Steve, The regs and PSW as they were when SVC dump got control are in the SDUMP 4K buffer, which is pointed to by the field at X'24C' into the CVT (CVTSDBF).
In IPCS option one while browsing storage, type this on the command line: L 10?+24C? to display that area. The PSW and regs in the order zero through 15 are there with eyecatchers in front of them. I usually cut that display and save it in a file on my PC for later reference during dump analysis. As Tom pointed out, the system trace table's contents may help you find a loop pattern. Option 2 and then option 4 from the IPCS main menu will provide a formatted control block set (TCBs, RBs) for the active address space. The RTM2WA and the TCB summary appear at the bottom of that display and contain very useful information. If you have MVS/QuickRef installed, you can type QW SYSTRACE to see documentation on the format of the system trace table entries. We also carry syntax descriptions for all of the IPCS commands in the database; type this under ISPF to see a list of IPCS commands: QW L=V P='Z/OS IPCS COMMANDS' Mike Shaw MVS/QuickRef Support Group Chicago-Soft, Ltd. On Sun, May 19, 2024, 9:41 PM Steve Estle < [email protected]> wrote: > Hello All, > > Way back in the day I used to read dumps fairly handily in the MVS/XA > era. But have been away for so long I know things have evolved but appears > everything is basically still intact relative to ASCB to PRB > relationships. I'm working on a hang/loop condition that prevents started > task from being stopped normally (P STC) and have taken SVC dump and want > to interpret it. I'm somewhat fluent with IPCS and can bring up via > panels, but from there am struggling with where to go to identify where the > hang/loop condition is happening. > > Any shares of doc, presentations, tips, etc. are much appreciated as I > still think this is one of the lost arts that in the end to be a top notch > systems programmer you need to be able to interpret. I know IBM used to > teach whole classes on this but believe much of that has gone way of dodo > bird... > > Thanks in advance. > > Steve Estle > > ---------------------------------------------------------------------- > 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
