Monitor Class Collection
Class Name Mechanism 0 PERFORM Timer requests
1 RESPONSE MC instructions
2 SCHEDULE MC instructions
3
2
4 USER Timer requests
5 INSTSIM MC instructions
6 DASTAP Timer requests
7 SEEKS MC instructions
8 SYSPROF Collected via class 2
Another function, separate from the VM/SP Monitor, is also handled by the MONITOR command. The MONITOR command can stop and start CP internal
trace table data collection, which is not initiated by MONITOR CALLs.
Note: The VM/SP Monitor record format and the contents of the record are
shown in "Appendix B. Monitor Tape Format and Content."
The class A and E MONITOR command: Stops and starts CP internal trace table data collection.
Displays the status of the internal trace table and each implemented class of VM/SP Monitor data collection. Displays the specifications for automatic
monitoring defined by the SYSMON macro in DMKSYS. In addition, it dis­
plays those specifications for automatic monitoring that are overridden by
Monitor commands. It also displays whether the tape or spool file is the
recording medium. Starts and stops VM/SP data collection using tape or spool file. It also closes
the spool file, if desired.
Specifies VM/SP monitor classes of data collection enabled, number of buffers
used, and time of data collection. It also specifies other options which override
the specifications for automatic monitoring on the SYSMON macro contained inDMKSYS. Specifies the interval to be used for timer driven data collection.
Specifies direct access devices that are to be included or excluded from a list of
devices. The list defines direct access devices for which CP is to collect data
for the SEEKs class. See the VM / SP Operator's Guide for the format and details of the MONITOR command.
Performance Observation and Analysis 53
Implemented Classes
Monitor
Class
o
1
2
3
3
5
Keyword PERFORM RESPONSE SCHEDULE
USER
INSTSIM
The following MONITOR CALL classes correlate with the corresponding classes
in control register 8. Refer to the System/3 70 Principles of Operation for details of
the MC instruction and the bits in control register 8.
Data Collection Function
Samples system resource usage data by accessing system
counters of interest to system performance analysts.
Collects data on terminal I/O. Simplifies analyses of com­
mand usage, user, and system response times. It can relate
user activity to system performance. This class is invalid and
no data can be collected for it unless the system programmer
changes the LOCAL COpy file and reassembles
DMKMCC.
Collects data about scheduler queue manipulation, monitors
flow of work through the system, and indicates the resource
allocation strategies of the scheduler.
Reserved.
Periodically scans the chain of VMBLOKs in the system, and
extracts user resource utilization and status data.
Records every virtual machine privileged instruction handled
by the control program (CP) standard simulation routines (DMKPRV, DMKPRW). Because simulation of privileged
instructions is a major source of overhead, this data may lead
to methods of improving performance.
The fast path simulation routines (DMKFPS) result in signif­
icantly less control program overhead than the standard
paths. Therefore, privileged instructions simulated by DMKFPS are not recorded.
If the VMA feature is active, the number of privileged
instructions that are handled by the control program is
reduced for those virtual machines that are running with the
feature activated.
54 VM/SP System Programmer's Guide
Previous Page Next Page