IRPCOUNT sets the number of preallocated intermediate request
    packets. Each packet requires 160 bytes of permanently resident
    memory. If IRPCOUNT is too large, physical memory is wasted.
    If IRPCOUNT is too small, the system increases its value
    automatically, as needed, to permit proper performance.
    However, the system cannot increase IRPCOUNT beyond the value
    of IRPCOUNTV.

    Allowing this growth causes a physical memory penalty. If
    IRPCOUNT is underconfigured, the penalty is 4 percent of physical
    memory from the configured value to the actual value on the
    running system.

    You can use the DCL command SHOW MEMORY/POOL/FULL to determine
    IRPCOUNT usage.

    IRPCOUNT has the GEN and MAJOR attributes.