JPH0844687A - Virtual memory management system utilizing memory server - Google Patents

Abstract

PURPOSE:To shorten the time for program processing by reducing I/O caused by paging to a disk to be frequently generated at a personal computer(PC) which does not mount any large capacity memory. CONSTITUTION:By providing a managing zone showing the semi-valid page of intermediate existence between a valid page and an invalid page and by placing a substance corresponding to the semi-valid page in a real storage space 5 on a server machine, paging processing is performed with a real storage space 4 of a client PC. Thus, since paging processing is performed while positioning the real storage space 5 between the real storage space 4 on the client PC and a paging file on a hard disk 6, the I/O caused by paging to the hard disk is decreased, and the time for program processing can be shortened.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to virtual memory management using a memory server, and more particularly to a personal computer (or WS).
Relates to a virtual memory management method in a client / server environment.

[0002]

2. Description of the Related Art A conventional paging mechanism is carried out by providing a page table for each process as shown in FIG.

The page table 2 stores page frame addresses for virtual page numbers so that the virtual storage address space 1 and the real storage space 4 can be linked. When the page frame corresponding to the virtual page is paged out and is not in the actual storage, the disk address is stored in the page table as an invalid page. When a process accesses the invalid page again, a page fault occurs and virtual memory management loads the page on the hard disk (in the paging file) into real memory based on the disk address stored in the page table. To do. At this time, when there is no page load area on the real memory, the virtual memory management causes a page-out according to the longest time unused method (LRU) to make a free area on the real memory.

Japanese Unexamined Patent Publication No. 2-28748 discloses, as a "network virtual memory space management device", a device for accelerating the access of an object in the virtual memory space by hardware in a networked computer system. However, it was necessary to incorporate various dedicated circuits and the like.

[0005]

In the conventional paging mechanism, virtual pages in the virtual address space are
If you are trying to run a program that requires a large amount of memory on a personal computer, assuming only exchange between local real memory and hard disk, you must install a large amount of memory on that personal computer, There is a problem that paging / swapping on the real memory and the hard disk frequently occurs and the processing time of the program is delayed.

[Object of the Invention] Although the resources required by the OS and applications are increasing year by year,
At present, it is difficult to add a memory to each personal computer. Therefore, the present invention constructs a virtual memory management system that uses a large-capacity memory on a server machine (memory server), considering the shortage of memory on each personal computer.

[0007]

According to the present invention, a semi-valid page is provided separately from the valid page invalid page managed on the page table used in the paging mechanism, and the page is a server. Stored in real memory on the machine. That is, the real memory and hard disk (local or remote) of the client PC
The real memory of the server machine is located between and, and the semi-valid page (which is an intermediate management target between the valid page and the invalid page) is stored therein.

At present, the memory used by each personal computer exists on each personal computer, and the memory paging / swapping area also exists on each personal computer.

The points of the present invention are listed below. The memory used by each personal computer is mapped to the physical memory space on the server machine. Each personal computer and server machine are connected by a high-speed line such as Ethernet (Fig. 6). Programs and drivers running on the client personal computer are basically loaded into the physical memory space existing on the client. With existing memory management, the valid page in the virtual memory space exists in the physical address space, and the invalid page exists on the hard disk, but here, the management target is the semi-valid page, which is an intermediate position between valid and invalid. Create and place the semi-valid page in the physical memory space on the server machine. In short, unlike the conventional management (paging / swapping processing between the physical memory space and the hard disk), the physical memory space on the server machine is allocated between the physical memory space on the client and the hard disk. The paging process is performed between each set (FIG. 5).

[0010]

In the prior art, the programs and drivers operating on the personal computer can use only the memory on the personal computer, and the program does not operate on the personal computer that does not have a large capacity of memory. Or, paging / swapping frequently occurred and the operation speed was decreased due to input / output to / from the hard disk.

However, in the present invention, by utilizing the physical memory space on the server machine, the memory can be effectively utilized, and the large-capacity memory can be realized without adding or upgrading the memory of the personal computer currently installed. A program that requires can be operated without problems.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram schematically showing the positional relationship in management of the valid page 7, the invalid page 8 and the semi-valid page 9 in the present invention.

FIG. 2 is a diagram showing the paging / swapping mechanism of the present invention, in which (a) is an invalid page 8.
In the above example, (b) shows an example of the semi-effective page 9.

FIG. 3 is a diagram schematically showing the paging process between the real storage space 4 (on the client personal computer), the real storage space 5 on the server machine, and the hard disk 6.

Hereinafter, the valid page 7, the invalid page 8, and the semi-valid page 9 will be described with reference to FIG.

In virtual memory management, a virtual memory address space 1 is provided for each process, and the virtual memory address space 1 and the real memory space 4 are linked by a page table 2. The page table 2 is provided with management sections such as a valid page 7, an invalid page 8 and a semi-valid page 9 for each virtual memory page frame. The valid page 7 exists in the real storage space 4, and the invalid page 8 exists in the paging file 6 on the hard disk. In addition, the semi-effective page 9 which is a management section newly provided in the present invention exists in the real storage space 5 on the server machine.

The page on the virtual memory address space 1 and the real memory space 4, the real memory space 5 on the server machine, and the paging file 6 on the hard disk are linked by the page table 2, and in the case of an effective page, the real memory is stored. If the page address in the space is invalid, the hard disk address is managed, and in the case of the semi-valid page, the page address in the server machine real storage space is managed.

Next, the actual paging mechanism will be described with reference to FIG. First, the case of an invalid page will be described with reference to (a). When a process 10 accesses a page of the virtual memory address space 1 (), the virtual memory management determines that the corresponding page is the invalid page 8 according to the page table 2, and a page fault occurs (). Then, the corresponding page frame 11 in the hard disk paging file 6 is loaded into the real storage space 4 (on the client personal computer) (). At this time, when there is no area for loading a page on the real storage space 4, the virtual storage management causes a page-out according to the LRU to make an empty area on the real storage space 4 (on the client personal computer).

Next, the case of the semi-effective page 9 will be described with reference to FIG. When a process 10 accesses the semi-valid page 9 (,), the virtual memory management loads a page frame from the real memory space 5 on the server machine into the real memory space 4 (), Tie (). At this time, when there is no free area in the real storage space 4, the virtual storage management causes a page-out according to the LRU, and creates a free area in the real storage space 4.

Next, the processing relationship among the real storage space 4, the server machine real storage space 5, and the paging file 6 on the hard disk will be described with reference to FIG.

The page-out processing from the real storage space 4 (on the client personal computer) is executed in accordance with the LRU, and is performed on the server machine real storage space 5. The paging out from the server machine real storage space 5 is performed according to the LRU and is performed on the paging file 6 on the hard disk.

The page-in (load) process is performed from the server machine real storage space 5 and the paging file 6 on the hard disk (on the client personal computer) to the real storage space 4.
, When a page fault occurs. That is, the server machine real storage space 5 is positioned between the real storage space 4 (on the client personal computer) and the paging file 6 on the hard disk, and paging processing is performed.

[0024]

As described above, according to the present invention, in addition to a valid page and an invalid page, a management section called a semi-valid page is provided, and a real storage space on a client personal computer and a paging file on a hard disk are provided. By locating the real storage space on the server machine and performing the paging process, the paging process for the paging file on the hard disk can be reduced, and as a result, the number of i / O to the hard disk can be reduced. It has the effect of reducing the processing time of the program.

[Brief description of drawings]

FIG. 1 is a diagram showing a positional relationship in management of a valid page, an invalid page, and a semi-valid page according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a paging / swapping mechanism of the present invention.

FIG. 3 is a schematic diagram showing a paging process of the present invention.

FIG. 4 is a schematic diagram showing a conventional technique.

FIG. 5 is a schematic diagram showing a paging process of the present invention.

FIG. 6 is a schematic diagram showing a system environment of the present invention.

[Explanation of symbols]

 1 virtual memory address space 2 page frame 3 page number 4 real memory space 5 third machine real memory space 6 hard disk paging file 7 valid page 8 invalid page 9 semi-valid page 10 process 11 page frame

Claims (4)

[Claims] 1. In a computer system including a client and a server, a physical memory space on a server machine is placed between a physical memory space on the client and a hard disk, and paging processing is performed between them. A virtual memory management method using a memory server. 2. In a client / server environment composed of personal computers, a semi-effective page is provided which is an intermediate position between an effective page and an invalid page in virtual memory management of each client personal computer. A virtual memory using a memory server, characterized in that a paging / swapping process is performed between the real storage space of the client personal computer and the real storage space of the server machine. Management method. 3. The page address in the real storage space of the client in the case of the valid page, the hard disk address in the case of the invalid page, and the server machine real storage space in the case of the semi-valid page. The virtual memory management method using a memory server according to claim 2, further comprising a page table for storing and managing page addresses. 4. The page frame according to claim 2, wherein when the semi-valid page is accessed, a page frame is loaded from the real storage space on the server machine into the real storage space of the client and linked with the virtual storage address space. Virtual memory management method using a memory server.