Page of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829
Contents
The entries in this Table of Contents are accumulative. They list additions to this
publication by the following VM/370 System Control Proqram Products: • VM/370 Basic System Extensions, program Number 5748-XX8 • VM/370 System Extensions, program Nu mber 5748-XEl However, the text within the publication is not accumulative; it only relates to the one SCP program product that is installed on your system. Therefore, there may be topics ana references listed in this Tarle of contents that are not contained in the body of this P ubI ica tion.
Summary of Amendments. xiii PART 1. DEBUGGING WITH VM/370. • • 1 INTRODUCTION TO DEEUGGING.. • .3
How To Start Debugging • • • • .3
Does a Problem Exist? •• 4 Identifying the Problem. • ••••• 7
Analyzing the Problem. • • 13
How To Use VM/370 Facilities To Debug •• 18
Abend. • • • • • • • • 18 CP Abend • • • • • • • • • 18 CMS Abend. • • • • • • • • 19 Virtual Machine Abend (other than CM S). • • • • • • Un exp ect ed Results • • • • • • Unexpected Results in CP • • Unexpected Results in a Virtual • 23 • 24 • 24 Machine • • • • • 24 Loop • • • • • • • • • 25 CP Disabled Loop •• • • • • 25
wait • • • • • • • • 27
Summary of VM/370 Debugging • 32
Comparison of CP and CMS Facilities for
Debugging • • • • • • • • • • • • • • • 37
An Overview of VM/370 Commands That Can
Be Used for Debugging • • • • • • • 38
Commands that Display or Dump
virt ual Machine Data. • • • • • • 38
Commands That Set and Query System
Features, Conditions, and EVents ••• 39
Commands To Collect and Analyze System
Information • • • • • • • • • • • • • 40 Commands That Trace EVents in Virtual Machines •••••••••••• Commands That Alter the Contents of
storage • • . • • • • • • • • • Debugging CP on a Virtual Machine. CP Internal Trace Table. • • • Abend Dumps •••••••••• • 40 • 41 • 42 • 42 • 44
How To Print a CP Abend Dump From Tape 45 Reading CP ABEN D Dumps
Reason for tbe Abend
Collect Information •• Register Usage • • • • • ••• • 46 • 46 • 47 • 48 Save Area Conventions. • Virtual and Real Control
Identifying and Locating • 48 Elock Status. 50 a pageable
Module. • • • • ••••••••••• 63 VMDUMP Records: Format and Content 63
Locating Logical Dump Records. • 64 DEBUGGING WITH CMS • • CMS Debugging Commands • DEBUG. • • •• • • • • 64.2 •• 64.2 • 65
Nucleus Load Map ••••• Load Map • • • • • • • Reading CMS Abend Dumps •• • • • • • 66
Reason for the Abend
Collect Inf ormation.
Register Usage ••• PART 2. CONTROL PROGRAM (CP) VM/370 •••••••••••••• Introduction to the VM/370 Control • 68 • 68 • 69 • 70 • 72 • 73 • 75
Program • • • • • • • • • • • •• • 75 Virtual Machine Time Management. .' 76 Virtual Machine Storage Management • • 76 Virtual Storage Preservation ••••••••••••• 78.1 Virtual Storage Preservation (.2148-1 E i). • • • • • • • • • Virtual Machine I/O Management • Spooling Functions • • 78.1 • 79 • 80 Spool File Recovery. • 81 CP Commands. • 82 PROGRAM STATES • • 83 USING PROCESSOR RESOURCES. 84 Queue 1 •••••••••••••• Queue 2. • • • • • • • • • • • • • • 84 • 84 Deadline Priority Deadline Priority Queue 3 • • • • Queue 3 (5748-XE1) INTERRUPTION HANDLING •• INTERRUPTION HANDLING (5748-XX8) INTERRUPTION HANDLING I/O Interrupts • • • • • • • I/O InterrUpts (.2148-XX.m"-. • • • 85 • 85 • 86 • 86 • 8E 86.1 • • • 86.1 • 86 • •• 86.1 • •• 86.1 · 86 • • • • • 86.1 I/O Interrupts (5748-XEj) •• Program Interrupt. • • • • • Program Interrupt (5748-XX8) Program Interrupt Machine Check Interrupt. • • • 86.1 • 86
Contents vii

Paqe of GC20-1807-7 As Updated April 1, 1981 by TNL GN25-0829 Check Interrupt • Machine Check Interrupt • svc Interrupt. • . • • • ••• External Interrupt • • • ••• Synchronous Interrupts In An Attached Processor System •• Real I/O Interrupts •• PERFORMANCE GUIDELINES. • 86. 1 • 86.1 • • 87 • • 87 • 87 • 87 • • 88
General Information ••• virtual Machine I/O ••• paqinq Considerations. • • • • • 88 • 89 • • 90 Locked Pages Option •• Peserved Page Frames Option. • • • • • 91
virtual=Re al 0 pt ion. • • • • vM/370 Performance Options. F' a vored Execu t ion. • • • • • Priority ••••••••• User priority (2148-Xl§) • User Priority • 92
92 • 93 • • 93 • 95 • 95 • • 95 • 95
. • • • • • 95 ReseL ved Paqe Fra mes • Virtual=Real • • • • • •• Affinity • • • • • • • • Multiple Shadow Table Support • 97 . • • • • • • •• •• 98
Shadow Table Bypass . 98.1
virtual Machine Assist Feature. • 98 (S148=!]1). • • • • • • • • • • 98.2
virtual Machine Assist Feature ••••• 98 rysing the Virtual Machine Assist Peature • • • • • • • • • • • • • • • 99
Restr icted Use of the Virtual Machine Feature •••••••••••• 99 Extended Control-Program Support (ECPS). • . • . • ••••••••••• 99
TJsinq the VM/370 Extended
Cont r01- proqram Support • • • • • • .101 The virtual Block Multiplexer Channel Option. • • . • • • • • • • • • .102 Alternate Path Support •••••••• 102 qVS/System Extensions Support (5748-XE1) •••••••••••••• 102.1 Lo;-iddress Protection Facility . • • • • • • • • • • • 10 2. 1
Common segment Facility • 102.2 Special MVS Instruction Operation Handlinq Facilities • • 102.2 Enablinq MVS/System Extensions Support ( 5748- X E 1). . . • • • • • • • • . • 102. 2 Sinqle-processor Mode • 102. 2
Dynamic SCP Transition to or From
Native Mode (57!!8-1£:.1) •••••• 102.3 PERFORMANCE OBSERVATION AND ANALYSIS •• 103 Load Indicators. • • . • • • • • .103 'I'h e I n d i cat e Com man d • . • • • • 1 03 The Class G INDICATE Command. • .104 The Class E INDICATE Command. • .106 The Class E INDICATE FAVORED Command . • • • • • • • • •••• 109 Class E INDICATE FAVORED Command (51!!]:!£; 1). . • • • • • • • • • 109 ':"he MIGRATE Command .109 and Settinq the System Variables LS1!!§:XX§). . • • • • • • • • • 109 Querying and Setting the System Resource M anagem en t Va r iab Ie s (2148- !E1). • • • • • 110 Querying and Setting the Paging Variable • • • 110 Querying and Setting the Paging Variable The MONITOR Command. • • ••• .110 .110 The MONITOR Command (5748-XX8) • .110.1 The MONITOR Command (5748-XE1) • .110.1 .119 Implemented Classes •• •• VM/370 Monitor Response to Unusual Tape C ondi tions • • • • • • • • VM/370 Monitor Consideratioas •• VM/370 Monitor Data Volume and Overhead. • • • • • • • • • • Load Environments of VM/370. ACCOUNTING RECORDS Accounting Records for Virtual Machine
Resource Usage. • Accounting Records for
Devices and Temporary
Accounting Records for
Devices and Temporary
Dedicated
Disk Space. Dedicated
Disk Space .121 • 122
.123
.124
.127
.127
.128
( .214 8- X X • • • • • • • • • • • • • • 1 2 7
Accounting Records for Dedicated
Devices and Temporary Disk Space ( 57 !is-XE1). • • • • • • • • • • • Accounting Records for LOGON, AUTOLOG, .127
and LINK Journaling • Accounting Records Created Operational Notes ••••• User Accounting Options •• • •••••• 128
by the User .129 • • •• 130 • • • • • • • 130 GENERATING SAVED SYSTEMS. .132
The NAMESYS Macro For Saved Systems ••• 132 Using the SAVESYS Command •••••••• 134 Shared Segments ••••••••••••• 135 Special Considerations for Shared Segments. • • • • • • • • .135
Discontiguous Saved Segments •••••• 135 User Reguirements ••••••••••• 136
The NAM ESYS Macro for D iscont iquous Saved Segments. • • • • • • • • .137
Loading and Savinq Discontiquous Shared Segments ••••••••••• 138
How The Interface Works. • • .139 Shared Segment Protection. • .140 Virtual Machine Operation. • .142
THE VIRTUAL MACHINE COMMUNICATION FACILITY •••••••••••••••• 143 Using the Virt ual Machine C ommu nica ti on
Facility. • • • • • • • • • • .145 VMCF Applications. • • • • • .145
security and Data Integrity. .146 Performance Considerations. .147
General Considerations. • • • • .148 VMCF Protocol. • • • • • • • • • • .148
The SEN D Protocol. • • • .148
The SENDjRECV Protocol. • • • • .150 The SENDX Protocol • • • .151
The IDENTIFY Proto col. • • 152
Descriptions of VMCF Subfunctions. .153
The Control Subfunctions • • • .153
The Data Transfer Functions.. • • .155