Hints for PVFS (v1)

For PVFS control is provided for the use of the listio interface. This interface to PVFS allows for a collection of noncontiguous regions to be requested (for reading or writing) with a single operation. This can result in substantially higher performance when accessing noncontiguous regions. Support for these operations in PVFS exists after version 1.5.4, but has not been heavily tested, so use of the interface is disabled in ROMIO by default at this time. The hints to control listio use are:

• romio_pvfs_listio_read - Controls use of listio for reads. Valid values are enable, disable, and automatic. Default is disable.
• romio_pvfs_listio_write - Controls use of listio for writes. Valid values are enable, disable, and automatic. Default is disable.