> We are running z/OS 1.5 at two client sites under VM on two separate > z/196's. Admittedly not 1.4, but then again, not much difference > either. Both are in the process of upgrading to z/OS 1.13.
The APAR for the z/OS bug was OA30777. No fix was ever created in our code database for z/OS 1.4 or z/OS 1.5. My recollection is that during initial z/OS bringup on the z196 on the hardware test floor, this problem was a pretty solid occurrence IPLing z/OS as SIE Guest-1 (i.e., not under VM). There are TLB-related differences when running as SIE Guest-2 (i.e. under VM), and here may be more frequent TLB purges when running under VM. Some of these things might contribute to making the problem less frequent, or possibly unlikely, under VM. Also, I am thinking that we did not find an actual storage reference which was installing a TLB entry without the common bit for the segments in question, and that we speculated that it may have been due to speculative execution. But that was three years ago, and my memory isn't as sharp as it once was. Well, unless we are talking about dialog from Star Trek (The Original Series), or TV and radio commercial jingles from the 1960s. 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: INFO IBM-MAIN
