The CU (Core Usage) command displays information about the memory usage either of a particular task or of the entire system.
Only the CU and CU AVAIL forms of the command can be used in conjunction with the ADM command.
Memory disk, if used, is not included in the display; to display memory disk information, use the MM (Memory Module) command.
For detailed information about the buffer statistics refer to the SF (Set Factor) command and the File Attributes Programming Reference Manual. For detailed information about the overlay mechanism, refer to the Managing Memory section of the System Operations Guide.
Syntax
Explanation
<mix number list> CU
Displays memory usage statistics for the tasks in the specified mix number list. These statistics include total and save sizes of both the stack and the code. If the system schedules the specified task, the display shows the number of words required for the task.
CU
Displays information about memory usage, ASD usage, and logical I/O buffer usage for the entire system. The memory information includes the number of available words, the number of in-use words (both save and nonsave), and the number of words overlaid to the DL OVERLAY family (or families). The ASD information includes the percentage of in-use ASDs. The logical I/O buffer information is broken down by the source of the buffersize (buffergoal, buffersize, or blocksize).
Displays the Memory Summary section similar to the normal CU command, a modified ASD Information section, and replaces the Buffer Statistics section with the Avail Mem Totals section.
The Avail Mem Totals section provides a list of the number of words in nonsave available lists, save available lists, and not linked available areas. The number of words from the nonsave and save counts are not mutually exclusive because the same area of available words can be in both the lists, depending on their address and the relationship of the address to the amount of in-use nonsave and save memory. This means that the total of nonsave available, save available, and not linked available words might be greater than the available words listed in the memory summary.
The Available Areas value represents the number of linked areas in save and nonsave lists. This value represents the number of available areas that constitute the Save and Non Save Avail Mem Totals and provides an idea of the amount of checkerboarding present in memory. The higher the value, the greater the number of available areas interspersed among in-use areas.
The Not Linked Areas value represents the number of areas that are not linked in save or nonsave lists and corresponds to the word value of Not Linked Avail Mem Totals. These areas are too small to hold in-use memory due to link requirements and are reclaimed only when an adjacent in-use area is deallocated or moved.
Displays statistics about the four largest available lists of save available memory and the four largest available lists of overlayable available memory. Specifically, each set of lists is detailed with the maximum size area in the list, the minimum size area in the list, the total number of areas in the list, and the total number of words in the list. Note that an available memory area might appear in both a save and an overlayable available memory list. Overlayable memory is non save memory.
This statistical data is provided to indicate whether or not the initiation of applications such as a database transaction environment could possibly lead to excessive demand overlay because of the lack of sufficiently large available save memory areas for the application or database buffers. The administrator might choose to increase the system factors or delay the initiation of the application in order to avoid or minimize the possibility of high OTHERPBIT and false idle utilization times that could result from excessive demand overlay.
CU AVAIL OLAYLISTS
Displays memory usage data similar to the CU AVAIL LISTS command, but only includes detailed statistics about the largest available lists of available overlayable memory. This command shows the eight largest lists rather than the four shown by CU AVAIL LISTS.
CU AVAIL SAVELISTS
Displays memory usage data similar to the CU AVAIL LISTS command, but only includes detailed statistics about the largest available lists of available save memory. This command shows the eight largest lists rather than the four shown by CU AVAIL LISTS.
CU POOLS
Displays the statistics of the memory pool mechanism implemented to improve management of small memory size segments. There are no tuning mechanisms available to modify the general implementation. However, an increase in the value of the AVAILMIN (SF 2) system factor causes memory management to bias allocation of small objects away from memory pools for overlayable segments when available memory falls below this value. An increase in OVERLAYABLEMIN (SF 4) causes memory management to bias these allocations for save segments when available memory falls below the overlay memory minimum.
Memory pool areas contain individual ASD segments referred to as pool objects. Each pool area is divided into a number of fixed size areas that allow allocation of a range of values. Pool areas are further subdivided into Save and Non Save Pool areas. The CU POOLS command displays the CU output followed by the memory statistics for all allocated memory pool areas under the heading Memory Pools Summary. Memory Pools Summary is further divided into the following headings:
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Memory Summary
The Memory Summary area of the display shows total values of the Available and In Use areas. The In Use values are further divided into Non Save and Save values as well as pool object Fragments and pool area Not Linked. Fragments represent the portion of the pool object that exceeds the segment requirement of the object. For example, if the pool area contains all objects from 8 to 15 words, and the actual segment requirement is 10 words, the fragment is incremented by five words. The Not Linked value represents the total overhead of pool area management regions.
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Non Save and Save Pools
The remainder of the display splits the memory statistics into Non Save and Save pool area summaries. The left column in the first three rows of the Non Save and Save pool area summaries shows the number of objects Available, Inuse, and the Total. The right column in the three rows shows the core value in words represented by the object counts and the corresponding total. For the Fragments row, the left column in the Non Save and Save pool area summaries shows the percentage of in-use pool object memory. The right column shows the value in words of pool object fragments. The Not Linked row shows the percentage value of pool area memory and the corresponding number of words in pool area not linked memory. The Areas row displays the number of Non Save and Save pool areas and their corresponding word requirements.
CU AVAIL POOLS
Displays the Memory Pools Summary as described for CU POOLS. The output is displayed below the CU AVAIL output instead of the CU display.
Examples
Example 1
The following example of a CU display shows all memory used by the process and main memory usage:
CU -------------------------SYSTEM MEMORY USAGE----------------------------- -- Memory Summary -- ---ASD Information---- ----Buffer Statistics--- Available 5,309,139 Total ASDs 41,942 Size source Number Memory Non save 2,090,869 In use 25% Buffergoal 0 0 Save 988,600 Maximum in use 26% Buffersize 0 0 Total 8,388,608 Factor 50 Words/ASD Blocksize 5 2,420 Overlaid 158,712
Example 2
The following shows a <mix number> CU command and the resulting display:
9508 CU
9508 Memory: Total Save Stack 8,592 4,782 Code 23,075 2,949 Total 31,667 7,731
Example 3
The following shows a CU AVAIL command and the resulting display that shows individual available memory totals:
CU AVAIL --------------------------SYSTEM MEMORY USAGE--------------------------- --- Memory Summary --- --- ASD Information --- -- Avail Mem Totals --- Available 372,682,673 Available 2,337,304 Non Save 156,754,772 Non save 121,433,589 In use 425,693 Save 166,913,864 Save 55,337,562 Maximum 440,990 Not Linked 278,845 Total 549,453,824 Total 2,762,997 Available Areas 4,227 Overlaid 0 In use 15% : Max 16% Not Linked Areas 99,587
Example 4
The following shows a CU AVAIL LISTS command and the resulting display that shows individual available memory totals as well as the statistics for the four largest sets of save and non save available memory lists.
-------------------------- SYSTEM MEMORY USAGE -------------------------
--- Memory Summary --- --- ASD Information --- --- Avail Mem Totals ---
Available 323,947,481 Available 2,337,304 Non Save 156,754,772
Non save 162,473,238 In use 425,693 Save 166,913,864
Save 63,033,105 Maximum 440,990 Not Linked 278,845
Total 549,453,824 Total 2,762,997 Available Areas 4,227
Overlaid 0 In use 15% : Max 16% Not Linked Areas 99,587
-------------- Largest Available Save Lists Statistics --------------
-- Maximum Size -- - Minimum Size - - Total Areas - - Total Words -
155,576,136 4,273,905 2 159,850,041
330,936 280,123 2 611,059
258,625 156,367 4 756,817
83,260 65,580 2 148,840
-------------- Largest Available Non Save Lists Statistics --------------
- Maximum Size - -- Minimum Size -- - Total Areas - -- Total Words --
139,460,604 574,691 15 153,335,648
8,198 8,195 370 3,033,060
8,182 7,973 7 56,927
6,994 6,994 1 6,994
Example 5
The following shows a CU AVAIL OLAYLISTS command and the resulting display that shows individual available memory totals as well as the statistics for the largest eight sets of avail overlayable memory; that is, the statistics for the largest non save available memory areas and their associated lists.
-------------------------- SYSTEM MEMORY USAGE ---------------------------
----- Memory Summary ---- -- ASD Information -- --- Avail Mem Totals ---
Available 329,040,480 Available 2,337,304 Non Save 156,754,772
Non save 157,801,347 In use 425,693 Save 166,913,864
Save 62,611,997 Maximum 440,990 Not Linked 278,845
Total 549,453,824 Total 2,762,997 Available Areas 4,227
Overlaid 0 In use 15% : Max 16% Not Linked Areas 99,587
------------- Largest Available Non Save Lists Statistics -------------
- Maximum Size - - Minimum Size - - Total Areas - -- Total Words --
139,460,604 574,691 15 153,471,384
403,252 312,397 2 715,649
253,144 131,157 8 1,502,222
124,157 66,088 12 1,143,896
64,672 32,791 21 942,207
32,741 25,025 5 139,251
19,489 16,394 4 69,797
14,357 14,357 1 14,357
Example 6
The following shows a CU AVAIL SAVELISTS command and the resulting display that shows individual available memory totals as well as the statistics for the largest eight sets of avail overlayable memory; that is, the statistics for the largest non save available memory s and their associated lists.
-------------------------- SYSTEM MEMORY USAGE ----------------------------
----- Memory Summary ---- --- ASD Information -- --- Avail Mem Totals ---
Available 329,171,666 Available 2,337,304 Non Save 156,754,772
Non save 157,594,776 In use 425,693 Save 166,913,864
Save 62,687,382 Maximum 440,990 Not Linked 278,845
Total 549,453,824 Total 2,762,997 Available Areas 4,227
Overlaid 0 In use 15% : Max 16% Not Linked Areas 99,587
---------------- Largest Available Save Lists Statistics ----------------
-- Maximum Size -- -- Minimum Size -- - Total Areas - - Total Words -
155,576,136 4,273,905 2 159,850,041
280,123 280,123 1 280,123
228,028 131,088 4 698,960
127,530 65,580 5 465,459
63,567 32,835 15 675,041
32,249 24,591 16 432,859
24,255 16,389 15 301,373
15,128 15,128 1 15,128
Example 7
The following shows a CU AVAIL POOLS command and the resulting display.
-------------------------- SYSTEM MEMORY USAGE -------------------------
--- Memory Summary --- --- ASD Information --- --- Avail Mem Totals ---
Available 440,930,713 Available 2,343,478 Non Save 421,388,917
Non save 47,204,160 In use 398,548 Save 317,350,749
Save 57,124,647 Maximum 408,283 Not Linked 23,847
Total 545,259,520 Total 2,742,026 Available Areas 8,479
Overlaid 0 In use 15% : Max 15% Not Linked Areas 9,414
------------------------ Memory Pools Summary ------------------------
-- Memory Summary -- ------- Non Save Pools ------ --- Save Pools ---
Available 520,720 Avail 1,270 211,632 3,507 309,088
Non save 18,970,444 In use 224,594 18,970,444 65,290 4,565,468
Save 4,565,468 Total 225,864 19,182,076 68,797 4,874,556
Fragments 931,608 Fragments 3.25% 637,828 6.05% 293,780
Notlinked 451,560 Notlinked 1.86% 376,516 1.43% 75,044
Total 25,439,800 Areas 2,469 20,196,420 641 5,462,116
