MSCH trace records

An MSCH record represents a modify subchannel operation.

MSCH.... shhhh ASCB.... hhhhhhhh CPUID... hhhh     JOBN.... cccccccc
               SID..... hhhhhhhh CC...... hh       OPT..... hh
               OPT2.... hh       IOSLVL.. hh       SCHIB1.. hhhhhhhh
                        hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                        hhhhhhhh UCBLVL.. hh       SCHIB2.. hhhhhhhh
                        hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh hhhhhhhh
                        hhhhhhhh
                        hhhhhhhh UCBWGT.. hh       BASE.... shhhh

MSCH shhhh

Device number from the UCBCHAN field of the UCB with subchannel set identifier when appropriate.

ASCB hhhhhhhh

Address of the ASCB for the address space that started the modify subchannel operation.

CPU hhhh

Address of the processor on which the modify subchannel started.

JOBN cccccccc

One of the following:

cccccccc

Name of the job associated with the task that requested the modify subchannel operation

N/A

Not applicable

SID hhhhhhhh

Subchannel ID from the UCBSID field of the UCB.

CC hh

MSCH condition code in bits 2 and 3.

OPT hh

IOSB option bytes from the IOSOPT field of the IOSB.

OPT2 hh

IOSB option bytes from the IOSOPT field of the IOSB.

IOSLVL hh

Function level to provide serialization of I/O requests. This value comes from the IOSLEVEL field of the IOSB.

SCHIB1 hhhhhhhh ... hhhhhhhh

First 7 words of the subchannel information block. Input from the caller of modify subchannel instruction. SCHIB address from the IOSSCHIB field of the IOSB.

UCBLVL hh

UCB level value from the UCBLEVEL field of the UCB.

SCHIB2 hhhhhhhh ... hhhhhhhh

First 7 words of the subchannel information block resulting from the modify subchannel instruction.

UCBWGT hh

Flags from the UCBWGT field of the UCB.

BASE shhhh

Device number from the UCBCHAN field of the UCB, which includes the subchannel set identifier when appropriate.