r ,1 STOP ISPOOL I i ICPTRACEI L CLOSE stops VM/370 Monitor data collection to a spool file or tape, or stops the CP internal trace If no option is
specified and the VM/370 Monitor is active, then data
collection is terminated, whether or not a spool file or tape
is in use. Internal tracing can only be stopped by specific
use of the CPTRACE option. If automatic VM/370 Monitor data
collection is active when the MONITOR STOP SPOOL command is
issued, monitoring ceases and will not start again (even if
the current time is within the bounds of the TIME operand of
the SISMON macro) unless the system abnormally terminates or
is shut down and reloaded.
The STOP TAPE command stops data collection by VM/370 Monitor onto tape. A zero mask is immediately stored in control
register 8, thus disabling MONITOR CALL The
last partially filled page is written out, two tape marks are
written, and the tape is rewound and unloaded. The two buffer
pages, which were obtained at the time the MONITOR START TAPE command was issued, are released.
The STOP CPT RACE command terminates the tracing of events
occurring on the real machine. Event recording ceases but the
pages of storage containing the CP internal trace table are
not released. Tracing can be restarted at any time by issuing MONITOR START CPTRACE. The CPTRACE and TAPE operands of the MONITOR command
have completely separate functions. Commands affecting the
status of one function have no effect on the other.
may be used when VM/370 Monitor is collecting performance data
using a spool file and it is desirable to reduce the data
collected thus far. The command closes the current spool file
(thereby making it available to the reader of the recipient
virtual machine) and causes monitoring to continue
uninterrupted with a new spool file. AUTOdisk {ON } OFF may be used to override the specification for automatic
monitoring in the SISMON macro. Its only use is to affect the
automatic startup of monitoring. If automatic monitoring is
already active, it may only be stopped manually by a MONITOR STOP command. Note that in general, any attempts to override
the definitions of the SISMON macro with commands are
temporary. No monitor checkpointing is attempted, so that an IPL or abnormal termination causes full restoration of the
initial automatic monitoring definitions.
lThe default value is the active trace facility that is SPOOL or TAPE. Part 2. Control program (CP) 117

TIME r IFROM IFOR IALL INONE L
,
h1.m1 to h2.m21 hh.mm I I I specifies that the automatic monitoring start and stop times defined by the SYSMON macro should be temporarily overridden (until the next IPL or the next MONITOR TIME command). The FROM, ALL, and NONE options are equivalent to their
counterparts in the TIME operand of the SISMON macro (see the The FOR option
is provided specifically to simplifY data collection during
benchmarking or testing. If AUTO ON is in effect, spool
monitoring will start immediately and run for the specified
period of time. Note that if automatic monitoring is imminent
and the FOR option is specified, the period of monitoring
defined by the SISMON macro will be overridden.
r , LIMIT n ,STOP , ,SAMPLEI L specifies that the LIMIT options of the SISMON macro should be
temporarily overridden (until the next system IPL or the next MONITOR LIMIT command) • The maximum buffer count in each
spool file may be changed with the n parameter (within the 10 to 50000 range of the SISMON macro). If it is necessary to
change whether or not automatic monitoring should continue
after the limit has been reached and the spool file closed,
then the STOP, NOSTOP options may te specified. If this
should be done without changing the limit number, an asterisk
(*) may be specified for "nne When SAMPLE is specified, n defines how frequently the VM/370 Monitor is to close the monitor spool file and send it to the
virtual reader of the data reduction virtual machine. To
determine when to close the file, the VM/370 Monitor counts
the number of data samples it takes for the PERFORM, USER, and DASTAP classes. When this count equals the value of n, the VM/370 Monitor closes the file. After the file is closed,
monitoring continues using a new file.
The following example shows how the INTERVAL parameter and the
LIMIT parameter work together. If the INTERVAL parameter
specifies an interval of 30 seconds and the LIMIT parameter is
coded as LIMIT 10 SAMPLE, the VM/370 Monitor closes the spocl
file every 300 seconds (30x10). The LIMIT parameter may be specified for automatic monitoring
by using the SISMON macro instruction in module DMKSIS. Instructions for using this macro instruction are in the '18 IBM VM/370 System Programmer's Guide