JP2002244869A - Memory management device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the insufficiency of a main storage for important job groups by determining job groups to perform a page steal on the basis of previously set importance of a job and securing blank pages according to the determination. SOLUTION: This device is formed by a central processing unit 102, a job group determination unit 105 for registering the job in the job group formed by grouping the jobs according to importance, a memory management unit 106 comprising a memory allotting process unit for allotting real pages and a memory feeding process unit 109 for releasing a memory, and a memory monitoring unit 107 for monitoring a using state of the main storage. The memory monitoring unit 107 determines the job groups to perform page steal on the basis of previously set importance of the job and releases the real pages for securing blank pages via the memory feeding process unit 109 on the basis of the determination when blank pages of the memory are insufficient.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory management device, and more particularly to a memory management device capable of determining a job group for performing page stealing based on a preset job importance.

[0002]

2. Description of the Related Art In an operating system using multiple virtual storage, paging occurs because a virtual storage having a larger capacity than that of a mounted main storage is developed.
Since the occurrence of paging affects the performance of the entire computer system, pages to be paged out are selected while suppressing the frequency of paging processing. The working set method is known as the method (November 1976
25th, “Operating System”, pages 171 to 189, “3.6.
From “2.3 Page Replacement Algorithm” to “3.
Up to 6.3.3 Working Set Theory). According to this method, a reference bit provided in a page unit of a main storage device is checked at predetermined time intervals, a page which is recently referred to is left, and other pages are paged out to create a free page.

As a method for guaranteeing the assignment of real pages to a group of jobs of high importance, jobs are grouped, and the upper and lower limits of the actual pages to be assigned to each group are set (literature name: Technical No.
te, URL: http: // www. im. co.
jp / techni21. http and http: // www
w. im. co. jp / techni22. htm), and tuning is performed by guaranteeing the assignment of real pages to be assigned to each group.

[0004]

In the computer system, the method for guaranteeing the allocation of the real page includes:
By performing page stealing from a page having a low reference frequency, it is possible to suppress the frequency of occurrence of paging and to guarantee the allocation of real pages to important job groups. As a result, a response can be guaranteed, but only two types of weighting, ie, important and insignificant, are considered for the job. For this reason, when the number of actual pages becomes short, the range of the page stealing target job becomes too large, and a response may not be guaranteed. Also, the guaranteed value of the real page set in the job group is such that even if there is enough real page space, a page-out occurs to guarantee the upper limit, and the
Load O.

The present invention has been made in view of the above problems, and determines a job group for performing page stealing based on the importance of a job set in advance and secures an empty page based on the determination. In addition, it is possible to avoid a shortage of main storage for a group of jobs having high importance.

[0006]

The present invention employs the following means in order to solve the above-mentioned problems.

A central processing unit, a job group determining unit for registering a job in a job group formed by grouping jobs according to importance, a memory allocation processing unit for allocating real pages, and a memory supply for releasing memory A memory management unit including a processing unit; and a main storage device including a memory monitoring unit that monitors the usage status of the main memory. The memory monitoring unit performs page stealing when the number of free pages in the memory is insufficient. The job group is determined based on the job importance set in advance, and based on the determination, real pages are released through the memory replenishment unit to secure empty pages.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a diagram showing a memory management device according to an embodiment of the present invention. In the figure,
The computer 101 includes a central processing unit 102 and a main storage device 103. The main storage device 103 is managed in a unit called a page, and can be put into a use state or a free state in a page unit according to a request.

The OS 104 is a multiple virtual storage operating system executed by the central processing unit 102 in the computer 101. The OS 104 writes information that cannot be arranged in the main storage device 103 mounted on the computer 101 to the auxiliary storage device 115, and reads the information as needed. The storage is expanded on the computer 101.

The OS 104 has a job group determining unit 105 for controlling job execution, a memory managing unit 106 for allocating and releasing real pages, and a memory monitoring unit 107 for monitoring the use status of the main storage device 103. Then, the group of business A jobs 118, the group of business B jobs 119, and the group of development jobs 120 are started to manage the main storage device resources.

Parameter setting unit 1 in memory monitoring unit 107
10 reads the definition information of the job group from the parameter file 117 and creates a management table. In the parameter file 117, job group information of a group of business A jobs 118, a group of business B jobs 119, and a group of development jobs 120 is defined.

The job group determining unit 105 sorts each job into a group to which the job belongs. When a request to use a real page is issued from each job, the memory management unit 106
The memory allocation processing unit 108 in the inside allocates real pages. When the use request of the real page exceeds the threshold value for the mounted capacity of the main storage device 103 and the available real page becomes insufficient, the memory replenishment schedule unit 112 in the memory monitoring unit 107 is activated. Memory replenishment schedule 112
The unit determines a job group to perform page stealing according to the setting of the parameter file 117, and calls the memory supply instruction unit 113. The memory replenishment instruction unit 113 determines a job to perform page stealing, calls the memory replenishment processing unit 109 in the memory management unit 106 that actually performs the actual page replenishment process, and secures a free real page. In order to prevent the job group from securing real pages exceeding the real page usage defined for each job group, the memory usage monitoring unit 111 periodically monitors the real page usage of the job group. Call the memory replenishment instruction unit 113,
By performing page stealing, the usage of real pages is suppressed. The statistics unit 114 includes a memory usage monitoring unit 111
, And records the frequency of page stealing and the status of use of the main storage device in the statistical information file 116. 121
Reference numeral denotes a memory management table including a job group management table, a job management table, and a memory management table, as will be described later. Reference numeral 122 denotes a state holding table that holds the state of the memory.

FIG. 2 is a diagram showing memory allocation when there is a shortage of free real pages, and FIG. 2A is a diagram showing real page allocation when a real page is short when the present invention is not applied. As shown in the figure, when the actual page usage of the job of the business B system increases and the free actual page shortage state occurs,
Since page stealing is performed from a job of the business A system having a high degree of importance and a real page is assigned to a job of the business B system, a response of the business A system job may be adversely affected.

FIG. 2B is a diagram showing real page allocation when a real page shortage occurs when the present invention is applied. As shown in the upper part of the figure, when the real page usage of the job of the business B system increases and the real page shortage occurs, as shown in the middle part of FIG. Instead, page stealing is performed from a development job having a low importance, and a real page is assigned to a job of the business B. Therefore, the response of the job of the business A having a high importance is not adversely affected. Further, by setting the upper limit and the lower limit of the actual page usage amount for each job group as shown in the lower part of the figure, it is possible to prevent the actual page amount used by the specific job group from continuing to increase.

FIG. 3 shows a job group management table 30.
1 is a diagram showing the configuration of a job management table 320 and a memory management table 330. As shown, the job group management table 301, the job management table 3
20 and the memory management table 330 are created for each job group.

The job group management table 301 is a management table for storing information related to a job group. The job group management table 301 includes a NEXT pointer a 302 for queuing the job group management table 301, a job group number 303 defining the number of the job group, a priority order 304 indicating the importance of the job group, and a job group. Memory frame maximum value 30 that defines the maximum capacity of real pages to be used
5. Memory frame minimum value 306 defining the minimum guaranteed capacity of real pages used by the job group, and retained memory size a30 indicating the amount of real pages retained by the job group
7. A page steal count 308 indicating the actual number of pages that have been page stealed from the job group, a steal pointer 309 pointing to the job management table 320 for page stealing, and a job pointing to the job management table 320 managing the job group belonging to the job group A management table queue pointer 310 is provided.

The job management table 320 is a table for managing job information, and is queued at a job management table pointer 310 in the job group management table 301 of the job group to which the job belongs. The job management table 320 includes another job management table 3
NEXT pointer b32 for queuing 20
1, a memory size b 322 indicating the number of real pages held by the job, and a memory management table queue pointer 323 pointing to the memory management table 330 for managing the real pages held.

The memory management table 330 includes a NEXT pointer c331 for queuing another memory management table, and a status bit 332 indicating whether or not a page can be stealed. FIG. 13 is a diagram illustrating queuing in a management table having a plurality of job group management tables, a plurality of job management tables, and a plurality of memory management tables. As shown, the NEXT pointer a 302 and the job management table pointer 310 of the job group management table can queue other job group management tables and job management tables, respectively. The NEXT pointer b 321 and the memory management table queue pointer 323 of the job management table can queue other job management tables and memory management tables, respectively. The NEXT pointer c331 of the memory management table can queue another memory management table.

FIG. 4 is a diagram showing the configuration of the state holding table 401. The state holding table 401 stores constants defined by the system and data transferred between the processing units.

The free main storage page counter 402 stores the number of free real pages in the system. Main memory shortage threshold a40
3 stores a threshold value for identifying a severe empty real page shortage state, and a main storage insufficient threshold value b404 stores a threshold value for identifying a mild empty real page shortage state. The free main storage page target value 405 stores a threshold value for resolving a free real page shortage state. Steel indicated value 4
Reference numeral 06 stores the number of steal request pages of real pages to the memory supply instruction unit 113. Steel achievement counter 4
07 stores the number of pages for which the memory replenishment processing unit 109 has performed page stealing. Steel remaining page counter 40
Reference numeral 8 indicates a deficiency of the actual value of the page steal with respect to the indicated steal value.

FIG. 5 is a diagram showing the processing of the parameter setting unit 110. In step 501, the parameter setting unit 110 reads parameters from the parameter file 117 when the OS 104 is started and when parameters are changed, and analyzes the read parameters. In step 501, FIG.
NEXT in the job group management table 301 indicated by
Pointer a 302, job group number 303, priority 304, memory frame maximum value 305, memory frame minimum value 30
6 is created, and the job group management table 301 is queued in ascending order of priority.

FIG. 6 is a diagram showing the processing of the job group judgment unit 105. In step 601, when a job is started, the job group determination unit determines the job group management table 30 based on the information defined for the job.
Search for 1. Applicable job group management table 3
If 01 exists, the process proceeds to step 602; otherwise, the process proceeds to step 603. In step 602, the job management table 320 of the job is queued in the job management table queue pointer 310 or the NEXT pointer b321. In step 603, the job is set as the job group having the lowest importance, and the job management table 320 of the job is queued in the job management table queue pointer 310 or the NEXT pointer b321.

FIG. 7 is a diagram showing the processing of the memory allocation processing unit 108. In step 701, when a real page allocation request occurs, the memory allocation processing unit 1
08 is started. The memory allocation processing unit 108 executes the job management table 320 according to the real page use request.
In the memory management table queue pointer 323 or the NEXT pointer c331 in the memory management table 33
Queue 0 and allocate free pages. In addition,
Real pages are allocated in units of one page. Step 7
In step 02, the retained memory size b322 in the job management table 320 is incremented by one, and in step 703, the free main storage page counter 402 is decremented by one. In step 704, the free main storage page counter 40
It is determined whether the value of 2 is equal to or less than the free main memory shortage threshold value a403 (free real page shortage). If the value is equal to or smaller than the threshold value, the process proceeds to step 705. If not, the process ends. In step 705, the memory replenishment schedule unit 112 is started.

FIG. 8 shows a memory replenishment schedule section 112.
It is a figure which shows the process of. In step 801, the memory replenishment schedule unit 112 sets the free main storage target value 40
The value of the free main storage page counter 402 is subtracted from 5 to calculate a target value of the number of real pages to be stolen to secure a free real page (step 801). Step 80
In 2, the job group with the lowest importance is selected, and it is determined whether or not the free main memory target value is achieved by selecting the job group. If so, the process ends; otherwise, the process proceeds to step 803. In step 803, the value obtained by subtracting the memory frame minimum value 306 from the retained memory size a307, which is the number of actual pages currently retained by the job group, is compared with the value set in step 801. In step 804, the smaller value is set. Is selected as the target of the number of actual pages to be stolen from the job group, and set as the steal indication value 406. In step 805, the memory replenishment instruction unit 113 performs page stealing of the number of pages indicated by the steal instruction value 406 from the job group obtained in step 802.
And the process returns to step 801.

Thereafter, in step 802, the free main storage page counter 402 sets the free main storage page target value 4
The processing of steps 801 to 805 is repeated while increasing the importance and selecting a job group until it becomes 05 or more. Also, when the processing of steps 801 to 805 has been performed for all the job groups, the processing is terminated.

FIG. 9 is a diagram showing the processing of the memory supply instruction unit 113. In step 901, the memory replenishment schedule unit 112 or the memory usage monitoring unit 11
The stealing instruction value 406 designated from 1 is set in the still remaining page counter 408. In step 902, a job to perform page steal is selected from the steal pointer 309 in the job group management table 301 of the steal target job group. In this step, whether the still page counter is 0 or not
Alternatively, when there is no steal target job, the process ends. In step 903, the memory replenishment processing unit 109 is called to steal the page of the still page counter 408 from the job selected in step 902. In step 904, the memory supply processing unit 109
When the number of page steals processed from the job space is returned to the steal record counter 407, the steal remaining page counter 408 outputs the steal record counter 40
7 is subtracted, and the steal remaining page counter is re-set.
In step 905, the next job management table is pointed to the still pointer 309, and the process returns to step 902.

FIG. 10 is a diagram showing the processing of the memory replenishment processing unit 109. The memory replenishment processing unit 109, according to the instruction of the memory replenishment instruction unit 113,
Perform page stealing for the number of pages specified in 8. First, in step 1001, the steel achievement counter 407 is cleared to zero. In step 1002, the memory management table 3 queued from the memory table queue pointer 323 of the job management table 320
Select 30. In step 1003, it is determined whether or not the page is stealable. If stealable, the process proceeds to step 1004; otherwise, the process returns to step 1002. In step 1004, page stealing is performed, and the memory management table 330 is deleted from the queue. In step 1005, the retained memory size 322b in the job management table 320 of the job is decremented by one, and the retained memory size a307 in the job group management table 301 of the job group to which the job belongs is decremented by one. In step 1006, the steal record value counter 407 and the page steal count 308 are incremented by one. In step 1007, the steel actual counter 407 indicates the steel indicated value 40.
5 or the actual number of pages of the job group is equal to or less than the memory frame minimum value 306 defined for the job group. It is determined whether or not the processing in step 1006 has been performed. If any of them is true, the processing ends; otherwise, the flow returns to step 1002.

FIG. 11 is a diagram showing the processing of the memory usage monitoring unit 111. The memory usage monitoring unit 111 is started periodically and monitors the usage status of the actual pages of the job group. In step 1101, job groups to be monitored are sequentially selected from the top of the job group management table 301. When all the job groups have been selected, the process ends. In step 1102,
The actual pages held by the job group are recalculated, and the held memory size a3 in the job group management table 301 is calculated.
07. In step 1103, the value of the free main storage page counter 402 is changed to the main storage shortage threshold b40.
If the value is larger than the value of 4, it is determined that there are sufficient free real pages (step 1103, YES), and the process returns to step 1101 to select the next job group. If the value of the free main storage page counter 402 is equal to or less than the value of the main storage shortage threshold b404, it is determined that there is a free real page shortage (step 11).
03NO) Proceed to step 1104. Step 1104
, It is determined whether or not the retained memory size a307 of the job group exceeds the maximum memory frame value 305 in order to secure free real pages. Owned memory size a30
If 7 does not exceed the memory frame maximum value 305 (NO in step 1104), the process returns to step 1101. If the possessed memory size a 307 exceeds the memory frame maximum value 305 (step 1104: YES), the process proceeds to step 1105. In step 1105, the stored memory size a3
A value obtained by subtracting the memory frame maximum value 305 from 07 is set as the stealing instruction value 406. In step 1106, the memory replenishment instruction unit 113 is called, and page steal of the number of pages indicated by the steal instruction value 406 is instructed from the job group. In step 1107, the statistical unit 114 is called, and the monitoring result is recorded. Thereafter, steps 1101 to 1106 are repeated for all job groups.

FIG. 12 is a diagram showing the processing of the statistics section. In step 1201, job groups are selected in order from the top of the job group management table 301. When the selection for all the job groups is completed, the process ends. In step 1201, differences are calculated for the page steal counter 308 and its operation time and the current page steal counter 308 and its time for each job group recorded when the statistics unit was last operated. In step 1203, it is determined whether or not the retained memory size a307 of the job group exceeds the memory frame maximum value 305. Retained memory resize a30
If 7 does not exceed the memory frame maximum value 305 (NO in step 1203), the flow returns to step 1201. If the possessed memory size a 307 exceeds the memory frame maximum value 305 (YES in step 1203), the process proceeds to step 1204. In step 1204, the difference of the page steal counter 308 calculated in step 1202 is divided by the time difference. If this value exceeds the value defined in the system (YES in step 1204), step 120
Go to step 5, otherwise return to step 1201.
In step 1205, the system determines that the setting of the memory frame maximum value 305 is invalid, and
In accordance with the designation of 7, the memory frame maximum value 305 of the job group is increased. In step 1206, the fact that the memory frame maximum value 305 has been updated is notified to the statistical information file 1
Record at 16. From Step 1201 to Step 1
Step 206 is repeated for all job groups.

As described above, in the case where a group of important jobs, for example, a production job having a high importance and a group of a development job having a low importance are operated simultaneously in one computer system, for example, the If a low-priority job becomes inadequate in the main storage device by using the main storage device more than expected due to a defect or a setting error, paging is performed stepwise from the job group in the development job group and the memory is used. Since the replenishment is performed, it is possible to prevent the production-related important job group and the development-related job group having high importance from being affected by the shortage of the main storage device.
For this reason, it is possible to avoid an adverse effect due to a shortage of the main memory on the important work, without executing the production-related important work and the development-related work on different OSs.

[0031]

As described above, according to the present invention, a job group for performing page stealing is determined based on the importance of a preset job and the like, and an empty page is secured based on the determination. It is possible to avoid a shortage of main storage for a job group with high degree.

[Brief description of the drawings]

FIG. 1 is a diagram showing a memory management device according to an embodiment of the present invention.

FIG. 2 is a diagram showing memory allocation when a free page is insufficient.

FIG. 3 is a diagram illustrating configurations of a job group management table, a job management table, and a memory management table.

FIG. 4 is a diagram showing a configuration of a state holding table.

FIG. 5 is a diagram illustrating processing of a parameter setting unit.

FIG. 6 is a diagram illustrating a process of a job group determination unit.

FIG. 7 is a diagram showing processing of a memory allocation unit.

FIG. 8 is a diagram illustrating processing of a memory replenishment schedule unit.

FIG. 9 is a diagram showing processing of a memory replenishment instruction unit.

FIG. 10 is a diagram illustrating processing of a memory replenishment processing unit.

FIG. 11 is a diagram showing processing of a memory usage monitoring unit.

FIG. 12 is a diagram illustrating processing of a statistics unit.

FIG. 13 is a diagram illustrating queuing in a management table.

[Explanation of symbols]

 Reference Signs List 101 computer 102 central processing unit 103 main storage device 104 OS 105 job group determination unit 106 memory management unit 107 memory monitoring unit 108 memory allocation processing unit 109 memory replenishment processing unit 110 parameter setting unit 111 memory usage monitoring unit 112 memory replenishment schedule unit 113 Memory replenishment instructing unit 114 Statistical unit 115 Auxiliary storage device 116 Statistical information file 117 Parameter file 118 Business A system job 119 Business B system job 120 Development system job 121 Management table 122 State holding table

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Fukunaga 5030 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Software Division of Hitachi, Ltd. (72) Kazuhide Hasegawa 5030 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa F-term in the Software Division of Hitachi, Ltd. (Reference) 5B005 JJ11 KK12 MM31 QQ04 VV02 5B060 AA09 AA12 AA19 AC06 5B098 GA02 GA03 GB05 GB10 GC03 GD03 GD12 GD17 GD22

Claims (5)

[Claims] 1. A central processing unit, a job group determination unit that registers a job in a job group formed by grouping jobs according to importance, a memory allocation processing unit that allocates real pages, and releases memory. A memory management unit having a memory replenishment processing unit, and a main storage device having a memory monitoring unit for monitoring the use status of the main memory, wherein the memory monitoring unit performs page stealing when the number of free pages in the memory is insufficient. A memory management device that determines a job group to perform the job based on the job importance set in advance, and releases a real page via the memory replenishing unit to secure a free page based on the determination. 2. A central processing unit, a job group determining unit that registers a job in a job group formed by grouping jobs according to importance, a memory allocation processing unit that allocates real pages, and releases memory. A memory management unit having a memory replenishment processing unit, and a main storage device having a memory monitoring unit for monitoring the use status of the main memory, wherein the memory monitoring unit performs page stealing when the number of free pages in the memory is insufficient. Is determined based on the job importance set in advance, and real pages are gradually released from the jobs belonging to the low importance group based on the determination through the memory supply unit. A memory management device for securing empty pages. 3. The memory monitoring unit according to claim 1, wherein the memory monitoring unit executes page stealing from a group exceeding the upper limit of the actual page usage via the memory replenishing unit. Memory management device. 4. The memory monitoring unit according to claim 1, wherein the memory monitoring unit includes a memory monitoring unit that monitors upper and lower limits of a memory usage for each job group. A memory management device for allocating and releasing memory based on the memory. 5. The memory monitoring unit according to claim 1, wherein the memory monitoring unit includes a statistic unit that stores a frequency of page stealing and a memory use state in a statistic information file. Memory management device.