Data Type

Integer

Default Value

Usually 0, but may be different on some machines.

Description

This parameter determines the system service used for allocating FMS memory. Not all options are available on all machines. The following options are available:

  • 0, mmap
    This is the preferred method and is used when available. It provides for a paging file in case the pages are faulted. This page file may be the system page file ( NPOAGE=-1) or a private page file ( NPOAGE=0).
  • 1, malloc
    Where mmap is not available, this service is used. The amount of memory available may be limited.
  • 2, shm
    On some systems, this service can provide special features, including large page sizes. Usually the amount of shared memory available must be created prior to the run. Memory allocated using shm is usually not swapped to disk.
  • 3, cudaHostAlloc
    Provides for page locked memory that cannot be swapped to disk. The cuda runtime library takes advantage of this to do DMA transfers to the cuda devices, resulting in significantly improved transfer rates. Applicable only to systems having supported cuda devices and the cuda runtime library.

    You may need to increase the memlock limit, which determines amount of memory a user can pin. To find the limit in Kbytes on Unix systems enter the following command (note the argument is lower case L): 

    ulimit -l
    You may change this limit (may need to be SU) by 
    ulimit -l unlimited
    or by editing the /etc/security/limits.conf file.

  • 4, fixed array of 5 Mbytes
    This option is mostly used for testing or debugging.

Because this parameter affects actions during FMSINI, it must be set in the License File.