JPH0566954A - Time slice optimization system - Google Patents

Abstract

PURPOSE:To facilitate the effective operation of a time slice optimization system by adjusting automatically the time slice value of each program in accordance with the system state. CONSTITUTION:A time slice information storing part 1 stores the time slice information on each program. A dispatching part 4 dispatches a CPU to each program based on the time slice value stored in the part 1. A system load state monitoring part 2 monitors the load state of the system. Then a time slice optimizing part 3 optimizes the time slice value of each program stored in the part 1 based on the information that is carried out through the part 4 at a fixed interval and acquired through the part 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-programming system in which CPUs are dispatched using different time slices for each program, and the time slice value can be automatically adjusted according to the load condition of the system. The present invention relates to a slice optimization method.

[0002]

2. Description of the Related Art Conventionally, in a multi-programming system, CPU dispatching has been performed using a time slice in order to prevent a specific program from occupying a CPU for a long time. This time slice is set for each program or for each program group including a plurality of programs. In general, in the case of a program whose main processing is calculation processing, the dispatched CPU is often abandoned by using time slices. Conversely, in the case of a program whose main processing is interactive processing or input / output processing, the dispatched CPU is The time slice is often used up and abandoned due to reasons such as waiting for I / O completion and waiting for other events. Also, when CPU usage is abandoned, the dispatching process is executed and becomes part of the system overhead. Therefore, in order to improve system usage efficiency, increase the time slice value and dispatching per unit time. It is useful to reduce the number of processing executions.

However, if the time slice value of each program is increased, it does not cause a problem especially when the system load is light, but when the system load increases, the response of the program mainly for interactive processing becomes extremely slow. Will end up. Therefore, a long time slice value is effective while the system load is light, and a short time slice value is effective when the system load is high.

[0004]

The above-mentioned conventional method has a problem that the time slice set in each program is fixed and cannot be automatically changed according to the state of the system.

[0005]

According to the time slice optimization method of the present invention, in a multi-programming system which performs CPU dispatch using different time slice values for each program, the program is executed for each program currently being executed. A time slice information storage unit that stores time slice information about the system, a system load state monitoring unit that monitors the system load status at regular intervals,
A time slice optimization unit that optimizes the time slice value of each program stored in the time slice information storage unit based on the system load state of the period acquired from the system load state monitoring unit at regular intervals, and this time slice optimization A dispatching unit that dispatches the CPU to the program by the time slice value stored in the time slice information storage unit after being optimized by the optimization unit is provided, and the time slice value is automatically adjusted according to the state of the system. It was done.

[0006]

In the present invention, the time slice value of each program is reviewed at regular intervals depending on the system load state during that period, and the time slice value is automatically adjusted so that optimum system operation can be performed.

[0007]

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, 1 is a time slice information storage unit that stores time slice information about each program currently being executed, and 2 is a system load state monitoring unit that monitors the system load condition at regular intervals. 3 is a time slice optimization unit that optimizes the time slice value of each program stored in the time slice information storage unit 1 based on the system load state of the period acquired from the system load state monitoring unit 2 at regular intervals. It is a dispatch unit that dispatches the CPU to the program with the time slice value stored in the time slice information storage unit 1 after being optimized by the time slice optimization unit 3.

Here, the system load state monitoring unit 2 is a system load state monitoring unit that periodically monitors the system load state, and the time slice optimizing unit 3 is a system load state monitoring unit at regular intervals. 2 is a time slice optimizing unit that adjusts the time slice value of each program stored in the time slice information storage unit 1 by calculating an adjustment value for the time slice value set for each program according to the current system load status obtained from 2. .. Further, the dispatch unit 4 determines the program to be executed next, dispatches the CPU to the program with the time slice value stored in the time slice information storage unit 1, and executes the time slice optimization unit 3 at regular intervals. It is a dispatch unit that does. The time slice value is automatically adjusted according to the state of the system.

FIG. 2 is an explanatory diagram showing a configuration example of the time slice information storage unit 1 in FIG. In FIG. 2, 11 indicates a time slice initial value initially set in the program, 12 indicates a current time slice value,
Reference numeral 13 indicates the maximum possible time slice value, and 14 indicates the minimum time slice value. And
These pieces of information are newly prepared and their values are stored when the corresponding program becomes executable. In this case, the current time slice value 12 is the time slice initial value 1
The same value as 1 is stored.

FIG. 3 is a flow chart showing an example of the algorithm of the dispatch unit 4 in FIG. First, the interval at which the dispatch unit 4 executes the time slice optimization unit 3 when the system is started is set (step 101). Next, the program to be executed is determined, the time slice information storage unit 1 storing the time slice information of the program is referred to, and the CPU is dispatched to the program by the current time slice value 12 shown in FIG. (Steps 102-104). Then, when the program abandons the use of the CPU, the dispatch unit 4 checks whether or not the set period has elapsed since the time slice optimizing unit 3 was previously executed (steps 105, 10).
6). If the time has passed, the time slice optimizing unit 3 is executed, and the period until the time slice optimizing unit 3 is executed next is set (steps 107 and 108). After that, the dispatch unit 4 returns to the selection of the program to be executed next.

FIG. 4 is a flowchart showing an example of an algorithm of the time slice optimizing unit 3 in FIG.
First, the time slice optimization unit 3 is executed by the dispatch unit 4 at regular intervals. Then, the time slice optimizing unit 3 acquires from the system load state monitoring unit 2 the load status of the system up to the time of the previous check. In this example, the system load status is the idle CP during that period.
The U ratio is acquired (step 201). Next, based on the system load condition, it is determined whether or not the time slice value should be adjusted, and if so, how much the adjustment value should be. In this case, Idle CP
If the U ratio is 25% or less, the system load is considered to be high (step 202), and a negative value (-Δ) is set as an adjustment value to reduce the time slice value from the next time (step 203). Conversely, when the idle CPU ratio is 75% or more (step 204), it is considered that the system load is light, and a positive value (+ Δ) is set as an adjustment value to increase the time slice value from the next time (step 205). ). Here, the idle CPU ratio is 25%
If it is neither below nor above 85%, it is considered that the current time slice value is appropriate and the time slice value is not adjusted.

Next, the time slice information storage unit 1 corresponding to each running program is sequentially examined (step 2
06), the above adjustment value is added to the value of the current time slice value 12 in the time slice information storage unit 1 (step 2).
07). However, when the value after the addition is larger than the maximum value 13 of the time slice values in the time slice information storage unit 1 (step 208), the current time slice value 12 is set to the maximum value of the time slice values. 13 (step 209). This is to prevent the time slice value from becoming infinitely large. If the added value is smaller than the minimum time slice value 14 in the time slice information storage unit 1 (step 210), the current time slice value 12 is set to the minimum time slice value. The value is set to 14 (step 211). This is to prevent the time slice value from becoming "0" or less.

In addition to the method of the example of FIG. 4, the table of FIG. 5 can be used to determine the adjustment value. FIG. 5 is an explanatory diagram showing an example of a table for determining adjustment values used by the time slice optimizing unit 3 in FIG. In this case, the idle C obtained from the system load state monitoring unit 2
It is assumed that the condition part of the table is searched by the PU ratio, the adjustment value on the side of the matched condition part is used as the time slice adjustment value, and if the value is “0”, no adjustment is necessary.

FIG. 6 is a block diagram showing a configuration example of the system load state monitoring unit 2 in FIG. The system load state monitoring unit 2 includes a timer unit 21 that generates an interrupt at regular time intervals, and a system state examining unit 22 that checks the system load state for each interrupt generated by the timer unit 21.
And a system state recording unit 24 for recording and saving the result of the system state investigation unit 22, and a time slice optimization unit 3
In response to a status inquiry from the system status recording unit 24
It is composed of a system status reply unit 23 which answers the current load status of the system from the contents of.

FIG. 7 is a flow chart showing an example of the algorithm of the system state investigation unit 22 in FIG. At startup, the system state investigation unit 22 first clears each value in the system state recording unit 24 to "0" (step 301), and then tells the timer unit 21 an interrupt interval indicating an interval for monitoring the system state. Set (Step 3)
02). Whenever an interrupt from the timer unit 21 occurs, C
Check the state of the PU (steps 303, 304), CPU
If is in use (step 305), "1" is added to the CPU busy count in the system state recording unit 24 (system 306). If it is not in use, "1" is added to the CPU idle count in the system state recording unit 24 (step 307). After that, it returns to waiting for an interrupt again.

FIG. 8 shows the system status reply section 2 in FIG.
7 is a flowchart showing an example of the algorithm of No. 3. First, the system status replying unit 23 is executed by the time slice optimizing unit 3 and checks the contents of the system status recording unit 24 to reply the load status of the system. In this example, first
As the system load state, the first step 401 in FIG.
The idle CPU ratio calculated by is calculated. Next, each value in the system state recording unit 24 is cleared to "0" (step 402). Finally the idle CP obtained above
Time slice optimization unit 3 which is the source of the inquiry about the U ratio
Is answered (step 403).

[0017]

As described above, according to the present invention, the time slice value of each program is reviewed according to the system load state during a certain period, and the time slice value is automatically adjusted so that the optimum system operation can be performed. Since this is done, the time slice value of each program can be automatically adjusted according to the system load condition at regular intervals, and there is an effect that efficient and optimal system operation can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a configuration example of a time slice information storage section in FIG.

3 is a flowchart showing an example of an algorithm of a dispatch unit in FIG.

FIG. 4 is a flowchart showing an example of an algorithm of a time slice optimizing unit in FIG.

5 is an explanatory diagram showing an example of a table for determining adjustment values used by the time slice optimizing unit in FIG. 1. FIG.

6 is a block diagram showing a configuration example of a system load state monitoring unit in FIG.

FIG. 7 is a flowchart showing an example of an algorithm of the system state investigation unit in FIG.

FIG. 8 is a flowchart showing an example of an algorithm of a system status reply section in FIG.

[Explanation of symbols]

 1 time slice information storage unit 2 system load state monitoring unit 3 time slice optimization unit 4 dispatch unit

Claims (1)

[Claims] 1. A multi-programming system that performs CPU dispatch using different time slice values for each program, and a time slice information storage unit for storing time slice information relating to each program currently being executed, A system load status monitoring unit that monitors the system load status at regular intervals,
A time slice optimization unit that optimizes the time slice value of each program stored in the time slice information storage unit based on the system load state of the period acquired from the system load state monitoring unit at regular intervals, and this time slice optimization A dispatch unit that dispatches the CPU to the program with the time slice value stored in the time slice information storage unit after being optimized by the optimization unit is provided, and the time slice value is automatically adjusted according to the state of the system. A time-slice optimization method characterized by the above.