JPS6353660A - Control system for virtual storage space - Google Patents

Abstract

PURPOSE:To eliminate such a disadvantage that a part of virtual storage space can not be used because of an access to another process space by comparing a number of a base register with the value of a boundary register group and selecting one from plural pieces of virtual storage space information. CONSTITUTION:This is such a case as a process A accesses a segment 54 in a process B. When an instruction 1A from the process A accesses a virtual storage space using a base register 31 in a base register group 3A, the number of the base register in the register 31 and the value of the boundary register 6 are compared by a comparator 7. Thus two pieces of the storage information 21 and 22 in the process A are selected by a selector 8. In this case, the storage space information 22 is selected and a segment table 46 is indicated by that information. Still more by the value of the register 31 a segment descripter 461 in the table 46 is indicated. By the value, the process A is accessed to the segment 54 which is the virtual space of the process B.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a virtual storage space control method in an information processing device that supports virtual storage space.

[Conventional technology]

Generally, in an information processing apparatus in which a plurality of processes are executed in parallel, an independent storage space is supported for each process, and each process can access only the storage space allocated to itself.

On the other hand, processes that need to manage the entire system are
It is necessary to access the storage space of all processes to be managed.

The storage space allocated to a process is divided into units called segments, and each segment is managed.

Conventionally, by making this segment common to different processes, it was possible to access the memory space of other processes. Next, a conventional virtual storage space control method will be explained with reference to FIG.

The instruction IA of the process A points to the base register 31 in the base register group 3A, and executes the instruction using that address. The pace register 31 is.

From the segment table 41 pointed to by the storage space information 2A held by the process IA, it points to a segment descriptor 412 that stores information about the hexegment to be accessed.

Based on the information in this segment descriptor 412, segment 5
2 can be accessed.

On the other hand, the instruction 1B of Froseth B is the pace register group 3B.
Points to the base register 32 in the , and executes the instruction using that address. The base register 32 is the process I
Segment table 4 pointed to by storage space information 2B held by B
2 indicates a segment descriptor 421 that stores information regarding the segment to be accessed. The information in this segment descriptor 421 allows access to the segment 52.

By making the information of the segment descriptor 412 of process A common to the information of the segment descriptor 421 of process B, the segment descriptors 412 and 421
When accessing using the segment 52, both processes A and B can access the segment 52.

[Problem to be Solved by the Invention] However, in the conventional virtual storage space control method described above, the more common segments that processes have, the more the storage space that can be logically accessed by processes becomes smaller. The disadvantage is that it decreases.

[Failure to solve the problem]

A virtual storage space control method according to the present invention provides a means for holding a plurality of virtual storage space information and a boundary for dividing pace register groups assigned pace register numbers into a plurality of groups in an information processing device that Zaports a virtual storage space. It has a register group, a comparator that compares the pace register number designated by the instruction with the value of the boundary register group, and means for selecting one from a plurality of pieces of virtual storage space information based on the output of the comparator.

〔Example〕

Hereinafter, two embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, a virtual storage space control system according to an embodiment of the present invention is shown in a Zorock diagram, and parts having the same functions as those in FIG. 2 are given the same reference numerals.

In this embodiment, the storage space information 2A of the process A holds two types of storage space information 21 and 22, of which the storage space information 22 holds the same information as the storage space information 2B of the process B. ing. The boundary register 6 is set with a value for dividing the pace register group 3A to which pace register numbers are assigned into a plurality of groups. The values of these storage space information 21, 22, boundary register 6, etc. can be rewritten by instructions from the information processing device. however,
This type of instruction is strongly checked during execution as a privileged instruction. The comparator 7 compares the pace register number of the base register 31 specified by the instruction IA of Zoroses A with the value of the boundary register 6. Referring to FIG. 1, the process A accesses the segment 54 of the process B. The operation when doing so is explained below.

When the instruction lA of Zoroses A accesses the storage space using the base register 31 in the pace register group 3A, the pace register number of the base register 31 and the value of the boundary register 6 are compared by the comparator 7, and the process A The storage space information 21 or 22 is selected by the selector 8. in this case.

Storage space information 22 is selected and segment table 46 is indicated by that information. Furthermore, base register 3
A value of 1 points to segment descriptor 461 in segment table 46. This value allows access to segment 54, which is the storage space of f process B.

Note that in the above embodiment, the storage space information 22 is
However, by setting the storage space information 22 as storage space information for processes other than process B, it is also possible to access the storage spaces of processes other than process B. or.

In the two-legged embodiment, since the process A has two types of storage space information, the boundary register 6 and the comparator 7 each have one type.
There are only pieces. In general, if there are N (N≧2) types of storage space information, the boundary register and comparator are each (N−
1) pcs are required.

〔Effect of the invention〕

As explained above, the present invention is effective in cases such as operating systems, where the processing is not confined only to the virtual memory space within a process, but requires access to the virtual memory space of other processes. . By using the virtual storage space control method according to the present invention, system programs such as operating systems can no longer use part of the virtual storage space given to two original processes for accessing other process spaces. will disappear. It is also possible to coexist with conventional methods.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a virtual storage control method according to an embodiment of the present invention, and FIG. 2 is a block diagram showing a conventional virtual storage control method. IA...Instruction of process A + IB...Process B
instruction, 2A... Storage space information of process A, 2B.
...Storage space information of process B, 21.22...Storage space information, 3A, 3B...Base register group, 3
1...Pace...Segment, 6...Boundary register, 7...Comparator. 8...Selector.

Claims (1)

[Claims] 1. In an information processing device that supports virtual storage space, there is a means for holding a plurality of pieces of virtual storage space information, a boundary register group that divides a base register group to which base register numbers are given into a plurality of groups, and a comparator for comparing the base register number and the value of the boundary register group; and means for selecting one of the plurality of virtual storage space information based on the output of the comparator. Space control method.