TWI447557B - System and method for analyzing a cpu usage rate - Google Patents

Description

CPU usage analysis system and method

The present invention relates to a CPU usage analysis system and method, and more particularly to a CPU usage analysis system and method for use in a mobile device.

ARM (Advanced RISC Machines) architecture mobile devices (such as mobile phones and PDAs) mostly use the Nucleus operating system. In the Nucleus operating system, there is no work administrator program provided by the Windows operating system, allowing users to view CPU usage. In order to analyze the performance of mobile devices.

At present, some mobile devices can calculate the CPU usage through a software timer (such as the software management software, Software Log), but the results obtained by using the software timer calculation are not accurate enough.

In view of the above, it is necessary to provide a CPU usage analysis system and method that can accurately calculate the CPU usage of a mobile device.

The CPU usage analysis system is applied to a mobile device configured with a hardware timer. The system includes: a parameter setting module for setting a CPU usage analysis period and a length of time for each analysis; and a time reading module for suspending a thread during each CPU usage analysis period Reading the current time of the hardware timer and resetting the value of the hardware timer to the maximum value. At the same time, the task scheduling list in the mobile device operating system determines the next executed thread; Calculating the time taken by the suspended thread to occupy the CPU according to the current time of the read hardware timer, and storing the calculated time in an array element, the suspended thread occupies the CPU time equal to hard The maximum value of the body timer minus the current time of the hardware timer; the calculation module is further configured to calculate the CPU usage rate according to the values of all the elements in the array when the time length of each analysis arrives.

The CPU usage analysis method is applied to a mobile device configured with a hardware timer. The method includes the steps of: setting a CPU usage analysis period and a length of time for each analysis; during each CPU usage analysis period, when a thread is suspended, reading the current time of the hardware timer, and The value of the hardware timer is reset to the maximum value, and the task scheduling list in the mobile device operating system determines the next executed thread; the suspended thread is calculated according to the current time of the read hardware timer Occupies the CPU time, and stores the calculated time in an array element. The time that the suspended thread occupies the CPU is equal to the maximum value of the hardware timer minus the current time of the hardware timer; When the length of time arrives, the CPU usage is calculated based on the values of all the elements in the array.

Compared with the prior art, the CPU usage analysis system and method are applied to a mobile device, and the CPU usage of the mobile device can be accurately calculated.

Referring to FIG. 1, a hardware architecture diagram of a preferred embodiment of a CPU usage analysis system of the present invention is shown. The system is applied to a mobile device (the mobile phone is taken as an example in the embodiment), and mainly includes a central processing unit (CPU) 1, a memory 2, an input/output device 3, and a mobile phone motherboard 4. The central processing unit 1 is connected to the storage unit 2, the input/output device 3 and the mobile phone main board 4, and the storage unit 2 is connected to the mobile phone main board 4. The input/output device 3 includes an LCD liquid crystal display screen and a keyboard for displaying data and inputting information. The storage 2 includes a work system 21 and a CPU usage analysis unit 20.

The operating system 21 includes a task scheduling list for controlling execution of the thread. For example, when a thread is suspended, the task schedule list will determine the next thread to execute.

The central processing unit 1 is configured to call the CPU usage analysis unit 20 and control the execution of the CPU usage analysis unit 20. The CPU usage analysis unit 20 is configured to calculate the CPU usage rate using the hardware timer 40 in the mobile phone motherboard 4.

The hardware timer 40 is embedded in the mobile phone motherboard 4, and the hardware timer 40 can be a Time1 timer, a Time2 timer, and a Watchdog timer (watchdog timer). In this embodiment, the Time2 timer is used. Device. The hardware timer 40 can be accurate to nanoseconds (ns). For example, the accuracy of the Time2 timer can reach 2.4623 nanoseconds, while the software timer can only be accurate to milliseconds (ms), typically 4.615 milliseconds.

Referring to FIG. 2, it is a functional module diagram of the CPU usage analysis unit 20 shown in FIG. 1. The CPU usage analysis unit 20 includes a parameter setting module 201, a thread setting module 202, a time reading module 203, and a computing module 204. The module referred to in the present invention is a computer program segment for performing a specific function, and is more suitable for describing the execution process of the software in the computer than the program. Therefore, the following description of the software is described in the module.

The parameter setting module 201 is configured to set a CPU usage analysis period and a length of time for each analysis, wherein the length of each analysis starts from the time when the CPU usage analysis period arrives, and each analysis is performed. The length of time is less than or equal to the CPU usage analysis period. Assuming that the CPU usage analysis period is 10 minutes and the length of each analysis is 100 seconds, the usage rate of the current CPU in 100 seconds is analyzed every 10 minutes.

The thread setting module 202 is configured to set a thread with the lowest priority as an idle running thread, and place the idle running thread in an infinite loop to prevent the operating system 21 from entering the sleep mode. The idle running thread may be a new Idle thread or set an existing thread to the lowest priority order as an idle running thread.

The time reading module 203 is configured to read the current time of the hardware timer 40 when a thread is suspended during each CPU usage analysis period. At the same time, the task scheduling list of the operating system 21 will determine the next thread to execute. The time reading module 203 resets the value of the hardware timer 40 to the maximum value each time the current time of the hardware timer 40 is read. In the present embodiment, the maximum value of the hardware timer 40 is 0×FFFF.

Among them, a situation in which a thread is suspended includes:

(1) The thread is executed;

(2) When the thread is running, the operating system 21 issues an interrupt request;

(3) When the thread is running, there are other higher priority threads that need to be executed. The thread actively releases a signal and is suspended.

The computing module 204 is configured to calculate the time that the suspended thread occupies the CPU according to the current time of the hardware timer 40, and store it in an array element. The time that the suspended thread occupies the CPU is equal to the maximum value of the hardware timer 40 minus the current time of the hardware timer 40.

The computing module 204 is further configured to calculate the CPU usage rate according to the values of all the elements in the array when the time length of each analysis arrives. Specifically, first, the calculation module 204 sums the total time of all the elements in the array to obtain the CPU usage time of all threads, and then calculates the average time occupied by each thread, and the average time occupied by each thread is The sum of the time taken by all threads to occupy the CPU divided by the number of threads executed during this period. Finally, the CPU usage in this cycle is calculated. The CPU usage is equal to the average time spent by each thread on the CPU divided by the length of each analysis.

For example, suppose the length of each analysis is 100 seconds. There are 3 threads (Thread A, Thread B, and Thread C) executed in this cycle. Thread A takes up CPU time for 30 seconds. Thread B The CPU usage time is 40 seconds, and the Thread C CPU time is 50 seconds. The average time that each thread occupies the CPU is (30+40+50)/3 seconds, that is, 40 seconds. The CPU usage in this cycle is 40/100, which is 40%.

Referring to FIG. 3, it is a flow chart of a preferred embodiment of the CPU usage analysis method of the present invention. In step S1, the CPU usage analysis period and the length of each analysis are set by the parameter setting module 201.

In step S2, the time reading module 203 reads the current time of the hardware timer 40 when a thread is suspended during each CPU usage analysis period. At the same time, the task scheduling list of the operating system 21 will determine the next thread to execute. The time reading module 203 resets the value of the hardware timer 40 to the maximum value each time the current time of the hardware timer 40 is read. In the present embodiment, the maximum value of the hardware timer 40 is 0×FFFF.

Among them, a situation in which a thread is suspended includes:

(1) The thread is executed;

(2) When the thread is running, the operating system 21 issues an interrupt request;

(3) When the thread is running, there are other higher priority threads that need to be executed. The thread actively releases a signal and is suspended.

In step S3, the calculation module 204 calculates the time taken by the suspended thread to occupy the CPU according to the current time of the read hardware timer 40, and stores it in an array element. The time that the suspended thread occupies the CPU is equal to the maximum value of the hardware timer 40 minus the current time of the hardware timer 40.

In step S4, the calculation module 204 calculates the CPU usage rate according to the values of all the elements in the array when the time length of each analysis arrives. Specifically, first, the calculation module 204 sums the total time of all the elements in the array to obtain the CPU usage time of all threads, and then calculates the average time occupied by each thread, and the average time occupied by each thread is equal to The sum of the time taken by all threads to occupy the CPU divided by the number of threads executed during this period. Finally, the CPU usage in this cycle is calculated. The CPU usage in this cycle is equal to the average time spent by each thread on the CPU divided by the length of each analysis.

In other embodiments, the method may further include the following steps: before step S2, the thread setting module 202 sets a thread with the lowest priority as the idle running thread, and places the idle running thread in an infinite loop. To prevent the operating system 21 from entering the sleep mode. The idle running thread can be a new Idle thread or set an existing thread to the lowest priority order as an idle running thread.

In this embodiment, the mobile device may be an electronic device with a data processing function such as a mobile phone or a PDA (Personal Digital Assistant).

It should be noted that the above embodiments are merely illustrative of the technical solutions of the present invention, and the present invention is not limited thereto. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that Modifications or equivalents are made without departing from the spirit and scope of the invention.

1. . . CPU

2. . . Storage

3. . . Input/output device

4. . . I

20. . . CPU usage analysis unit

twenty one. . . working system

40. . . Hardware timer

201. . . Parameter setting module

202. . . Thread setting module

203. . . Time reading module

204. . . Computing module

S1. . . Set the CPU usage analysis period and the length of each analysis

S2. . . The current time to read the hardware timer when a thread is suspended

S3. . . Calculate the time that the suspended thread occupies the CPU and store it in an array element

S4. . . Calculate CPU usage when the analysis time length arrives

1 is a hardware architecture diagram of a preferred embodiment of a CPU usage analysis system of the present invention.

FIG. 2 is a functional block diagram of the CPU usage analysis unit in FIG. 1.

3 is a flow chart of a preferred embodiment of the CPU usage analysis method of the present invention.

S1. . . Set the CPU usage analysis period and the length of each analysis

S2. . . The current time to read the hardware timer when a thread is suspended

S3. . . Calculate the time that the suspended thread occupies the CPU and store it in an array element

S4. . . Calculate CPU usage when the analysis time length arrives

Claims (10)

A CPU usage analysis method is applied to a mobile device, the mobile device being configured with a hardware timer, the method comprising the steps of: setting a CPU usage analysis period and a length of time for each analysis; analyzing each CPU usage rate During the period, when a thread is suspended, the current time of the hardware timer is read, and the value of the hardware timer is reset to the maximum value, and the task scheduling list in the mobile device operating system determines the next one. Executing thread; calculating the time taken by the suspended thread to occupy the CPU according to the current time of the read hardware timer, and storing the calculated time in an array element, the suspended thread occupies the CPU The time is equal to the maximum value of the hardware timer minus the current time of the hardware timer; and when the length of each analysis arrives, the CPU usage is calculated based on the values of all the elements in the array. The CPU usage analysis method of claim 1, wherein before the current time of reading the hardware timer, the step further comprises: setting a thread with the lowest priority as the idle running thread, and running the idle operation. The thread is placed in an infinite loop. The CPU usage analysis method according to claim 2, wherein the idle running thread is a newly added idle thread, or an existing one thread is set to a lowest priority order as an idle running thread. The CPU usage analysis method of claim 1, wherein the thread is suspended: the thread is executed; when the thread is running, the mobile device operating system issues an interrupt request; When the thread is running, there are other higher-priority threads that need to be executed. The thread actively releases a signal and is suspended. The CPU usage analysis method according to claim 1, wherein the step of calculating a CPU usage rate according to values of all elements in the array includes: summing all elements in the array to obtain CPU usage of all threads. The sum of time; calculate the average time that each thread occupies the CPU, the average time taken by each thread to occupy the CPU is equal to the sum of the time of all threads occupying the CPU divided by the number of threads executed in the current cycle; The usage rate of the CPU in the sub-period, the usage rate of the CPU in the current cycle is equal to the average time occupied by the CPU per thread divided by the length of time for each analysis. A CPU usage analysis system is applied to a mobile device, wherein the mobile device is configured with a hardware timer, and the system includes: a parameter setting module, configured to set a CPU usage analysis period and a length of each analysis a time reading module for reading the current time of the hardware timer and resetting the value of the hardware timer to the maximum when a thread is suspended during each CPU usage analysis period The value, at the same time, the task scheduling list in the mobile device operating system determines the next executed thread; the computing module is configured to calculate the time taken by the suspended thread to occupy the CPU according to the current time of the read hardware timer, And storing the calculated time in an array element, the time that the suspended thread occupies the CPU is equal to the maximum value of the hardware timer minus the current time of the hardware timer; and the computing module is further used When the length of time for each analysis arrives, the CPU usage is calculated based on the values of all elements in the array. The CPU usage analysis system of claim 6, wherein the system further comprises: a thread setting module, configured to set a thread with the lowest priority as an idle running thread, and place the idle running thread In an infinite circle. The CPU usage analysis system of claim 6, wherein the maximum value of the hardware timer is: 0XFFFF. The CPU usage analysis system of claim 6, wherein the thread is suspended: the thread is executed; when the thread is running, the mobile device's operating system issues an interrupt request; When the thread is running, there are other higher-priority threads that need to be executed. The thread actively releases a signal and is suspended. The CPU usage analysis system according to claim 6, wherein the calculation module calculates the CPU usage rate according to the values of all the elements in the array, including: summing all the elements in the array to obtain all thread occupations. The sum of the time of the CPU; calculate the average time that each thread occupies the CPU, the average time taken by each thread to occupy the CPU is equal to the sum of the time of all threads occupying the CPU divided by the number of threads executed in the current cycle; The usage rate of the CPU in the current cycle, the usage rate of the CPU in the current cycle is equal to the average time occupied by the CPU per thread divided by the length of time for each analysis.