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Programming Interface Information:
The Monitor Records are intended Programming Interfaces that allow the customer to write programs to obtain services of z/VM. |
MRIODDEV
PrologControl Block Contents
Cross Reference
MRIODDEV Prolog
DSECT NAME - IODDEV
FUNCTION - Map a Monitor record.
LOCATED BY -
Through the Monitor Control Area
REFERENCED CONTROL BLOCKS -
MRRECHDR Monitor Record Header
NAME - MRIODDEV
DESCRIPTIVE NAME - Monitor Sample Record
Domain 6 - I/O Domain
Record 3 - Device Activity
DESCRIPTION - Describes I/O activities of a real device. A separate
record is generated for each online device that is
enabled for monitoring.
NOTES:
- Fields labeled by the prefix, 'IODDEV_HF', are high-frequency
counters.
- When a virtual machine owning the device uses SIE ASSIST, CP
does not handle the normal I/O and cannot update the RDEV
counters. Therefore, for a device that had been in SIE ASSIST,
some RDEV or high-frequency counters may not correctly reflect
real device activity.
- "SCM Facility Data." Data obtained from the Subchannel
Management Facility. Not valid if the device was in SIE ASSIST
and the V=R specifies that an Alternate Measurement Block is to
be used. (Note: this data will always be valid for a 370 V=R
guest since VM/370 does not support Alternate Measurement Block)
- "SIE ASSIST Activity Data." This data indicates how often and
for how long the device had been in each respective state.
There may be situations that would cause the device to be
pulled out of SIE ASSIST and later put back in it. Some
devices may take longer than others to get out of SIE ASSIST.
This can degrade the performance of the preferred guest.
SIE ASSIST Activity Data is valid only for devices that are
eligible for SIE ASSIST, indicated by IODDEV_VDEVIOP1.
A SIE Assisted (I/O Assisted) device must be in one of three
states: OUT, IN, LEAVING assist. For each state a count of
transitions into the state and a count of accumulated time in
the state are kept. However, since the time accumulator can
only be updated when a device changes states, the accumulators
reported in this monitor record (IODDEV_VIUTIMOT,
IODDEV_VIUTIMIN, and IODDEV_VIUTIMLV) do not include time for
the state the device is in when the monitor record is created.
To determine the unassigned time, calculate the delta of the
MRHDRTOD and IODDEV_VIUSTAMP. This delta should be converted
to microseconds and then added to the accumulator for the
state indicated by the IODDEV_VIUSTATE field.
MRIODDEV Control Block Contents
Offsets
Dec Hex Type Len Name (Dim) Description
0 0 Structure 200 IODDEV
0 0 Character 0 IODDEV_MRHDR Record header. See MRRECHDR for
details.
0 0 Character 20 MRHDR
0 0 Unsigned 2 MRHDRLEN record length in bytes
2 2 Unsigned 2 MRHDRZER field of zeros
4 4 Unsigned 1 MRHDRDM domain identifier
5 5 Unsigned 1 *
6 6 Unsigned 2 MRHDRRC record identifier
8 8 Character 8 MRHDRTOD Time at which this record was
built. In time-of-day (TOD) clock
format. See IBM System 370 XA
Principle of Operation for
explanation of format.
16 10 Character 4 *
20 14 Character 0 MRHDR_END End of header
20 14 Bitstring 1 IODDEV_RDEVAFLG Device allocation flag
21 15 Bitstring 1 IODDEV_RDEVLPM logical path mask -logically
available channel paths to this
device
22 16 Bitstring 1 IODDEV_VDEVIOP1 SIE ASSIST flags
1... .... IODDEV_VDEVIOPX Eligible for SIE ASSIST to XA
guest
.1.. .... IODDEV_VDEVIOP3 Eligible for SIE ASSIST to 370
guest
..1. .... *
...1 .... *
.... 1... *
.... .1.. *
.... ..1. *
.... ...1 *
23 17 Bitstring 1 IODDEV_CALFLAG1 Flags byte.
1... .... IODDEV_CALMDCNO Device is not eligible for
minidisk cache.
.1.. .... IODDEV_CALMDCDN Caching on for this device,
except for minidisks that are
explicitly set off.
..1. .... IODDEV_CALMDCDF Caching off for this device,
except for minidisks that are
explicitly set on.
...1 .... IODDEV_CALMDCOF Caching set off for this device.
.... 1... IODDEV_RDEVSHAR DASD is shareable.
.... .1.. IODDEV_CALSCMBK RDEVMBLK is non-zero indicating
that an SCMBK is assigned to this
device
.... ..1. IODDEV_CALTHROT Device belongs to throttle set.
.... ...1 *
24 18 Unsigned 4 IODDEV_RDEVSID host subchannel I.D. number
defined at initialization
28 1C Character 8 IODDEV_RDEVCHPS The eight channel path IDs
available to access a device
36 24 Character 6 IODDEV_RDEVSER DASD volume serial identifier
42 2A Character 8 IODDEV_CALUSER Userid of current owner (for
dedicated devices only)
50 32 Unsigned 2 IODDEV_RDEVLCNT Cardinal count of minidisks
defined on all or any part of this
real DASD volume
52 34 Unsigned 2 IODDEV_SCMSSCH SCM Facility Data (see notes in
prolog). Cumulative count of SSCHs
and RSCHs for this device. This
value may be wrapped when format-1
measurement blocks are being used
(MTRSYS_CALFLG2 = x'80').
54 36 Unsigned 2 IODDEV_SCMCOUNT SCM Facility Data (see notes in
prolog). Cumulative sample count.
Incremented whenever any
measurement fields are updated.
This value may be wrapped when
format-1 measurement blocks are
being used (MTRSYS_CALFLG2 =
x'80').
56 38 Unsigned 4 IODDEV_SCMCNTIM SCM Facility Data (see notes in
prolog). The time the device is
connected to the channel. This is
the sum of time intervals measured
whenever the device is logically
connected to the channel path for
purposes of transferring
information between it and the
channel subsystem.
60 3C Unsigned 4 IODDEV_SCMFPTIM SCM Facility Data (see notes in
prolog). Device function pending
time, the time interval between
acceptance of the start function
at the subchannel and acceptance
of the first command associated
with the initiation of
channel-program execution at the
device.
64 40 Unsigned 4 IODDEV_SCMDDTIM SCM Facility Data (see notes in
prolog). Device disconnect time.
The sum of the time intervals
measured whenever the device is
logically disconnected from the
channel subsystem while the
subchannel is active
68 44 Unsigned 4 IODDEV_HFRDEVCT Number of high frequency samples
done
72 48 Unsigned 4 IODDEV_HFCTIO High-frequency Count. Number of
SSCH, HSCH, and CSCH I/O requests
queued, excluding the active
request. RDEVCTIO
76 4C Unsigned 4 IODDEV_RDEVCTSR Cumulative count of SSCHs done
for error recovery purposes
80 50 Unsigned 4 IODDEV_RDEVRCWH Cumulative count of real reserve
CCWs that have been sent to a
device and are held immediately
84 54 Unsigned 4 IODDEV_RDEVRCWP Cumulative count of real reserve
CCWs that have been sent to a
device and are held pending
88 58 Character 8 IODDEV_RDEVRTPD Cumulative amount of real time a
real reserve CCW is held pending
96 60 Unsigned 4 IODDEV_RDEVCTSI Cumulative count of solicited
interrupts for this device
100 64 Unsigned 4 IODDEV_RDEVCTUI Cumulative count of unsolicited
interrupts for this device
104 68 Unsigned 4 IODDEV_RDEVMICT Cumulative count of missing
interrupts detected for this
device. Incremented only when the
SET MITIME command is active for
this device
108 6C Unsigned 4 IODDEV_RDEVCTRG Cumulative count of RDEV lock
requests granted immediately for
this device
112 70 Unsigned 4 IODDEV_RDEVCTRD Cumulative count of RDEV lock
requests that were deferred for
this device
116 74 Unsigned 4 IODDEV_RDEVSKCT Cumulative count of DASD access
arm position changes (Seek I/O)
executed on this device. NOTE:
accuracy is not guaranteed since
counts may be skipped on
multi-track operations on a cache
control unit.
120 78 Unsigned 4 IODDEV_RDEVSKSM Cumulative amount of DASD access
arm movement (displacements). This
is the sum of absolute
differences, in cylinders, between
successive Seeks.
124 7C Unsigned 4 IODDEV_RDEVWRCT Cumulative number of WRITE
channel programs that have
occurred on this device
128 80 Unsigned 4 IODDEV_RDEVRDCT Cumulative number of READ
channel programs that have
occurred on this device
132 84 Unsigned 4 IODDEV_RDEVMCIA Cumulative count of SSCH's
avoided due to Minidisk Cache read
hit
136 88 Unsigned 4 IODDEV_VIUCNTIN SIE ASSIST Activity Data (see
notes in prolog). Cumulative count
of times the device was in SIE
ASSIST.
140 8C Unsigned 4 IODDEV_VIUTIMIN SIE ASSIST Activity Data (see
notes in prolog). Cumulative time,
in micro seconds, spent in SIE
ASSIST, including getting there.
Accumulated after the device
starts to leave SIE ASSIST (e.g.,
it stays zero until after the
device leaves SIE ASSIST for the
first time). This field will wrap
around after a total of about 71
minutes (1.1 hours).
144 90 Unsigned 4 IODDEV_VIUCNTLV SIE ASSIST Activity Data (see
notes in prolog). Cumulative count
of times the device started to
leave SIE ASSIST.
148 94 Unsigned 4 IODDEV_VIUTIMLV SIE ASSIST Activity Data (see
notes in prolog). Cumulative time,
in mirco seconds, spent in the
process of leaving SIE ASSIST.
Accumulated after the device has
completed the process (e.g., it
stays zero until after the device
is out of SIE ASSIST for the first
time). This field will wrap around
after a total of about 71 minutes
(1.1 hours).
152 98 Unsigned 4 IODDEV_VIUCNTOT SIE ASSIST Activity Data (see
notes in prolog). Cumulative count
of times the device is out of SIE
ASSIST. Initialized to one.
156 9C Unsigned 4 IODDEV_VIUTIMOT SIE ASSIST Activity Data (see
notes in prolog). Cumulative time,
in micro seconds, spent outside of
SIE ASSIST. Accumulated after the
device has gone into SIE ASSIST
(e.g., it stays zero until after
the first time the device goes
into SIE ASSIST). This field will
wrap around after a total of about
71 minutes (1.1 hours).
160 A0 Unsigned 4 IODDEV_SCMDATIM SCM Facility Data (see notes in
prolog). Device-active-only time.
The sum of the time intervals when
the subchannel is device-active
but not subchannel-active at the
end of an I/O operation or chain
of I/O operations initiated by
START SUBCHANNEL.
164 A4 Character 8 IODDEV_VIUSTAMP SIE ASSIST Activity Data (see
notes in prolog). Time stamp of
last transition between I/O Assist
states.
172 AC Bitstring 1 IODDEV_VIUSTATE SIE ASSIST Activity Data (see
notes in prolog). VDEV state in
I/O Assist. X'00' = device is OUT
of Assist, X'01' = device is IN
Assist, X'02' = device is LEAVING
Assist
173 AD Character 3 * Reserved and available for IBM
use.
176 B0 Unsigned 4 IODDEV_THRDLYS Cummulative count of the number
of times I/O was delayed for a
throttled device.
180 B4 Unsigned 4 IODDEV_SCMCQTIM SCM Facility Data (see notes in
prolog). Control Unit Queuing
time. The sum of the time
intervals measured by the control
unit whenever the device is
logically disconnected from the
channel subsystem during an I/O
operation while the device is busy
with an operation initiated from a
different system.
184 B8 Unsigned 4 IODDEV_SCMDBTIM SCM Facility Data (see notes in
prolog). Accumulated device-busy
time. The sum of the time
intervals when the subchannel is
device busy during an attempt
initiate a start function or
resume function at the subchannel.
188 BC Unsigned 4 IODDEV_SCMIRTIM SCM Facility Data (see notes in
prolog). Accumulated initial-
command-response time. The
initial-command-response time for
a start or resume function is the
time interval beginning from when
the first command of the channel
program is sent to the device
until the device indicates it has
accepted the command.
192 C0 Unsigned 4 IODDEV_SCGSSCH SCM Facility Data (see notes in
prolog). Cumulative count of SSCHs
and RSCHs for this device. This is
the fullword count which is stored
when format-1 measurement blocks
are being used (MTRSYS_CALFLG2 =
x'80').
196 C4 Unsigned 4 IODDEV_SCGCOUNT SCM Facility Data (see notes in
prolog). Cumulative sample count.
Incremented whenever any
measurement fields are updated.
This is the fullword count which
is stored when format-1
measurement blocks are being used
(MTRSYS_CALFLG2 = x'80').
200 C8 Character 0 IODDEV_END
MRIODDEV Cross Reference
Hex Hex
Name Offset Length Value
IODDEV 0 200
IODDEV_CALFLAG1 17 1
IODDEV_CALMDCDF 17 20
IODDEV_CALMDCDN 17 40
IODDEV_CALMDCNO 17 80
IODDEV_CALMDCOF 17 10
IODDEV_CALSCMBK 17 04
IODDEV_CALTHROT 17 02
IODDEV_CALUSER 2A 8
IODDEV_END C8 0
IODDEV_HFCTIO 48 4
IODDEV_HFRDEVCT 44 4
IODDEV_MRHDR 0 0
IODDEV_RDEVAFLG 14 1
IODDEV_RDEVCHPS 1C 8
IODDEV_RDEVCTRD 70 4
IODDEV_RDEVCTRG 6C 4
IODDEV_RDEVCTSI 60 4
IODDEV_RDEVCTSR 4C 4
IODDEV_RDEVCTUI 64 4
IODDEV_RDEVLCNT 32 2
IODDEV_RDEVLPM 15 1
IODDEV_RDEVMCIA 84 4
IODDEV_RDEVMICT 68 4
IODDEV_RDEVRCWH 50 4
IODDEV_RDEVRCWP 54 4
IODDEV_RDEVRDCT 80 4
IODDEV_RDEVRTPD 58 8
IODDEV_RDEVSER 24 6
IODDEV_RDEVSHAR 17 08
IODDEV_RDEVSID 18 4
IODDEV_RDEVSKCT 74 4
IODDEV_RDEVSKSM 78 4
IODDEV_RDEVWRCT 7C 4
IODDEV_SCGCOUNT C4 4
IODDEV_SCGSSCH C0 4
IODDEV_SCMCNTIM 38 4
IODDEV_SCMCOUNT 36 2
IODDEV_SCMCQTIM B4 4
IODDEV_SCMDATIM A0 4
IODDEV_SCMDBTIM B8 4
IODDEV_SCMDDTIM 40 4
IODDEV_SCMFPTIM 3C 4
IODDEV_SCMIRTIM BC 4
IODDEV_SCMSSCH 34 2
IODDEV_THRDLYS B0 4
IODDEV_VDEVIOPX 16 80
IODDEV_VDEVIOP1 16 1
IODDEV_VDEVIOP3 16 40
IODDEV_VIUCNTIN 88 4
IODDEV_VIUCNTLV 90 4
IODDEV_VIUCNTOT 98 4
IODDEV_VIUSTAMP A4 8
IODDEV_VIUSTATE AC 1
IODDEV_VIUTIMIN 8C 4
IODDEV_VIUTIMLV 94 4
IODDEV_VIUTIMOT 9C 4
MRHDR 0 20
MRHDR_END 14 0
MRHDRDM 4 1
MRHDRLEN 0 2
MRHDRRC 6 2
MRHDRTOD 8 8
MRHDRZER 2 2
This information is
based on z/VM V4R4.0.
Last updated on 22 Jul 2003 at 15:04:23.
Copyright IBM Corporation, 1990, 2003