DASTAP SEEKS SYSPROF active, the number of privileged instructions handled by the
control program are reduced for those virtual machines that
are running with the feature activated.
'periodically sa.ples device I/O activity counts (SIO), for
tape and DASD devices only.
collects data for every I/O request to DASD devices. Reveals
channel, control unit, or device contention and arm .ove.ent
interference proble.s. No meaningful inforaation is extracted for V=R regions
if SET NOTRANS is in effect.
adds to the DASTAP and SCHEDULE detailed nprofile
n
of system examination of DASD utilization.
classes to
performance
support a more through closer • Every MONITOR ENABLE command yields a new .ask. Thus, for example, if PERFORM and USER classes are currently being collected and you enter MONITOR ENABLE INSTSIM, then PERFORM. and USER classes are
stopped and INSTSIM is started. • The DASTAP operand in the MONITOR ENABLE co.mand .ust be specified
prior to the MONITOR START TAPE com.and. DASTAP may be disabled at
any time by respecifying the MONITOR ENABLE command with DASTAP absent from the class list. • The SYSPROF class cannot be activated unless both the D1ST1P and SCHEDULE classes are also active. • If data collection is in progress when you issue a BONITOR EIABLE command and CP detects an error in the coa.and line, no change is made to the monitoring status. Unrecognizable keywords and
conflicting operands generate appropriate error .essages. If you do
not specify operands, an error aessage results. r , INTERVAL nnnnn ISECI mm IMINI L Use this operand if a class that involves collecting data at
periodic intervals is enabled or will be enabled, and if you
want to override the default intervals of 60 seconds and 2
seconds. The 60 second interval can be considered as the priaary sampling interval. It deteraines the frequency ,with which the PERFORM, USER and DAST1P classes of monitor are collacted.' The two second interval applies to the
high-frequency data sampling routine. This routine collects
utilization statistics froa the I/O (channels,
control units, and devices) when the DAST1P class' ··is enab led.
The value specified by nnnnn is the interval between data
collections. If you give no interval on the MONITOR INTERVAL command, an error aessage occurs. Either SEC or MIN may follow nnnnn to specify whether nnnnn represents seconds or
minutes. If you give an interval but enter neither SEC nor MIN, the default is SEC. The aaxiau. allowable interval is
nine hours (540 ainutes or 32,400 seconds). The a1n1aua is
five seconds. If no interval is specified in nnnnn, an error
message occurs. The.. field is used to change the collection
interval for the high-frequency saapler. This operand applies
to the DASTAP class of data collection only. The default Section 3. CP Coaaands 91

START value for.. is two seconds. If specified, the interval may range from 1 to 99 seconds. It must be less than the
specified value of nnnnn.
If the MONITOR INTERVAL command is not issued, the default
interval is 60 seconds for the primary sampling interval, and
2 seconds for the high-frequency sampling interval. The MONITOR INTERVAL command can be issued at any time; however, if data collection is already in progress, the new interval
does not take effect until the current interval has elapsed.
The MONITOR interval is reset to the defaults when: • Iou issue MORITOR STOP, or the monitor stops automatically. • The system stops the monitor because of an unrecoverable I/O error. • The end-of-tape is reached, or the spool record limit is
reached. r ISPOOLI [to userid] {BUFFS n]
, I , ICPTRACE ITAPE r ,
raddr I MODE { 800} I [BUFFS n] I I I I I 1600 I I I 6250 I L L J J If SPOOL is specified, VM/370 Monitor data collection is begun
to the spool file or tape, or the CP internal trace table is
started. If no optional parameter is provided, SPOOL is the
default. When data collection is stopped and the spool is closed, the
spool file is added to the chain of reader files destined for
the virtual reader of the virtual machine defined by "to userid." The userid may be specified as an asterisk (*) if
the recipient virtual machine is to be the one from which the START co.mand is issued. If the "to userid" option is omitted, the userid specified in the SISMON macro instruction i-su-se4. (See II!- &!anninq AI!,g The "to userid" option overrides
the SISMON specification and stays in effect until the system is re-IPLed or a new co.mand that uses the "to userid- option
is entered.
The monitor spool file is closed by a MONITOR STOP or MONITOR CLOSE co •• and, or when the record count limit is reached (as
specified in the SISMON macro), or when a system restart or system shutdown occurs.
The filename and filetype of the monitor spool file are
generated internally with the filetype, identifying date and time of starting. The class of spool file is specified in the SISMOB macro and defaults to "ft." If no classes of data
collection have been specified with an ENABLE command, those
specified with the SISSON macro are used.
The number of monitor buffers used are as specified SISMON macro, or as requested with the BUFFS option START co.mand. The BUFFS option overrides the
in the
of the SISMON 'The default value is the active trace facility that is SPOOL or TAPE.
98 VM/370 Operator's Guide