IBM General Parallel File System for AIX: Administration and Programming Reference

gpfsFreeRange_t Structure

Name

gpfsFreeRange_t - Undeclares an access range within a file for an application.

Structure

typedef struct
{
  int          structLen;
  int          structType;
  offset_t     start;
  offset_t     length;
} gpfsFreeRange_t;

Description

The application will no longer access file offsets within the given range. GPFS flushes the data at the file offsets and removes it from the cache.

Multi-node applications that have finished one phase of their computation may wish to use this hint before the file is accessed in a conflicting mode from another node in a later phase. The potential performance benefit is that GPFS can avoid later synchronous cache consistency operations.

Members

structLen

Length of the gpfsFreeRange_t structure.

structType

The hint identifier GPFS_FREE_RANGE.

start

The start of the access range offset, in bytes, from beginning of file.

length

Length of the access range.

0 indicates to end of file.