JPS6344258A - Managing method for auxiliary memory space in virtual memory control - Google Patents

Abstract

PURPOSE:To increase processing speed in a computer of virtual memory control system, by using an auxiliary memory space copy managing table provided corresponding to an auxiliary memory space map. CONSTITUTION:The auxiliary memory space copy managing table E corresponds to all of the pages of the auxiliary memory space map C, and the page having the content of zero in the table E shows the nounse of the page of a corresponding auxiliary memory space. The page having the number of the content other than zero shows that the table of respective corresponding auxiliary memory space is referred at present by the program of the number. The content of each page of the auxiliary memory space copy managing table E is set at 1 when the page of corresponding auxiliary memory space can be obtained, and one is added at every copying of the page, and one is subtracted at every page-in, or every deletion of the page, and when a result shows 0, the page of the auxiliary memory space is designated as a vacant page.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for managing auxiliary storage space in an operating system capable of controlling virtual memory of a computer.

[Conventional technology]

In the conventional auxiliary storage space management method as described above, a user program running under virtual memory control copies its own operating state and environment exactly;
After that, the copy source (parent) program also becomes the copy destination (child).
The program also runs independently (
(commonly called a fork) works.

When using such a fork function, it is natural to copy the environment that has been paged in to the main memory space, but it is also necessary to copy the environment that has been paged out to the auxiliary memory space, which reduces the time required to perform the function. This method has disadvantages in that it is greatly affected by the input/output time between auxiliary storage devices, and information of the same environment must be allocated and stored multiple times in the auxiliary storage space. In particular, there is a problem in that the higher the percentage of parent programs that are paged out, the longer the time required to perform the JR functions, and the greater the effect on the processing speed of the program.

For example, in a page management system using a virtual memory system as shown in Figure 3, a program [(parent)
After a program (program) copies itself, when a request is issued for a function (hereinafter referred to as a fork system call) that allows both the parent and copy program (child program) to run independently, it copies its own page management table. By referring to it, it acquires free pages in the main memory space (Map■) and auxiliary memory space (Matsup◎) for each page being paged in and paged out. Create a page management table ■. Thereafter, regarding the information in the main memory space, for example, two pages of information indicated by M+ and Mz are copied to pages 7 and 9, respectively, which were acquired for the program (2).

On the other hand, the information paged out in the auxiliary storage space (Map ◎) is also copied to the acquired page in the same way as the main memory space (Map ■), but at this time, for example,
Since the information indicated by (2) must be first input into the main memory and then output to the intended auxiliary memory, the required time becomes significantly longer.

In addition, the code IN in the figure indicates the page-in state, the number after it indicates the absolute page number allocated to the main memory space, and the code OUT indicates the page-out state, and the number after it indicates the page number allocated to the auxiliary storage space. indicates the absolute page number assigned.

In this way, the conventional page management system for virtual memory control allocates main memory space for pages that are being paged in for each user program that is running, and uses auxiliary information for pages that are being paged out. Storage space allocation consists of information as well as page unused information in the main memory and auxiliary memory space, and from the management program's perspective, it is only possible to determine whether or not it is being used, and as a result, the same There was a problem that environment information had to be copied.

[Means for solving problems]

The present invention, which was made to solve the above problems, is characterized in that, in a method for managing auxiliary storage space in virtual memory control, an auxiliary storage space copy management table provided corresponding to an auxiliary storage space map is used. do.

[Effect]

In the table management system for virtual memory control H in FIG. 3, V1 to V of the auxiliary storage space (map ◎),
This is because the information indicated by is paged in and used only when the program ■ or program ■ continues to run and is needed in the main memory (when a page hold phenomenon occurs in the virtual memory system). , and will not be changed during that time, so there is no need to take the trouble of having multiple copies.

The method of managing auxiliary storage space in virtual memory control of this invention is based on the above idea, and its principle is explained with reference to FIG. 1. The auxiliary storage space copy management table All pages (0~m
), and the pages whose contents are O in this table (■) indicate that the pages in the corresponding auxiliary storage space are unused.

A number of pages with content other than 0 indicates that the corresponding auxiliary storage space table is currently referenced by that number of programs. Therefore, the contents of each page of this auxiliary storage space management table are Set to 1 when a page in the auxiliary storage space to be used is acquired; ■ Add 1 each time a page in the corresponding auxiliary storage space is copied; ■ Each time the page is paged in, or when the program ends, the page is set to 1. Each time you delete , 1 is subtracted, resulting in 0
By making the page in the auxiliary storage space a free page when the page becomes empty, you can eliminate wasted input/output time and suppress the increase in page usage rate. Can be done.

〔Example〕

An embodiment of the auxiliary storage space management method in virtual memory control of the present invention will be described below with reference to FIG.

In the illustrated embodiment, as is clear from the page management table ■ of the program ■, there is a program ■ consisting of five pages, and two pages ll&lL2 and magnetic 5 are currently paged in, magnetic 2, 龙3 and ! l! l16 no 3
The page is paged out.

Now, if program I issues a fork system call and copies itself, it will create a page management table ■ for program ■, that is, a child program. Acquires the main memory space, sets the page number in the page management table of the program
And information about the parent program (program ■) that exists in 5! M, and M! are copied to pages 7 and 9 obtained as above, respectively. This operation is performed only on the main memory space and is much faster than copying the auxiliary memory space in conventional systems, so there is no need to take this into account.

Next, for the page in the page-out state indicated by OUT, set the page number of the auxiliary storage space (patient 2, floor 3, (6) as is) from the parent program's page management table ■ to the child program's page management table ◎. With,
1 is added to the page contents of the auxiliary storage space copy management table 0 corresponding to each of these pages.

The above operations complete the fork system call copy processing. As mentioned above, compared to conventional systems, this page management system does not require input/output processing to the auxiliary storage device, so it is possible to significantly increase computer processing speed and significantly reduce the usage rate of auxiliary storage space. can be reduced to

Furthermore, if a page-in occurs in response to the subsequent operation of the program, the relevant page in the auxiliary storage space is manually input, and the content of the relevant page in the auxiliary storage space copy management table (2) is subtracted by 1. If the content of the page becomes 0 at this point, the page in the auxiliary storage space is returned to the auxiliary storage free area management table.

After that, if a page-out occurs due to page-out processing and must be output to auxiliary storage space, if the content of that page has not been updated and the page number corresponding to the previous page-in is copied. If the content of the page in management table 0 is other than 0 and remains, 1 is added to the content and the page in the main memory space that was being used is returned to the main memory free area management table (2). By doing this, the time for page output can be shortened. Also, if the content of the above page has been updated,
Acquire a new page in the auxiliary storage space using the auxiliary storage free area management table ◎ and output to that page. At this time, the contents of the corresponding page of the auxiliary storage space copy management table are set to 1.

〔Effect of the invention〕

According to the auxiliary storage space management method of the present invention, the processing speed of a virtual memory control computer can be significantly improved, and the auxiliary storage capacity can be reduced.

[Brief explanation of drawings]

Figure 1 shows the virtual memory system of this invention? FIG. 2 is a schematic diagram for explaining the principle of the auxiliary storage space management method in 1N, FIG. 2 is a schematic diagram for explaining an embodiment of the present invention, and FIG. 3 is an example of a conventional page management system. FIG. ■・・・Main memory space map, ■・・・Program 1 page management table, ■・・・Auxiliary storage space map, ■・・・Program ■Copy management table, [F]... Auxiliary storage space copy management table.

Claims (2)

[Claims] (1) A method for managing auxiliary storage space in virtual memory control, characterized by using an auxiliary storage space copy management table provided corresponding to an auxiliary storage space map. (2) The auxiliary storage space copy management table is configured when there is a processing request to copy the program itself and subsequently execute the copy as an independent program, thereby copying the program existing in the auxiliary storage space. 2. A method for managing auxiliary storage space in virtual memory control according to claim 1, wherein the method is capable of executing the auxiliary storage space in virtual memory control.