Additional considerations
In addition to the previously described considerations for selecting
a virtual storage subpool, you should keep in mind the following:
- If your program obtains storage from a subpool shared between
a task and its attached subtasks, private storage ownership is assigned
as follows:
- For task owned storage: the owning task is the task that attached the subtasks.
- For job step task owned storage: the owning task is the job step task of the task that attached the subtasks.
The storage key associated with the shared subpool is determined at the time storage is first obtained from that subpool. All subsequent storage requests filled from that subpool have that storage key. For more information about shared subpools, see “Virtual Storage Management” in z/OS MVS Programming: Assembler Services Guide.
- If you are allocating a very large storage area, you might want to read z/OS MVS Diagnosis: Tools and Service Aids to find out what subpools are dumped by default during a stand-alone dump. If the data to be stored in the storage area would not be of interest in a stand-alone dump and the storage area is large (requires a long time to dump), you should obtain storage from a subpool that is not dumped by default.