JP2010271945A - Computer system and method for supporting kernel mode operation of application program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To run an application program in a kernel mode in order to improve performance without modifying the program, and to increase the speed of determining the operational mode. <P>SOLUTION: A computer system 1A includes: an operational mode determining unit 112 which determines an operational mode set by the application program, and a function call unit 113 which selects a method of calling a kernel function according to the operational mode determined by the operational mode determining unit 112. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a computer system, a kernel mode operation support method for an application program in the system, and a kernel mode operation support program, and more specifically, a technique for executing an application program using a kernel function provided by an operating system. About.

  Operating system (hereinafter referred to as OS: Operating System) provides input / output functions such as data input and screen output, and kernel functions commonly used by many application programs such as disk and memory management. to manage.

  Non-Patent Document 1 discloses an example of processing by the OS described above. According to Non-Patent Document 1, a computer system is composed of an application program that operates in a user mode and a kernel program that operates in a kernel mode, and the application program can use a function of a necessary kernel program by a system call. It is disclosed.

  In addition, the computer system controls information and parameters related to internal register groups and memory management in order to control the transition from the user mode to the kernel mode or from the kernel mode to the user mode before and after executing the target processing. Copy operations for saving and restoring files.

  The application program is executed in the user mode, and uses the function provided by the OS by switching to the kernel mode as necessary. When the operation mode is switched, the computer system generates overhead such as saving / returning internal registers and memory management information as described above, and the performance deteriorates. Therefore, in order to improve the performance, it is desirable to execute the program in the kernel mode. However, since the method of calling the kernel function from the user mode is different from the method of calling the kernel function from the kernel mode, the same processing program is executed. In some cases, it was necessary to implement two for user mode and one for kernel mode.

  On the other hand, in Patent Document 1, information for recognizing whether a computer system is currently operating in a supervisor mode (kernel mode) or a user mode is recorded in a virtual status register allocated on a shared memory. Techniques are disclosed. In other words, when a system call occurs, the computer system refers to the information in this memory, and in supervisor mode, does not save and restore internal registers, but directly calls a function to generate a system call. This saves unnecessary register saving / restoring operations and speeds up the process when switching modes.

JP 2001-109634 A

A. S. Tanenpaum, A.M. S. Woodhal "Operating System 2nd Edition" Prentice Hall, May 1998, pp 24-50

  The problem of the technique disclosed in Non-Patent Document 1 described above is that the program must be corrected when the application program is operated in the kernel mode in order to improve performance. Further, since an application program is developed for each mode, productivity and maintainability are deteriorated. The reason is that the kernel function call is different between the kernel mode and the user mode.

  On the other hand, the technique disclosed in Patent Document 1 refers to information recorded in the memory when a system call occurs, skips save / restore operations in the kernel mode, and performs high-speed processing when the system call occurs. I am trying to make it. This eliminates the need for unnecessary register and memory contents saving / restoring operations in the supervisor mode, thereby speeding up the processing. However, information indicating in which mode the computer system is currently operating is recorded in the memory, and the save / restore operation when a system call occurs is controlled with reference to this information. A new problem arises in terms of conversion.

(Object of invention)
An object of the present invention is to make it unnecessary to modify a program when an application program is operated in a kernel mode in order to improve performance, and to improve the operation mode determination, and to improve the speed of operation mode determination. It is an object to provide a kernel mode operation support method and a kernel mode operation support program.

  A first computer system of the present invention is a computer system that executes an application program using a kernel function provided by an operating system, and an operation mode determination unit that determines an operation mode set by the application program; A function call unit that selects a method for calling the kernel function according to the operation mode determined by the operation mode determination unit.

  A kernel mode operation support method for an application program in a second computer system of the present invention is a kernel mode operation support method for an application program in a computer system that executes an application program using a kernel function provided by an operating system, An operation mode determination step for determining an operation mode set by the application program; and a function call step for selecting a method for calling the kernel function according to the determined operation mode.

  A third kernel mode operation support program according to the present invention is a kernel mode operation support program for a computer system that is executed on a computer and executes an application program using a kernel function provided by an operating system. Then, an operation mode determination process for determining an operation mode set by the application program and a function call process for selecting a method for calling the kernel function according to the determined operation mode are executed.

  According to the present invention, it is not necessary to modify a program when an application program is operated in the kernel mode in order to improve performance, and the computer system and the application program in the system are improved in speeding up the operation mode determination. A kernel mode operation support method and a kernel mode operation support program can be provided.

  The reason is that the kernel function call method is automatically selected according to the determined operation mode, and further, at this time, the mode can be determined without referring to the memory.

It is a block diagram which shows the structure of the computer system by the 1st Embodiment of this invention. It is the block diagram which expanded the function and showed the program structure which the processor unit of the computer system by the 1st Embodiment of this invention performs. It is a flowchart which shows operation | movement of the computer system by the 1st Embodiment of this invention. It is the block diagram which expanded the function and showed the program structure which the processor unit of the computer system by the 2nd Embodiment of this invention performs. It is a flowchart which shows operation | movement of the computer system by the 2nd Embodiment of this invention.

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

(Configuration of the first embodiment)
FIG. 1 is a block diagram showing a configuration of a computer system 1A according to the first embodiment of the present invention.

  Referring to FIG. 1, a computer system 1A according to the first embodiment of the present invention includes a processor unit 11, a main memory 12, an auxiliary memory 13, and an input / output device 14. All of these are commonly connected to a system bus 15 including a plurality of lines for address, data, and control.

  The processor unit 11 serves as a control center of the computer system 1A. The processor unit 11 executes various programs stored in the main memory 12 and executes arithmetic control. In addition to the main memory 12, the auxiliary memory 13, and the input connected via the system bus 15. The output device 14 is controlled. Here, the processor unit 11 includes a mode register 110 that holds an operation mode that is dynamically set by executing an application program. The structure of the kernel mode operation support program executed by the processor unit 11 will be described later with reference to FIG.

  In the main memory 12, in addition to the OS and application programs described above, input / output drivers for controlling peripheral devices such as the auxiliary memory 13 and the input / output device 14 are allocated and stored. The respective areas 121, 122, 123, And a data area 124 used by these programs. The main memory 12 includes, for example, a randomly accessible storage device such as SRAM or DRAM, a nonvolatile semiconductor memory device, or the like.

  The auxiliary memory 13 stores various programs and data that cannot be accommodated in the main memory 12, and is configured by a large-capacity nonvolatile storage device such as a hard disk device or an optical disk device. The input / output device 14 is, for example, a keyboard or an LCD (Liquid Crystal Display Device) display.

  FIG. 2 is a functional block diagram showing the structure of the kernel mode operation support program executed by the processor unit 11 of the computer system 1A according to the first embodiment of the present invention. It is assumed that the kernel mode operation support program is stored in the main memory 12 as part of the OS or as middleware such as a utility program that does not belong to the OS or application program.

  Referring to FIG. 2, the kernel mode operation support program executed by the processor unit 11 has a structure including a program execution control unit 111, an operation mode determination unit 112, and a function call unit 113.

  The program execution control unit 111 has a function of sequentially reading and executing various programs such as an OS (area 121), an application program (area 122), and an input / output driver (area 123) stored in the main memory 12.

  The operation mode determination unit 112 has a function of referring to a mode register 110 built in the processor unit 11 that executes a program and determining an operation mode held in the mode register 110.

  The function call unit 113 has a function of selecting a kernel function call method according to the operation mode determined by the operation mode determination unit 112. Specifically, when the first operation mode (user mode described later) is set in the mode register 110, the function calling unit 113 sets the second operation mode (kernel mode described later) by a system call. If so, a kernel function call is selected and executed by a subroutine call.

  The kernel function here means the most central functional part that directly manages and operates the hardware in the OS. For example, when the application program issues an input / output command, the OS interprets this. The function that starts the input / output driver and provides the input / output service by the input / output driver.

(Operation of the first embodiment)

  In the configuration described above, the mode register 110 holds information for determining the operation mode of the processor unit 11. Here, the operation mode refers to a user mode and a kernel mode. When operating in the user mode, the processor unit 11 is only allowed to execute a predetermined group of instructions and access a fixed memory area of the main memory 12. On the other hand, there is no such limitation when operating in kernel mode.

  Further, the user mode is changed to the kernel mode by issuing a system call instruction, and the kernel mode is changed to the user mode by an interrupt return instruction. When the operation mode is changed, the program execution control unit 111 updates the mode register 110. Then, the operation mode determination unit 1112 determines the current operation mode from the contents of the mode register 110, and the function call unit 113 calls a kernel function according to the operation mode set in the operation mode determination unit 112. At this time, the function calling unit 113 issues a system call in the user mode, and calls a kernel function by a normal subroutine call in the kernel mode.

  Next, the operation of the computer system 1A according to the first embodiment of the present invention will be described with reference to the flowchart shown in FIG.

  Referring to FIG. 3, first, the application program (area 123) stored in the main memory 12 is started on the processor unit 11, and its execution is started (step S301).

  When executing the application program, the processor unit 11 (program execution control unit 111) determines whether or not a kernel function is called (step S302). Here, the presence / absence of a kernel function call refers to, for example, whether or not an input / output instruction that entrusts processing to an OS including an input / output driver is described in an application program. When the application program read from the main memory 12 indicates a normal instruction other than a kernel function call (step S302 “NO”), the program execution control unit 111 executes the normal instruction. (Step S303).

  On the other hand, in the case of a kernel function call (step S302 “YES”), the program execution control unit 111 transfers control to the operation mode determination unit 112, and the operation mode determination unit 112 that receives this refers to the mode register 110. (Step S304), the current operation mode is determined, and control is transferred to the function calling unit 113 (Step S305).

  If the operation mode is the user mode (step S305 “user”), a system call is issued to transfer control to the program execution control unit 111 (step S306). If the operation mode is the kernel mode (step S305 “kernel”), The function calling unit 113 executes a subroutine call as it is (step S307).

  The above-described processing is repeatedly executed until the program ends, and if there is a program end instruction (step S308 “YES”), the program execution control unit 111 performs the program end processing (step S309), and a series of processing by the application program Exit.

(Effects of the first embodiment)
In the computer system 1A according to the present embodiment, when a kernel function is called from an application program, the function call unit 113 calls an appropriate kernel function after the operation mode determination unit 112 determines the operation mode. Can develop an application program without having to be aware of the operation mode. Therefore, productivity and maintainability of the application program can be improved without requiring modification of the application program.

  This is because the user can develop a program without being aware of the operation mode.

  Further, the computer system 1A according to the present embodiment can realize high-speed processing at the time of operation mode determination.

This is because the operation mode can be determined by referring to the mode register 110 built in the processor unit 11 without referring to the low-speed main memory 12.

  2 may be realized entirely by software, or at least a part of them may be realized by hardware. For example, the operation mode determination unit 112 determines the operation mode set by the application program, and the function call unit 113 selects the kernel function call method according to the operation mode determined by the operation mode determination unit 112. The processing may be realized on a computer by one or a plurality of programs, and at least a part thereof may be realized by hardware.

(Configuration of Second Embodiment)
FIG. 4 is a block diagram showing the function of the structure of the program executed by the processor unit of the computer system according to the second embodiment of the present invention. Also in the second embodiment described below, the configuration of the computer system 1A shown in FIG. 1 is used as in the first embodiment described above.

  Referring to FIG. 4, a computer system 1B according to the second embodiment of the present invention has a structure that further includes a flag area 125 in addition to the program structure executed by the processor unit 11 of the first embodiment. Yes. This flag area 125 is allocated to a part of the main memory 12, and the operation mode is set and stored prior to the execution of the application program.

(Operation of Second Embodiment)
Next, the operation of the computer system 1B according to the second embodiment of the present invention will be described with reference to the flowchart shown in FIG.

  Referring to FIG. 5, first, an application program (area 123) stored in the main memory 12 is started on the processor unit 11, and its execution is started (step S501). In the second embodiment, the operation mode is set in advance prior to the start of the program, and the operation mode set here is recorded as a mode flag in the flag area 125, and this operation is performed when the program execution is started. It is assumed that the mode is copied to the mode register 201 (step S502).

  When executing the application program, the processor unit 11 (program execution control unit 111) determines whether or not a kernel function is called (step S503). When the application program read from the main memory 12 indicates a normal instruction other than the kernel function call (step S503 “NO”), the program execution control unit 111 executes the normal instruction. (Step S504).

  On the other hand, in the case of a kernel function call (step S503 “YES”), the program execution control unit 111 transfers control to the operation mode determination unit 112, and the operation mode determination unit 112 that receives this refers to the mode register 110. (Step S505) The current operation mode is determined, and the control is transferred to the function calling unit 113 (Step S506).

  When the operation mode is the user mode (step S506 “user”), a system call is issued to transfer control to the program execution control unit 111 (step S507). When the operation mode is the kernel mode (step S506 “kernel”), The function calling unit 113 executes the subroutine call as it is (step S508).

  The process described above is repeatedly executed until the program ends, and if there is a program end instruction (“YES” in step S509), the program execution control unit 111 performs a program end process (step S510), and a series of processes by the application program Exit.

(Effects of the second embodiment)
In the computer system 1B according to the present embodiment, the operation mode of the application program to be executed is set in the flag area 125 in advance, and after the operation mode determination unit 112 determines the operation mode, the function call unit 113 has an appropriate kernel function. Make a call. Therefore, as in the first embodiment described above, the programmer can develop an application program without being aware of the operation mode. Therefore, productivity and maintainability of the application program can be improved without requiring modification of the application program.

  This is because the user can develop a program without being aware of the operation mode.

  In the computer system 1B according to the present embodiment, high-speed processing at the time of operation mode determination can be realized.

  The reason is that, once the content of the mode flag set in the flag area 125 is copied to the mode register 110 built in the processor unit 11, the operation mode determination unit 112 refers to this mode register 110 to determine the operation mode. This is to make it possible.

  Note that all of the functions of the processor unit 11 in FIG. 4 may be realized by software, or at least a part thereof may be realized by hardware. For example, the operation mode determination unit 112 determines the operation mode set by the application program, and the function call unit 113 selects the kernel function call method according to the operation mode determined by the operation mode determination unit 112. The processing may be realized on a computer by one or a plurality of programs, and at least a part thereof may be realized by hardware.

  Although the present invention has been described with reference to the preferred embodiments and examples, the present invention is not necessarily limited to the above-described embodiments and examples, and various modifications may be made within the scope of the technical idea. Can be implemented.

  The present invention can be applied to all uses for speeding up the application program in the kernel mode operation.

1A, 1B: Computer system 11: Processor unit 12: Main memory 13: Auxiliary memory 14: Input / output device 15: System bus 110: Mode register 111: Program execution control unit 112: Operation mode determination unit 113: Function call unit 125: Flag area

Claims (12)

A computer system that executes an application program using a kernel function provided by an operating system,
An operation mode determination unit for determining an operation mode set by the application program;
A function calling unit that selects a calling method of the kernel function according to the operation mode determined by the operation mode determination unit;
A computer system comprising: The operation mode determination unit
2. The computer system according to claim 1, wherein an operation mode held in the mode register is determined with reference to a mode register built in a processor unit that executes the application program. A flag memory in which an operation mode is set prior to execution of the application program;
The operation mode determination unit
3. The computer system according to claim 1, wherein the operation mode set in the flag memory is held in the mode register. The function calling unit is
The kernel function is called by a subroutine call when the second operation mode is set by a system call when the first operation mode is set in the mode register. The computer system according to any one of claims 1 to 3. A kernel mode operation support method for an application program in a computer system that executes an application program using a kernel function provided by an operating system,
An operation mode determination step for determining an operation mode set by the application program;
A function call step of selecting a method of calling the kernel function according to the determined operation mode;
A kernel mode operation support method for an application program, comprising: The operation mode determination step includes
6. The kernel mode operation support of an application program according to claim 5, further comprising a sub-step of referring to a mode register built in a processor unit that executes the application program and determining an operation mode held in the mode register. Method. The operation mode determination step includes
7. The kernel of the application program according to claim 5, further comprising a sub-step of holding in the mode register an operation mode set in a flag memory in which an operation mode is set prior to execution of the application program. Mode operation support method. The function calling step includes:
Including a sub-step for executing a call to the kernel function by a subroutine call when the second operation mode is set by a system call when the first operation mode is set in the mode register. The kernel mode operation support method for an application program according to any one of claims 5 to 7. A computer system kernel mode operation support program that is executed on a computer and executes an application program using a kernel function provided by an operating system,
In the computer,
An operation mode determination process for determining an operation mode set by the application program;
A function call process for selecting a call method of the kernel function according to the determined operation mode;
A kernel mode operation support program characterized by causing The operation mode determination process includes
The kernel mode operation support program according to claim 9, wherein an operation mode held in the register is determined with reference to a register built in a processor unit that executes the application program. The operation mode determination process includes
11. The kernel mode operation support program according to claim 9, wherein an operation mode set in a flag memory in which an operation mode is set prior to execution of the application program is held in the mode register. The function call process is
When the first operation mode is set in the mode register, the kernel function is called by a subroutine call when the second operation mode is set by a system call. The kernel mode operation support program according to any one of claims 9 to 11.

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