IBM Mainframe Discussion List <[email protected]> wrote on 12/13/2007 03:33:56 PM:
> <rant> > Lots of really smart people have commented back and forth on this > subject and it is one of those perennial stocking stuffers without any > reasonable answer. Yes, vendors do "bad things" and customers do "dumb > things" and IBM gets a pass. We all meekly accept that > "one-size-fits-all" billy clubs like the IEFUSI exit represent an > acceptable management approach for virtual storage in the 21st century. > > Well, bah humbug! > > Here we have the most powerful operating system in the world, but it > still has 1960's constructs for dealing with memory. What a crock! Why > arbitrarily limit memory? Oh yeah, to prevent a runaway program from > nailing the system. Clue: The IEFUSI exit doesn't do anything to prevent > that. It really isn't even slightly helpful in that goal. It's like > sticking band-aids on cancer patients. > > Instead, the system programmer has to guess what a good system-wide > limit might be and then code it in assembler ferpetesakes!!!! Heaven > forefend having to make a midnight change so some critical job can run. > And what about the poor old JCL programmer who has to guess what each > program is going to need ahead of time, without knowing anything about > data volume, or workload... And let's not forget everyone else who gets > woken at o-dark thirty when things go bump in the night and then has to > second guess the first two without the aid of a crystal ball or even a > bowl of chicken entrails. Fact: Region related problems happen hundreds > of times more often in the wild than runaway storage users filling up > AUX. > > So why do we meekly accept it? This is really just a stupid, antiquated, > design (or lack of design) that had questionable merit in the first > place. If you want it "fixed", the only thing you can do is lean on IBM > for improvements. Arguably the combination of VSM, RSM and ASM could > observe the runaway and take action to slow it down, perhaps even to > cancel it, but it doesn't do anything like that. You have to guess for > yourself. > </rant> > > CC > (expecting a flame or two :-) Well, I type too slowly to do much flaming. And of course, I am willing to discuss this in great detail any time you come to Poughkeepsie and take me out for a beer. However, I am at somewhat of a loss to figure out how an operating system would distinguish between a program which intentionally uses a lot of storage, and a "runaway" program which unintentionally uses a lot of storage, without someone telling the operating system how much storage the program is intended to use. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- 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
