There is no convenient way to guarantee contiguous real frames in a z/OS application. There is (for now) V=R jobs (ADDRSPC=REAL). But z/OS 3.2 is the last release which supports V=R. It will be gone in the next release.
There are ways to ask for 1MB pages on the STORAGE macro and the IARV64 macro, but they do not guarantee that you will get 1MB pages. You could ask for a 1MB page, page fix it, and then check to see if you have contiguous real frames. Keep in mind that in addition to the storage being pagefixed, the address space must be made nonswappable in order to prevent a virtual page's real address from changing. Jim Mulder -----Original Message----- From: IBM Mainframe Discussion List <[email protected]> On Behalf Of Willy Jensen Sent: Thursday, January 8, 2026 11:40 AM To: [email protected] Subject: Is it possible to allocate contiguous real pages? I am playing around with the DIAGNOSE x'08' (Virtual console) instruction in z/OS. The instruction is described in the z/VM CP Programming Services manual where it says 'Command response. This address must be real to your virtual machine. The buffer can cross page boundaries.'. As one supplies the real starting address and a length, I assume that those pages have to be contiguous, but I cannot find how to do that. I tried to allocate 4k+ storage and check the real addresses and they certainly were not contiguous. Any idea? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
