HP OpenVMS Systems Documentation

Displays the contents of the stored machine check frame. This command is valid for the DEC 4000 Alpha, DEC 7000 Alpha, and DEC 10000 Alpha computers only.

Format

SHOW MACHINE_CHECK [/FULL] [cpu-id]

Parameter

cpu-id

Numeric value indicating the identity of the CPU for which context information is to be displayed. This parameter changes the SDA current CPU (the default) to the CPU specified with cpu-id. If you specify the cpu-id of a processor that was not active at the time of the system failure, SDA displays the following message:

%SDA-E-CPUNOTVLD, CPU not booted or CPU number out of range

If you use the cpu-id parameter, the SHOW MACHINE_CHECK command performs an implicit SET CPU command, making the CPU indicated by cpu-id the current CPU for subsequent SDA commands. (See the description of the SET CPU command and Section 2.5 for information on how this can affect the CPU context---and process context---in which SDA commands execute.)

Qualifier

/FULL

Specifies that a detailed version of the machine check information be displayed. This is currently identical to the default summary display.

Description

The SHOW MACHINE_CHECK command displays the contents of the stored machine check frame. A separate frame is allocated at boot time for every CPU in a multiple-CPU system. This command is valid for the DEC 4000 Alpha, DEC 7000 Alpha, and DEC 10000 Alpha computers only.

If you do not specify a qualifier, a summary version of the machine check frame is displayed.

The default cpu-id is the SDA current CPU.

Examples

SDA> SHOW MACHINE_CHECK 
CPU 00 Stored Machine Check Crash Data
--------------------------------------
Processor specific information: 
------------------------------- 
Exception address:    FFFFFFFF.800B0250    Exception Summary:  00000000.00000000 
Pal base address:     00000000.00008000    Exception Mask:     00000000.00000000 
HW Interrupt Request: 00000000.00000342    HW Interrupt Ena:   00000001.FFC01CE0 
MM_CSR                00000000.00003640    ICCSR:              00000002.381F0000 
D-cache address:      00000007.FFFFFFFF    D-cache status:     00000000.000002E0 
BIU status:           00000000.00000050    BIU address [7..0]: 00000000.000060E0 
BIU control:          00000008.50006447    Fill Address:       00000000.00006120 
Single-bit syndrome:  00000000.00000000    Processor mchck VA: 00000000.00006190 
A-box control:        00000000.0000040E    B-cache TAG:        00106100.83008828 
System specific information: 
---------------------------- 
Garbage bus info:     00200009 00000038    Device type:                 000B8001 
LCNR:                          00000001    Memory error:                00000000 
LBER:                          00000009    Bus error synd 0,1: 00000000 00000000 
Bus error cmd:        00048858 00AB1C88    Bus error synd 2,3: 00000000 0000002C 
LEP mode:                      00010010    LEP lock address:            00041108 
      

The SHOW MACHINE_CHECK command in this SDA display shows the contents of the stored machine check frame.

SDA> SHOW MACHINE_CHECK 1
CPU 01 Stored Machine Check Crash Data 
--------------------------------------
Processor specific information: 
------------------------------- 
Exception address:    FFFFFFFF.800868A0    Exception Summary:  00000000.00000000 
Pal base address:     00000000.00008000    Exception Mask:     00000000.00000000 
HW Interrupt Request: 00000000.00000342    HW Interrupt Ena:   00000000.1FFE1CE0 
MM_CSR                00000000.00005BF1    ICCSR:              00000000.081F0000 
D-cache address:      00000007.FFFFFFFF    D-cache status:     00000000.000002E0 
BIU status:           00000000.00000050    BIU address [7..0]: 00000000.000063E0 
BIU control:          00000008.50006447    Fill Address:       00000000.00006420 
Single-bit syndrome:  00000000.00000000    Processor mchck VA: 00000000.00006490 
A-box control:        00000000.0000040E    B-cache TAG:        35028EA0.50833828 
System specific information: 
---------------------------- 
Garbage bus info:     00210001 00000038    Device type:                 000B8001 
LCNR:                          00000001    Memory error:                00000080 
LBER:                          00040209    Bus error synd 0,1: 00000000 00000000 
Bus error cmd:        00048858 00AB1C88    Bus error synd 2,3: 00000000 0000002C 
LEP mode:                      00010010    LEP lock address:            00041108 
      

The SHOW MACHINE_CHECK command in this SDA display shows the contents of the stored machine check frame for cpu-id 01.

Displays the availability and usage of memory resources.

Format

SHOW MEMORY [/ALL][/BUFFER_OBJECTS][/CACHE][/FILES]
[/FULL][/GH_REGIONS][/PHYSICAL_PAGES][/POOL]
[/RESERVED][/SLOTS]

Parameters

None.

Qualifiers

/ALL

Displays all available information, that is, information displayed by the following qualifiers:

/BUFFER_OBJECTS
/CACHE
/FILES
/GH_REGIONS
/PHYSICAL_PAGES
/POOL
/RESERVED
/SLOTS

This is the default display.

/BUFFER_OBJECTS

Displays information about system resources used by buffer objects.

/CACHE

Displays information about either the Virtual I/O Cache facility or the Extended File Cache facility. The system parameter VCC_FLAGS determines which is used. The cache facility information is displayed as part of the SHOW MEMORY and SHOW MEMORY/CACHE/FULL commands.

/FILES

Displays information about the use of each paging and swapping file currently installed.

/FULL

When used with the /POOL and /CACHE qualifiers, displays additional information. This qualifier is ignored otherwise. For /CACHE, the additional information is only displayed when the Virtual I/O Cache facility is in use (Alpha only); /FULL is ignored if the Extended File Cache facility is in use. Additional information on how memory is being used by the Extended File Cache facility can be obtained using the XFC extension described in Chapter 9.

/GH_REGIONS

Displays information about the granularity hint regions (GHR) that have been established. For each of these regions, information is displayed about the size of the region, the amount of free memory, the amount of memory in use, and the amount of memory released to OpenVMS from the region. The granularity hint regions information is also displayed as part of SHOW MEMORY and SHOW MEMORY/ALL commands.

/PHYSICAL_PAGES

Displays information about the amount of physical memory and the number of free and modified pages.

/POOL

Displays information about the usage of each dynamic memory (pool) area, including the amount of free space and the size of the largest contiguous block in each area.

/RESERVED

Displays information about memory reservations.

/SLOTS

Displays information about the availability of process control block (PCB) vector slots and balance slots.

Description

For more information about the SHOW MEMORY command, see the description in the HP OpenVMS DCL Dictionary or online help.

Displays a range of system page table entries, the entire system page table, or the entire global page table.

Format

SHOW PAGE_TABLE [range | /FREE [/HEADER=address ]
| /GLOBAL | /GPT | /PT
| /INVALID_PFN [=option]
| /NONMEMORY_PFN [=option]
| /PTE_ADDRESS | /SECTION_INDEX=n
| /S0S1 (d) | /S2 | /SPTW | /ALL]
[/L1 | /L2 | /L3 (d)]

Parameter

range

Range of virtual addresses or PTE addresses for which SDA displays page table entries. If the qualifier /PTE_ADDRESS is given, then the range is of PTE addresses; otherwise, the range is of virtual addresses. The range given can be of process-space addresses.

If /PTE_ADDRESS is given, the range is expressed using the following syntax:

m	Displays the single page table entry at address m
m:n	Displays the page table entries from address m to address n
m;n	Displays n bytes of page table entries starting at address m

If /PTE_ADDRESS is not given, then range is expressed using the following syntax:

m	Displays the single page table entry that corresponds to virtual address m
m:n	Displays the page table entries that correspond to the range of virtual addresses from m to n
m;n	Displays the page table entries that correspond to a range of n bytes starting at virtual address m

Note that OpenVMS Alpha and Integrity servers page protections are slightly different. For additional information, see Section 2.8.

Qualifiers

/FREE

Causes the starting addresses and sizes of blocks of pages in the free PTE list to be displayed. The qualifiers /S0S1 (default), /S2, /GLOBAL, and /HEADER determine which free PTE list is to be displayed. A range cannot be specified, and no other qualifiers can be combined with /FREE.

/GLOBAL

Lists the global page table. When used with the /FREE qualifier, /GLOBAL indicates the free PTE list to be displayed.

/HEADER=address

When used with the /FREE qualifier, the /HEADER=address qualifier displays the free PTE list for the specified private page table.

/GPT

Specifies the portion of page table space that maps the global page table as the address range.

/INVALID_PFN [=option]

The /INVALID_PFN qualifier, which is valid only on platforms that supply an I/O memory map, causes SDA to display only page table entries that map to PFNs that are not in the system's private memory or in Galaxy-shared memory, and which are not I/O access pages.

/INVALID_PFN has two optional keywords, READONLY and WRITABLE. If neither keyword is specified, all relevant pages are displayed.

If READONLY is specified, only pages marked for no write access are displayed. If WRITABLE is specified, only pages that allow write access are displayed. For example, SHOW PAGE_TABLE/ALL/INVALID_PFN=WRITABLE would display all system pages whose protection allows write, but which map to PFNs that do not belong to this system.

/L1

/L2

/L3 (D)

Specifies the level for which page table entries are to be displayed for the specified portion of memory. You can specify only one level. /L3 is the default.

/NONMEMORY_PFN [=option]

The /NONMEMORY_PFN qualifier causes SDA to display only page table entries that are not in the system's private memory or in Galaxy-shared memory.

/NONMEMORY_PFN has two optional keywords, READONLY and WRITABLE. If neither keyword is specified, all relevant pages are displayed.

If READONLY is specified, only pages marked for no write access are displayed. If WRITABLE is specified, only pages that allow write access are displayed. For example, SHOW PAGE_TABLE/ALL/NONMEMORY_PFN=WRITABLE would display all system pages whose protection allows write, but which map to PFNs that do not belong to this system.

/PT

Specifies that the page table entries for the page table region of system space are to be displayed.

/PTE_ADDRESS

Specifies that the range given is of PTE addresses instead of the virtual addresses mapped by the PTEs.

/SECTION_INDEX=n

Displays the page table for the range of pages in the global section or pageable part of a loaded image. For pageable portions of loaded images, one of the qualifiers /L1, /L2, or /L3 can also be specified.

/S0S1 (D)

/S2

Specifies the region whose page table entries are to be displayed. When used with the /FREE qualifier, indicates the free PTE list to be displayed. By default, the page table entries or the free list for S0 & S1 space is displayed.

/SPTW

Displays the contents of the system page table window.

/ALL

Displays the page table entries for all shared (system) addresses. It is equivalent to specifying all of /S0S1, /S2, and /PT.

Description

If the /FREE qualifier is not specified, this command displays page table entries for the specified range of addresses or section of memory. For each virtual address displayed by the SHOW PAGE_TABLE command, the first eight columns of the listing provide the associated page table entry and describe its location, characteristics, and contents. SDA obtains this information from the system page table or from the process page table if a process_space address is given. Table 4-8 desand IMGACT process pools. cribes the information displayed by the SHOW PAGE_TABLE command.

If the /FREE qualifier is specified, this command displays the free PTE list for the specified section of memory.

The /L1, /L2, and /L3 qualifiers are ignored when used with the /FREE, /GLOBAL, and /SPTW qualifiers.

Table 4-8 Virtual Page Information in the SHOW PAGE_TABLE Display

Value	Meaning
MAPPED ADDRESS	Virtual address that marks the base of the virtual page(s) mapped by the PTE.
PTE ADDRESS	Virtual address of the page table entry that maps the virtual page(s).
PTE	Contents of the page table entry, a quadword that describes a system virtual page.
TYPE	Type of virtual page. Table 4-9 shows the eight types and their meanings.
READ	(Alpha only.) A code, derived from bits in the PTE, that designates the processor access modes (kernel, executive, supervisor, or user) for which read access is granted.
WRIT	(Alpha only.) A code, derived from bits in the PTE, that designates the processor access modes (kernel, executive, supervisor, or user) for which write access is granted.
MLOA	(Alpha only.) Letters that represent the setting of a bit or a combination of bits in the PTE. These bits indicate attributes of a page. Table 4-10 shows the codes and their meanings.
AR/PL	(Integrity servers only) The access rights and privilege level of the page. Consists of a number (0-7) and a letter (K, E, S, or U) that determines access to a page in each mode.
KESU	(Integrity servers only) The access allowed to the page in each mode. This is an interpretation of the AR/PL values in the previous column. For an explanation of the access codes, see Section 2.8, Page Protections and Access Rights.
MLO	(Integrity servers only) Letters that represent the setting of a bit or a combination of bits in the PTE. These bits indicate attributes of a page. Table 4-10 shows the codes and their meanings.
GH	Contents of granularity hint bits.

Table 4-9 Types of Virtual Pages

Type	Meaning
VALID	Valid page (in main memory).
TRANS	Transitional page (on free or modified page list).
DZERO	Demand-allocated, zero-filled page.
PGFIL	Page within a paging file.
STX	Section table's index page.
GPTX	Index page for a global page table.
IOPAG	Page in I/O address space.
NXMEM	Page not represented in physical memory. The page frame number (PFN) of this page is not mapped by any of the system's memory controllers. This indicates an error condition.

Table 4-10 Bits In the PTE

Column Name	Code	Meaning
M	M	Page has been modified.
L	L	Page is locked into a working set.
L	P	Page is locked in physical memory.
O	K	Owner is kernel mode.
O	E	Owner is executive mode.
O	S	Owner is supervisor mode.
O	U	Owner is user mode.
A	A	Address space match is set (Alpha only).

If the virtual page has been mapped to a physical page, the last five columns of the listing include information from the page frame number (PFN) database; otherwise, the section is left blank. Table 4-11 describes the physical page information displayed by the SHOW PAGE_TABLE command.

Table 4-11 Physical Page Information in the SHOW PAGE_TABLE Display

Category	Meaning
PGTYP	Type of physical page. Table 4-12 shows the types of physical pages.
LOC	Location of the page within the system. Table 4-13 shows the possible locations with their meaning.
BAK	Place to find information on this page when all links to this PTE are broken: either an index into a process section table or the number of a virtual block in the paging file.
REFCNT	Number of references being made to this page.
WSLX	Working Set List Index. This shows as zero for resident and global pages, and is left blank for transition pages.

Table 4-12 Types of Physical Pages

Page Type	Meaning
PROCESS	Page is part of process space.
SYSTEM	Page is part of system space.
GLOBAL	Page is part of a global section.
GBLWRT	Page is part of a global, writable section.
PPGTBL	Page is part of a process page table.
GPGTBL	Page is part of a global page table.
PHD 1	Page is part of a process PHD.
PPT(Ln) 1	Page is a process page table page at level n.
WSL 1	Page is part of a process's working list.
SPT(Ln) 2	Page is a system page table page at level n.
SHPT 3	Page is part of a shared page table.
PFNLST 2	Page is in a Shared Memory Common Property Partition PFN database.
SHM_REG 3	Page is in a Shared Memory Region.
UNKNOWN	Unknown.

SDA indicates pages are inaccessible by displaying one of the following messages:

 
-------   1 null page:       VA   FFFFFFFE.00064000     PTE   FFFFFFFD.FF800190 
 
------- 974 null pages:      VA   FFFFFFFE.00064000     PTE   FFFFFFFD.FF800190 
                             -to- FFFFFFFE.007FDFFF     -to-  FFFFFFFD.FF801FF8 

In this case, the page table entries are not in use (page referenced is inaccessible).

 
-------      1 entry not in memory:    VA   FFFFFFFE.00800000   PTE   FFFFFFFD.FF802000 
 
------- 784384 entries not in memory:  VA   FFFFFFFE.00800000   PTE   FFFFFFFD.FF802000 
                                       -to- FFFFFFFF.7F7FDFFF   -to-  FFFFFFFD.FFDFDFF8 

In this case, the page table entries do not exist (PTE itself is inaccessible).

 
-------    1 free PTE:    VA   FFFFFFFF.7F800000   PTE   FFFFFFFD.FFDFEOOO 
 
------- 1000 free PTEs:   VA   FFFFFFFF.7F800000   PTE   FFFFFFFD.FFDFE000 
                          -to- FFFFFFFF.7FFCDFFF   -to-  FFFFFFFD.FFDFFF38 

In this case, the page table entries are in the list of free system pages.

In each case, VA is the MAPPED ADDRESS of the skipped entry, and PTE is the PTE ADDRESS of the skipped entry.

Examples

For an example of SHOW PAGE_TABLE output when the qualifier /FREE has not been given, see the SHOW PROCESS/PAGE_TABLES command.

SDA> SHOW PAGE_TABLE/FREE
S0/S1 Space Free PTEs 
--------------------- 
 MAPPED ADDRESS        PTE ADDRESS             PTE           COUNT 
 
FFFFFFFF.82A08000   FFFFFFFD.FFE0A820   0001FFE0.A8580000   00000003 
FFFFFFFF.82A16000   FFFFFFFD.FFE0A858   0001FFE0.A8900000   00000003 
FFFFFFFF.82A24000   FFFFFFFD.FFE0A890   0001FFE0.B3C00000   00000003 
FFFFFFFF.82CF0000   FFFFFFFD.FFE0B3C0   0001FFE0.B4010000   00000001 
FFFFFFFF.82D00000   FFFFFFFD.FFE0B400   0001FFE0.B4680000   00000002 
   .
   .
   .
FFFFFFFF.82E48000   FFFFFFFD.FFE0B920   0001FFE0.B9390000   00000001 
FFFFFFFF.82E4E000   FFFFFFFD.FFE0B938   0001FFE0.BA200000   00000002 
FFFFFFFF.82E88000   FFFFFFFD.FFE0BA20   0001FFE0.C9780000   00000003 
FFFFFFFF.8325E000   FFFFFFFD.FFE0C978   0001FFE0.CC980000   00000003 
FFFFFFFF.83326000   FFFFFFFD.FFE0CC98   00000000.00000000   0000066D
      

This example shows the output when you invoke the SHOW PAGE_TABLE/FREE command.