You can use subpools to help manage your memory requirements in just the same way as you do on the mainframe. A subpool is a logical grouping of memory allocations that can be de-allocated with a single FREEMAIN or STORAGE RELEASE macro statement. Subpools are available for memory both above and below the line.
You create a subpool simply by including the SP parameter in a GETMAIN or STORAGE OBTAIN macro statement. Valid subpool numbers are 0 through to 127, 131 and 132. If you omit the SP parameter from your GETMAIN and STORAGE OBTAIN macro statements, all memory is allocated in subpool 0, unless you specify the NONCAN Linker directive, in which case all memory is allocated in subpool 132.