Releasing main storage

Under some circumstances, DFSORT uses all the available storage in your REGION. This normally will not occur for storage above 16MB virtual (if it does, use the ARESINV or ARESALL options or lower your SIZE/MAINSIZE value). This section explains how to release storage within your REGION.

When SIZE/MAINSIZE=n is in effect and n is greater than the REGION parameter or the default REGION value, or when SIZE/MAINSIZE=MAX and TMAXLIM is greater than your REGION, specify the storage you need released in the following way:

For applications with user exits:
- For directly invoked DFSORT, you can choose one of the following:
  - Use the m parameter of the MODS control statement.
  - If SIZE=MAX is in effect, you can use the RESALL option.
  - Change your REGION so that REGION is greater than SIZE/MAINSIZE (the difference is available).
  - If the OVERRGN installation option is smaller than your system IEFUSI value, this difference is available. (OVERRGN is an installation option that can be modified only by your system programmer.)
- For program invoked DFSORT, you can choose one of the following:
  - If the user exit address is not passed in the parameter list (that is, it is specified with a MODS statement), use the m parameter on the MODS statement.
  - If the user exit address is passed in the parameter list,and SIZE/MAINSIZE=MAX is in effect, use the RESINV option.
  - If the user exit address is passed in the parameter list, and SIZE/MAINSIZE=n is in effect, change your REGION so that the REGION is greater than SIZE/MAINSIZE (the difference is available).
  - If many of your DFSORT applications pass the user exit address in the parameter list and SIZE/MAINSIZE=n is in effect, then consider having the OVERRGN value changed by your system programmer to less than your IEFUSI value.
For applications without user exits:
- For directly invoked DFSORT, you can choose one of the following:
  - If SIZE/MAINSIZE=MAX is in effect, use the RESALL option.
  - If SIZE/MAINSIZE=n is in effect, change your REGION so that REGION is greater than SIZE/MAINSIZE (the difference is available).
  - Have the OVERRGN value changed by your system programmer to less than your IEFUSI value.
- For program invoked DFSORT, you can choose one of the following:
  - If SIZE/MAINSIZE=MAX is in effect, use the RESINV option.
  - If SIZE/MAINSIZE=n is in effect, change your REGION so that REGION is greater than SIZE/MAINSIZE (the difference is available).
  - Have the OVERRGN value changed by your system programmer to less than your IEFUSI value.

When SIZE/MAINSIZE is less than REGION, make sure the difference between SIZE/MAINSIZE and your REGION specification value or default provides sufficient storage for system or user exit routine use.