JP5703799B2 - Computer, control method and program - Google Patents

Description

  The present invention relates to a computer, a control method, and a program.

  2. Description of the Related Art Conventionally, in a computer, there is a virtualization system that executes a plurality of virtual machines by operating a plurality of OSs (Operating Systems, operating systems) on a single physical CPU (Central Processing Unit). In the virtualization system, a virtual battery is provided to each virtual machine, and if the virtual machine is running, the CPU usage time is converted into a discharge amount, and if the virtual machine is stopped, the stop time is converted into a charge amount. There is a technique for controlling the remaining amount of the virtual battery. In addition, there is a technique for reducing power consumption by shifting a physical CPU, which has no virtual machine assigned as a result of deleting a virtual machine assigned to a physical CPU, to a sleep state. In addition, there is a technique for allocating at least some physical resources of a set of physical resources to a partition generated in the data processing system and reducing power consumption of physical resources that have not been allocated. In addition, there is a technique for reducing power consumption by lowering a clock frequency supplied to a physical resource.

JP 2010-33207 A JP 2009-140157 A JP 2004-192612 A

  However, in the conventional technology, each virtual machine operates at a preset clock frequency regardless of the physical load state of the CPU. For this reason, the physical CPU is in a low-load state, so if each virtual machine can be executed at a low speed but a high clock frequency is set for the virtual machine, A typical CPU may operate at a high clock frequency. Also, when the clock frequency of the physical CPU is increased or decreased according to the load of the physical CPU, even when a virtual machine that may have a low clock frequency is assigned to the physical CPU, When the CPU load is high, the physical CPU may operate at a high clock frequency. Thus, even in a situation where the physical CPU can operate at a low clock frequency, the physical CPU may operate at a higher clock frequency, and thus wasteful power is consumed. There is a problem.

  An object of the present invention is to provide a computer, a control method, and a program that can reduce power consumption.

  The computer includes one or more physical processors, a management table, a determination unit, and a change unit. The management table manages control information for controlling the clock frequency for each of a plurality of virtual machines. The virtual machine is realized by being executed by a physical processor. The control information is set according to the type of virtual machine. The determination unit obtains a threshold value for each virtual machine based on the control information in the management table. The determination unit determines a clock frequency for each virtual machine based on a threshold value and a physical processor utilization rate. The changing unit changes the clock frequency of the physical processor based on the clock frequency determined by the determining unit.

  According to this computer, control method, and program, power consumption can be reduced.

FIG. 1 is a block diagram of the computer according to the first embodiment. FIG. 2 is a block diagram of a hardware configuration of the computer according to the second embodiment. FIG. 3 is a block diagram of a functional configuration of the computer according to the second embodiment. FIG. 4 is a table illustrating an example of a management table of a computer according to the second embodiment. FIG. 5 is a flowchart of the CPU frequency periodic update process in the control method according to the second embodiment. FIG. 6 is a flowchart of the virtual machine assignment process in the control method according to the second embodiment. FIG. 7 is a flowchart of the CPU frequency switching process in the control method according to the second embodiment. FIG. 8 is a flowchart of the front coefficient setting changing process in the control method according to the second embodiment. FIG. 9 is a chart showing an example of various types of information in an example where the CPU usage rate decreases. FIG. 10 is a schematic diagram illustrating an example of the CPU frequency in an example in which the CPU usage rate decreases. FIG. 11 is a chart showing an example of various information in an example in which the usage rate of the CPU increases. FIG. 12 is a schematic diagram illustrating an example of a CPU frequency in an example in which the CPU usage rate increases. FIG. 13 is a chart showing an example of various information in an example of switching virtual machines operating in the foreground. FIG. 14 is a schematic diagram illustrating an example of a CPU frequency in an example of switching a virtual machine operating in the foreground. FIG. 15 is a chart illustrating an example of various information in an example in which a virtual machine is newly activated. FIG. 16 is a schematic diagram illustrating an example of a CPU frequency in an example in which a virtual machine is newly started.

  Exemplary embodiments of a computer, a control method, and a program will be described below in detail with reference to the accompanying drawings. For each virtual machine, the computer, the control method, and the program obtain a threshold value based on control information corresponding to the type of virtual machine, and determine the clock frequency based on the threshold value and the processor utilization rate (load). Then, the clock frequency of the processor is changed to the determined clock frequency. In the following description of each embodiment, the same components are denoted by the same reference numerals, and redundant descriptions are omitted.

(Example 1)
FIG. 1 is a block diagram of the computer according to the first embodiment. As shown in FIG. 1, the computer includes one or more physical processors 3, a management table 4, a determination unit 5, and a change unit 6.

  The management table 4 manages control information for controlling the clock frequency for each of the plurality of virtual machines 1 and 2. The virtual machines 1 and 2 are realized by being executed by the physical processor 3. The control information is set according to the type of the virtual machines 1 and 2. The determination unit 5 determines a threshold value for each of the virtual machines 1 and 2 based on the control information in the management table 4. The determining unit 5 determines the clock frequency for each of the virtual machines 1 and 2 based on the threshold value and the physical processor 3 utilization rate. The changing unit 6 changes the clock frequency of the physical processor 3 based on the clock frequency determined by the determining unit 5.

  According to the first embodiment, the clock frequency of the virtual machines 1 and 2 is determined according to the type of the virtual machines 1 and 2, and the clock frequency of the physical processor 3 is changed accordingly. For example, in the case of virtual machines 1 and 2 whose clock frequency fluctuates in conjunction with the utilization rate of the physical processor 3, the physical processor 3 operates at a clock frequency that is linked to the utilization rate of the physical processor 3. To do. In the case of the virtual machines 1 and 2 that are linked to the utilization rate of the physical processor 3 and whose clock frequency varies by weighting, the virtual machines 1 and 2 that are linked to the utilization rate of the physical processor 3 and that have a weighted clock frequency. The physical processor 3 operates. In the case of the virtual machines 1 and 2 that operate at a constant clock frequency, the physical processor 3 operates at a constant clock frequency. That is, when the physical processor 3 can operate at a low clock frequency, the physical processor 3 operates at a low clock frequency, so that the power consumption of the computer can be reduced.

(Example 2)
FIG. 2 is a block diagram of a hardware configuration of a computer according to the second embodiment. As shown in FIG. 2, the computer includes, for example, a CPU 11, a display unit 12, a key 13, a main memory 14, and a NAND (Not AND) memory 15 as physical processors. The CPU 11, display unit 12, key 13, main memory 14, and NAND memory 15 are connected to the bus 16.

  The CPU 11 controls the entire computer. The CPU 11 executes programs to be described later, and implements various virtual machines (VMs) and virtual machine monitors to be described later. The CPU 11 can dynamically change the clock frequency (CPU frequency) and the driving voltage. The display unit 12 includes a liquid crystal panel, for example. The key 13 includes keys and buttons for inputting numbers and characters, for example. The key 13 may be provided with a touch panel integrated with the display unit 12, and a number or a character may be input by touching an image of the key displayed on the display unit 12.

  The main memory 14 is used as a work area for the CPU 11. For example, an OS or an application program may be expanded in the main memory 14. The CPU 11 may execute an OS or application program expanded in the main memory 14. The main memory 14 includes, for example, a RAM (Random Access Memory).

  The NAND memory 15 stores an OS and application programs, for example. The OS and application programs may be read from the NAND memory 15 and expanded in the main memory 14. The NAND memory 15 may include, for example, a NAND flash memory as a nonvolatile memory. The computer may include other nonvolatile memory instead of the NAND memory 15.

  When the computer is a wireless communication terminal such as a mobile phone, the computer includes a wireless communication unit. The computer may also include a DSP (Digital Signal Processor) that performs image processing and sound processing, an interface with an external memory, and the like.

FIG. 3 is a block diagram of a functional configuration of the computer according to the second embodiment. As shown in FIG. 3, the computer includes a plurality of virtual machines 21 to 25 and a virtual machine monitor 26. The virtual machines 21 to 25 and the virtual machine monitor 26 may be realized by the CPU 11 executing a program for realizing the virtual machine and the virtual machine monitor. For example, in each of the virtual machines 21 to 25, the OS may be executed independently. In the following description, IDs (identifiers) of the virtual machines 21 to 25 are, for example, A, B, C, D, and E.

  The virtual machines 21 and 22 are guest virtual machines (hereinafter referred to as guest VMs). The guest virtual machine 21 and the guest virtual machine 22 may be referred to as a guest VM-A 21 and a guest VM-B 22 respectively. The guest VM-A 21 and the guest VM-B 22 are virtual machines that operate applications used by the user. Only one guest VM or a plurality of guest VMs may be activated depending on the usage pattern.

  The guest VM includes front-end drivers 27 and 28, for example. The front-end drivers 27 and 28 are modules used when the guest VM operates the device. The front-end drivers 27 and 28 perform processing for operating a device in cooperation with a driver virtual machine described later.

  The virtual machines 23 and 24 are driver virtual machines (hereinafter referred to as driver VMs). The driver virtual machine 23 and the driver virtual machine 24 may be referred to as a driver VM-C23 and a driver VM-D24, respectively. The driver VM-C 23 and the driver VM-D 24 are virtual machines that operate device drivers that control devices. Since the driver VM may be activated for each device type, a plurality of driver VMs may be activated.

  The driver VM includes back-end drivers 29 and 30, for example. The back-end drivers 29 and 30 operate the device in response to requests from the front-end drivers 27 and 28 of the guest VM. In the illustrated example, for example, the back-end driver 29 of the driver VM-C 23 operates the key 13. For example, the back end driver 30 of the driver VM-D 24 operates the NAND memory 15.

  The virtual machine 25 is a service virtual machine (hereinafter referred to as a service VM). The service virtual machine 25 may be referred to as a service VM-E25. The service VM-E 25 is not directly operated by the user but operates in the background. The service VM-E 25 implements auxiliary services necessary for the system such as virus checking.

  The virtual machine monitor 26 performs control to use one CPU 11 as a plurality of virtual machines. Thereby, one CPU 11 can be used as a plurality of virtual machines. The virtual machine monitor 26 includes, for example, a guest power control module 31 as a determination unit. The guest power control module 31 includes a guest power control management table 32 as a management table, for example.

  The guest power control module 31 operates at regular intervals or when the guest VM is switched, refers to the guest power control management table 32, and updates the guest power control management table 32 when updating is necessary. The guest power control module 31 determines whether or not it is necessary to change the CPU frequency of each virtual machine. If the change is necessary, the guest power control module 31 performs CPU frequency switching processing described later.

  The guest power control management table 32 holds information necessary for performing power control for each virtual machine according to the type and operating state of the virtual machine. The guest power control management table 32 is stored, for example, in the main memory 14 or the NAND memory 15. Examples of the virtual machine type include the guest VM, the driver VM, and the service VM described above. The operation state of the virtual machine includes, for example, a state operating in the foreground and a state operating in the background.

  Further, as a part of the guest power control management table 32 or separately from the guest power control management table 32, the Max default value and the Min default value, which will be described later, and the default value of the front coefficient are, for example, the main memory 14 and the NAND memory 15. May be stored.

  The virtual machine monitor 26 includes a screen switching control module 33, a CPU scheduler 34, and a CPU frequency change processing module 35 as a change unit, for example. The screen switching control module 33 is called when the user performs a screen switching operation such as pressing a screen switching key (not shown) of the computer. The screen switching control module 33 determines a guest VM that is newly operated on the front screen, that is, a guest VM that operates in the foreground, and switches the guest VM that is operated on the front screen.

  The CPU scheduler 34 performs control to allocate a virtual machine to the CPU 11. As an example of the allocation method, for example, there are policies such as CREDIT, SEDF (Simple Early Deadline First), and BVT (Borrowed Virtual Time). Moreover, you may make it select and assign suitably from several policies. The CPU scheduler 34 calls the CPU frequency switching process of the guest power control module 31 in accordance with the switching of the virtual machine operated by the CPU 11. The CPU frequency change processing module 35 executes processing for changing the CPU frequency of the CPU 11.

Example of Guest Power Control Management Table FIG. 4 is a table illustrating an example of a computer management table according to the second embodiment. As shown in FIG. 4, the guest power control management table 32 has, for example, a VM_ID field, a VM type coefficient field, a front coefficient field, and a CPU frequency field. The VM_ID field stores the virtual machine ID. In the VM type coefficient field, the value of the VM type coefficient is stored as control information related to the type of virtual machine. Control information related to the type of virtual machine may be set in advance according to the type of virtual machine.

  In the front coefficient field, the value of the front coefficient is stored as control information related to the operating state of the virtual machine. The control information related to the operation state of the virtual machine may change dynamically depending on whether the virtual machine is operating in the foreground or the background. The CPU frequency field stores the CPU frequency set in the CPU 11 when the virtual machine operates.

An example of a method for determining the CPU frequency of the virtual machine The value of the VM type coefficient and the value of the front coefficient are used in, for example, the following expressions (1) and (2). In the expressions (1) and (2), the threshold value Max and the threshold value Min are the maximum value and the minimum value of the threshold value to be compared with the usage rate of the CPU 11, respectively. The guest power control module 31 increases the CPU frequency of the virtual machine when the usage rate of the CPU 11 is larger than the threshold value Max, and the CPU of the virtual machine when the usage rate of the CPU 11 is smaller than the threshold value Min. Control to lower the frequency. The Max default value and the Min default value are the default values of the maximum value and the minimum value of the threshold value, respectively, and may be set in advance.

  According to the expressions (1) and (2), if the value of the VM type coefficient is large, both the threshold value Max and the threshold value Min are large. Therefore, the CPU frequency of the virtual machine has a large utilization rate of the CPU 11. Even if it becomes, it will become difficult to become high, and it will become low easily when the utilization factor of CPU11 becomes small. That is, a virtual machine having a large VM type coefficient is controlled to operate at the lowest possible CPU frequency.

  On the other hand, if the value of the VM type coefficient is small, both the threshold value Max and the threshold value Min are small. Therefore, the CPU frequency of the virtual machine is likely to increase as the usage rate of the CPU 11 increases, and the usage of the CPU 11 is increased. Even if the rate decreases, it is difficult to decrease. That is, a virtual machine having a small VM type coefficient is controlled to operate at the highest CPU frequency possible.

  For example, in the example illustrated in FIG. 4, the standard value of the VM type coefficient is, for example, 1. The VM type coefficients of guest VMs whose virtual machine IDs are A and B are set to standard values. The guest VM is a virtual machine whose CPU frequency varies in conjunction with the usage rate of the CPU 11.

  The VM type coefficient of the driver VM whose virtual machine IDs are C and D is set to a standard value or a value different from the standard value, for example, 1 or 1.2. The driver VM is a virtual machine that is linked to the usage rate of the CPU 11 and that is weighted to change the CPU frequency. For example, since the value of the VM type coefficient of the driver VM-C is 1 and the value of the VM type coefficient of the driver VM-D is 1.2, the driver VM-C has a higher CPU frequency than the driver VM-D. It is set to be easy to operate.

  The value of the VM type coefficient of the service VM whose virtual machine ID is E is set to 0, for example. A virtual machine in which the value of the VM type coefficient is set to 0, for example, is a virtual machine that operates at a constant CPU frequency without being linked to the usage rate of the CPU 11.

  The same applies to the value of the front coefficient, and a virtual machine having a large front coefficient value is controlled to operate at the lowest possible CPU frequency. A virtual machine having a small front coefficient value is controlled to operate at a CPU frequency as high as possible.

  For example, in the example shown in FIG. 4, the default value of the front coefficient is, for example, 0.9. The front coefficient of the guest VM whose virtual machine ID is A is set to a default value. The front coefficient of the guest VM whose virtual machine ID is B is set to a value larger than the default value, for example, 1. Therefore, the guest VM-A is set to operate at a higher CPU frequency than the guest VM-B, the guest VM-A operates in the foreground, and the guest VM-B operates in the background. Will be.

・ Explanation of control method [CPU frequency periodic update processing]
FIG. 5 is a flowchart of the CPU frequency periodic update process in the control method according to the second embodiment. The CPU frequency periodic update process is periodically performed by the guest power control module 31 at regular intervals.

  As shown in FIG. 5, the CPU frequency periodic update process is started at regular intervals, for example, by interruption of a timer built in the computer. When the CPU frequency periodic update process is started, the guest power control module 31 first calls, for example, a CPU load measurement module (not shown in FIG. 3) of the CPU scheduler 34 to determine the usage rate of the CPU 11 in the latest entire computer. Calculate (step S1).

  Next, the guest power control module 31 refers to the guest power control management table 32 and determines whether or not the value of the VM type coefficient of the first virtual machine is 0 (step S2). Step S2 may be performed before step S1. When the value of the VM type coefficient is not 0 (step S2: No), the guest power control module 31 refers to the guest power control management table 32 and performs, for example, the above-described formulas (1) and (2). The threshold value Max and the threshold value Min are calculated (step S3). Note that step S2 and step S3 may be performed before step S1.

  Next, the guest power control module 31 determines whether or not the usage rate of the CPU 11 calculated in step S1 is larger than the threshold value Max or smaller than the threshold value Min (step S4). When it is larger than the threshold value Max or smaller than the threshold value Min (step S4: Yes), the guest power control module 31 determines the CPU frequency of the virtual machine. If the determined CPU frequency is different from the current set value, the guest power control module 31 updates the stored value corresponding to the virtual machine in the CPU frequency field of the guest power control management table 32 (step S5). ).

  In step S5, for example, when the usage rate of the CPU 11 is larger than the threshold value Max, the CPU frequency of the virtual machine may be set higher than the current set value. When the CPU frequency is set higher than the current set value, for example, the highest CPU frequency that can be set in multiple stages may be set. For example, when the CPU frequency can be set in four stages of 600 MHz, 500 MHz, 250 MHz, and 125 MHz, the highest 600 MHz may be set.

  For example, when the usage rate of the CPU 11 is smaller than the threshold value Min, the CPU frequency of the virtual machine may be set lower than the current set value. When the CPU frequency is set lower than the current set value, for example, a frequency that is one step lower than the CPU frequency that can be set in multiple stages may be set. For example, if the CPU frequency can be set in four stages of 600 MHz, 500 MHz, 250 MHz, and 125 MHz, and the current setting value is 500 MHz, 250 MHz that is one step lower may be set.

  Next, the guest power control module 31 calls the CPU frequency change processing module 35 when the virtual machine whose stored value in the CPU frequency field of the guest power control management table 32 is currently being operated by the CPU 11. The called CPU frequency change processing module 35 updates the CPU frequency setting of the CPU 11 to the frequency determined in step S5 (step S6).

  Then, the process proceeds to step S7. On the other hand, when the value of the VM type coefficient of the virtual machine is 0 (step S2: Yes), or when the usage rate of the CPU 11 is not less than the threshold value Min and not more than the threshold value Max (step S4: No). Also proceeds to step S7.

  The guest power control module 31 determines whether or not the above-described series of update processing has been completed for all virtual machines having an entry in the guest power control management table 32 (step S7). If completed (step S7: Yes), a series of CPU frequency regular update processing is completed. If not completed (step S7: No), the guest power control module 31 refers to the guest power control management table 32 and performs the processes of step S2 to step S7 for the next virtual machine. The guest power control module 31 repeats the above series of processes until all the virtual machines having entries in the guest power control management table 32 are finished.

[Virtual machine assignment processing]
FIG. 6 is a flowchart of the virtual machine assignment process in the control method according to the second embodiment. The virtual machine assignment process is performed by the CPU scheduler 34.

  As shown in FIG. 6, the virtual machine allocation process is started by interruption of a timer built in the computer, for example. When the virtual machine assignment process is started while the virtual machine in the CPU 11 is assigned and operating, the CPU scheduler 34 displays the state of the virtual machine that has been operating in the CPU 11 until then in the main memory 14 and the NAND memory 15. (Step S11). The state of the virtual machine operating on the CPU 11 is obtained from the register of the CPU 11.

  Next, the CPU scheduler 34 selects a virtual machine to be operated next in accordance with the policy, and determines an operation time of the selected virtual machine (step S12). Next, the CPU scheduler 34 sets an interrupt timing of the next timer after the operation of the virtual machine selected in step S12 is started, that is, an activation timing of the CPU scheduler 34 (step S13).

  Next, the CPU scheduler 34 performs a process of switching the CPU frequency of the CPU 11 (step S14). Processing for switching the CPU frequency of the CPU 11 (CPU frequency switching processing) will be described later. Next, the CPU scheduler 34 reads the state of the virtual machine selected in step S12 from the previously saved memory area, sets the state of the virtual machine in the register of the CPU 11, and restores it (step S15). As a result, execution of the virtual machine newly scheduled by the CPU scheduler 34 is started. Then, the CPU scheduler 34 ends the virtual machine assignment process.

[CPU frequency switching processing when switching virtual machines]
FIG. 7 is a flowchart of the CPU frequency switching process in the control method according to the second embodiment. The CPU frequency switching process at the time of virtual machine switching is called from the CPU scheduler 34 at the time of switching the virtual machine described above.

  As shown in FIG. 7, in the CPU frequency switching process, the guest power control module 31 refers to the CPU frequency of the virtual machine before switching and the CPU frequency of the virtual machine after switching from the guest power control management table 32 ( Step S21). The virtual machine before switching is a virtual machine currently operating on the CPU 11. The virtual machine after switching is a virtual machine that operates next.

  Next, the guest power control module 31 determines whether or not the CPU frequency of the virtual machine before switching is different from the CPU frequency of the virtual machine after switching (step S22). If they are different (step S22: Yes), the guest power control module 31 calls the CPU frequency change processing module 35. The called CPU frequency change processing module 35 updates the CPU frequency setting of the CPU 11 to the CPU frequency of the virtual machine that operates next (step S23). Then, the process returns to the virtual machine assignment process by the CPU scheduler 34.

  On the other hand, when the CPU frequency of the virtual machine before switching and the CPU frequency of the virtual machine after switching are the same (step S22: No), the CPU scheduler 34 returns to the virtual machine allocation processing.

[Front coefficient setting change processing]
FIG. 8 is a flowchart of the front coefficient setting changing process in the control method according to the second embodiment. When the screen switching control module 33 is called by the screen switching operation by the user, the screen switching control module 33 calls the front coefficient setting change process.

  As shown in FIG. 8, when the front coefficient setting change process is started, the guest power control module 31 refers to the guest power control management table 32 and determines whether the first virtual machine is operating in the foreground. Judgment is made (step S31). When operating in the foreground (step S31: Yes), the guest power control module 31 sets the stored value corresponding to the virtual machine in the front coefficient field of the guest power control management table 32 to a default value (step S32). ).

  Then, the process proceeds to step S34. On the other hand, when the virtual machine is not operating in the foreground (step S31: No), the stored value corresponding to the virtual machine in the front coefficient field of the guest power control management table 32 is set to a value larger than the default value ( Step S33). Then, the process proceeds to step S34.

  The guest power control module 31 determines whether the above-described series of change processing has been completed for all virtual machines having entries in the guest power control management table 32 (step S34). If it has been completed (step S34: Yes), a series of front coefficient setting change processing is completed. If it has not ended (step S34: No), the guest power control module 31 refers to the guest power control management table 32 and performs the processing of steps S31 to S34 for the next virtual machine. The guest power control module 31 repeats the above series of processes until all the virtual machines having entries in the guest power control management table 32 are finished.

Specific Examples of Operation In the following specific examples, the configuration shown in FIG. 3 will be described as an example. For example, description will be made assuming that the CPU frequency that can be set is 600 MHz, 500 MHz, 250 MHz, and 125 MHz. For example, it is assumed that the Max default value is 80% and the Min default value is 75%. Further, when the CPU frequency is set higher than the current set value, the highest settable CPU frequency is set. When the CPU frequency is set lower than the current set value, the settable CPU frequency is set. A description will be given assuming that a lower frequency is set. The CPU frequency, the Max default value, and the Min default value that can be set are not limited to this, and the case where the CPU frequency setting value is changed is not limited to this example.

[Specific Example 1. Example of CPU usage rate going down]
FIG. 9 is a chart showing an example of various types of information in an example where the CPU usage rate decreases. In the chart shown in FIG. 9, the threshold value Max and the threshold value Min of each virtual machine are calculated from the above-described equations (1) and (2) (also in FIGS. 11, 13, and 15). the same). In specific example 1, the guest VM-A21, the guest VM-B22, the driver VM-C23, and the driver VM-D24 have a CPU frequency of 600 MHz, and the service VM-E25 has a CPU frequency of 250 MHz.

  FIG. 10 is a schematic diagram illustrating an example of the CPU frequency in an example in which the CPU usage rate decreases. When the most recent CPU utilization is 100%, the guest VM-A21, guest VM-B22, driver VM-C23 and driver VM-D24 are the highest because the CPU utilization exceeds the threshold Max. A frequency of 600 MHz is set. In the service VM-E 25, the threshold value Max and the threshold value Min are both zero. The CPU frequency of the virtual machine whose threshold Max and threshold Min are both 0 remains constant regardless of the CPU usage rate. Therefore, the CPU frequency of the service VM-E 25 remains 250 MHz.

  When the latest CPU usage rate becomes 85%, the CPU usage rate is smaller than the threshold value Min for the driver VM-D24, so 500 MHz which is a lower frequency is set. The CPU frequency of other virtual machines does not change. In this case, the stored value corresponding to the driver VM-D 24 in the CPU frequency field of the guest power control management table 32 is 500 MHz.

  When the most recent CPU usage rate becomes 70%, the guest VM-B22, the driver VM-C23 and the driver VM-D24 have a CPU usage rate smaller than the threshold value Min, so that the respective lower frequencies are 500 MHz, 500 MHz and 250 MHz are set. The CPU frequency of other virtual machines does not change. In this case, the stored values corresponding to the guest VM-B 22, the driver VM-C 23, and the driver VM-D 24 in the CPU frequency field of the guest power control management table 32 are 500 MHz, 500 MHz, and 250 MHz, respectively.

  When the most recent CPU usage rate is 65%, the guest VM-A21, guest VM-B22, driver VM-C23, and driver VM-D24 have a lower CPU usage rate than the threshold value Min, and therefore are one step lower. The frequencies 500 MHz, 250 MHz, 250 MHz, and 125 MHz are set. The CPU frequency of the service VM-E25 does not change. In this case, the stored values corresponding to the guest VM-A21, guest VM-B22, driver VM-C23 and driver VM-D24 in the CPU frequency field of the guest power control management table 32 are 500 MHz, 250 MHz, 250 MHz and 125 MHz, respectively. Become.

  As described above, when the CPU usage rate decreases, the CPU frequency of the guest VM-B operating in the background is preferentially lower than the CPU frequency of the guest VM-A operating in the foreground. It will become. Further, even for the same driver VM, the CPU frequency of a virtual machine having a large VM type coefficient value is preferentially lowered.

[Specific Example 2. Example of increasing CPU usage rate]
FIG. 11 is a chart showing an example of various information in an example in which the usage rate of the CPU increases. In specific example 2, the guest VM-A21, the guest VM-B22, the driver VM-C23, and the driver VM-D24 have a CPU frequency of 125 MHz, and the service VM-E25 has a CPU frequency of 250 MHz.

  FIG. 12 is a schematic diagram illustrating an example of a CPU frequency in an example in which the CPU usage rate increases. When the latest CPU usage rate is 65%, the guest VM-A21, guest VM-B22, driver VM-C23, and driver VM-D24 have a CPU usage rate smaller than the threshold value Min, so that the frequency is one step lower. Is set. Here, since the current setting value is the lowest 125 MHz, 125 MHz is set. The CPU frequency of the service VM-E25 remains 250 MHz.

  When the most recent CPU usage rate is 75%, the guest VM-A 21 has the highest frequency of 600 MHz because the CPU usage rate exceeds the threshold Max. The CPU frequency of other virtual machines does not change. In this case, the stored value corresponding to the guest VM-A 21 in the CPU frequency field of the guest power control management table 32 is 600 MHz.

  When the most recent CPU usage rate is 85%, the guest VM-A21, guest VM-B22, and driver VM-C23 have a CPU usage rate that exceeds the threshold Max, so the highest frequency of 600 MHz is set. Is done. The CPU frequency of other virtual machines does not change. In this case, the stored value corresponding to the guest VM-A 21, guest VM-B 22, and driver VM-C 23 in the CPU frequency field of the guest power control management table 32 is 600 MHz. The same applies when the most recent CPU usage rate reaches 95%.

  As described above, when the CPU utilization rate increases, the CPU frequency of the guest VM-A 21 operating in the foreground is preferentially higher than the CPU frequency of the guest VM-B 22 operating in the background. It will become. Further, even for the same driver VM, the CPU frequency of a virtual machine having a small VM type coefficient value is preferentially increased.

[Specific Example 3. Example of switching virtual machines running in the foreground]
FIG. 13 is a chart showing an example of various information in an example of switching virtual machines operating in the foreground. In specific example 3, as in FIG. 11 of specific example 2, the CPU frequency of guest VM-A21, guest VM-B22, driver VM-C23 and driver VM-D24 is 125 MHz, and the CPU frequency of service VM-E25 is A description will be given from the state of 250 MHz. The various types of information shown in FIG. 13 are information after switching virtual machines that operate in the foreground.

  FIG. 14 is a schematic diagram illustrating an example of a CPU frequency in an example of switching a virtual machine operating in the foreground. When the latest CPU usage rate is 65%, the CPU frequency of 125 MHz is set for the guest VM-A 21, guest VM-B 22, driver VM-C 23, and driver VM-D 24 as in the second specific example. The CPU frequency of the service VM-E25 remains 250 MHz.

  When the most recent CPU usage rate becomes 75%, the CPU frequency of the guest VM-A 21 is set to 600 MHz as in the second specific example. The CPU frequency of other virtual machines does not change.

  Although the CPU usage rate remains 75%, when the virtual machine operating in the foreground is switched from the guest VM-A 21 to the guest VM-B 22, the guest VM-A 21 is switched to the operation in the background. As a result, as shown in FIG. 13, the front coefficient of the guest VM-A 21 is updated to 1, and the front coefficient of the guest VM-B 22 is updated to 0.9. Then, the threshold value Max and the threshold value Min of the guest VM-A 21 are updated to 80% and 75%, respectively. Further, the threshold value Max and the threshold value Min of the guest VM-B 22 are updated to 72% and 68%, respectively.

  Therefore, for the guest VM-B22, since the CPU utilization rate exceeds the threshold value Max, 600 MHz, which is the highest frequency, is set. The CPU frequency of other virtual machines does not change. In this case, as shown in FIG. 13, the stored value corresponding to the guest VM-B 22 in the CPU frequency field of the guest power control management table 32 is 600 MHz.

  When the most recent CPU usage rate becomes 70%, the CPU usage rate becomes smaller than the threshold value Min for the guest VM-A 21, the driver VM-C 23, and the driver VM-D 24, so a frequency that is one step lower is set. The CPU frequency of the guest VM-A 21 is set to 500 MHz. About driver VM-C23 and driver VM-D24, since the present setting value is the lowest 125 MHz, 125 MHz is set (not appearing in FIG. 14). The CPU frequency of other virtual machines does not change. In this case, the stored value corresponding to the guest VM-A 21 in the CPU frequency field of the guest power control management table 32 is 500 MHz.

  As described above, as the CPU usage rate increases, the CPU frequency of the guest VM-A 21 operating in the foreground is preferentially higher than the CPU frequency of the guest VM-B 22 operating in the background. To go. When the virtual machine operating in the foreground is switched, the CPU frequency of the guest VM-B 22 that newly operates in the foreground is higher than the CPU frequency of the guest VM-A 21 that newly operates in the background. Will also increase preferentially. Further, when the CPU usage rate decreases, the CPU frequency of the guest VM-A 21 operating in the background is preferentially lower than the CPU frequency of the guest VM-B 22 operating in the foreground.

[Specific Example 4. Example of newly starting virtual machine]
FIG. 15 is a chart illustrating an example of various information in an example in which a virtual machine is newly activated. In specific example 4, as in FIG. 9 of specific example 1, the CPU frequency of guest VM-A21, guest VM-B22, driver VM-C23 and driver VM-D24 is 600 MHz, and the CPU frequency of service VM-E25 is A description will be given from the state of 250 MHz. The various types of information illustrated in FIG. 15 are information after a virtual machine with a new VM_ID F (referred to as a guest VM-F) is started.

  FIG. 16 is a schematic diagram illustrating an example of a CPU frequency in an example in which a virtual machine is newly started. When the latest CPU usage rate is 100%, a CPU frequency of 600 MHz is set for the guest VM-A 21, guest VM-B 22, driver VM-C 23 and driver VM-D 24 as in the first specific example. The CPU frequency of the service VM-E25 remains 250 MHz.

  When the latest CPU usage rate becomes 85%, the CPU frequency of the driver VM-D 24 is set to 500 MHz, as in the first specific example. The CPU frequency of other virtual machines does not change.

  Here, it is assumed that the CPU utilization rate remains 85%, but the guest VM-F is newly activated. When the guest VM-F operates in the background, as shown in FIG. 15, since the CPU utilization rate exceeds the threshold value Max (80%) of the guest VM-F, the CPU frequency of the guest VM-F is The highest frequency is set to 600 MHz.

  When the most recent CPU usage rate is 70%, the guest VM-B22, the driver VM-C23, the driver VM-D24, and the guest VM-F have a lower CPU usage rate than the threshold value Min, and thus are one step lower. The frequencies 500 MHz, 500 MHz, 250 MHz, and 500 MHz are set. The CPU frequency of other virtual machines does not change. In this case, the stored values corresponding to the guest VM-B22, driver VM-C23, driver VM-D24, and guest VM-F in the CPU frequency field of the guest power control management table 32 are 500 MHz, 500 MHz, 250 MHz, and 500 MHz, respectively. Become.

  When the most recent CPU usage rate is 65%, the CPU usage rate is smaller than the threshold value Min for the guest VM-A21, guest VM-B22, driver VM-C23, driver VM-D24, and guest VM-F. Therefore, a lower frequency is set. The CPU frequency of the guest VM-A 21 is set to 500 MHz. The CPU frequency of the guest VM-B22, driver VM-C23, and guest VM-F is set to 250 MHz. The CPU frequency of the driver VM-D 24 is set to 125 MHz. The CPU frequency of the service VM-E25 remains 250 MHz. In this case, the stored values corresponding to the guest VM-A21, guest VM-B22, driver VM-C23, driver VM-D24 and guest VM-F in the CPU frequency field of the guest power control management table 32 are 500 MHz and 250 MHz, respectively. 250 MHz, 125 MHz, and 250 MHz.

  In this way, even if a new virtual machine is activated, the CPU frequency is controlled in the same manner as the already activated virtual machine.

  According to the second embodiment, the same effect as the first embodiment can be obtained.

  The following additional notes are disclosed with respect to the first and second embodiments.

(Supplementary Note 1) For one or more physical processors and a plurality of virtual machines realized by being executed by the physical processors, a clock frequency set according to the type of the virtual machine is set. A management table for managing control information to be controlled; and for each virtual machine, a threshold value is obtained based on the control information in the management table, and a clock is obtained based on the threshold value and the utilization rate of the physical processor. A computer comprising: a determining unit that determines a frequency; and a changing unit that changes a clock frequency of the physical processor based on the clock frequency determined by the determining unit.

(Supplementary note 2) The control information includes, for each virtual machine, information set according to whether the virtual machine is operating in the foreground or the background. The calculator described in.

(Additional remark 3) The said determination part calculates | requires the maximum value and minimum value of the said threshold value for every said virtual machine, and when the utilization factor of the said physical processor is larger than the maximum value of the said threshold value 3. The computer according to appendix 1 or 2, wherein the clock frequency is increased, and the clock frequency is determined to be decreased when the utilization rate of the physical processor is smaller than the minimum value of the threshold value.

(Additional remark 4) The said determination part updates the said management table based on the determined clock frequency for every said virtual machine, The computer as described in any one of Additional remark 1-3 characterized by the above-mentioned.

(Supplementary Note 5) One of the types of the virtual machines is any one of Supplementary Notes 1 to 4, wherein the virtual machine has a clock frequency that varies in accordance with a utilization rate of the physical processor. Listed calculator.

(Additional remark 6) One of the types of the said virtual machines is a virtual machine which is linked with the utilization rate of the said physical processor, and is weighted and the clock frequency fluctuates, Any of additional remarks 1-5 A calculator according to one of the above.

(Additional remark 7) One of the said virtual machine types is a virtual machine which operate | moves with a fixed clock frequency, The computer as described in any one of additional marks 1-6 characterized by the above-mentioned.

(Supplementary Note 8) Obtaining the utilization rate of a physical processor, and for each of a plurality of virtual machines realized by being executed by the physical processor, a clock frequency set according to the type of the virtual machine A control method comprising: obtaining a threshold value based on control information to be controlled, and determining a clock frequency based on the threshold value and a utilization rate of the physical processor for each virtual machine.

(Supplementary note 9) The control method according to supplementary note 8, wherein the clock frequency of the physical processor is changed based on the determined clock frequency.

(Additional remark 10) The said control information contains the information set according to whether the said virtual machine is operate | moving in a foreground, or is operating in the background for every said virtual machine Or the control method of 9.

(Supplementary Note 11) For each of the virtual machines, obtain the maximum value and the minimum value of the threshold value, and increase the clock frequency when the utilization rate of the physical processor is larger than the maximum value of the threshold value, The control method according to any one of appendices 8 to 10, wherein when the utilization rate of the physical processor is smaller than the minimum value of the threshold value, the clock frequency is determined to be lowered.

(Additional remark 12) Obtaining the utilization rate of the physical processor, for each of a plurality of virtual machines realized by being executed by the physical processor, the clock frequency set according to the type of the virtual machine, Read control information to be controlled from a memory, obtain a threshold value based on the control information, and determine a clock frequency based on the threshold value and the utilization rate of the physical processor for each virtual machine. A program that causes a computer to execute processing.

(Supplementary note 13) The program according to supplementary note 12, wherein the clock frequency of the physical processor is changed based on the determined clock frequency.

(Supplementary note 14) The control information includes, for each virtual machine, information set according to whether the virtual machine is operating in the foreground or the background. Or the program of 13.

(Supplementary note 15) For each of the virtual machines, the maximum value and the minimum value of the threshold value are obtained, and when the utilization rate of the physical processor is larger than the maximum value of the threshold value, the clock frequency is increased, 15. The program according to any one of appendices 12 to 14, wherein when the usage rate of the physical processor is smaller than the minimum value of the threshold value, it is determined to lower the clock frequency.

1, 2, 21-25 Virtual machine 3, 11 Processor 4, 32 Management table 5, 31 Determining unit 6, 35 Changing unit

Claims (5)

One or more physical processors;
A management table for managing control information for controlling the clock frequency, which is set according to the type of the virtual machine, for each of the plurality of virtual machines realized by being executed by the physical processor;
For each of the virtual machines, a threshold indicating a utilization rate of the physical processor capable of providing the processing capability required for the virtual machine based on the control information of the management table is obtained, and the threshold and the threshold A determination unit that determines a clock frequency based on a comparison result with a utilization rate of a physical processor;
A changing unit that changes the clock frequency of the physical processor based on the clock frequency determined by the determining unit;
A computer comprising:   The said control information contains the information set according to whether the said virtual machine is operate | moving in the foreground or the background for every said virtual machine. calculator.   The determination unit obtains the maximum and minimum values of the threshold value for each virtual machine, and increases the clock frequency when the physical processor utilization rate is larger than the maximum value of the threshold value. 3. The computer according to claim 1, wherein, when the utilization factor of the physical processor is smaller than the minimum value of the threshold value, it is determined to lower the clock frequency. 4. Find the physical processor utilization,
Requested by the virtual machine based on control information for controlling a clock frequency, which is set according to the type of the virtual machine for each of a plurality of virtual machines realized by being executed by the physical processor Determining a threshold value indicating a utilization rate of the physical processor capable of providing processing power ;
A control method, comprising: determining a clock frequency for each virtual machine based on a comparison result between the threshold and a utilization rate of the physical processor. Find the physical processor utilization,
For each of a plurality of virtual machines realized by being executed by the physical processor, the control information for controlling the clock frequency, which is set according to the type of the virtual machine, is read from the memory and based on the control information Obtaining a threshold value indicating a utilization rate of the physical processor capable of providing the processing capability required for the virtual machine ,
For each virtual machine, a clock frequency is determined based on a comparison result between the threshold and the physical processor utilization rate.
A program that causes a computer to execute processing.

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