t *bytes_written_p, CUstream stream)

  Variables
CUfileOpError

Detailed Description

cuFile C APIs This file contains all the C APIs to perform GPUDirect Storage supported IO operations

Macro Definition Documentation

  #define CU_FILE_CUDA_ERR(status) ((status).cu_err)

  #define CU_FILE_RDMA_REGISTER 1

  #define CU_FILE_RDMA_RELAXED_ORDERING (1<<1)

  #define CU_FILE_STREAM_FIXED_BUF_OFFSET 1

  #define CU_FILE_STREAM_FIXED_FILE_OFFSET 2

  #define CU_FILE_STREAM_FIXED_FILE_SIZE 4

  #define CU_FILE_STREAM_PAGE_ALIGNED_INPUTS 8

  #define CUFILE_ERRSTR(err) cufileop_status_error((CUfileOpError)abs((err)))

  #define cuFileDriverClose cuFileDriverClose_v2

  #define IS_CUDA_ERR(status) ((status).err == CU_FILE_CUDA_DRIVER_ERROR)

  #define IS_CUFILE_ERR(err) (abs((err)) > CUFILEOP_BASE_ERR)

error macros to inspect error status of type CUfileOpError

Typedef Documentation

  typedef void* CUfileBatchHandle_t

  typedef enum cufileBatchMode CUfileBatchMode_t

  typedef struct CUfileDescr_t CUfileDescr_t

  typedef enum CUfileDriverControlFlags CUfileDriverControlFlags_t

  typedef enum CUfileDriverStatusFlags CUfileDriverStatusFlags_t

  typedef struct CUfileDrvProps CUfileDrvProps_t

  typedef struct CUfileError CUfileError_t

cufileop status string

  typedef enum CUfileFeatureFlags CUfileFeatureFlags_t

  typedef struct CUfileFSOps CUfileFSOps_t

  typedef void* CUfileHandle_t

File handle type.

  typedef struct CUfileIOEvents CUfileIOEvents_t

  typedef struct CUfileIOParams CUfileIOParams_t

  typedef enum CUfileOpcode CUfileOpcode_t

  typedef struct cufileRDMAInfo cufileRDMAInfo_t

  typedef enum CUFILEStatus_enum CUfileStatus_t

  typedef struct sockaddr sockaddr_t

Enumeration Type Documentation

  enum cufileBatchMode

Enumerator

CUFILE_BATCH

  enum CUfileDriverControlFlags

Enumerator

CU_FILE_USE_POLL_MODE
    use POLL mode. properties.use_poll_mode

CU_FILE_ALLOW_COMPAT_MODE
    allow COMPATIBILITY mode. properties.allow_compat_mode

  enum CUfileDriverStatusFlags

Enumerator

CU_FILE_LUSTRE_SUPPORTED
    Support for DDN LUSTRE

CU_FILE_WEKAFS_SUPPORTED
    Support for WEKAFS

CU_FILE_NFS_SUPPORTED
    Support for NFS

CU_FILE_GPFS_SUPPORTED

CU_FILE_NVME_SUPPORTED
    < Support for GPFS Support for NVMe

CU_FILE_NVMEOF_SUPPORTED
    Support for NVMeOF

CU_FILE_SCSI_SUPPORTED
    Support for SCSI

CU_FILE_SCALEFLUX_CSD_SUPPORTED
    Support for Scaleflux CSD

CU_FILE_NVMESH_SUPPORTED
    Support for NVMesh Block Dev

CU_FILE_BEEGFS_SUPPORTED
    Support for BeeGFS

  enum CUfileFeatureFlags

Enumerator

CU_FILE_DYN_ROUTING_SUPPORTED
    Support for Dynamic routing to handle devices across the PCIe bridges

CU_FILE_BATCH_IO_SUPPORTED
    Unsupported

CU_FILE_STREAMS_SUPPORTED
    Unsupported

CU_FILE_PARALLEL_IO_SUPPORTED
    Unsupported

  enum CUfileFileHandleType

Enumerator

CU_FILE_HANDLE_TYPE_OPAQUE_FD
    Linux based fd

CU_FILE_HANDLE_TYPE_OPAQUE_WIN32
    Windows based handle (unsupported)

CU_FILE_HANDLE_TYPE_USERSPACE_FS

  enum CUfileOpcode

Enumerator

CUFILE_READ

CUFILE_WRITE

  enum CUFILEStatus_enum

Enumerator

CUFILE_WAITING

CUFILE_PENDING

CUFILE_INVALID

CUFILE_CANCELED

CUFILE_COMPLETE

CUFILE_TIMEOUT

CUFILE_FAILED

Function Documentation

  CUfileError_t cuFileBatchIOCancel (CUfileBatchHandle_t batch_idp)

  void cuFileBatchIODestroy (CUfileBatchHandle_t batch_idp)

  CUfileError_t cuFileBatchIOGetStatus (CUfileBatchHandle_t batch_idp, unsigned min_nr, unsigned * nr, CUfileIOEvents_t * iocbp, struct timespec * timeout)

  CUfileError_t cuFileBatchIOSetUp (CUfileBatchHandle_t * batch_idp, unsigned nr)

  CUfileError_t cuFileBatchIOSubmit (CUfileBatchHandle_t batch_idp, unsigned nr, CUfileIOParams_t * iocbp, unsigned int flags)

  CUfileError_t cuFileBufDeregister (const void * bufPtr_base)

deregister an already registered device or host memory from cuFile

Parameters:
    bufPtr_base buffer pointer to deregister

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_INVALID_VALUE on invalid memory pointer or unregistered memory pointer

See also:
    cuFileBufRegister

    cuFileRead

    cuFileWrite

  CUfileError_t cuFileBufRegister (const void * bufPtr_base, size_t length, int flags)

register an existing cudaMalloced memory with cuFile to pin for GPUDirect Storage access or register host allocated memory with cuFile.

Parameters:
    bufPtr_base buffer pointer allocated
    length size of memory region from the above specified bufPtr
    flags CU_FILE_RDMA_REGISTER

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_NVFS_DRIVER_ERROR

    CU_FILE_INVALID_VALUE

    CU_FILE_CUDA_ERROR for unsuported memory type

    CU_FILE_MEMORY_ALREADY_REGISTERED on error

    CU_FILE_GPU_MEMORY_PINNING_FAILED if not enough pinned memory is available

Note:
    This memory will be use to perform GPU direct DMA from the supported storage.

Warning:
    This API is intended for usecases where the memory is used as streaming buffer that is reused across multiple cuFile IO operations before calling cuFileBufDeregister

See also:
    cuFileBufDeregister

    cuFileRead

    cuFileWrite

  CUfileError_t cuFileDriverClose (void)

  CUfileError_t cuFileDriverClose_v2 (void)

reset the cuFile library and release the nvidia-fs driver

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_CLOSING if there are any active IO operations using cuFileRead or cuFileWrite

See also:
    cuFileDriverOpen

  CUfileError_t cuFileDriverGetProperties (CUfileDrvProps_t * props)

Gets the Driver session properties.

Returns:
    CU_FILE_SUCCESS on success

See also:
    cuFileDriverSetPollMode

    cuFileDriverSetMaxDirectIOSize

    cuFileDriverSetMaxCacheSize

    cuFileDriverSetMaxPinnedMemSize

  CUfileError_t cuFileDriverOpen (void)

Initialize the cuFile library and open the nvidia-fs driver.

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED

    CU_FILE_DRIVER_VERSION_MISMATCH on driver version mismatch error

See also:
    cuFileDriverClose

  CUfileError_t cuFileDriverSetMaxCacheSize (size_t max_cache_size)

Control parameter to set maximum GPU memory reserved per device by the library for internal buffering.

Parameters:
    max_cache_size The maximum GPU buffer space per device used for internal use in KB

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_DRIVER_VERSION_MISMATCH, CU_FILE_DRIVER_UNSUPPORTED_LIMIT on error

Warning:
    This is an advanced command and should be tuned based on supported GPU memory

See also:
    cuFileDriverGetProperties

  CUfileError_t cuFileDriverSetMaxDirectIOSize (size_t max_direct_io_size)

Control parameter to set max IO size(KB) used by the library to talk to nvidia-fs driver.

Parameters:
    max_direct_io_size maximum allowed direct io size in KB

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_DRIVER_VERSION_MISMATCH, CU_FILE_DRIVER_UNSUPPORTED_LIMIT on error

Warning:
    This is an advanced command and should be tuned based on available system memory

See also:
    cuFileDriverGetProperties

  CUfileError_t cuFileDriverSetMaxPinnedMemSize (size_t max_pinned_size)

Sets maximum buffer space that is pinned in KB for use by cuFileBufRegister.

Parameters:
    max_pinned_size maximum buffer space that is pinned in KB

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_DRIVER_VERSION_MISMATCH, CU_FILE_DRIVER_UNSUPPORTED_LIMIT on error

Warning:
    This is an advanced command and should be tuned based on supported GPU memory

See also:
    cuFileDriverGetProperties

  CUfileError_t cuFileDriverSetPollMode (bool poll, size_t poll_threshold_size)

Sets whether the Read/Write APIs use polling to do IO operations.

Parameters:
    poll boolean to indicate whether to use poll mode or not
    poll_threshold_size max IO size to use for POLLING mode in KB

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_DRIVER_VERSION_MISMATCH, CU_FILE_DRIVER_UNSUPPORTED_LIMIT on error

Warning:
    This is an advanced command and should be tuned based on available system memory

See also:
    cuFileDriverGetProperties

  CUfileError_t cuFileGetVersion (int * version)

Returns:
    cufile library version.

version is returned as (1000 major + 10 minor). example, CUFILE 1.7.0 would be represented by 1070.

Note:
    This is useful for applications that need to inquire the library.

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_INVALID_VALUE if the input parameter is null.

    CU_FILE_DRIVER_VERSION_READ_ERROR if the version is not available.

  void cuFileHandleDeregister (CUfileHandle_t fh)

releases a registered filehandle from cuFile

Parameters:
    fh CUfileHandle_t file handle

Returns:
    void

See also:
    cuFileHandleRegister

  CUfileError_t cuFileHandleRegister (CUfileHandle_t * fh, CUfileDescr_t * descr)

cuFileHandleRegister is required, and performs extra checking that is memoized to provide increased performance on later cuFile operations.

Parameters:
    fh CUfileHandle_t opaque file handle for IO operations
    descr CUfileDescr_t file descriptor (OS agnostic)

Returns:
    CU_FILE_SUCCESS on successful completion. fh will be updated for use in cuFileRead, cuFileWrite, cuFileHandleDeregister

    CU_FILE_DRIVER_NOT_INITIALIZED on failure to load driver

    CU_FILE_IO_NOT_SUPPORTED - if filesystem is not supported

    CU_FILE_INVALID_VALUE if null or bad api arguments

    CU_FILE_INVALID_FILE_OPEN_FLAG if file is opened with unsupported modes like no O_DIRECT

    CU_FILE_INVALID_FILE_TYPE if filepath is not valid or is not a regular file

    CU_FILE_HANDLE_ALREADY_REGISTERED if file handle/descriptor is already registered

Description cuFileHandleRegister registers the open file descriptor for use with cuFile IO operations.

This API will ensure that the file’s descriptor is checked for GPUDirect Storage support and returns a valid file handle on CU_FILE_SUCCESS.

Note:
    the file needs to be opened in O_DIRECT mode to support GPUDirect Storage.

See also:
    cuFileRead

    cuFileWrite

    cuFileHandleDeregister

  ssize_t cuFileRead (CUfileHandle_t fh, void * bufPtr_base, size_t size, off_t file_offset, off_t bufPtr_offset)

read data from a registered file handle to a specified device or host memory

Parameters:
    fh CUfileHandle_t opaque file handle
    bufPtr_base base address of buffer in device or host memory
    size size bytes to read
    file_offset file-offset from begining of the file
    bufPtr_offset offset relative to the bufPtr_base pointer to read into.

Returns:
    size of bytes successfully read

    -1 on error, in which case errno is set to indicate filesystem errors.

    all other errors will return a negative integer value of CUfileOpError enum value.

Note:
    If the bufPtr is not registered with cuFileBufRegister, the data will be buffered through preallocated pinned buffers if needed.

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

See also:
    cuFileBufRegister

    cuFileHandleRegister

    cuFileWrite

  CUfileError_t cuFileReadAsync (CUfileHandle_t fh, void * bufPtr_base, size_t * size_p, off_t * file_offset_p, off_t * bufPtr_offset_p, ssize_t * bytes_read_p, CUstream stream)

Parameters:
    fh The cuFile handle for the file.
    bufPtr_base base address of buffer in device or host memory
    size_p pointer to size bytes to read

Note:
    *size_p if the size is not known at the time of submission, then must provide the max possible size for I/O request.

Parameters:
    file_offset_p pointer to file-offset from begining of the file
    bufPtr_offset_p pointer to offset relative to the bufPtr_base pointer to read into.
    bytes_read_p pointer to the number of bytes that were successfully read.
    CUstream stream cuda stream for the operation.

Returns:
    size of bytes successfully read in *bytes_read_p

    -1 on error, in which case errno is set to indicate filesystem errors.

    all other errors will return a negative integer value of CUfileOpError enum value.

Note:
    If the bufPtr_base is not registered with cuFileBufRegister, the data will be buffered through preallocated pinned buffers.

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

    If the stream is registered with cuFileStreamRegister, the IO setup and teardown overhead will be reduced.

    on cuda stream errors, the user must call cuFileStreamDeregister to release any outstanding cuFile resources for the stream.

See also:
    cuFileBufRegister

    cuFileHandleRegister

    cuFileRead

    cuFileStreamRegister

    cuFileStreamDeregister

  CUfileError_t cuFileStreamDeregister (CUstream stream)

Parameters:
    CUstream cuda stream for the operation.

Note:
    deallocates resources used by previous cuFile asynchronous operations for the cuda stream

    highly recommend to call after cuda stream errors to release any outstanding cuFile resources for this stream

    must be called before cuStreamDestroy call for the specified stream.

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_INVALID_VALUE if the stream is invalid

See also:
    cuFileReadAsync

    cuFileWriteAsync

    cuFileStreamRegister

  CUfileError_t cuFileStreamRegister (CUstream stream, unsigned flags)

Parameters:
    CUstream cuda stream for the operation.
    flags for the stream to improve the stream execution of IO based on input parameters.

Note:
    supported FLAGS are

    CU_FILE_STREAM_FIXED_BUF_OFFSET - buffer pointer offset is set at submission time

    CU_FILE_STREAM_FIXED_FILE_OFFSET - file offset is set at submission time

    CU_FILE_STREAM_FIXED_FILE_SIZE - file size is set at submission time

    CU_FILE_STREAM_PAGE_ALIGNED_INPUTS - size, offset and buffer offset are 4k aligned

    allocates resources needed to support cuFile operations asynchronously for the cuda stream

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

Returns:
    CU_FILE_SUCCESS on success

    CU_FILE_DRIVER_NOT_INITIALIZED if the driver is not initialized

    CU_FILE_INVALID_VALUE if the stream is invalid

See also:
    cuFileReadAsync

    cuFileWriteAsync

    cuFileStreamDeregister

  long cuFileUseCount (void)

returns use count of cufile drivers at that moment by the process.

  ssize_t cuFileWrite (CUfileHandle_t fh, const void * bufPtr_base, size_t size, off_t file_offset, off_t bufPtr_offset)

write data from a specified device or host memory to a registered file handle

Parameters:
    fh CUfileHandle_t opaque file handle
    bufPtr_base base address of buffer in device or host memory
    size size bytes to write
    file_offset file-offset from begining of the file
    bufPtr_offset offset relative to the bufPtr_base pointer to write from.

Returns:
    size of bytes successfully written

    -1 on error, in which case errno is set to indicate filesystem errors.

    all other errors will return a negative integer value of CUfileOpError enum value.

Note:
    If the bufPtr is not registered with cuFileBufRegister, the data will be buffered through preallocated pinned buffers if needed.

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

See also:
    cuFileBufRegister

    cuFileHandleRegister

    cuFileRead

  CUfileError_t cuFileWriteAsync (CUfileHandle_t fh, void * bufPtr_base, size_t * size_p, off_t * file_offset_p, off_t * bufPtr_offset_p, ssize_t * bytes_written_p, CUstream stream)

Parameters:
    fh The cuFile handle for the file.
    bufPtr_base base address of buffer in device or host memory
    size_p pointer to size bytes to write.

Note:
    *size_p if the size is not known at the time of submission, then must provide the max possible size for I/O request.

Parameters:
    file_offset_p pointer to file-offset from begining of the file
    bufPtr_offset_p pointer to offset relative to the bufPtr_base pointer to write from.
    bytes_written_p pointer to the number of bytes that were successfully written.
    CUstream cuda stream for the operation.

Returns:
    size of bytes successfully written in *bytes_written_p

    -1 on error, in which case errno is set to indicate filesystem errors.

    all other errors will return a negative integer value of CUfileOpError enum value.

Note:
    If the bufPtr_base is not registered with cuFileBufRegister, the data will be buffered through preallocated pinned buffers.

    This is useful for applications that need to perform IO to unaligned file offsets and/or size. This is also recommended for cases where the BAR1 memory size is smaller than the size of the allocated memory.

    If the stream is registered with cuFileStreamRegister prior to this call, the IO setup and teardown overhead will be reduced.

    on cuda stream errors, the user must call cuFileStreamDeregister to release any outstanding cuFile resources for the stream.

See also:
    cuFileBufRegister

    cuFileHandleRegister

    cuFileWrite

    cuFileStreamRegister

    cuFileStreamDeregister

Variable Documentation

  CUfileOpError

Author

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