JPS6143743B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Technical Field of the Invention The present invention enables individual areas of a virtual space to be dynamically shared with other virtual spaces in a computer system that employs a multiplexed virtual memory system. The present invention relates to an overlay control method based on virtual space sharing that enables high-speed overlay control by using an area as a save area for an overlay load module.

(2) Background of the technology In recent years, an increasing number of computer systems have adopted a multiple virtual memory method in order to eliminate limitations on main memory capacity and improve processing efficiency.
In the multiple virtual memory system, for example, a virtual space is allocated for each job that executes a certain set of processing, and this virtual space is made to correspond to the real space by a segment table and a page table, which are address translation tables.

For example, if a virtual address is represented by 24 bits, one virtual space has a size of 16 megabytes. In general, this virtual space consists of a system common area that is substantially common to each virtual space, such as areas such as the core of the system and control tables involved in controlling the entire system, and an individual system area that has content unique to each virtual space. It has a region. Particularly in large-scale systems, the size of the system common area increases as the system becomes more sophisticated and control becomes more diverse, forcing the individual areas to be reduced accordingly. , large jobs require large individual areas to implement desired services.

(3) Prior art and problems Conventionally, segment tables and page tables for system common areas were made common to each virtual space by copying or pointing to a prototype, but for individual areas, Each of them had its own page table, which caused the following problems.

Because individual areas cannot be shared by each virtual space,
Even if it is a load module that can be used in common,
As for the individual areas, it is necessary to load each virtual space separately, which poses a problem in that the ratio of the input/output load required for loading increases. If these load modules are rotated to the system common area mentioned above, they will occupy virtual addresses, which will put unnecessary pressure on individual areas for spaces that do not need to be shared. .

In order to reduce pressure on such an area, overlay control is used to alternately load a plurality of load modules that have the same virtual address and operate exclusively in one virtual space. Conventionally, when performing this overlay control, input/output to a magnetic disk device or the like has always been required. As a result, there are disadvantages in that quick processing is not possible and the load on the input/output device increases. Therefore, it is not practical to use an overlay, especially in a load module that performs control processing for the entire system that operates in a system common area, which causes an increase in the system common area.

(4) Purpose of the Invention The present invention aims to solve the above-mentioned problems, enables dynamic sharing of individual areas of a virtual space, and quickly performs overlay control by using the shared virtual space. The purpose is to do so.

(5) Structure of the Invention The overlay control method based on virtual space sharing of the present invention includes a system common area that has content common to each virtual space, and an individual area that has content unique to each virtual space. A system that performs virtual memory control that corresponds to the real space using a table that maps addresses for each virtual space, and that alternately places multiple load modules in a designated overlay area in the virtual space. In an overlay control method for controlling loading into a shared virtual space where the individual area is shared with another virtual space, means for setting an overlay/load module evacuation area in the individual area on a shared virtual space; In response to a load request to the above overlay area, if the overlay area is occupied by another load module, the other load module is updated by updating the table that maps the above address. , means for saving to the overlay/load module saving area; and a means for saving the load module to the overlay/load module saving area for which a load request has been issued to the overlay/load module saving area. The present invention is characterized by comprising means for preparing the load module in the overlay area by updating the table mapping the addresses at some time.

(6) Examples of the invention This will be explained below with reference to the drawings.

FIG. 1 is a diagram illustrating the sharing of a virtual space related to the present invention. FIG. 2 is a diagram illustrating the processing operation of a shared virtual space allocating section.

Before explaining an overlay control method that is an embodiment of the present invention, first, dynamic sharing of a virtual space related to the present invention will be explained with reference to FIGS. 1 and 2. In FIG. 1, 1 is a data processing device, 2 is an application processing unit, 3 is a system control unit, 4 is a shared virtual space allocation unit, 5 is a multiple virtual space, and 6-0
is a shared virtual space, 6-1 to 6-3 are normal virtual spaces, 7-1 to 7-3 are segment tables (SGT), 8-0 and 8-1 are page tables (PGT), 9-0 to 9-3 is an area, 10 is a real memory, 11-0 and 11-1 are areas on the real memory, 12 is a magnetic disk, and 13 is a load module library.

The data processing device 1 performs dynamic address conversion from a virtual address to a real address on the real memory 10 based on a segment table pointed to by a control register (not shown) and a page table pointed to by the segment table. The instructions are successively fetched and executed. Since this dynamic address translation mechanism is a well-known technology, a detailed explanation will be omitted.

The application processing unit 2 operates in the virtual spaces 6-1 to 6-3, particularly in the individual areas P1, P2, and P3, and performs processing in response to user requests. The system control unit 3 operates in a system common area C common to each of the virtual spaces 6-1 to 6-3, supports the processing of the application processing unit 2, and controls the entire system.

For example, if addresses are expressed in 24 bits, each virtual space 6-1 to 6-3 is
It has a size of 16 MB. For example, virtual space 6
Area B on -1 9-1 is segment table 7
-1 and the real page address are converted into a real address on the real memory 10 by the page table 8-1 stored in correspondence with the virtual page address,
It is associated with area 11-1 on real memory. Conventionally, the individual areas P1, P2, and P3 have their own page tables 8-1, and therefore, for example, the virtual space 6-2 and the virtual space 6-
3, it was not possible to have a common area in the individual areas P2 and P3. Therefore, for example, if you want to perform inter-job communication or use a common load module between virtual spaces 6-2 and 6-3, you must provide the necessary area in system common area C. This will also affect the unrelated virtual space 6-1.

In this example, the solution is as follows. The application processing unit 2 operating in a virtual space that requires a shared area with the virtual space in an individual area dynamically requests that area from the shared virtual space allocation unit 4 when necessary. The shared virtual space allocation unit 4 newly opens a shared virtual space 6-0 and secures an area 9-0 on the individual area P0. By securing the area 9-0, the page table 8-0 is created, and the virtual address a of the area 9-0 is associated with the real address r0. For example, the request source is virtual space 6-2
If so, the segment table 7-2 points to the page table 8-0 of the shared virtual space 6-0. Then virtual space 6-2
The area 9-2 will be associated with the area 11-0 on the real memory. On the other hand, assume that a sharing request is issued from the virtual space 6-3 regarding the same area.
The shared virtual space allocation unit 4 has already created the page table 8.
-0 has been created, so that page table 8
-0 from the segment table 7-3. By doing this, area 9-
3 is also associated with area 11-0 on real memory,
Individual areas P2, P of virtual spaces 6-2 and 6-3
It becomes possible to share the area on 3. If a load module is loaded into this shared area from the load module library 13 on an external storage device such as the magnetic disk device 12, the load module can be shared, and the I/O can be used for memory saving and loading. /O frequency can be reduced. In addition, virtual space 6 that you do not want to share
-1 has its own page table 8-1, so it can use the entire individual area P1 regardless of the shared area.

Next, the processing operation of the shared virtual space allocation unit 4 will be explained with reference to FIG. In response to a sharing request, the shared virtual space allocation unit 4 first checks whether there is a sharing qualification for security protection (processing in FIG. 2). If there is no shared qualification, an error is returned. Next, it is determined whether the shared virtual space has already been opened (processing in FIG. 2). If it has not been established yet, a shared virtual space is also established (processing in Figure 2). If it has already been opened, it is checked whether the specified area exists therein (processing in Figure 2). When a new shared virtual space is opened, or when a designated area does not exist even if it has already been opened, an area is secured in the shared virtual space and a page table is created (processing in FIG. 2). Next, the real address of the page table of the shared virtual space is obtained (processing in FIG. 2), and it is pointed from the segment table of the requesting virtual space (processing in FIG. 2), and the processing is ended.

FIG. 3 shows the configuration of an embodiment of the present invention, FIG. 4 is an explanatory diagram of an area management table, FIG. 5 is an example of the processing operation of the application processing section, and FIG. 6 is an explanatory diagram of the processing operation of the virtual load/store processing section. FIG. 7 shows an example of an overlay for the system common area.

In the figure, codes 1 to 3, 6-0 to 6-3,
7-1, 8-0 and 8-1, 10, 12 are the first
Corresponding to the figure, 14 is a virtual load/store processing unit;
Reference numeral 15 represents an area management table, 16 an overlay area, 17 an evacuation area, and 18 a load module.

For example, in order to effectively utilize a limited area in one virtual space, an overlay is used in which a plurality of load modules that operate exclusively use the area alternately.
Conventionally, switching between overlaid load modules always required I/O to a magnetic disk device or the like. Therefore, when performing quick processing, overlays could not be used.
The present invention enables high-speed processing even when using an overlay.

In FIG. 3, a shared virtual space 6-0 is used as an overlay evacuation space. For example, assume that the application processing section 2 alternately loads and executes module M1 and module M2 into area A by overlaying them, as shown in FIG. Application processing section 2
First, secure the overlay area A.16.
Page table 8-1 is created and area A/16
It becomes possible to use The size of area A・16 is
The size is adjusted to match the largest size of the load module 18 to be overlayed. Next, the virtual load/store processing section 14 is called to read the module M1 from the magnetic disk device 12.
When module M1 finishes executing and transfers area A.16 to module M2, the virtual load/
The store processing unit 14 is called. The virtual load/store processing unit 14 replaces module M1 in area A 16 with module M2.
evacuate. As the evacuation area, the evacuation area 17 of the shared virtual space 6-0 is used instead of the magnetic disk device 12. Actually, virtual space 6-1
Page table 8-1 for area A-16 of
The pointer from the segment table 7-1 to the page table 8-0 of the shared virtual space 6-0
This is done by replacing it with a pointer to . Therefore, data is not transferred and is processed at extremely high speed. Area management in this process is performed by the area management table 15. The area management table 15 stores the contents as shown in FIG. 4, for example, the area name, start address, area size, target load module name and various status information, etc., and performs virtual load/store processing. Part 14
executes processing while referring to and updating the area management table 15. When module M2 is loaded and executed and module M1 is called again, since module M1 has already been saved and exists in the shared virtual space 6-0, page table 8-0 and page table 8-1 are All that is required is an exchange. At the same time that module M1 is called to area A.16, module M2
The storage to the save area 17 will be executed. The processing is repeated as described above, and when all the processing is completed, the application processing section 2 releases the area A 16. Information regarding area A on area management table 15 will also be deleted. Note that, in the above processing, the contents of the real addresses of the page tables 8-0 and 8-1 may be updated instead of changing the pointers to the page tables, which is substantially the same.

For the virtual load/store processing unit 14, area A
When a virtual load request for module M1 is issued, the virtual load/store processing unit 14 processes as shown in FIG. First, module M is placed in area A.
1 exists using the area management table 15 (processing in FIG. 6). Module M1
If already exists, the processing request is satisfied and the processing is terminated. Next, it is checked whether area A is vacant (processing in FIG. 6). If the module M1 is vacant, the module M1 is loaded from a magnetic disk device or the like (processing in FIG. 6). For example, assume that module M2 exists in area A and is not vacant. In that case, it is first checked whether an evacuation space has been established (processing in FIG. 6). If it is not opened, a virtual space for evacuation is opened (processing in Figure 6), and module M
2 is secured (processing in FIG. 6).
Then, the pointer to the page table of the segment table is exchanged, module M2 is saved to the shared virtual space (processing in Figure 6), module M1 is loaded into area A (processing in Figure 6), and the process ends. .

If it is found in the check in the above process that an evacuation space has been opened, it is checked whether the module M1 is evacuation there (processing in FIG. 6). If it has not been evacuated, perform the processes after the above process, and if it has been evacuated, exchange the pointer to the page table (processing in FIG. 6), return module M1 to area A, and end the process. .

The above overlay control can also be applied to the load module in the system common area C. Conventionally, even if there were modules M1, M2, and M3 that operated exclusively as shown in FIG. was. Applying the present invention, FIG. 7B
As shown in the figure, area A is secured on system common area C, and evacuation areas for each load module M1, M2, and M3 are provided in individual area P0 of shared virtual space 6-0, and area A is used alternately. This solves the problem of processing speed and allows the system common area C to be reduced.

FIG. 8 shows an example of an invention different from the present invention that utilizes a shared virtual space. As shown in FIG. 8, a shared virtual space 6-0 is secured as a virtual input/output control (VIO) space, and a designated data set is read in advance and stored as a set in page data. Page table 8- for this page dataset
0 from the segment tables 7-1, 7-2, etc. of other virtual spaces 6-1, 6-2, etc., it is possible to specify page data sets that are subject to virtual input/output between each virtual space. can be shared,
Efficient access to data sets is possible.

If the above processing is executed within the system, the functionality can be expanded without any need to change the user's processing module.

(7) Effects of the Invention As explained above, according to the present invention, an overlay load module evacuation area is provided in a shared virtual space, and segment tables, page tables, etc. are saved for load modules to be overlayed. Just by updating, the data is evacuated from the overlay area and returned to the overlay area, making it possible to perform extremely high-speed overlay control. In particular, since the CPU load and I/O load associated with overlay control are small, it is easier to introduce overlays even for load modules that are loaded into the system common area and are executed frequently, reducing the system common area. It also becomes possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the sharing of a virtual space related to the present invention, FIG. 2 is a diagram explaining the processing operation of the shared virtual space allocation unit, FIG. 3 is a diagram illustrating the configuration of an embodiment of the present invention,
Figure 5 is an explanatory diagram of the area management table, Figure 5 is an example of the processing operation of the application processing unit, Figure 6 is an illustration of the processing operation of the virtual load/store processing unit, Figure 7 is an example of overlay for the system common area, FIG. 8 shows an example of an invention different from the present invention that utilizes a shared virtual space. In the figure, 1 is a data processing device, 2 is an application processing unit,
3 is a system control unit, 4 is a shared virtual space allocation unit,
5 is a multiple virtual space, 6-0 is a shared virtual space, 6-
1 to 6-3 are virtual spaces, 7-1 to 7-3
is a segment table, 8-0 and 8-1 are page tables, 9-0 to 9-3 are areas, 10
is real memory, 11-0 and 11-1 are real memory areas, 12 is a magnetic disk device, 13 is a load module library, 14 is a virtual load/store processing unit, 15 is an area management table, 16 is an overlay area, 17 represents an evacuation area, and 18 represents a load module.

Claims (1)

[Claims] 1. A system comprising a system common area having contents common to each virtual space and an individual area having contents unique to each virtual space, and using a table mapping addresses for each virtual space. In an overlay control system that performs virtual memory control that corresponds to a real space, the overlay control method performs control to alternately load a plurality of load modules into a designated overlay area in the virtual space. means for setting an overlay/load module save area in a shared virtual space in which the individual area is shared with other virtual spaces; , when the overlay area is occupied by another load module,
A means for saving the other load module to the overlay load module save area by updating a table that maps the above address; means for preparing the load module in the overlay area by updating the table mapping the address when the module is saved in the overlay/load module save area. This is an overlay control method based on virtual space sharing, which is characterized by: