The posix_fadvise64() function is a large-file version of the posix_fadvise() function defined in ISO POSIX (2003). It shall advise the implementation on the expected behavior of the application with respect to the data in the file associated with the open file descriptor, fd, starting at offset and continuing for len bytes. The specified range need not currently exist in the file. If len is zero, all data following offset is specified. The implementation may use this information to optimize handling of the specified data. The posix_fadvise() function shall have no effect on the semantics of other operations on the specified data, although it may affect the performance of other operations.
The advice to be applied to the data is specified by the advice parameter, as specified in posix_fadvise().
On success, posix_fadvise64() shall return 0. Otherwise an error number shall be returned to indicate the error. See posix_fadvise() for possible error values.