JPH01177638A - System for scheduling job - Google Patents

Abstract

PURPOSE:To average the processing of the whole calculation system by scheduling a selective job and suppressing the schedule according to the load condition of a CPU decided based on the number of CPU queuing jobs at every job priority. CONSTITUTION:A CPU queuing job number measuring means 1 measures the number of the CPU queue jobs which is the number of the jobs made into a CPU queuing condition at every job priority designated to respective jobs. A schedule deciding means 2 obtains the CPU load of the selective job based on the number of the CPU queuing jobs at every job priority measured by the CPU queuing job number measuring means 1, and whether the schedule is executed or not is decided. Further, a job scheduling means 3 executes either of the schedule of the selective job or the suppression of the schedule of the selective job based on the decision of the schedule deciding means 2. Thus, a condition can be reduced in which, while many resources are assigned to the job in the CPU queuing condition, the resources cannot be utilized by the other jobs, and the using efficiency of the resources of the computer system can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a job scheduling method, and particularly to a job scheduling method in a computer system in which a plurality of jobs are executed.

[Conventional technology]

Conventionally, in this type of job scheduling method, job scheduling (selection of jobs for which a job start request should be issued) is performed based on the priority of the job.

Scheduling is a method of controlling multiple jobs by appropriately scheduling each job or inhibiting the schedule, or by dividing jobs into schedule classes and dividing jobs into schedule classes based on the priority of the job. A method of scheduling jobs was used.

All of these methods basically schedule jobs in descending order of priority specified by a user or the like for each job.

However, in the method of using schedule classes, the resources (input/output devices) that are mainly used by jobs are the first resource.

External storage devices, special devices, and CPU (Central
Each job is divided into schedule classes according to the method (Processing Unjt), etc.), and the priority among schedule classes, the maximum number of scheduled jobs, etc. are set for each schedule class. As a result, within each schedule class, jobs are scheduled in descending order of priority, but in order to avoid only jobs that use specific resources being scheduled, job priorities are changed between jobs in different schedule classes. Even low-ranking jobs are controlled to be scheduled preferentially in some cases.

However, in these job scheduling methods, jobs are scheduled (job activation requests) regardless of the load state of the CPU (the frequency of use of the CPU). In other words, even with a method that uses schedule classes, a job start request is issued based only on the priority between schedule classes and the maximum number of scheduled jobs set for each schedule class, regardless of the CPU load status. .

[Problem to be solved by the invention]

In the conventional job scheduling method described above, the CP
Since jobs are scheduled regardless of the load status of the CPU, jobs are submitted to the CPU in excess of the CPU's capacity, resulting in a high CPU load (the CPU is used more frequently and jobs are waiting for the CPU). The disadvantage is that the processing of the entire computer system becomes extremely slow.

Furthermore, since there are a large number of jobs waiting for the CPU as described above, there is a drawback that resources other than the CPU allocated to these jobs cannot be used by other jobs.

In view of the above-mentioned points, an object of the present invention is to average out the processing of the entire computer system (in some cases, increase the processing speed) without causing jobs to be submitted to the CPU in excess of the CPU's capacity. It happens that the CPU is very slow at times, and many resources other than the CPU are used by the CPU.
To provide a job scheduling method that improves the utilization efficiency of resources of a computer system by reducing the situation where a job remains assigned to a waiting job and cannot be used by other jobs.

[Failure to solve the problem]

The job scheduling method of the present invention measures the number of CPU-waiting jobs, which is the number of jobs in a CPU-waiting state, for each job priority specified for each job.
PU waiting job number measuring means and CPU for each job priority measured by this CPU waiting job number measuring means
A schedule determining means for calculating the CPU load of the selected job based on the number of waiting jobs and determining whether or not to schedule the selected job, and either scheduling the selected job or inhibiting the scheduling of the selected job based on the determination by the schedule determining means. and job scheduling means for doing so.

[Effect]

In the job scheduling method of the present invention, the CPU waiting job number measuring means measures the number of CPU waiting jobs, which is the number of jobs in the CPU waiting state, for each job priority specified for each job, and the schedule determining means determines whether or not to schedule the selected job by determining the CPU load of the selected job based on the number of CPU waiting jobs for each job priority measured by the CPU waiting job number measuring means, and the job scheduling means determines whether or not to schedule the selected job. Based on the determination, either the schedule of the selected job or the schedule of the selected job is suppressed.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an embodiment of the job scheduling method of the present invention. The job scheduling method of this embodiment calculates the number of jobs waiting for the CPU, which is the number of jobs waiting for the CPU (not shown), according to the job priority specified for each job in the table 4 for the number of jobs waiting for the CPU ( CP for each job priority measured by the CPU waiting job number measuring means 1 (see Part 2) and the CPU waiting job number measuring means 1
Based on the number of U-waiting jobs, the CPU load of the selected job (the contents of the "selected job" will be described later) (CPU with a job priority higher than the job priority of the selected job)
A schedule determining means 2 determines whether or not to schedule the selected job by determining whether or not to schedule the selected job by determining whether the selected job has a high CPU load when there are many jobs in the waiting state; The job scheduling unit 3 includes a job scheduling unit 3 that performs either scheduling or inhibiting the schedule of a selected job.

Referring to FIG. 2, the CPU waiting job number table 4 used for measurement by the CPU waiting job number measuring means 1 has the job priority i (i=o~10°) of the job waiting for the CPU at that time. For convenience, the job priority is specified as an integer from 0 to 10, and the larger the number, the more preferentially a job start request is issued.It goes without saying that the job priority is not limited to these numbers. It is configured with an entry for job priority O to an entry for job priority 10, in which the number n1 (no to n1o (0 and positive integer)) of jobs of 0 to 10 are stored.

Referring to FIG. 3, the processes of the schedule determining means 2 and the job scheduling means 3 include a job selection step 10, a resource allocation step 11, an allocation success determination step 12, a resource release step 13, and a schedulability/impossibility determination. It consists of step 14 and job start request step 15.

Next, the operation of the job scheduling method of this embodiment configured as described above will be explained.

In order to schedule a plurality of jobs on a computer system having the job scheduling method of this embodiment, the number of CPU waiting jobs is measured by the CPU waiting job number measuring means 1 for each job priority.

In this measurement, the table 4 for the number of jobs waiting for the CPU is used (it goes without saying that measurement can be performed by a method other than using the table 4 for the number of jobs waiting for the CPU).

In other words, when a new job start request is issued for a job with job priority i, or when a job with job priority i is forcibly released from the CPU due to time-sharing processing or the like and enters the CPU wait state, etc. , 1 is added to ni in the job priority quantity entry in the CPU waiting job number table 4 by the CPU waiting job number measuring means 1.

Further, when the CPU assignment to the job with job priority i that was in the CPU wait state is completed.

When a job with job priority i releases the CPU because it is in a waiting state for a resource other than the CPU, or when a job with job priority i releases the CPU to synchronize with other jobs, the CPU wait state The job number measuring means 1 subtracts 1 from ni in the job priority amount entry in the CPU waiting job number table 4.

Furthermore, if the job priority of a job waiting for the CPU is changed from i to j (j=o~10.i#j) (
The job priority is specified by the user, but may be changed by instructions from the operating system (not shown), etc.). 1 is subtracted from ni in the quantity entry and 1 is added to nj in the job priority quantity entry.

CP by the CPU waiting job number measuring means 1 as described above
On the premise that the number of U-waiting jobs is being measured, the schedule determining means 2 and job scheduling means 3 perform the following processing.

First, based on the priority of the job with respect to resources other than the CPU (input/output devices, external storage devices, etc., not shown),
(The job scheduling method of the prior art is applied to resources other than the CPU), and the job scheduling means 3 selects a job that should issue a job start request with priority (the jobs selected in this way are referred to as "selected jobs"). '') (step 10), and resources other than the CPU requested by the selected job are allocated to the selected job (step 11).

Next, it is determined whether resources other than the CPU requested by the selected jobs have been successfully allocated to all selected jobs (step 12).

If the resource allocation fails in this judgment, the resources already reserved for the selected job are released (the released resources can be effectively used by jobs other than the selected job) (Step 13) .

If the resource allocation is successful in the determination in step 12, the job scheduling means 3 inquires whether the selected job can be scheduled in view of the low CPLI load of the selected job. 2.

The schedule determining means 2 determines the job priority (k(k-0 to 10) received from the job scheduling means 3.
)) is determined as follows (step 1).
4).

That is, first, the number of jobs in the CPIJ waiting state that has a job priority equal to or higher than the job priority of the selected job related to the inquiry from the job scheduling means 3 is Nk'IJ<C
CPU created by PU waiting job number measurement means 1
It is determined by the following equation based on the number of waiting jobs table 4.

Nk=n1O+n9+・-+n (k-1)+nk (Here, it is assumed that ≦7) Here, since CPU allocation is performed in order of job priority, the selected job that received an inquiry from the job scheduling means 3 It can be said that the larger the number Nk of jobs in the CPU wait state having a job priority equal to or higher than the job priority, the higher the CPU load for the job selected as the job priority.

Therefore, Nk obtained in this way is compared with a preset darkness value L (positive integer), and Nk is
If k > L, "scheduling not possible (selected job should not be scheduled considering the CPU load status)"
” is determined by the schedule determining means 2, and Nk≦L
If so, the schedule determining means 2 determines that the selected job should be scheduled in consideration of the load status of U (schedulable (C)), and the result of this determination is passed to the job scheduling means 3.

When the job scheduling unit 3 receives the determination that “scheduling is not possible” from the schedule determining unit 2, the scheduling of the selected job is suppressed and the resources already reserved for the selected job are released (stenope 3), and the process of step 10 is performed. control is transferred to

The job scheduling unit 3, which has received the “schedulable” determination from the schedule determining unit 2, schedules the selected job, issues a job start request for the selected job (step 15), and controls the processing in step 10. Move.

〔Effect of the invention〕

As explained above, in the present invention, when scheduling a plurality of jobs, a selected job is scheduled or the schedule is inhibited depending on the CPU load state determined based on the number of CPU waiting jobs for each job priority. By doing this, jobs will not be submitted to the CPU in excess of its capacity, and the processing of the entire computer system will be averaged (the load on the CPU of the computer system will be averaged over time). effective.

In addition, when the CPU load of the selected job is high, the schedule of the selected job is suppressed and the resources other than the CPU that have been allocated to the selected job are released. This has the effect of reducing the number of jobs that remain allocated but cannot be used by other jobs, and improving the efficiency of resource usage in the computer system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention; FIG. 2 is a diagram showing the configuration of a CPU waiting job number table used by the CPU waiting job number measuring means in FIG. 1; FIG. 2 is a flowchart showing the processing of the schedule determining means and job scheduling means in FIG. 1. FIG. In the figure, 1... CPU waiting job number measuring means, 2... Schedule determining means, 3... Job scheduling means, 4... CPU waiting job number table.

Claims (1)

[Scope of Claims] CPU-waiting job number measuring means for measuring the number of CPU-waiting jobs, which is the number of jobs in a CPU-waiting state, for each job priority specified for each job; a schedule determining means for calculating the CPU load of the selected job based on the number of CPU waiting jobs for each job priority measured by the measuring means and determining whether or not to schedule the selected job; and based on the determination by the schedule determining means. A job scheduling method comprising: job scheduling means for either scheduling a selected job or inhibiting the scheduling of a selected job.