HP OpenVMS Systems Documentation

OpenVMS Alpha System Analysis Tools Manual

If the virtual page has been mapped to a physical page, the last six columns of the listing include information from the page frame number (PFN) database; otherwise, the section is left blank. Table 4-8 describes the physical page information displayed by the SHOW PAGE_TABLE command.

**Table 4-8 Physical Page Information in the SHOW PAGE_TABLE Display**
Category	Meaning
PGTYP	Type of physical page. Table 4-9 shows the types of physical pages.
LOC	Location of the page within the system. Table 4-10 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.
FLINK	Forward link within PFN database that points to the next physical page (if the page is on one of the lists: FREE, MODIFIED, BAD, or ZEROED); this longword also acts as the count of the number of processes that are sharing this global section.
BLINK	Backward link within PFN database (if the page is on one of the lists: FREE, MODIFIED, BAD, or ZEROED); also acts as an index into the working set list.

**Table 4-9 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.
PPGTBL	Page is part of a process page table.
PHD ¹	Page is part of a process PHD.
PPT(Ln) ¹	Page is a process page table page at level n.
SPT(Ln) ¹	Page is a system page table page at level n.
GPGTBL	Page is part of a global page table.
GBLWRT	Page is part of a global, writable section.
SHPT ²	Page is part of a shared page table.
UNKNOWN	Unknown.

¹These page types are variants of the PPGTBL page type.
²The SHPT page type is a variant of the GBLWRT page type.

**Table 4-10 Location of the Page**
Location	Meaning
ACTIVE	Page is in a working set.
MFYLST	Page is in the modified page list.
FRELST	Page is in the free page list.
BADLST	Page is in the bad page list.
RELPND	Release of the page is pending.
RDERR	Page has had an error during an attempted read operation.
PAGOUT	Page is being written into a paging file.
PAGIN	Page is being brought into memory from a paging file.
ZROLST	Page is in the zeroed-page list.
UNKNWN	Location of page is 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

#1

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.

SHOW PARAMETER

Displays the name, location, and value of one or more SYSGEN parameters at the time that the system dump is taken.

Format

SHOW PARAMETER [SYSGEN_parameter]
[/ACP][/ALL][/CLUSTER][/DYNAMIC][/GALAXY]
[/GEN][/JOB][/LGI][/MAJOR][/MULTIPROCESSING]
[/PQL][/RMS][/SCS][/SPECIAL][/SYS][/STARTUP]
[/TTY]

Parameter

SYSGEN_parameter
The name of a parameter to be displayed. The name given may include wildcards. However, a truncated name is not recognized, unlike the equivalent SYSGEN and SYSMAN commands.

Qualifiers

/ACP
Displays all Files-11 ACP parameters.
/ALL
Displays the values of all parameters except the special control parameters.
/CLUSTER
Displays all parameters specific to clusters.
/DYNAMIC
Displays all parameters that can be changed on a running system.
/GALAXY
Displays all parameters specific to Galaxy systems.
/GEN
Displays all general parameters.
/JOB
Displays all Job Controller parameters.
/LGI
Displays all LOGIN security control parameters.
/MAJOR
Displays the most important parameters.
/MULTIPROCESSING
Displays parameters specific to multiprocessing.
/PQL
Displays the parameters for all default and minimum process quotas.
/RMS
Displays all parameters specific to OpenVMS Record Management Services (RMS).
/SCS
Displays all parameters specific to OpenVMS Cluster System Communications Services.
/SPECIAL
Displays all special control parameters.
/STARTUP
Displays the name of the site-independent startup procedure.
/SYS
Displays all active system parameters.
/TTY
Displays all parameters for terminal drivers.

Description

The SHOW PARAMETER command displays the name, location and value of one or more SYSGEN parameters at the time that the system dump is taken. You can specify either a parameter name, or one or more qualifiers, but not both a parameter and qualifiers. If you do not specify a parameter nor qualifiers, then the last parameter displayed is displayed again.
The qualifiers are the equivalent to those available for the SHOW [parameter] command in the SYSGEN utility and the PARAMETERS SHOW command in the SYSMAN utility. See the OpenVMS System Management Utilities Reference Manual: M--Z for more informaton about these two commands. You can combine qualifiers, and all appropriate SYSGEN parameters are displayed.

Note
To see the entire set of parameters, use the SDA command
SHOW PARAMETER /ALL /SPECIAL /STARTUP.

Examples

This example shows all parameters that have the string "SCS" in their name. Note that for parameters defined as a single bit, the name and value of the bit offset within the location used for the parameter are also given.

This example shows all parameters whose names begin with the string "WS". Note that for parameters that have both an external value (pagelets) and an internal value (pages), both are displayed.

This example shows all the parameters specific to multiprocessing, plus the name of the site-independent startup command procedure.

SHOW PFN_DATA

Displays information that is contained in the page lists and PFN database.

Format

SHOW PFN_DATA {[/qualifier]|pfn [{:end-pfn|;length}]}
or
SHOW PFN_DATA/MAP

Parameters

pfn
Specifies the page frame number (PFN) of the physical page for which information is to be displayed.
length
Specifies the length of the PFN list to be displayed. When you specify the length parameter, a range of PFNs is displayed. This range starts at the PFN specified by the pfn parameter and contains the number of entries specified by the length parameter.
end-pfn
Specifies the last PFN to be displayed. When you specify the end-pfn parameter, a range of PFNs is displayed. This range starts at the PFN specified by the pfn parameter and ends with the PFN specified by the end-pfn parameter.

Qualifiers

/ADDRESS=<PFN-entry-address>
Displays the PFN database entry at the address specified. The address specified is rounded to the nearest entry address so if you have an address that points to one of the fields of the entry, the correct database entry will still be found.
/ALL
Displays the following lists:
free page list
zeroed free page list
modified page list
bad page list
untested page list
private page lists, if any
per-color free and zeroed free page lists
entire database in order by page frame number

This is the default behavior of the SHOW PFN_DATA command. SDA precedes each list with a count of the pages it contains and its low and high limits.
/BAD
Displays the bad page list. SDA precedes the list with a count of the pages it contains, its low limit, and its high limit.
/COLOR [={n|ALL}]
Displays data on page coloring. Table 4-11 shows the command options available with this qualifier.

Table 4-11 Command Options with the /COLOR and /RAD Qualifiers
Options Meaning

/COLOR ¹ with no value Displays a summary of the lengths of the color ¹ page lists for both free pages and zeroed pages.

/COLOR= n where n is a color number Displays the data in the PFN lists (for the specified color) for both free and zeroed pages.

/COLOR=ALL Displays the data in the PFN lists (for all colors), for both free and zeroed free pages.

/COLOR= n or /COLOR=ALL with /FREE or /ZERO Displays only the data in the PFN list (for the specified color or all colors), for either free or zeroed free pages as appropriate. The qualifiers /BAD and /MODIFIED are ignored with /COLOR= n and /COLOR=ALL.

/COLOR without an option specified together with one or more of /FREE, /ZERO, /BAD, or /MODIFIED Displays the color summary in addition to the display of the requested list(s).

¹Wherever COLOR is used in this table, RAD is equally applicable, both in the qualifier name and the meaning.

For more information on page coloring, see OpenVMS System Management Utilities Reference Manual: M--Z.

/FREE

Displays the free page list. SDA precedes the list with a count of the pages it contains, its low limit, and its high limit.

/MAP

Displays the contents of the PFN memory map. On platforms that support it, the I/O space map is also displayed. The /MAP qualifier cannot be combined with any parameters or other qualifiers.

/MODIFIED

Displays the modified page list. SDA precedes the list with a count of the pages it contains, its low limit, and its high limit.

/PRIVATE [=address]

Displays private PFN lists. If no address is given, all private PFN lists are displayed; if an address is given, only the PFN list whose head is at the given address is displayed.

/RAD [={n|ALL}]

Displays data on the disposition of pages among the Resource Affinity Domains on applicable systems. See Table 4-11 for the command options available with this qualifier.

/SYSTEM

Displays the entire PFN database in order by page frame number, starting at PFN 0000.

/UNTESTED

Displays the state of the untested PFN list that was set up for deferred memory testing.

/ZERO

Displays the contents of the zeroed free page list.

Description

For each page frame number it displays, the SHOW PFN_DATA command lists information used in translating physical page addresses to virtual page addresses. The display has two lines of information. Table 4-12 shows the first line's fields; Table 4-13 shows the second line's fields.

Table 4-12 Page Frame Number Information---Line One Fields
Item Contents

PFN Page frame number.

DB ADDRESS Address of PFN structure for this page.

PT PFN PFN of the page page table page that maps this page.

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.

FLINK Forward link within PFN database that points to the next physical page (if the page is on one of the lists: FREE, MODIFIED, BAD, or ZEROED); this longword also acts as the count of the number of processes that are sharing this global section.

BLINK Backward link within PFN database (if the page is on one of the lists: FREE, MODIFIED, BAD, or ZEROED); also acts as an index into the working set list.

SWP/BO Either a swap file page number or a buffer object reference count, depending on a flag set in the page state field.

LOC Location of the page within the system. Table 4-10 shows the possible locations with their meaning.

FLAGS The flags in text form that are set in page state. Table 4-14 shows the possible flags and their meaning.
Table 4-13 Page Frame Number Information---Line Two Fields
Item Contents

Blank

PTE ADDRESS Virtual address of the page table entry that describes the virtual page mapped into this physical page. If no virtual page is mapped into this physical page then "<no backpointer>" is displayed.

PTE Type If a virtual page is mapped into this physical page, a description of the type of PTE is provided in the next two or three columns: one of "System-space PTE", "Global PTE", "Process PTE (process index nnnn"). If no virtual page is mapped into this physical page, these columns are left blank.

REFCNT Number of references being made to this page.

PAGETYP Type of physical page. See Table 4-9 for the types of physical pages and their meanings.
FLAGS
If the page is a page table page, then the contents of the PRN$W_PT_VAL_CNT, PFN$W_PT_LCK_CNT, and PFN$W_PT_WIN_CNT fields are displayed. The format is as follows:
VALCNT = nnnn LCKCNT = nnnn WINCNT = nnnn
Table 4-14 Flags Set in Page State
Flag Meaning

BUFOBJ Set if any buffer objects reference this page

COLLISION Indicates an empty collision queue when page read is complete

BADPAG Indicates a bad page

RPTEVT Indicates a report event on I/O completion

DELCON Indicates a delete PFN when REFCNT= 0

MODIFY Indicates a dirty page (modified)

UNAVAILABLE Indicates PFN is unavailable; most likely a console page

Examples

SDA> SHOW PFN_DATA/MAP
System Memory Map
-----------------

Start PFN   PFN count   Flags
---------   ---------   -----
00000000    000000FA    0009  Console Base
000000FA    00003306    000A  OpenVMS Base
00003C00    000003FF    000A  OpenVMS Base
00003FFF    00000001    0009  Console Base
00003400    00000800    0010  Galaxy_Shared

This example shows the output when you invoke the SHOW PFN/MAP command.

This example shows the output from SHOW PFN for a range of pages.

SHOW POOL

Displays the contents of the nonpaged dynamic storage pool, the bus-addressable pool, and the paged dynamic storage pool. You can display part or all of each pool. If you do not specify a range or qualifiers, the default is SHOW POOL/ALL. Optionally, you can display the pool history ring buffer and pool statistics.

Format

SHOW POOL {{range|/ALL (d)|/BAP |/NONPAGED|/PAGED} [/BRIEF|/CHECK|/FREE|/HEADER
|/MAXIMUM_BYTES [=n]|/SUMMARY |/TYPE=packet-type
|/SUBTYPE=packet-type|/UNUSED] |/RING_BUFFER
|/STATISTICS [= ALL] [{/NONPAGED|/BAP|/PAGED}]}

Parameter

range
Range of virtual addresses in pool that SDA is to examine. You can express a range using the following syntax:

m:n Range of virtual addresses in pool from m to n

m;n Range of virtual addresses in pool starting at m and continuing for n bytes

Qualifiers

/ALL
Displays the entire contents of dynamic storage pool, except for those portions that are free (available). This is the default behavior of the SHOW POOL command.
/BAP
Displays the contents of the bus-addressable dynamic storage pool currently in use.
/BRIEF
Displays only general information about dynamic storage pool and its addresses.
/CHECK
Checks all free packets for POOLCHECK-style corruption, in exactly the same way that the system does when generating a POOLCHECK crashdump.
/FREE
Displays the entire contents, both allocated and free, of the specified region or regions of pool. Use the /FREE qualifier with a range to show all of the used and free pool in the given range.
/HEADER
Displays only the first 16 longwords of each data packet found within the specified region or regions of pool.
/MAXIMUM_BYTES [=n]
Displays only the first n bytes of a pool packet; default is 64 bytes.
/NONPAGED
Displays the contents of the nonpaged dynamic storage pool currently in use.
/PAGED
Displays the contents of the paged dynamic storage pool currently in use.
/RING_BUFFER
Displays the contents of the nonpaged pool history ring buffer if pool checking has been enabled. Entries are displayed in reverse chronological order, that is, most to least recent.
/STATISTICS [= ALL]
Displays usage statistics about each lookaside list and the variable free list. For each lookaside list, its queue header address, packet size, the number of packets, attempts, fails, and deallocations are displayed. (If pool checking is disabled, the attempts, fails, and deallocations are not displayed.) For the variable free list, its queue header address, the number of packets and the size of the smallest and largest packets are displayed. /STATISTICS can be further qualified by using either /NONPAGED, /BAP, or /PAGED to display statistics for a specified pool area. (Note that paged pool has no lookaside lists; therefore, only variable free list statistics are displayed.)
If /STATISTICS is specified without the ALL keyword, only active lookaside lists are displayed. Use /STATISTICS = ALL to display all lookaside lists.
/SUBTYPE=packet-type
Displays the packets within the specified region or regions of pool that are of the indicated packet-type. For information on packet-type, see packet-type in the Description section.
/SUMMARY
Displays only an allocation summary for each specified region of pool.
/TYPE=packet-type
Displays the packets within the specified region or regions of pool that are of the indicated packet-type. For information on packet-type, see packet-type in the Description section.
/UNUSED
Displays only variable free packets and lookaside list packets, not used packets.

Description

The SHOW POOL command displays information about the contents of any specified region of dynamic storage pool. There are several distinct display formats, as follows:

Pool layout display. This display includes the addresses of the pool structures and lookaside lists, and the ranges of memory used for pool.
Full pool packet display. This display has a section for each packet, consisting of a summary line (the packet type, its start address and size, and, on systems that have multiple Resource Affinity Domains (RADs), the RAD number), followed by a dump of the contents of the packet in hexadecimal and ASCII.
Header pool packet display. This display has a single line for each packet. This line contains the packet type, its start address and size, and, on systems that have multiple RADs, the RAD number, followed by the first sixteen bytes of the packet, in hexadecimal and ASCII.
Pool summary display. This display consists of a single line for each packet type, and includes the type, the number of occurrences and the total size, and the percentage of used pool consumed by this packet type.
Pool statistics display. This display consists of statistics for variable free pool and for each lookaside list. For variable free pool, it includes the number of packets, the total bytes available, and the sizes of the smallest and largest packets. In addition, if pool checking is enabled, the total bytes allocated from the variable list and the number of times pool has been expanded are also displayed.
For lookaside lists, the display includes the listhead address and size, the number of packets (both the maintained count and the actual count), the operation sequence number for the list, the allocation attempts and failures, and the number of deallocations.
On systems with multiple RADs, statistics for on-RAD deallocations are included in the display for the first RAD.
Ring buffer display. This display is only available when pool checking is enabled. It consists of one line for each packet in the ring buffer and includes the address and size of the pool packet being allocated or deallocated, its type, the PC of the caller and the pool routine called, the CPU and IPL of the call, and the system time.

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OpenVMS Alpha System Analysis Tools Manual

Examples

SHOW PARAMETER

Format

Parameter

SYSGEN_parameter

Qualifiers

/ACP

/ALL

/CLUSTER

/DYNAMIC

/GALAXY

/GEN

/JOB

/LGI

/MAJOR

/MULTIPROCESSING

/PQL

/RMS

/SCS

/SPECIAL

/STARTUP

/SYS

/TTY

Description

SHOW PFN_DATA

Format

Parameters

pfn

length

end-pfn

Qualifiers

/ADDRESS=<PFN-entry-address>

/ALL

/BAD

/COLOR [={n|ALL}]

/FREE

/MAP

/MODIFIED

/PRIVATE [=address]

/RAD [={n|ALL}]

/SYSTEM

/UNTESTED

/ZERO

Description

Examples

SHOW POOL

Format

Parameter

range

Qualifiers

/ALL

/BAP

/BRIEF

/CHECK

/FREE

/HEADER

/MAXIMUM_BYTES [=n]

/NONPAGED

/PAGED

/RING_BUFFER

/STATISTICS [= ALL]

/SUBTYPE=packet-type

/SUMMARY

/TYPE=packet-type

/UNUSED

Description