JP2009288849A - Information processing apparatus, and memory management method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a memory management technique of more general demand paging type. <P>SOLUTION: In a system executing a program performing a function call through a function pointer table, and adopting a demand paging memory management system, this information processing apparatus has: a memory arranged with a function; and a control part counting a calling frequency upon the function call of the program, periodically monitoring the calling frequency, and changing the memory arrangement of the function according to the calling frequency. The control part operates such that the function having the relatively small calling frequency is driven out from the memory by demand paging. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an information processing apparatus, and more particularly to a memory management method thereof.

  Of the control methods in information processing equipment, the memory management method of the equipment plays an important role, but in general demand paging memory management, functions with few reads and many functions are mixed on the same page. In this case, although a function with a small number of readings is not necessary, the page is not paged out and the memory use efficiency is poor.

On the other hand, as an outline in Patent Document 1, in the demand paging / swap-out method, the swap-out page selection means, the time stamp value (current time) of the target page, and the priority P are averaged based on the swap-out priority of each page. A method for calculating the swap-out time and aiming at effective use of memory resources is described. However, this is a demand paging / swap-out method in the kernel space, and there is a limitation in technology in a virtual memory computing system that adopts a monolithic kernel generated as a single load module.
Japanese Patent No. 3726701

  An object of the present invention is to provide a more general demand paging type memory management technique.

  In order to solve the above problems, an information processing apparatus of the present invention executes a program that performs a function call via a function pointer table, and in a system employing a demand paging memory management method, a memory in which a function is arranged, A control unit that counts the number of calls at the time of a function call of a program, periodically monitors the number of calls, and changes the memory arrangement of the function according to the number of calls, the control unit relative to the number of calls It is characterized in that a small number of functions work to be evicted from the memory by demand paging.

  According to the present invention, a more effective demand paging memory management technique can be obtained.

  Embodiments of the present invention will be described below.

  A first embodiment of the present invention will be described with reference to FIGS. First, the configuration of an information processing apparatus according to an embodiment of the present invention will be generally described with reference to FIGS. This information processing apparatus is realized as, for example, a notebook personal computer 10.

  FIG. 6 is a front view of the notebook personal computer 10 with the display unit opened. The computer 1 0 is composed of a computer main body 1 1 and a display unit 12. The display unit 12 incorporates a display device composed of an LCD (Liquid Crystal Display) 17, and the display screen of the LCD 17 is located substantially at the center of the display unit 12. .

The display unit 1 2 is attached to the computer main body 1 1 so as to be rotatable between an open position and a closed position. The computer main body 11 has a thin box-shaped housing. On the upper surface of the computer main body 11, a keyboard 1 3, a power button 14 for powering on / off the computer 1, an input operation panel 1 5, and a touch pad 16 are provided. Etc. are arranged.

The input operation panel 1 5 is an input device for inputting an event corresponding to the pressed button, and includes a plurality of buttons for starting a plurality of functions. These button groups also include a TV start button 15A and a DVD / CD start button 15B. The TV start button 1 5 A is a button for starting a TV function for reproducing and recording TV broadcast program data. When the TV start button 1 5 A is pressed by the user, the TV application program for executing the TV function is automatically started.

In this computer, in addition to a general-purpose main operating system, a dedicated sub-operating system for processing AV (audio / video) data is installed. The TV application program is a program that operates on the sub-operating system.

When the power button 1 4 is pressed by the user, the main operating system is activated. On the other hand, when the TV start button 15A is pressed by the user, the sub operating system is started instead of the main operating system, and the TV application program is automatically executed. The sub-operating system has only a minimum function for executing the AV function. For this reason, the time required for booting up the sub operating system is much shorter than the time required for booting up the main operating system. Therefore, the user can immediately perform TV viewing / recording simply by pressing the TV start button 15A.

The DVD / CD activation button 15B is a button for playing back video content recorded in DVD or CD. When the D V D / C D activation button 1 5 B is pressed by the user, a video reproduction application program for reproducing video content is automatically activated. This video playback application program is also an application program that runs on the sub-operating system. When the DVD / CD start button 15B is pressed by the user, the sub operating system is started instead of the main operating system, and the video playback application program is automatically executed.

Next, the system configuration of the computer 10 will be described with reference to FIG.
As shown in FIG. 7, the computer 10 includes a CPU 1 1 1, a north bridge 11 2, a main memory 1 1 3, a graphics controller 1 1 4, a south bridge 1 1 9, a BIOS − ROM 1220, hard disk drive (HD D) 1 2 1, optical disk drive (OD D) 1 2 2, TV tuner 1 2 3, embedded controller / keyboard controller IC (EC / KBC) 1 2 4, network controller 12 5, and the like.

CP U 1 1 1 is a processor provided for controlling the operation of the computer 1 0, and is a main operating system (loaded from the hard disk drive (HD D) 1 2 1 to the main memory 1 1 3). The main OS) / sub operating system (sub OS) and various application programs are executed.

The CP U 1 1 1 also executes a system basic input output system (BIOS) stored in the BIOS-ROM 1220. The system BIOS is a program for hardware control.

The north bridge 1 1 2 is a bridge device that connects the local bus of the C P U 1 1 1 and the south bridge 1 1 9. The north bridge 1 1 2 also includes a memory controller that controls access to the main memory 1 1 3. The north bridge 112 also has a function of executing communication with the graphics controller 11 4 via an AGP (Accelerated Graphics Port) bus or the like.

The graphics controller 1 1 4 is a display controller that controls L CD 1 7 used as a display monitor of the computer 1 0. The graphics controller 1 1 4 has a video memory (VRAM) 1 1 4 4 A, and a display image to be displayed on the LCD 1 7 from display data written in the video memory by the OS / application program. Is generated.

The south bridge 1 1 9 controls each device on a low pin count (LPC) bus and each device on a peripheral component interconnect (PCI) bus. The south bridge 119 incorporates an IDE (Integrated Drive Electronics) controller for controlling the HD 1 12 1 and O DD 1 12 2. Further, the south bridge 11 9 also has a function of controlling the TV tuner 1 2 3 and a function of controlling access to the BIOS-RO M 1 2 0.

H D D 1 2 1 is a storage device that stores various software and data. This H D D 1 2 1 is configured to operate according to the A T A command and supports the ATA-5 command set. H D D 1 2 1 has a main O S region 1 2 1 A and a sub O S region 1 2 1 B. In the main OS area 1 2 1 A, the above-described main OS and an application program group operating on the main OS are installed. The main OS area 1 2 1 A is managed by the main OS. In the secondary OS area 1 2 1 B, the secondary OS, TV application program, and video playback application program described above are installed. The secondary OS area 1 2 1 B is managed by the secondary OS. The secondary OS region 1 2 1 B is concealed from the main OS by being managed by the secondary OS. H D D 1 2 1 may be in the form of an external type.

The optical disk drive (ODD) 1 2 3 is a drive unit for driving a storage medium such as DVD and CD in which video content is stored. The TV tuner 1 2 3 is a receiving device for receiving broadcast program data such as TV broadcast programs from the outside.

The embedded controller / keyboard controller IC (EC / KBC) 1 2 4 is an integrated controller for power management and a keyboard controller for controlling the keyboard (KB) 1 3 and the touch pad 1 6. 1-chip microcomputer. The embedded controller / keyboard controller I C (EC / KBC) 1 2 4 has a function of powering on / off the computer 10 in accordance with the operation of the power button 14 by the user. Furthermore, the embedded controller / keyboard controller I C (EC / KBC) 1 2 4 is used for the computer according to the operation of the TV start button 15 A and the DV D / CD start button 15 B by the user. 10 can also be powered on.

The network controller 1 2 5 is a communication device that executes communication with an external network such as the Internet.
Now, FIG. 1 has shown the functional block block diagram of embodiment.
In a system having a CPU 111, a RAM 113, and an external storage device 121, a program stored in the external storage device 121 is copied to the RAM 113 and executed. In order to perform demand paging as a memory management function, for example, only necessary pages are copied and executed for each page of 4 KB size. Also, pages that are not executed for a while are deleted from the RAM 113 and copied from the external storage device 121 at the time of execution again, thereby efficiently using the RAM 113.

  In the system of this embodiment, a program calls a function via a function table. As shown in Figure 2, when calling the function FuncB from the function FuncA, it jumps to Stat_Call, which is a common function call code (a type of application program), increments the number of calls to the function table 1, and then the FuncB in the function table It jumps to the address pointed to by the function pointer. After executing FuncB, return to FuncA.

The number of calls S in the function table is used to count the number of calls within a certain time N (for example, about 1 second). Used to understand short-term call status.
The number of calls L is a counter that is incremented when called even once during a fixed time N, and is used for grasping a long-term call state.
The offset and size indicate the offset and function size on the program file, and the page link is a link connecting the functions in the same page. Used to reload code in page fault handling.

  FIG. 3 is a flowchart of the function call number monitoring process processed by the OS in parallel with the execution of the program. After the program is started, at a certain time N (step S301), the number of calls S within a certain time is checked by referring to the number-of-calls information in the function table for all the targeted functions. If the number of calls S is 0 (YES in step S302) and the function is not being executed, the corresponding function is relocated to the end of the code area (step S303), and the function pointer in the function table is relocated (Step S304). If the number of calls S is other than 0 (NO in step S302), the number of calls L is incremented (step S305), and the number of calls S is cleared to zero (step S306).

Further, at an interval M (for example, about several minutes) longer than the predetermined time N (step S307), the number of calls L is cleared to zero (step S308).
FIG. 4 is a diagram showing the function relocation processing of the code area of the program. Before relocation, FunDD with 0 calls and FuncC with 4 calls were included in the same page, so the function FuncD was less likely to be paged out. After the rearrangement, the function FuncD is arranged on another page, so that the possibility of being paged out increases. When there are a plurality of functions having the number of calls S of 0, it is possible to operate more efficiently by arranging the function table with a smaller number of calls L behind.

Further, by arranging the function group having the number of calls of 0 so that the top of the function group is a page boundary, it is possible to efficiently page out.
FIG. 5 is a diagram showing the relationship between the page entry and the function table. The page table information for managing the physical memory includes a page address Ad indicating an actual physical address and a function entry En indicating a function table entry.

When a page fault occurs, the function table is traced from the page table, the function offset and size information are referenced, and the function code is copied from the external storage device to the RAM.

  In general, when a function with a small number of reads and a function with a large number of reads are mixed on the same page, a function with a small number of reads is not required, but the page is not paged out and the memory usage efficiency is poor. In the embodiment, since the functions are rearranged according to the number of function reads, functions with a low number of reads are grouped on the same page, and are easily paged out, improving the memory usage efficiency.

  After the program is executed, it is possible to execute the optimized program without the overhead of the common function call code by discharging the information on the number of calls to the outside and relinking the program to the optimal function layout based on that information. It becomes possible.

  That is, by dynamically changing the arrangement of the function in the memory according to the number of times the function is called, a page where the function with a small number of calls is present can be easily removed from the memory, and the memory can be used efficiently. Since the functions are rearranged according to the number of function reads, functions with a low number of reads are grouped on the same page, and are easily paged out, improving the memory usage efficiency.

  In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary, it can implement in various modifications. You may implement not with PC but with DTV (Digital Television).

  Various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements according to different embodiments may be appropriately combined.

1 is a schematic block diagram showing an apparatus (system) according to an embodiment of the present invention. The block diagram which shows the function call procedure of an Example. The flowchart figure of the function call frequency monitoring process of an Example. Diagram showing function relocation processing of program code area Diagram showing page management structure The perspective view showing the general view of the computer concerning one embodiment of the present invention. The block diagram which shows the system configuration | structure of the computer of FIG.

Explanation of symbols

  1 0... Computer, 1 1 1... C PU, 1 1 3... R A M, 1 2 1.

Claims (4)

In a system that uses a demand paging memory management method to execute a program that calls a function via a function pointer table
The memory where the function is located,
Counting the number of calls at the time of a function call of the program, periodically monitoring the number of calls, comprising a control unit for changing the memory arrangement of the function according to the number of calls,
The information processing apparatus, wherein the control unit operates such that the function with a relatively small number of calls is evicted from the memory by demand paging.   When the call count counter in the control unit refers to the change in the number of call of the function at a fixed time interval N after the program is started, if there is no change in the call count, the function is rearranged at the end of the memory, and the function table The information processing apparatus according to claim 1, wherein the function pointer is updated.   The call count data consists of the call count S and the call count L. The call count S is counted up for each call. If the call count S is 1 or more at a fixed time interval N, the call count L is counted up. The number of calls S is cleared, and the number of calls L is cleared at a fixed time M longer than N, and the number of calls is evaluated for a long time by evaluating the number of calls S after evaluating the number of calls S during function relocation. The information processing apparatus according to claim 1, wherein the information processing apparatus functions so as to dispose a function that is not rearranged. In a system that uses a demand paging memory management method to execute a program that calls a function via a function pointer table
The number of calls is counted when a function is called in the program, the number of calls is periodically monitored, the memory allocation of the function is changed according to the number of calls, and a function with a small number of calls is evicted from the memory by demand paging. A memory management method characterized by operating as described above.

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