You have IPLed DDRXA. It probably is running with interrupts disabled and is using TSCH to determine the status of its I/O. If that is so, all you will see will be the SSCH and TSCH instructions. It is most likely that stand-alone utilities do not want to be distracted by I/O interrupts from extraneous devices, so they may well run with I/O interrupts disabled. It is also likely that they do not want the complexity of having first and second level interrupt handlers, so they use the TSCH loops as Alan suggested.
Your trace results are undoubtedly correct and correct. Regards, Richard Schuh > -----Original Message----- > From: The IBM z/VM Operating System > [mailto:ib...@listserv.uark.edu] On Behalf Of Alan Altmark > Sent: Wednesday, June 17, 2009 11:25 AM > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: Trace I/O for a 3490 tape drive > > On Wednesday, 06/17/2009 at 12:58 EDT, "Hughes, Jim" > <jim.hug...@doit.nh.gov> wrote: > > I?d like to trace all i/o, interrupts, etc for a 3490 tape drive. > ... > > My trace command is: > > CP TRACE IO 181 CCW INS INT BOTH RUN > > > > I?ve used various other combinations of TRACE SIO and TRACE > SSSCH and > etc? > > with no happiness. > > > > I can get the TSCH and SSCH commands to appear and nothing else. > > > > What can I do to get ALL the tape i/o for address 181 to show up? > > What other I/O were you expecting? If the guest is in a TSCH > loop, it typically won't get I/O interrupts. They will be > drained by the TSCH. > > Alan Altmark > z/VM Development > IBM Endicott >
