JPH0237443A - Main storage management system for electronic computer system - Google Patents

Abstract

PURPOSE:To reduce the overhead for process replacement or the like and to improve the performance of a system by using physical pages, which are not mapped on logical pages, to preserve processes. CONSTITUTION:A logical address converting means 14 converts a logical address to a physical address at the time of accessing a main storage from software. Information managed by a dynamic main storage management means 11 and the logical address converting means 14 is so changed that this information indicates that logical pages assigned to a process are not mapped on logical pages and the process is preserved in these assigned physical pages, thereby releasing the logical address space of the process. Information managed by the dynamic main storage management means 11 and the logical address converting means 14 is so changed that this information indicates that logical pages where the process is preserved are mapped on logical pages, thereby assigning the logical address space to the process. Thus, the performance of the system is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a main memory management system in an electronic computer system.

[Conventional technology]

Generally, in a computer system, the maximum size of a logical address space that is a continuous address space that can be used by a machine is determined by the architecture of the computer system. Conventional computer systems that use the real memory method use a physical address space (main memory address space) that is equal to or smaller than the size of the logical address space. By making a correspondence with the space, a process assigned to the logical address space is also assigned to the physical address space and executed. Also, when releasing the logical address space allocation from a process to create a free area in the logical address space,
Conventionally, when allocating a logical address space to a process that is the opposite, the process existing in the physical address space of main memory is flushed out to an external storage device, or the process stored in the external storage device is moved to the physical address space of main memory. Loading into space.

[Problem to be solved by the invention]

However, the access time of external storage devices is orders of magnitude slower than that of main memory, so if processes are frequently moved in and out of external storage devices and main memory, the performance of the computer system will be significantly degraded. Become.

The present invention has been made in view of these circumstances, and its purpose is to provide main memory (physical address space) that is larger than the logical address space that can be accessed by software.
An object of the present invention is to provide a main memory management method in a computer system that can implement the system and effectively use all its areas.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a main memory management method for a computer system in which multiple processes are executed in parallel. dynamic main memory management means for managing the usage status of an address space and the usage status of a physical address space that has a larger size than the logical address space and is divided into physical pages of the same size as the logical page; and a logical address conversion means for managing the mapping status to the physical page and converting a logical address into a physical address, and when releasing a logical address space to a process,
the dynamic main memory management means and the logical address translation means so as to indicate that the physical page allocated to the process is not mapped to a logical page and the process is stored in the allocated physical page; When changing the information managed by the dynamic main memory management means and allocating a logical address space to a process, the dynamic main memory management means and the logical The address conversion means is configured to change information managed by the address conversion means.

[Operation] In the main memory management method in the computer system of the present invention, the dynamic main memory management means monitors the usage status of a logical address space divided into fixed-length logical pages and the size of the logical address space that is larger than the logical address space. Further, the logical address conversion means manages the usage status of the physical address space divided into physical pages of the same size as the logical page, and
It manages the mapping status of logical pages to physical pages, converts logical addresses to physical addresses when accessing main memory from software, and releases the logical address space for a process when the physical page allocated to that process is This is done by changing the information managed by the dynamic main memory management means and the logical address translation means to indicate that the process is not mapped to a logical page and is stored in the physical page to which it was allocated. The allocation of a logical address space to a process is information managed by a dynamic main memory management means and a logical address translation means to indicate that the physical page storing the process has been mapped to a logical page. This is done by changing the .

[Example] Next, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram of the main parts of an electronic computer system to which the present invention can be applied, in which .largecircle. is an arithmetic processing unit and 2 is a main storage device. The arithmetic processing unit 1 includes a dynamic main memory management means 11.
It includes a process control means 12 and a main memory access means 13, and the main memory access means 13 has a logical address conversion means 14.

A logical address space, which is a continuous address space accessible from software running on the arithmetic processing unit 1, is divided into fixed-length logical pages. Now, if the size of one logical page is X and the number of divisions is "8",
The logical address space has a size of 8X, e.g. 8 logical pages L#I each of size X as shown in FIG.
-L#8.

On the other hand, the physical address space composed of the main storage device 2 is
It has a larger size than the logical address space and is divided into physical pages of the same size X as the logical page. That is,
Assuming that the size of the physical address space is 13X, the physical address space is composed of 13 physical pages P#1 to P#13, each of size X, as shown in FIG.

The process control means 12 in FIG. 1 is means for operating a plurality of processes in parallel on the physical address space as described above.

Further, the logical address conversion means 14 included in the upper storage access means 13 stores the mapping status between logical pages in the logical address space and physical pages in the physical address space on an internal address conversion table 141 as shown in FIG. This is a means of converting a logical address into a physical address by holding the mapping status and referring to this mapping status. Now, as illustrated in FIG. 2, assume a situation where each logical page in the logical address space is mapped to a physical page in the physical address space as follows.

L#1→P#I L#2→P#4L#3→P#3
L#4→P#6L#5→P#10 L#6
→P#11L#7→P$7 L#8→P#8 At this time, in the address translation table 141 held by the logical address translation means 14, each logical page L#
The starting addresses 0, 3X, 2X, 5X, 9X, IOX, 6X, and 7X of the physical pages to which L#8 are mapped are stored.

In this state, when the software sequentially accesses logical page L#1 to logical page L#8,
When logical address information 16 is sequentially added to main memory access means 13 from process control means 12 in FIG. 1, physical page P#1. P#4. P#3. P#6. P#
10. P#11. P#7. The physical address space, that is, the main storage device 2, is accessed in the order of P#8. Focusing on one piece of logical address information 16 at this time, the operation of the logical address converting means 14 will be explained with reference to FIG. 3 as follows. That is, the logical address information 16 notified from the process control means 12 is composed of a logical page number and an intra-page relative address, and the logical address conversion means 14 stores the information in the address conversion table 141 corresponding to the logical page number. The physical address information 3 is obtained by reading the top address of the physical page and adding the read top address and the relative address within the page in the logical address information 16.

The dynamic main memory management means 11 shown in FIG. 1 is a means for performing processes such as releasing a logical address space for a process and allocating a logical address space in response to a request from the process control means 12. For example, a logical address space management table 111 as shown in FIG. 4 is used to manage the usage status of each logical page, and a physical address space management table 112 as shown in FIG. 5 is used to manage the usage status of each physical page. Manages usage. In FIG. 4, the used/unused flag is set to "1" when the logical page is used by a process, and set to "0" when the logical page is not used. In addition, in Fig. 5, the used/unused flag indicates "IJ
The mapping flag is set to "0" when it is unused, and the mapping flag is set to "1" when a physical page is mapped to a logical page.
．． It is set to "0" when it is not mapped. Therefore, a physical page with both the used/unused flag and the muffing flag as I"1" is a physical page in which a process is stored and is mapped to a logical page, and a physical page with the used/unused flag as "1" is a physical page that is mapped to a logical page. Ping flag is “0”
The physical page of is a physical page that is not mapped to a logical page but stores a process, and the physical page of r This is also a physical page that has not been mapped.

Next, the operation of the embodiment of the present invention will be described, for example, as shown in the logical address space management table 111 of FIG.
#6. An example will be described below in which the process A existing in L#7 is released from the logical address space and the logical address space is then reassigned to the released process A.

During the operation of the computer system shown in FIG. A notification is sent to the dynamic main memory management means 11 that the data can be removed from the logical address space.

The dynamic main memory management means 11, which has been notified by the control signal 17 that process A can be removed from the logical address space, executes the following process to remove process A from the logical address space and restore the original physical address space. Save on page.

■Logical page L#6 corresponding to process A from the logical address space management table 111 in FIG. Recognizes L#7 and gets its page number ``2J.''

■Search the physical address space management table 112 in FIG. 5 and find the number of pages of process A that are physical pages that are not allocated to the logical address space in the physical address space and that are not saved by other processes. Find minutes. As a result, for example, the physical page P shown in FIG.
#2. P#5 can be found.

■Logical page L#6 of the logical address space management table 111 in FIG. The used/unused flag corresponding to L#7 is set to "0", and the logical page L#6. L#7 to physical page P#2. The page switching signal 15 notifies the logical address conversion means 14 to map to P#5. In response, the logical address conversion means 14 changes the physical page start address corresponding to logical page L#6 in the address conversion table 141 of FIG. 3 from 10X to X, and changes the physical page start address corresponding to logical page L#7 to Change from 6X to 4X. As a result, process A is no longer visible to software and has been deleted from the logical address space.

■Physical page P#11 of the physical address space management table 112 in FIG. By setting the mapping flag corresponding to P#7 to "0", process A
11. Record that it was saved in P#7.

(2) Notify the process control means 12 by the control signal 17 that process A has been removed from the logical address space.

Next, when the process A is no longer waiting for an event and it becomes necessary to load process A onto the logical address space, the process control means 12 controls the dynamic main memory management means 11 to process the Requests that A be expanded into the logical address space.

The dynamic main memory management means 11, which receives a request to expand the process A onto the logical address space by the control signal 17, executes the expansion by performing the following processing.

■Search the physical address space management table 112 in FIG. 5 and find the physical page P#11 where process A is stored.
．． Recognize P#7.

(2) Search the logical address space management table 111 in FIG. 4 to find two consecutive unused logical pages in the logical address space. At this time, for example, logical page L#4. If L#5 were an unused logical page, it would be found.

■Unused logical page L#4. When L#5 is found, this logical page L#4. Physical page P#11. where process A is stored in L#5. The logical address conversion means 1 is activated by the page switching signal 15 to allocate P#7.
Notify 4. In response to this, the logical address conversion means 14
sets IOX to the physical page first address corresponding to logical page L#4 in the address conversion table 141 of FIG. 3, and sets 6X to the physical page first address corresponding to logical page L#5. This allows process A to be accessed by software.

■Logical page L#4 of the logical address space management table 111 in FIG. The used/unused flag of L#5 is set to "1", the process name is set to "A", and the physical page P#1 of the physical address space management table 112 in FIG.
1. Set the mapping flag of P#7 to rl.

[Phase] The process control means 12 is notified by the control signal 17 that the process A has been expanded into the logical address space. As a result, the process control means 12 resumes execution of process A.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various other additions and changes are possible. For example, at the same time as excluding a process on a logical address space, a process may be executed to expand another process to the logical page occupied by the excluded process.

〔Effect of the invention〕

As explained above, the main memory management method in the computer system of the present invention can handle a physical address space that has a larger size than the logical address space, and allows processes to store physical pages that are not mapped to logical pages. Compared to the conventional method in which processes are stored in an external storage device, the overhead required when replacing processes can be reduced and the performance of the computer system can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the main parts of a computer system to which the main memory management method of the present invention is applied. FIG. 2 is a diagram showing an example of the configuration of a logical address space and a physical address space and an example of their mapping. An explanatory diagram of the logical address conversion means 14, FIG. 4 is a diagram showing an example of the logical address space management table 111 possessed by the dynamic main memory management means 11, and FIG. 5 is an illustration of the physical address possessed by the dynamic main memory management means 11. 3 is a diagram showing an example of a space management table 112. FIG. In the figure, 1... Arithmetic processing unit 2... Main memory device 3... Physical address information 11... Dynamic main memory management means 12... Process control means 13... Main memory access means 14 ...Logical address conversion means 15...Page switching signal 16...Physical address information 17...Control signal L#1 to L#8...Logical page P#1 to P#13...Physical Page Main part block diagram of a computer system to which the present invention is applied Part 1

Claims (1)

[Claims] In a main memory management method in a computer system that executes a plurality of processes in parallel, the use of a logical address space divided into fixed-length logical pages and a size larger than the logical address space is disclosed. and a dynamic main memory management means that manages the usage status of a physical address space divided into physical pages of the same size as the logical page, and a dynamic main memory management means that manages the status of mapping of the logical page to the physical page, and stores the logical address in the physical page. logical address conversion means for converting into an address, when the logical address space is released to the process, the physical page allocated to the process is not mapped to the logical page, and the process is saved in the allocated physical page. The information managed by the dynamic main memory management means and the logical address translation means is changed to indicate that the process has been stored in a physical page when a logical address space is allocated to the process. A main memory management method in a computer system, characterized in that information managed by the dynamic main memory management means and the logical address conversion means is changed to indicate that the information has been mapped to a logical page.