JPH07141207A - Information processing system - Google Patents

Abstract

PURPOSE:To reduce the frequency of a switching processing for virtual spaces and to shorten the program processing time by providing a equality means which decide whether or not data stored in a temporary storage means are altered according to a system call and stores them in a data storage area for process management when the data are altered. CONSTITUTION:A process management part 3 is provided with the equality part 33 which is executed before the process management part 3 performs a processing using data. This equality part 33 decides whether the data held in the temporary storage part 22 are already altered by a processing executed with the system call for altering data for process management. When the data are already altered, the equality part 33 stores the data, held in the temporary storage part 22, in a data storage area for process management. Consequently, the processing which uses the data of the process management part 3 is performed by using the latest data at all times and the frequency of the switching processing for virtual spaces can be decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing system which individually has a virtual space of a user (hereinafter referred to as user space) and a virtual space of an operating system (hereinafter referred to as system space), and controls the virtual space.

[0002]

2. Description of the Related Art Unix (UNIX: Unix System Labora
Conventional operating systems (such as tories (USL) licensed operating systems) have separate user space and system space, and operating system data is mapped to the system space. A user program is mapped in the user space, and a process for each virtual space executes this. A process prohibits memory access to data in different virtual spaces by the operating system. This protects the operating system data from unauthorized access by the process.

A process can request data processing of the operating system by using a system call prepared by the operating system.
When a system call is called by a process, a trap occurs and the access destination of the execution instruction or data is switched from the user space to the system space. Then, a system call is executed to perform data processing of the operating system. For more information on Unix virtual space and system call processing, see “Unix 4.3 BS (BSD)”.
Design and implementation ”by SJ Leffler et al., Published by Maruzen Co., Ltd.

[0004]

The virtual space switching is mainly performed by saving and restoring contexts (processor registers, program counters, stack pointer values) and saving and restoring registers that point to the page table area. become. Programs that frequently change or read data in the operating system often switch between virtual spaces. Therefore, the program processing time of the process is increased.

The above problem will be described in detail by taking the conventional process management unit shown in FIG. 2 as an example. In FIG. 2, 1
Reference numerals 1, 12, and 13 are programs executed by each process. Information of each process is managed by the process management unit 3. The process is in the user space, and the process management unit 3
Are respectively mapped to the system space.

Each process has a priority order for determining the order of execution, and the priority order data is held in the priority order storage unit 34 of the process management unit 3. When a process changes its priority, it executes a priority change system call 110. By this system call, the context save operation unit 31 of the process management unit 3
Switch the virtual space to the system space. After that, the context save operation unit 31 changes the context information of the currently executing process (process 1 in the example of FIG. 2) to
Save in the context storage unit 32. Next, the scheduler 35 changes the priority value of the process 1 held in the priority storage unit 34, searches the priority storage unit 34, detects the process having the highest priority, and The recovery operation unit 36 stores the context of the process having the highest priority in the context storage unit 3.
From 2 to the processor, the user space is switched to the virtual space of the process. Through the above processing, the processing of the process having the highest priority value is started.

As described above, when the priority order is changed by the process management unit 3, the process management unit 3 performs scheduling for reselecting the process to be executed. This is because the priority of the running process (that is, the process that has the highest priority among the runnable processes) has been changed, so the process other than the currently running process has the highest priority. This is because there is a possibility that it has become a value.

However, when a process raises its priority, the priority of the process is normally the highest among the operable processes in the system because it is already scheduled. The process selected by the above scheduling is running. Therefore, in such a case, the process of switching the virtual space and the scheduling process are executed by useless system calls.

In the above example, the priority value is mapped in the system space, and the virtual space switching occurs in accordance with the change of the value. However, in addition to this, in some system space. When the process causes the operating system to change the value, in order to change the value in the system space, the process of switching the virtual space from the user space to the system space always occurs, and the process is controlled again. In order to return, the process of returning the virtual space from the system space to the user space must be performed. However, the values in the system space do not always need to be referenced by the operating system. Therefore, when the operating system does not need to refer to it, it can be said that the above virtual space switching processing is substantially useless processing. This is because it is considered possible to switch only when it is necessary to refer to it.

Therefore, an object of the present invention is to provide an information processing system in which the program processing time is shortened by reducing the number of times of virtual space switching processing.

[0011]

In order to achieve the above object, the present invention executes an operating system realized in a system space and a user program.
A process realized in a user space, the operating system has a process management means for managing the process, and the process management means includes a process management data storage area and the process management data. According to the above, the process comprises a means for performing a predetermined process, wherein the process has a means for executing a system call for causing the process management means to perform the predetermined process,
The process has a temporary storage unit for holding the process management data and a temporary storage changing unit for changing the value held by the temporary storage unit when a request for changing the process management data is made. The process management means determines whether or not the data held in the temporary storage means is changed according to the system call, and if the data is changed, the data held in the temporary storage means is changed to the above-mentioned data. There is provided an information processing system characterized by comprising a matching means for storing in a process management data storage area.

Further, according to the present invention, the process determines whether or not the system call is required to be executed when a request to change the process management data is made, and if the determination requires the execution, An information processing system having a change determination means for executing the system call; and the temporary storage means provided in the user space that can be commonly accessed by one or more processes, Will be provided.

Further, according to the present invention, the process management data may be a process priority. The predetermined process of the process management unit is a scheduling process, and the change determination unit determines whether the changed process management data has the highest priority order. There is also provided an information processing system including means for executing the system call. The process management data may be the effective user ID. In this case, the predetermined process of the process management means may be a file access permission examination process.

[0014]

In the present invention, the virtual space is not always switched even when the process instructs the process management data to be changed. In order to eliminate useless space switching processing, the present invention provides a temporary storage means which is a storage area of the data in the user space so that the process can refer to and change the process management data. The process can change the contents of the temporary storage means by the temporary storage changing means.
Furthermore, in the present invention, the process is provided with a change determination means. The change determination means determines which of the temporary storage change means and the system call is to be executed when a request to change the process management data is made.

As a result, according to the present invention, even when the above-mentioned process management data is changed, the temporary storage changing means can be used in the user space until the system actually needs to perform processing using the data. The system call is not executed, only the processing for changing the data of the above is performed. Therefore, in such a case, the process of switching the virtual space to the system space and the process of switching the system space to the user space associated with the system call are not performed.

Further, the process management means is provided with a matching means that is executed before the process management section performs the processing using the data. The matching means determines whether or not the data held in the temporary storage means has already been changed by the process in the process executed by the system call for changing the process management data. If it has already been changed, the matching means
The data held in the temporary storage means is stored in the process management data storage area.

As a result, when the system call is executed, before the process management unit performs the processing using the data, the contents of the temporary storage means in the user space and the storage area of the data in the system space are stored. The contents of are in agreement, and the process using the data of the process management unit is
The latest data is always used.

In the case similar to the example using FIG. 2 described above, the operation of the present invention will be described by exemplifying a case where the present invention is applied to holding and management of priority order data. The process management unit 3 that executes a system call for referring to and changing priority data is mapped in the system space. The process management unit 3 includes a priority order storage unit 34 for holding priority order data. In this example, the process management data is data representing a priority order.

When a process makes a system call,
The virtual space is switched to the system space, and control is passed to the process management unit 3. In the process management unit 3 of the present invention, first, the matching unit copies the changed data in the temporary storage unit to the priority storage unit 34, and the contents of the priority storage unit 34 in the system space are updated. Will be Next, the process management unit 3 performs a scheduling process by using the data held in the priority storage unit 34 having the latest contents, switches the virtual space to the user space of the highest priority process, and Pass control to.

Even when the process requests the change of the priority order, if the changed priority order is the highest priority order as in the present case, the process management section 3 need not perform the scheduling process. Absent. Therefore, it can be said that a process may make a system call only when the process management unit 3 actually needs to perform the scheduling process.

Therefore, in the present invention, the process includes a change determination means. In this example, the change determination means determines whether or not the changed priority is the highest priority, and if the highest priority is given, the temporary storage changing means is executed, and if the highest priority is not given, the system call is made. To execute. As a result, in the present invention, the system call is executed only when the priority of the process being executed is not the highest priority due to the change.

As described above, according to the present invention, the number of virtual space switching processes can be reduced, and the program processing time can be shortened. The present invention is directed to Japanese Patent Application No. 5-10.
It is especially effective for running programs that frequently change priorities, as proposed by 8417.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. (Embodiment 1) First, a configuration example when this embodiment is realized on a computer will be described with reference to FIG. Programs 11, 12 and 13 executed by the process, and temporary storage management unit 2
Then, the process management unit 3 is loaded from the disk 42 to the memory 43 during system operation. Then, the processor 41 executes these programs and the management unit. The computer 4 of this embodiment includes the display 44, the mouse 45, and the keyboard 46 as input / output devices, but the input / output devices are not limited to these.

FIG. 1 shows the configuration of the temporary storage management unit 2 and the process management unit 3 of this embodiment. In FIG. 1, 11, 1
Reference numerals 2 and 13 are programs executed by each process (1 to N). In addition, in FIG. 1, a dotted arrow indicates a data flow, and a solid arrow indicates a control flow.

The programs 11 to 13 are mapped in the virtual space of each process. The temporary storage management unit 2 for changing the priority order of the temporary storage unit and for reading the temporary storage unit 2 has a user space common to each process (
It is mapped to a space that can be referred to and updated without switching the virtual space), and each process can cause the temporary storage management unit 2 to perform processing without switching the virtual space. The temporary storage management unit 2 of this embodiment is realized as a library routine "SETPRIO". The process management unit 3 that manages process information is a part of the operating system and is mapped in the system space.

The temporary storage management unit 2 includes a temporary storage unit 22 in which the priority of each process is registered, and a temporary storage unit 22.
Based on the contents stored in the next candidate storage unit 23 and the next candidate storage unit 23, which holds the second highest value among the priorities of all the processes registered in the process management unit 3, A change determination unit 21 (change determination means) for determining whether to change 34 is provided.

The process management section 3 stores a context saving operation section 31 for saving the current context in order to process the system space, a context storage section 32 as a context saving area for each process, and a temporary storage section 22.
The priority change information stored in the priority storage unit 34 is stored in the priority storage unit 34.
And a priority order storage section 3 for holding the priority order of all operable processes.
4, a scheduler for selecting a process to be executed next based on the priority storage unit 34, and a context recovery operation unit 36 for loading the context of the process selected by the scheduler 35 from the context storage unit 32 into the processor. Is equipped with.

The temporary storage unit 22 serves as a temporary storage means, and as shown in FIG. 6, a process name storage area 221 for holding the process name of the process for each process, and the priority of the process. It has a priority storage area 222 for holding the order and a change flag storage area 223 for holding the change flag indicating whether or not the priority of the process is changed in the temporary storage management unit 2. . All the change flags are normally cleared to "0", and when the priority is changed, the flag corresponding to the process whose priority has been changed becomes "1". The space for the temporary storage unit 22 is created by the process that operates first. Each of the processes generated thereafter allocates a free area in the temporary storage unit 22 to itself, stores the own process name in the process name storage area 221 of the area, and uses it.

As shown in FIG. 7, the next candidate storage unit 23 has the second highest priority value among the priorities of all the processes registered in the temporary storage unit 22, that is, the priority of the next candidate process. This is a storage area for holding rank values. This is managed by the scheduler 35 of the process management unit 3 which will be described later, and is used for determining whether process scheduling is necessary. Next candidate storage unit 2
3 is not always necessary. Because, "SET PRIO"
It is possible to determine whether or not the process scheduling is required by the call of by comparing the values held in all the priority storage areas 222 in the temporary storage unit 22 with the arguments of the "SETPRIO" call. Is. However, if the next candidate storage unit 23 is prepared in advance and the value of the second highest priority is stored, the next candidate storage unit 2
Just compare the value of 3 and the argument of "SET PRIO",
There is an advantage that it is possible to determine whether process scheduling is required at high speed.

As shown in FIG. 4, the context storage unit 32 includes, for each process, a process name storage area 321 for holding the process name of the process and a register for saving the register contents of the process. And a storage area 322. The register saving area 322 is an area 322 for saving the contents of the registers of the processor.
And an area for storing the contents of registers for specifying the virtual space.

As shown in FIG. 5, the priority storage unit 34 has a priority recording table 340 for associating the process name with the priority for each process, and the priority recording table 340 is linked by a pointer. The priority record table 340 includes a process name storage area 341 that holds a process name, a priority order storage area 342 that holds a priority value, and a pointer storage area 343. When the operating system creates a process, the operating system creates a priority record table 340 holding the process name and priority of the process, and the newly created priority record table 340 is stored in the priority storage area 342 of the table. According to the value held by, the existing link in the priority storage unit 34 is allowed to participate.
The pointers stored in the pointer storage area 343 have such values that the priority record tables 340 are linked in descending order of priority 343. When the priority order is changed and the order is changed, the content of the pointer storage area 343 is also changed so that the priority order recording tables 340 are linked in descending order of priority.

A. When a library call for changing the process priority (call of "SETPRIO" in this embodiment) is described in the processing program of the temporary storage management unit 2, control is temporarily performed by executing the library call. It is moved to the storage management unit 2. The library call takes a value after changing the priority as an argument.

When the library routine "SETPRIO" is called from the process 1 according to the code described in the program (shown by 111 in FIG. 1), the control is first transferred to the change determination unit 21 of the temporary storage management unit 2. Be done. A flowchart showing the operation of the change determination unit 21 is shown in FIG.

(1) First, the change determining unit 21 stores the priority order storage area 2 corresponding to the process in the temporary storage unit 22.
22 stores and modifies the argument of the call of "SETPRIO" (this is a function as a temporary memory modification means of the modification judgment unit 21 of the present embodiment), and modifies the modification flag storage area 223 corresponding to the process. , "1" are stored (step 81).

(2) Next, the change determination unit 21 reads the value held in the next candidate storage unit 23 (step 82), and the value held in the next candidate storage unit 23 and the argument of the "SETPRO" call. Are compared (step 83). If the value held in the next candidate storage unit 23 is smaller, the change determination unit 2
The processing of No. 1 is ended, and the processing of the process is restarted. This is because the currently scheduled process 1 still has a higher priority after the change than the next candidate process.

(3) When the value held in the next candidate storage unit 23 is larger, the change determination unit 21 causes the process management unit 3 to perform scheduling processing in order to preferentially execute the process of the next candidate. It needs to be done. Therefore, the change determination unit 21 executes a system call (“setprio”) for changing the priority order data (211 in FIG. 1).
(Illustrated in). By the "setprio" call 211, control is transferred to the process management unit 3 (step 84), and the processing of the change determination unit 21 ends. The system call "setpri
"o" has no arguments. In addition, in this embodiment, "SETPR
It is assumed that “IO” and “setprio” can change only the priority of the own process, but the present invention can be applied to the case where the priority of another process can be changed.

B. When the processing system call “setprio” of the process management unit 3 is executed, the control is transferred to the process management unit 3. Below, the process management unit 3
The operation of will be described. The operation of the process management unit 3 is shown in FIG.

(1) First, the context save operation unit 31 of the process management unit 3 switches the virtual space to the system space. After that, the context save operation unit 31 stores the context information of the currently executing process (process 1 in this example) in the register save area 322 assigned to the process in the context storage unit 32 (step 91).

(2) Next, the matching unit 33 of the process management unit 3 causes the change flag storage area 223 of the temporary storage unit 22.
Search for processes whose contents are "1" (step 9)
2). If there is a process whose flag is "1", the matching unit 33 stores the contents of the priority storage area 222 of the process in the temporary storage unit 22 and the process name of the process in the priority storage unit 34 as the process name. The data is stored in the priority storage area 343 of the priority recording table 340 held in the area 341, and "0" is stored in the change flag storage area 223 of the process (step 93). The matching unit 33 repeats the processes of steps 92 and 93 until there is no process having the change flag of "1". As a result, the changed priority value is copied into the priority storage unit 34 in the system space.

(3) When the copying of the priority values is completed,
The scheduler 35 of the process management unit 3 searches the priority storage unit 34 to detect the highest priority value and the second priority value (step 94), and determines the second priority value. , Next candidate storage unit 23 (step 9)
5).

(4) Finally, in step 94, the context recovery operation unit 36 of the process management unit 3
The context of the process having the highest priority value detected by the scheduler 35 is read from the context storage unit 32 into the processor, the user space is switched to the virtual space of the process, and control is passed to the process (step 96). . With that, the process of the process management unit 3 is completed. Through step 96, the process with the highest priority value begins processing. In FIG. 1, as an example, the flow of control in the case where the process N has the highest priority because the priority of the process 1 has been changed is illustrated by an arrow 212.

In the present embodiment, "process"
May have a plurality of "threads" (see Japanese Patent Application No. 5-108417) or "lightweight processes" inside. Further, in this embodiment, the priority order information is processed by the temporary storage management unit 2 and the matching unit 33.
You can also target other data in the kernel. For example, it is effective for information that a user may explicitly or implicitly update, such as process attribute data such as an effective user ID (identifier), a real user ID, and a process group identifier.

(Embodiment 2) Temporary storage manager 2 and process manager 3 when the present invention is applied to an effective user ID.
10 shows an example of the configuration of the above.

The temporary storage management unit 2 according to the second embodiment includes an effective user ID temporary storage unit 25 that temporarily holds an effective user ID and a temporary storage change unit 24 that updates the contents of the effective user ID temporary storage unit 25. With. The effective user ID temporary storage unit 25 stores a process name storage area and an effective user ID.
A storage area and a change flag storage area are provided. The initial value of the change flag is "0" as in the first embodiment.

The process management unit 3 according to the second embodiment includes a context save operation unit 31, an effective user ID matching unit (matching unit) 39 for copying an effective user ID into the system space, and an effective user ID. An effective user ID storage unit 37, which is a storage area in the system space, and an effective user ID
And an effective user ID processing unit 38 which performs processing by referring to
Context storage unit 32 and context recovery operation unit 3
6 and 6.

In this embodiment, the process is the effective user I
When it becomes necessary to change D, the library call 112 to the temporary storage management unit 2 causes the temporary storage changing unit 24 to store the effective user ID stored in the effective user ID temporary storage unit 25.
To change. At this time, the temporary storage changing unit 24 stores "1" in the change flag storage area assigned to the process.

On the other hand, a system call that requires the operating system to refer to the effective user ID, for example,
System calls for communication processing, etc. (2 in FIG. 10)
13) is performed by the process, the process management unit 3 performs the following processing.

(1) First, as in the first embodiment, the context save operation unit 31 switches the virtual space to the system space and stores the context information of the process currently being executed in the context storage unit 32.

(2) Next, the effective user ID matching unit 3
If the content of the change flag storage area 223 of the effective user ID temporary storage unit 25 of the process currently being executed is "1", the effective user ID of the process held in the effective user ID temporary storage unit 25 is , Effective user ID storage unit 3
7 is stored in the effective user ID storage area assigned to the process, and is stored in the change flag storage area of the process.
0 "is stored.

(3) Since the value of the effective user ID storage unit 37 in the system space matches the latest value by the processing of (2) above, the effective user ID processing unit 38 stores the effective user ID storage unit 37 in the effective user ID storage unit 37. The processing is performed by referring to the value held. For example, this is a process such as a file owner access permission check in the file access process.
In the access permission examination process, the effective user ID processing unit 38 performs a process for checking whether or not there is an access right based on the effective user ID held in the effective user ID storage unit 37.

(4) Finally, as in the first embodiment, the context recovery operation unit 36 reads the context of the process being executed (process 1 in the example of FIG. 10) from the context storage unit 32 into the processor, and the user The space is switched to the virtual space of the process and control is passed to the process.

(Effect of each of the above embodiments) According to each of the above embodiments, even when the process requests the process of changing the priority order, the virtual space is set only when the scheduling process is required immediately. Switch to system space, otherwise make a system call and change only data in temporary storage inside user space. This allows
The number of system calls can be reduced and the program processing time can be reduced. Furthermore, in this embodiment, the number of scheduling can be reduced,
The program processing time can be further reduced.

[0053]

According to the present invention, there is provided an information processing system in which the program processing time is shortened by reducing the number of virtual space switching processes.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a temporary storage management unit and a process management unit when the present invention is applied to holding and updating a priority order.

FIG. 2 is a configuration diagram of a conventional process management unit.

FIG. 3 is an example of a configuration diagram in which a temporary storage management unit and a process management unit are realized on a computer.

FIG. 4 is a configuration diagram of a context storage unit.

FIG. 5 is a configuration diagram of a priority order storage unit.

FIG. 6 is a configuration diagram of a temporary storage unit.

FIG. 7 is a configuration diagram of a next candidate priority storage unit.

FIG. 8 is a flowchart showing an operation of a change determination unit.

FIG. 9 is a flowchart showing an operation of a process management unit.

FIG. 10 is a configuration diagram of a temporary storage management unit and a process management unit when the present invention is applied to holding and updating an effective user ID.

[Explanation of symbols]

11, 12, 13 ... Program executed by the process,
2 ... Temporary storage management unit, 3 ... Process management unit, 21 ... Change determination unit, 22 ... Temporary storage unit, 23 ... Next candidate storage unit, 24 ... Temporary storage change unit, 25 ... Effective user ID
Temporary storage unit, 31 ... Context save operation unit, 32 ...
Context storage unit 33 ... Matching unit, 34 ... Priority order storage unit, 35 ... Scheduler, 36 ... Context recovery operation unit, 37 ... Effective user ID storage unit, 38
... Effective user ID processing unit, 39 ... Effective user ID matching unit, 4 ... Calculator, 41 ... Processor, 42 ... Magnetic disk device, 43 ... Main storage device, 44 ... Display, 45 ... Mouse, 46 ... Keyboard.

Claims (8)

[Claims] 1. An operating system realized in a system space and a process realized in a user space for executing a user's program, wherein the operating system comprises process management means for managing the process. The process management means includes a storage area for process management data and a means for performing a predetermined process according to the process management data, and the process performs the predetermined process. In the information processing system having means for executing a system call for causing the process management means to perform, in the process, a temporary storage means for holding the process management data and a request for changing the process management data are generated. In this case, change the temporary memory to change the value held in the temporary memory. The process management means determines whether or not the data held in the temporary storage means is changed according to the system call, and if the data is changed, the process management means holds the data in the temporary storage means. An information processing system comprising a matching means for storing the data in the process management data storage area. 2. The process according to claim 1, wherein the process receives a request to change the process management data,
An information processing system, comprising: a change determining unit that determines whether or not to execute the system call and executes the system call when the system call is required by the determination. 3. The information processing system according to claim 1, wherein the temporary storage unit is provided in the user space that can be commonly accessed by one or more processes. 4. The information processing system according to claim 2, wherein the temporary storage unit is provided in the user space that can be commonly accessed by one or more processes. 5. The information processing system according to claim 4, wherein the process management data is a process priority. 6. The predetermined process of the process management means according to claim 5,
Scheduling processing, wherein the change determination means includes means for determining whether or not the changed process management data has the highest priority, and executing the system call if not the highest priority. Information processing system. 7. The information processing system according to claim 1, wherein the process management data is an effective user ID. 8. The predetermined process of the process management means according to claim 7,
An information processing system characterized by a file access permission investigation process.