JPS63216146A - Management system for main storage device - Google Patents

Abstract

PURPOSE:To prevent a fixed page from being concentrated onto a specific main storage address by selecting the page fixing to a specific main storage address according to the attribute of a virtual storage area and page fixing to an unspecified main storage address not depending on the attribute of the virtual storage area. CONSTITUTION:When a page fixing request comes to a virtual storage area in page residence, if the main storage address assigned at present is an address in matching with the attribute of the virtual storage area, the page fixing is applied as it is. On the other hand, the main storage address assigned at present is not in matching with the attribute of the virtual storage area, the other main storage area in matching with the attribute is selected and the present content is copied to a new main storage area and page fixing is applied. Thus, the concentration of page fixing request to a specific main storage area is avoided.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a main memory management method of an operating system, and particularly in an operating system that adopts a virtual memory method, programs with different addressing methods can be integrated into one operating system. The present invention relates to a main storage management method suitable for enabling simultaneous execution within a main storage device.

[Conventional technology]

Regarding the page fixing method of operating systems that employ conventional virtual memory methods, see ``Function and Structure of Large Operating System MVS J, June 1986, 5.
Published by Nippon, Kindai Kagakusha, written by Masahiko Senda, pages 48 to 5.
Discussed on page 1. According to the above literature, in the conventional page fixing means for a virtual storage area, the attributes (24-bit addressing method, etc.) when securing the virtual storage area are
The content of the page was fixed to a specific main memory address according to the following.

[Problem that the invention seeks to solve]

In the above conventional technology, for example, a program created using a 24-bit addressing method can only perform address operations on 24-bit virtual addresses and 24-bit real addresses, so the area of the program is stored in the main memory. When a page is fixed to a specific area, that is, a 24-bit main memory address, the page is automatically fixed to a specific area.

However, the purpose of page fixing the above program area is
Even when there is no need to access a 24-bit main memory address, for example, when page-out to virtual memory is simply prohibited to prevent performance degradation due to page-missing interrupts, conventional technology uses a 24-bit main memory address. It was assigned within the address. Therefore, when a large number of programs are executed simultaneously using the multiple address space method, there is intense competition for requests to use the 24-bit main memory area, which can sometimes become a bottleneck in system performance.

In order to avoid such conflicting requests for use of the 24-bit main memory area, in the conventional technology, an attribute that fixes the contents of the 24-bit virtual address area to a main memory address exceeding 24 bits is set to the virtual address area. It is possible to set this when securing storage area. However, in this case, if only a portion of the program area contains an area that must be page-fixed using a 24-bit main memory address, the entire area must be fixed at 24 bits when allocating the program area.
It is necessary to take measures such as setting an attribute that fixes the page to a 24-bit main memory address, or rewriting the program so that it does not depend on a 24-bit main memory address. Therefore, the conventional technology has problems in that it is not possible to perform fine-grained control to efficiently utilize the main storage device, and that it requires a great deal of effort and time to re-create the program.

The present invention was developed in view of the problems of the prior art described above, and prior to page fixing in the prior art, the page must be fixed using the attributes of the virtual storage area, that is, the 24-bit main memory address. By fixing a page to an arbitrary main memory address, regardless of whether the page must be fixed to a main memory address with more than 24 bits, most of the objectives of page fixing can be achieved, and even more truly the virtual storage area can be fixed. It is possible to perform two-stage page fixing in which page fixing is performed using conventional technology when page fixing according to attributes is required.

The purpose of this invention is to reduce the page fixation amount for the 24-bit main memory address area, eliminate contention, and achieve efficient use of the main memory.

[Means for solving problems]

The main memory management method of the present invention uses a page fixation processing function that fixes the correspondence between virtual memory and main memory and prohibits page-out from occurring.

In particular, it is characterized by selectively performing page fixation to a specific main memory address according to the attributes of the virtual storage area, and page fixation to an unspecified main memory address without following the attributes of the virtual storage area. .

[Effect]

That is, according to the present invention, in order to prevent page fixing from concentrating on a specific main memory address, page fixing can be performed on any main memory address regardless of the attributes of the virtual storage area, and Only those that require page fixation to a specific main memory address are page fixed to that specific main memory address. In the following description, the page fixation request for the above-mentioned arbitrary main memory address will be referred to as a page resident request.

The purpose of the page fixing request according to the prior art and the new page resident request must be correctly achieved even if each request is made to the same virtual storage area at the same time.

When a page fixation request is made to a page-resident virtual storage area, if the currently allocated main memory address matches the attributes of the virtual storage area,
Fix the page as it is.

On the other hand, if the currently allocated main memory address does not match the attributes of the virtual storage area, another main storage area that matches the attributes is selected, and the current contents are transferred to the new main storage area. By fixing the page after copying to the page, the purpose of both the page resident request and the page fixation request can be achieved.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to embodiments shown in the accompanying drawings.

FIG. 1 is a block diagram showing an embodiment of the main storage device management method of the present invention. In the figure, 11 is a page residency request program, and 12 is a main memory analysis section.

13 is a main memory selection section, 14 is a main memory copy section, and 15 is a page resident display section.

2 is a flowchart showing the contents of the page residency request program shown in FIG. 1.

The page residency request program 11 is executed by the main memory analysis unit 1 of the operating system when it is necessary to keep the main memory page allocated to the virtual storage area.
A page resident request is made to 2. Main memory analysis unit 12
analyzes the main memory allocation situation for the virtual storage area requested to be page resident. Either a main memory address has already been allocated to the requested virtual storage area, and a page fixing method has already been taken for the main memory allocation, or the main memory address exceeds 24 bits. If it is allocated on a storage address, the page resident display unit 15 is notified that the page may remain resident in the main storage area. In addition, if the main memory address has not been allocated yet, or even if it has been allocated, the main memory address is 24 bits or less and the page is not fixed, a new optimal allocation for the main memory will be performed. Main memory selection unit 13
to notify.

The main memory selection unit 13 preferentially selects an empty page having a main memory address exceeding 24 bits from the main memory area of the main memory in the system.

If there is no free page, select a free page with a main memory address of 24 bits or less. When allocating a main storage area for the first time to a virtual storage area for which page residency is requested, the main storage selection unit 13.

The page resident display unit 15 is notified that the selected main storage area may be page resident. When reallocating a main memory area with a new optimal main memory address to a virtual storage area to which a main memory area has already been allocated, the main memory selection unit 13 sends a message to the main memory copying unit I4. for,
Instructs to copy the contents of an area.

The main memory copy unit 14 copies the contents of the main memory area that was already allocated at the time of the page residency request to the optimal main memory area selected by the main memory selection unit 13, and The main memory address set in the address conversion table is also changed to a new main memory address. The main storage area, which is the original copy before change, is registered as a free page when all processing in the main storage copying unit 14 is completed.

The page resident display section I5 includes the main memory analysis section 12. For each page of the main memory area determined by the main memory selection unit 13 or the main memory copy unit 14, it is displayed that the page is in a page-resident state. This prevents the main storage area from being paged out'. After this, control is returned to the page residency request program 11.

Furthermore, when a page fixation request to a 24-bit main memory address is input to the main memory analysis unit 12 of the operating system, the main memory analysis unit 12 allocates the main storage device to the virtual storage area for which the page fixation request has been made. The allocation analyzes the status, and if the address is allocated to a main memory address exceeding 24 bits, the main memory selection unit 13
It is instructed to allocate it on a 24-bit main memory address.

The main memory selection unit 13 preferentially selects an empty page at a 24-bit main memory address, and the main memory copying unit 14 performs a process of copying to the empty page.

As is clear from the above explanation, according to this embodiment, it is possible to avoid concentration of page fixed states on the main storage area of 24-bit addresses, and the contention for a specific main storage area can be alleviated in the system as a whole. Effective in improving system performance.

In the above embodiment, page fixation for a 24-bit main memory address was explained as an example, but the present invention is not limited to this, and may be applied to other main memory addresses such as a 31-bit address. It is applicable.

〔Effect of the invention〕

According to the present invention, when programs with different addressing methods are simultaneously executed within one operating system, the main memory address when page-fixing the contents of the virtual storage area on the main memory device is set according to the addressing method of the program. This is because a large number of programs with the same addressing scheme can be executed, since they can be selected at independent locations. It is possible to avoid concentration of page fixing requests on a specific main storage area, and this is effective in improving system performance by distributing the load on the main storage area.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG. 2 is a flowchart of the page residency request program shown in FIG. DESCRIPTION OF SYMBOLS 11... Page resident request program, 12... Main memory analysis section, 13... Main memory selection section, 14... Main memory copying section, 15... Page resident display section.

Claims (1)

[Claims] 1. In a main storage management system having a page fixing processing function that fixes the correspondence between virtual memory and main memory and prohibits the occurrence of page out, page fixation is performed for a specific main memory address according to the attributes of the virtual storage area; A main storage management method characterized by selectively fixing a page to an unspecified main storage address without following the attributes of a virtual storage area.