JP2008046940A - Information processing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure free space in a memory module unit and save the power consumption by stopping power supply by the unit of the memory module unit to decrease power consumption by adding a function to control the amount of memory use and a function to control power supply by the unit of the memory module. <P>SOLUTION: An information processing apparatus includes a function which prohibits simultaneous operations of a plurality of applications to control the amount of memory use, a function which stops unnecessary processes and device drivers to swap them out, a function which shares a screen output pixel map, and a function which controls power supply in the memory module unit. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique for reducing power consumption of a main storage device (referred to as a DRAM in this specification, hereinafter referred to as a memory) mounted in an information processing apparatus.

  In current information processing apparatuses, an OS is designed to make maximum use of the installed memory. Therefore, while the information processing apparatus is operating, all the installed memories are refresh targets of the DRAM and consume refresh power.

  The following techniques are known as methods for reducing the refresh power. One is a dormant state implemented in, for example, an MS-Windows (registered trademark) OS.

In the hibernation state, when the PC is not used, the entire contents of the memory are saved in the HDD, and the power supply to the entire system including the memory is stopped to reduce the power consumption.
However, in the hibernation state, the information processing device is temporarily not used, but the purpose is to quickly return to the previous state when used later, and the use of the information processing device in the hibernation state is not considered. .

Japanese Patent Laid-Open No. 2004-133867 discloses a technique for reducing power consumption by saving (swapping out) data on a memory with low access frequency to a flash memory, increasing the free area of the memory, and stopping refreshing of the free area. Is disclosed.
However, since the capacity of the flash memory is smaller and the access speed is slower than that of the normal DRAM, there is a problem that the number of parts and the cost increase due to the swap-out in the memory module unit. In addition, there is a problem that the time overhead required for swap-in and swap-out is large.

  Also, in Patent Document 2, memory compaction (function to eliminate memory fragmentation) is executed and data is concentrated in a specific bank to secure an empty area in units of banks, and refresh is stopped in units of banks and consumed. Techniques for reducing power are disclosed.

  However, since the OS normally attempts to make maximum use of the memory, it is difficult to expect a sufficient power saving effect because it is unlikely that a large memory area will be freed simply by performing memory compaction. In addition, memory banks are often used to improve memory performance by memory interleaving, and if an empty area is created in units of memory banks, improvement in memory performance by memory interleaving cannot be expected.

JP 2002-132591 A JP 2004-47051 A

  For example, when a user uses a battery-powered PC while traveling on a transportation system, writing a word using a word processor, playing a game, watching a video using a viewer, etc. can be considered. One application (hereinafter referred to as an application) has been used for a long time, and it is possible to reduce power consumption by using this property.

  In other cases, when a user uses a PC, even if multiple applications are activated at the same time, it is rare to switch between multiple applications at short intervals, and only one application is used for a certain period of time. There is a nature that there is often no.

  Therefore, a problem to be solved by the present invention is to use this property to reduce power consumption by memory refresh without reducing user-friendliness.

  The power supply to the memory in the current information processing apparatus is directly performed from the power supply circuit shared by the memory module, and a switch is not installed for each memory module, so power supply control for each memory module is impossible. Therefore, a switch is provided so that power can be independently supplied to each memory module and power supply can be individually controlled by control from the OS.

  In addition, when only a single application is used, a mode that reduces the memory area required by swapping out other applications, collects unused memory by memory compaction, and suppresses power supply in units of memory modules ( (Hereinafter referred to as single application mode) is provided in the OS.

  Free space is secured by automatically swapping out libraries and device drivers (hereinafter referred to as “drivers”) that are not related to the operation of the app from the memory when transitioning to the single app mode.

  A table that describes the libraries and drivers related to the app when it is installed in order to determine the libraries and drivers that are related to the app running in single app mode and that should be left in memory without swapping out. And refer to this table when transitioning to single app mode to determine which libraries and drivers should not be swapped out.

In an OS adopting a multi-window system, a pixel map for screen output is assigned to a memory for various processes including the OS. As shown in FIG. 2, when the application screen and the OS main screen are displayed at the same time, the screen information of the portion that cannot be seen in duplicate is also held, so that the memory is wasted. On the other hand, if the application is displayed on the full screen, the pixel map used by another application becomes unnecessary, so that the memory is not wasted.
Further, while a certain application is displayed on the full screen, the main screen of the OS can be swapped out.

  The power consumption of the memory can be reduced for each memory module.

  As one example in which the present invention can be most effectively used, the present invention will be described in detail with reference to a notebook personal computer equipped with a plurality of memory modules and batteries.

  In the first and second embodiments, the state in which the power saving function of the present invention is being executed is referred to as a “single application mode”, and power supply and OS are implemented in order to realize a single application mode unique to the present invention. The mechanism for controlling the power is denoted as “power saving control process”.

  In addition, a normal operation state in which a plurality of applications can be executed simultaneously is referred to as “normal operation mode”. Transition from the normal operation mode to the single application mode is referred to as “transition to the single application mode”. Similarly, transition from the single application mode to the normal operation mode is referred to as “return from single application mode”.

An example in which the present invention is applied to a personal computer will be described. The personal computer assumed in the first embodiment is a computer in which the entire capacity of the installed memory can be used and all the connected devices are effective immediately after the power is turned on, when the user is ready to operate the personal computer. It is.
Hereinafter, an example in which the transition to the single application mode, the operation of the application during execution of the single application mode, and the return from the single application mode will be described.

  As shown in FIG. 1, the hardware greatly involved in the present invention is a power supply device, a control device, a memory, an arithmetic device, and an external storage device.

  The power supply device includes a main power supply device 0011 for supplying power to the personal computer from an outlet, and a battery 0012 that is an auxiliary power source for obtaining power for the personal computer when the power supply from the main power supply device 0011 is stopped. .

  The control device includes an MCU 0021 for controlling the memory and a controller 0022 for controlling the auxiliary storage device.

  The MCU 0021 is usually implemented as part of the North Bridge function. The controller 0022 is usually mounted as a part of the function of the south bridge.

In current personal computers, power is supplied to the memory directly from the power supply circuit. However, the power supply to the memory in FIG. 1 is controlled by the MCU 0021 in accordance with the instruction of the power saving control process.
Inside the MCU 0021, a power supply control switch for each memory module is provided. Furthermore, power supply lines 00311 and 00321 for connecting the MCU and the memory module are also provided for each memory module.

The MCU 0021 may not be provided with a function of controlling power supply to the memory, and may be controlled by arranging a switch in the middle of a circuit connecting the power supply circuit and the memory module.
Alternatively, a power line may not be provided for each memory module, but a switch may be provided inside each memory module and controlled individually.

  The memory is composed of memory modules 0031 and 0032. Although the memory in FIG. 1 is represented as two independent memory modules, the memory mounting form does not have to be a memory module, and may be directly attached to the motherboard.

  The arithmetic unit is composed of a CPU 0041 for processing the process.

The external storage device is a device that stores programs and data as files before being loaded into the memory. In the third embodiment, the external storage device includes the HDD0051.
Even if power supply to the external storage device is stopped, the programs and data stored in the external storage device are not deleted. The external storage device may be a flash memory or FDD.

  Next, the state of the memory map when the normal operation mode is executed will be described. FIG. 2 shows a screen in a state where two types of applications of OS (0101), word processor software (0102), and mailer (0103) are operating. FIG. 3 shows the state transition of the memory map indicating to which software the memory is allocated. Here, the memory map of the initial state corresponding to FIG. 2 is shown by “St0” in FIG. The OS screen 0101 is output using the pixel map “p0”. Similarly, the word processor software uses “p1” and the mailer uses “p2” for screen output.

  Next, the state transition of the memory map in an example of transition from the normal operation mode to the single application mode will be described. For example, when the power supply source to the MCU 0021 shifts to the single application mode on the condition that the main power supply unit 0011 is changed to the battery 0012, the power saving control process is notified that the power supply source has been changed. Then, according to the instruction of the power saving control process, the personal computer of this embodiment shifts to the single application mode.

  The conditions for shifting to the single app mode may include continuous operation of a single app for a certain period of time, pressing a shortcut key by the user, inputting a command by the user, starting an app specified by the user, or a combination of these. You may make it transfer to single application mode.

  For example, in an example in which a transition is made by activation of an application designated by the user, the user may register a specific application in the power saving control process in advance, and transition to the single application mode in conjunction with the activation of the application. Furthermore, as an example of a method for automating the application registration, an application that has been operated independently for a certain period of time may be automatically registered.

  Further, when shifting to a single application mode from a state in which a plurality of applications are operating simultaneously, the user may select an application to be continuously operated and shift to the single application mode. For example, as shown in FIG. 4, the user may move to the single application mode by a user key operation (for example, simultaneous pressing of the left and right keys of the mouse) after placing the cursor on the application displayed on the task bar.

  When the power saving control process detects a condition for shifting to the single application mode, a screen as shown in FIG. 5 for confirming whether to shift to the single application mode is displayed to the user. This confirmation screen allows you to choose not to transition from the normal operation mode to the single app mode when you plan to drive the auxiliary power supply for a very short time (eg, move from the office to the conference room). . Note that the display of this confirmation screen may be skipped.

When shifting to the single application mode, the memory usage is reduced (hereinafter referred to as purging) by terminating or pausing processes other than the process that is continuously executed. Here, suspending a process means saving the memory related to the process to the HDD so that the memory can be returned to the memory as needed, and setting the process so that the CPU is not assigned (in this specification as a kind of memory swap). This is called swap-out).
When the continuously executed process is an application, the memory usage is reduced by swapping out the memory used by the OS that is not related to the execution of the application.
In the transition from “St0” to “St1” in FIG. 3, OS (0101) is selected as the process to be continuously executed, and two types of applications of word processor software (0102) and mailer (0103) are purged, and free space Indicates an increase.

  Furthermore, an automatic processing process unrelated to the operation of the application executed in the single application mode is automatically purged from the memory modules 0031 and 0032 to reduce the memory usage. The purge process of the automatic process may be either terminated or swapped out to the HDD0051. It is desirable that the user can select the automatic processing process to be purged and the automatic processing process not to be purged.

  In the transition from “St1” to “St2” in FIG. 3, the process “anti-virus” for the anti-virus and the process “N management” for the network management are purged, and the free space is increased. Show. As the automatic processing process to be purged, security software, device utility software, etc. can be considered.

  Further, the device drivers unnecessary for the continuously executing process are purged from the memory modules 0031 and 0032. The transition from “St2” to “St3” in FIG. 3 indicates that the acoustic device driver “D0” and the TV tuner driver “D3” have been purged from the memory module 0031.

  Here, the device drivers necessary for each process are stored in the HDD 0051 as a link table indicating the relationship between the processes and the drivers as shown in FIG. For the sake of simplicity, in this embodiment, an audio device and a mouse driver are used for video playback software, a keyboard and mouse driver is used for word processing software, an audio device, a mouse and TV tuner driver, and a DVD playback software are used for TV viewing software. So, an acoustic device and a mouse driver are associated as necessary. Although omitted in FIG. 6, it is assumed that the drivers required during OS execution are a keyboard and a mouse.

  After these purge processes, memory compaction is executed, and if there is any unused memory module, power supply to this memory module is stopped. In the transition from “St3” to “St4” in FIG. 3, since unused areas scattered in the memory modules 0031 and 0032 are aggregated in the memory module 0032, it is no longer necessary to use the memory module 0032. Is stopped, and the value of the maximum amount of memory that can be used by the OS is changed.

  Next, the state transition of the memory map when the user activates the DVD playback software while the OS is running in the single application mode will be described. In the single application mode, the OS terminates applications other than the currently executed application, or swaps out and does not execute. Unless an application being executed is terminated and the OS is in an OS execution state or the next application is explicitly activated, no application other than the application being executed is executed. When the next application is explicitly started, the execution of the started application is started after the running application is terminated or swapped out.

  When the user activates the application, the OS refers to the link table 0211, purges the device driver not associated with the application (St5), and loads the program main body, library, necessary device driver, etc. of the application from the HDD0051. (St6), the application is activated.

  Here, the pixel map for DVD playback software is not in the memory module because the pixel map for OS can be assigned to the app by executing the app only in the full screen display mode in the single app mode. Because it is. Thereby, since only one pixel map area is required, the amount of memory used is suppressed.

  When the power supply to the memory module 0032 is stopped, if the application being executed requires more memory than the memory capacity of the memory module 0031, memory swaps frequently occur. The power saving control process monitors the number of memory swaps per unit time, and if it exceeds a certain value, it resumes power supply to the memory module 0032, initializes the memory module, etc., and the maximum amount of memory that can be used by the OS Increase the amount of memory used by changing the value of. Alternatively, when the number of memory swaps exceeds a certain value, the normal operation mode may be restored. Instead of the frequency of memory swap, the amount of memory may be simply increased when the memory usage exceeds a certain amount.

  Next, the state transition of the memory map in an example of transition from the single application mode to the normal operation mode will be described.

  As a condition for returning from the single application mode, it is assumed that the supply source of the power supplied to the MCU 0021 is changed from the battery 0012 to the main power supply unit 0011. Alternatively, the above-described increase in the required memory amount, pressing of a shortcut key by the user, command input by the user, or activation of software designated by the user may be used.

  The memory module 0032 whose power supply has been stopped is initialized in the same manner as the return from the hibernation state of MS-Windows (registered trademark). Next, all devices connected to the personal computer are validated, and the swapped out apps and automatic processing processes are swapped in, and then the normal operation mode is restored (St7).

In the first embodiment, an embodiment is described in which a transition is made to the single application mode based on the normal operation mode and the operation returns so as not to impair the operability of the conventional personal computer. However, if the usage is such that only one app normally operates, it is more efficient to set the single app mode to the normal state and to the normal operation mode only when operating multiple apps simultaneously. Desirable to reduce. In the personal computer shown in the second embodiment, immediately after the power is turned on, the usable memory area is limited in an arbitrary memory module unit and the minimum device is effective when the user becomes ready to operate the personal computer. Things.
In the second embodiment, even if the personal computer is activated with power supplied from the main power supply device 0011, the initial state is the single application mode.

  In an information processing apparatus such as a PDA or a pocket PC that is driven by battery rather than AC power supply, it starts up with limited memory at the time of startup as in the second embodiment, and increases the amount of available memory as necessary. However, there is no problem in use, which is rather desirable from the viewpoint of reducing power consumption.

  When the application is activated, the link table 0211 is referred to, and only the devices necessary for the operation of the application are validated. When the application is terminated, the program main body, the library, and the device driver are purged from the memory and returned to the state immediately after starting.

  On the other hand, the memory amount is increased when the frequency of memory swap is high or when the memory usage exceeds a certain amount.

  When the user starts multiple apps, once the mode is changed to the normal operation mode, apps that have not been accessed for a certain period of time are automatically swapped out and changed to the single app mode. It is possible to seamlessly transition between the single application mode and the normal operation mode without making the user feel.

It is a hardware structural example of the personal computer of an Example. It is an example of the screen in which the window of OS and an application is displayed in normal operation mode. It is an example of the state transition of a memory map. It is an example of the selection screen of the application to continue operation. It is an example of the screen which confirms with a user whether transfer to single application mode is possible. It is an example of the table which associates the device required for operation | movement of an application.

Explanation of symbols

0011: Main power supply 0012: Battery (auxiliary power supply)
0021: MCU (main memory control unit)
0022: Controller (auxiliary storage control device)
0031: Memory module (main storage device 1)
0032: Memory module (main storage device 2)
00300: Memory module shared data bus 00311: Power line for memory module 0031 1: Power line for memory module 0032: CPU (arithmetic unit)
0051: HDD (external storage device)
0101: OS main screen 0102: Word processor software screen 0103: Mailer screen 0211: Link table

Claims (8)

  In an information processing device using a volatile memory as a main storage device, a mode for limiting the amount of usable main storage device is provided. In this mode, power consumption is stopped by stopping power supply to an unused main storage device. Information processing apparatus characterized by reducing   A mode for restricting the amount of use of the main storage device according to claim 1, and when entering the mode, by swapping out an application that has not been accessed by a user for a certain period of time to a secondary storage device, An information processing apparatus having a mode for reducing usage.   3. An information processing apparatus according to claim 2, wherein in the mode for restricting the use amount of the main storage device according to claim 2, libraries and drivers necessary for an application not to be swapped out are not swapped out.   The related table indicating the relationship between the non-swap-out application described in claim 3 and the library or driver related to the non-swap-out is created at the time of installation of the application, and the mode is changed to the mode for limiting the use amount of the main storage device. An information processing apparatus characterized by determining a process to be swapped out by referring to the related table when performing the process.   In the mode for limiting the use amount of the main storage device according to claim 1, a single application is not swapped out when transitioning to this mode, the screen display of the application is set as a full screen display, and the pixel map of the OS is also set. An information processing apparatus characterized by being swapped out.   In the transition to the mode for limiting the usage amount of the main storage device according to claim 1, when the power supply source is changed from the main power supply device to the auxiliary power supply device, or the operation target by the user is a single application for a certain period of time. Or an information processing apparatus that changes state when an instruction to shift to a mode for restricting the amount of use of the main storage device by the user or a specific application specified by the user is started.   The signal indicating a specific operation by the user when the power supply source is changed from the auxiliary power supply to the main power supply in the return from the mode for limiting the usage amount of the main storage device according to claim 1 Or an information processing apparatus that makes a state transition when a specific application specified by a user is started. An information processing apparatus having a plurality of volatile memories as a main storage device, the information processing apparatus having a switch for controlling power feeding for each volatile memory.

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