cufile.h(3) Library Functions Manual cufile.h(3)

cufile.h - cuFile C APIs


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


#define CU_FILE_CUDA_ERR(status) ((status).cu_err)
#define CU_FILE_RDMA_REGISTER 1
#define CU_FILE_RDMA_RELAXED_ORDERING (1<<1)
#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 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


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 }
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 }


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 *devPtr_base)
deregister an already registered device memory from cuFile CUfileError_t cuFileBufRegister (const void *devPtr_base, size_t length, int flags)
register an existing cudaMalloced memory with cuFile to pin for GPUDirect Storage access. 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. 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 *devPtr_base, size_t size, off_t file_offset, off_t devPtr_offset)
read data from a registered file handle to a specified device memory long cuFileUseCount (void)
returns use count of cufile drivers at that moment by the process. ssize_t cuFileWrite (CUfileHandle_t fh, const void *devPtr_base, size_t size, off_t file_offset, off_t devPtr_offset)
write data from a specified device memory to a registered file handle


CUfileOpError

cuFile C APIs

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

error macros to inspect error status of type CUfileOpError

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

enum cufileBatchMode

Enumerator

enum CUfileDriverControlFlags

Enumerator

use POLL mode. properties.use_poll_mode
allow COMPATIBILITY mode. properties.allow_compat_mode

enum CUfileDriverStatusFlags

Enumerator

Support for DDN LUSTRE
Support for WEKAFS
Support for NFS
< Support for GPFS Support for NVMe
Support for NVMeOF
Support for SCSI
Support for Scaleflux CSD
Support for NVMesh Block Dev
Support for BeeGFS

enum CUfileFeatureFlags

Enumerator

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

enum CUfileFileHandleType

Enumerator

Linux based fd
Windows based handle (unsupported)

enum CUfileOpcode

Enumerator

enum CUFILEStatus_enum

Enumerator

CUfileError_t cuFileBatchIOCancel (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 * devPtr_base)

deregister an already registered device memory from cuFile

Parameters:

devPtr_base device 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 * devPtr_base, size_t length, int flags)

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

Parameters:

devPtr_base device pointer to allocated
length size of memory region from the above specified devPtr
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 unsupported 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

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

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

Parameters:

fh CUfileHandle_t opaque file handle
devPtr_base base address of buffer in device memory
size size bytes to read
file_offset file-offset from beginning of the file
devPtr_offset offset relative to the devPtr_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 devPtr 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.

See also:

cuFileBufRegister

cuFileHandleRegister

cuFileWrite

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

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

Parameters:

fh CUfileHandle_t opaque file handle
devPtr_base base address of buffer in device memory
size size bytes to write
file_offset file-offset from beginning of the file
devPtr_offset offset relative to the devPtr_base pointer to read into.

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 devPtr 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.

See also:

cuFileBufRegister

cuFileHandleRegister

cuFileRead

CUfileOpError

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Wed Dec 14 2022 GPUDirect Storage