JPH04336334A - Time slice value setting system - Google Patents

Abstract

PURPOSE:To improve the processing performance of the system since the frequency of CPU dispatching is decreased by automatically varying a time slice value to an effective time slice value. CONSTITUTION:A time slice control part 1 controls time slice values of respective programs. A CPU dispatch part 2 allows other programs to be executed when a program in execution fully use its time slice value or comes to wait for an input/output request. A detection part 3 detects CPU dispatch being performed because of the full use of the time slice value and requests the time slice control part 1 to increase the time slice value of the program which is fully used.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a time slice value setting method, and more particularly to a time slice value setting method for a multiprogramming system that dispatches a CPU according to a time slice value set for each program.

0002

2. Description of the Related Art In a conventional multi-programming system time slice value setting method, each program has a CP value set during the time slice value set for that program.
After using U, the CPU is dispatched to give other programs the right to execute the CPU, and this time slice value is usually constant and unless a change request is made from outside by a user etc. Not changed.

Further, dispatching of the CPU is performed even before the time slice value is used up, if the CPU is waiting for an input/output request to an input/output device or waiting for a specific event. However, there was no way to determine the reason for CPU dispatching.

0004

[Problems to be Solved by the Invention] In the time slice value setting method of the conventional multiprogramming system described above, programs that frequently make input/output requests to input/output devices are Setting a slightly larger time slice value will reduce the number of CPU dispatches.

[0005] If it is too small, two types of C
This is because PU dispatch will be performed.

On the other hand, for a program that is executed almost every time by using up the time slice value, the larger the time slice value is, the fewer times the CPU needs to perform dispatching processing.

However, if the time slice value is increased too much, the program will occupy the CPU. Therefore, it is desirable to set the time slice value to a moderate value.

[0008] However, in the conventional setting and changing of time slice values, manual operations are performed from outside, and there is no way to judge whether the time slice values are actually appropriate. The disadvantage is that you cannot make appropriate changes and do not know whether the value is valid for your system.

[0009]

[Means for Solving the Problems] The time slice value setting method of the present invention is a time slice value setting method for a multiprogramming system that performs CPU dispatch according to a time slice value set for each program. It is configured by detecting CPU dispatch as a result of using up the program, and automatically increasing the time slice value of the program that has been used up within the possible range.

0010

Embodiments Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the time slice value setting method of the present invention.

In FIG. 1, 1 is a time slice management unit that manages the time slice value of each program, 2 is a CPU dispatch unit that dispatches the CPU according to the time slice value, and 3 is a check whether the program has used up the time slice. This is a detection unit that detects whether the time slice value is changed and issues a request to change the time slice value.

FIG. 2 is a flowchart illustrating an example of the operation of this embodiment.

First, a case of a program that can use up the time slice value will be explained. When a program is input into the system (step 11), the time slice value of the program is stored in the time slice management section 1 (step 12).

Next, the CPU dispatch unit 2 grants the program the right to use the CPU, and the CPU executes the program (step 13). When the time slice value set for the program is used up, the program relinquishes the right to use the CPU (step 14).

At this time, the detection unit 3 detects that the CPU dispatch is performed by using up the time slice value (step 15), and sends a request to the time slice management unit 1 to increase the time slice value of the program. Issue (step 16).

[0017] The time slice management unit 1 that received the request,
The time slice value of the corresponding program is increased by a certain amount (step 17). The above process is repeated until the upper limit value is reached.

[0018] As a result, the CPU of this program
As the continuous usage time gradually increases, from the system's point of view,
The interval between CPU dispatching processes becomes longer. In other words, the number of times will decrease.

Next, the case of a program that frequently makes input/output requests will be explained. When a program is input into the system (step 11), the time slice value of the program is stored in the time slice management section 1 (step 12).

Next, the CPU dispatch unit 2 grants the program the right to use the CPU, and the CPU executes the program (step 13).

[0021] When the time slice value set in the program is used up and the right to use the CPU is relinquished (step 14), the detection unit 3 detects that the CPU dispatch is performed by using up the time slice value. (Step 15), and sends a request to increase the time slice value to the time slice management unit 1 (Step 16).

[0022] If before the time slice value is used up,
When the CPU enters the waiting state for an input/output request and relinquishes the right to use the CPU (step 14), the detection unit 3 detects that the CPU dispatch is not due to the time slice value being used up (step 15), and the time slice value is used up. Do not request an increase.

By repeating the above process, the time slice value is set to be larger than the issuance interval of the I/O request waiting state, and the CPU of this type of program
The usage rights are relinquished mainly by CPU dispatch due to waiting for input/output requests.

[0024] From the system's point of view, the number of times the CPU performs dispatching processing is reduced.

[0025]

As explained above, the time slice value setting method of the present invention automatically changes the time slice value to an effective time slice value, reduces dispatching processing, and provides an effective CPU usage pattern. This has the effect of realizing the following.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a time slice value setting method of the present invention.

FIG. 2 is a flowchart illustrating an example of the operation of this embodiment.

[Explanation of symbols]

1 Time slice management department 2 CPU dispatch section 3 Detection section

Claims (1)

[Claims] Claim 1: In a time slice value setting method for a multi-programming system that performs CPU dispatch according to a time slice value set for each program, the CPU as a result of using up the time slice value.
A time slice value setting method that detects a dispatch and automatically increases the time slice value of an exhausted program within a possible range.