As a general observation: In the Private area (as opposed to X-Private), your storage is obtained starting at the bottom of your space going toward the top. System control blocks needed for servicing your address space are obtained in LSQA (Local System Queue Area) which is at the top of your Private area. This is where TCB, xRB, IOB, etc. is allocated.
Now, if you specify REGION=0M (or equivalent), you effectively tell the system DO NOT RESERVE LSQA area. So if you write a storage hungry application, and you are doing lots of GETMAIN/FREEMAIN operations AND you get more than you free over time (not necessarily because of storage creep, but just doing more and more work) and at the same time you are doing LOAD, RACROUTE and/or ATTACH (or other system calls that cause LSQA to be used), then you are more likely to have the system and you collide. This will result in various SOS (short on storage) type ABENDs. Now, if you are APF authorized and you can get to KEY0, what you can do is calculate how much below the line storage you need, and then you can modify the LDA to "LIMIT" your below the line storage so that you have reserved LSQA space. In this way, you can use the 0M limit to give you all the space (above and below) that is available to the "catagory" of address space you are running in (your upper limit in above storage may be set differently depending on what kind of "access" you have). I'm sure if I missed anything, other posters will correct it right quickly. Regards, Steve Thompson ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
