Programming Interface Information:
The Monitor Records are intended Programming Interfaces that
allow the customer to write programs to obtain services of z/VM.

MRSEKSEK

Prolog
Control Block Contents
Cross Reference

MRSEKSEK Prolog

 DSECT NAME - SEKSEK
 FUNCTION - Map a Monitor record.
 LOCATED By -
        Through the Monitor Control Area
 REFERENCED CONTROL BLOCKS -
        MRRECHDR    Monitor Record Header
 NAME - MRSEKSEK
 DESCRIPTIVE NAME - Monitor Event Record
                    Domain 7 - Seek Domain
                    Record 1 - Seek Data
 DESCRIPTION - Record of access arm movement ("Seek I/O") on a DASD
               device or of a set paging parameter to a cache device.
               Generated each time an I/O channel program containing
               seek commands(s) is executed.
               This record contains seek data that may enable a
               user, such as an operating system developer, to tune
               DASD seek scheduling algorithms.  This record is NOT
               intended for DASD load balancing.  However, it can be
               used to tune a cached minidisk to minimize the number
               of tracks that must be cached.
 NOTES:
 --  Because of the frequency of seek I/O operations, an extremely
     large number of this record will be generated.  For this
     reason, seek-domain monitoring should be limited to specific
     devices or a specific set of devices.
 --  The order in which the records are generated may not be the
     order in which the commands are executed by the device.
 --  The seek may not be executed by a device when there is a
     permanent device error or when branching is done in the channel
     program which bypasses segments.

MRSEKSEK Control Block Contents

Offsets
Dec  Hex  Type        Len  Name (Dim)             Description
 
   0   0  Structure    84  SEKSEK                 Start of monitor record
   0   0  Character     0  SEKSEK_MRHDR           Record header. See MRRECHDR
                                                  for details.
   0   0  Character    20  MRHDR                  
   0   0  Unsigned      2  MRHDRLEN               
   2   2  Unsigned      2  MRHDRZER               
   4   4  Unsigned      1  MRHDRDM                
   5   5  Unsigned      1  *                      
   6   6  Unsigned      2  MRHDRRC                
   8   8  Character     8  MRHDRTOD               
  16  10  Character     4  *                      
  20  14  Character     0  MRHDR_END              
  20  14  Unsigned      4  SEKSEK_RDEVSID         Host subchannel I.D. number
                                                  defined at initialization
  24  18  Unsigned      2  SEKSEK_CALCURCY        Last seek cylinder for
                                                  previous DASD channel program
                                                  executed. RDEVCYL
                                                  SEKSEK_CALCURCY is deprecated
                                                  and should not be used for
                                                  further development. Code
                                                  should be changed to use
                                                  SEKSEK_CALCURCY32 defined
                                                  below. For values above
                                                  'FFFF'x then this field will
                                                  contain 'FFFF'x (and will not
                                                  wrap).
  26  1A  Unsigned      2  SEKSEK_CALSKCYL        First cylinder requested in
                                                  seek command(s) in this real
                                                  channel program. IORCYL
                                                  SEKSEK_CALSKCYL is deprecated
                                                  and should not be used for
                                                  further development. Code
                                                  should be changed to use
                                                  SEKSEK_CALSKCYL32 defined
                                                  below. For values above
                                                  'FFFF'x then this field will
                                                  contain 'FFFF'x (and will not
                                                  wrap).
  28  1C  Unsigned      2  SEKSEK_CALSKHD         First head number requested
                                                  in seek command(s) in this
                                                  real channel program. IORHEAD
  30  1E  Bitstring     1  SEKSEK_CALFLAGS        Flag byte
          1... ....        SEKSEK_IORDWRIT         ON=This is a WRITE channel
                                                  program. OFF=This is a READ
                                                  channel program.
          .1.. ....        *                       
          ..1. ....        *                       
          ...1 ....        *                       
          .... 1...        *                       
          .... .1..        *                       
          .... ..1.        *                       
          .... ...1        *                       
  31  1F  Bitstring     1  *                      Reserved for IBM use
  32  20  Character     8  SEKSEK_VMDUSER         Userid of requestor of seek
                                                  command(s) in this real
                                                  channel program. If 'SYSTEM',
                                                  CP is the requestor.
  40  28  Unsigned      4  SEKSEK_IORPOSCT        Number of DASD access arm
                                                  position changes within this
                                                  real channel program.
  44  2C  Unsigned      4  SEKSEK_IORPOSSM        Amount of access arm
                                                  movements (displacements).
                                                  Cumulative total of absolute
                                                  differences, in cylinders,
                                                  between successive seek
                                                  operation within this real
                                                  channel program
                                                  SEKSEK_IORPOSSM is deprecated
                                                  and should not be used for
                                                  further development. Code
                                                  should be changed to use
                                                  SEKSEK_IOSPOSSM64 defined
                                                  below. For values above
                                                  'FFFFFFFF'x then this field
                                                  will contain 'FFFFFFFF'x (and
                                                  will not wrap).
  48  30  Unsigned      2  SEKSEK_CALECYL         Final cylinder number
                                                  (position after this real
                                                  channel program completes).
                                                  IORECYL SEKSEK_CALECYL is
                                                  deprecated and should not be
                                                  used for further development.
                                                  Code should be changed to use
                                                  SEKSEK_CALECYL32 defined
                                                  below. For values above
                                                  'FFFF'x then this field will
                                                  contain 'FFFF'x (and will not
                                                  wrap).
  50  32  Unsigned      2  SEKSEK_VDEVDEV         Virtual device number of
                                                  the target device. Not
                                                  applicable if CP is the
                                                  requestor (i.e.,
                                                  SEKSEK_VMDUSER = 'SYSTEM').
  52  34  Character     8  SEKSEK_CALUSER         Userid of the owner of the
                                                  target device. Not applicable
                                                  if CP is the requestor (i.e.,
                                                  SEKSEK_VMDUSER = 'SYSTEM').
  60  3C  Unsigned      2  SEKSEK_RDEVDEV         Device number
  62  3E  Unsigned      2  *                      Reserved for IBM use
  64  40  Unsigned      4  SEKSEK_CALCURCY32      Last seek cylinder for
                                                  previous DASD channel program
                                                  executed. RDEVCYL
  68  44  Unsigned      4  SEKSEK_CALSKCYL32      First cylinder requested in
                                                  seek command(s) in this real
                                                  channel program. IORCYL
  72  48  Character     8  SEKSEK_IORPOSSM64      
  72  48  Unsigned      4  SEKSEK_IORPOSSM64_HI   
  76  4C  Unsigned      4  SEKSEK_IORPOSSM64_LO   Amount of access arm
                                                  movements (displacements).
                                                  Cumulative total of absolute
                                                  differences, in cylinders,
                                                  between successive seek
                                                  operation within this real
                                                  channel program.
  80  50  Unsigned      4  SEKSEK_CALECYL32       Final cylinder number
                                                  (position after this real
                                                  channel program completes).
                                                  IORECYL
  84  54  Character     0  SEKSEK_END             

MRSEKSEK Cross Reference

                      Hex           Hex
Name                  Offset Length Value 
 
MRHDR                      0     20
MRHDR_END                 14      0
MRHDRDM                    4      1
MRHDRLEN                   0      2
MRHDRRC                    6      2
MRHDRTOD                   8      8
MRHDRZER                   2      2
SEKSEK                     0     84
SEKSEK_CALCURCY           18      2
SEKSEK_CALCURCY32         40      4
SEKSEK_CALECYL            30      2
SEKSEK_CALECYL32          50      4
SEKSEK_CALFLAGS           1E      1
SEKSEK_CALSKCYL           1A      2
SEKSEK_CALSKCYL32         44      4
SEKSEK_CALSKHD            1C      2
SEKSEK_CALUSER            34      8
SEKSEK_END                54      0
SEKSEK_IORDWRIT           1E           80
SEKSEK_IORPOSCT           28      4
SEKSEK_IORPOSSM           2C      4
SEKSEK_IORPOSSM64         48      8
SEKSEK_IORPOSSM64_HI      48      4
SEKSEK_IORPOSSM64_LO      4C      4
SEKSEK_MRHDR               0      0
SEKSEK_RDEVDEV            3C      2
SEKSEK_RDEVSID            14      4
SEKSEK_VDEVDEV            32      2
SEKSEK_VMDUSER            20      8

This information is
based on z/VM V6R4.0.

Last updated on 5 Oct 2016 at 14:31:55.
Copyright IBM Corporation, 1990, 2016