JPH02136948A - Input/output control system - Google Patents

Abstract

PURPOSE:To shorten the turn-around time TAT of a job having the high priority by performing a process to discontinue an input/output instruction under execution even when no fault occurs. CONSTITUTION:An input/output instruction 3 given to a disk is sent to an input/ output control part IOC 1 together with the job priority 2 of the job that produced the instruction 3. The IOC 1 checks whether the disk shown by a disk number part 31 in the instruction 3 is busy or not, i.e., whether the instruction 3 is executed or not by reference to a busy register group 5 corresponding to a disk group 15. In the case the execution is impossible for the input/output instruction of a job having the high priority due to the busy state of a peripheral device caused by the input/output of another job having the lower priority, the input/output of the job of the lower priority is discontinued and the input/ output instruction of the job of the higher periority is carried out. As a result, the TAT is shortened for the job of the higher priority.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an input/output control method, and particularly to an input/output control method in computer processing.

(Prior Art) Conventionally, in computer input/output control systems, -W
Except when an error occurs, no processing is performed to cancel an input/output command in progress.

(Problem to be Solved by the Invention) In the conventional input/output control method described above, since there is no need to cancel an input/output command that is being executed, the input/output operation of a job with a high processing priority is assigned to a job with a lower priority. The disadvantage is that the user is forced to wait until the input/output operation of the job with the specified time is completed. In other words, even if the processing priority of a job that requires a lot of input/output operations is increased, input/output operations will become a bottleneck in a multi-job environment, and the turnaround time (T
There is a problem that AT) cannot be shortened.

<-;Means for Solving aM) The input/output control method according to the present invention includes means for stopping the input/output operation of a peripheral device midway, and a register that stores the processing priority of the job that has issued the input/output command. and when a new input/output request is issued to a peripheral device that is currently performing input/output, the priority stored in the storage register and the priority of the job that issued the new input/output request are If the priority of the job that issued the new I/O request is high, the currently executing I/O is immediately stopped, the new I/O command is executed, and the I/O with the high priority is After the instruction is completed, the aborted input/output instruction is re-executed.

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

FIG. 1 is a configuration block diagram showing an embodiment of the input/output control method according to the present invention, and FIG. 2 is a processing flow thereof.

The input/output command 3 for the disk is sent to the input/output control unit 1 (I
Arrive at OC). In l0CI, if the disk indicated by the disk number field 31 in the input/output instruction 3 is set to ``G'', that is, whether or not the input/output instruction to the disk is being executed is determined by the ``G'' register group 5. Please refer to to find out.

Each register in the busy register group 5 is set to "1" if the disk corresponding to the register is busy; otherwise, "0" is set. In addition, each priority storage register of the priority storage register group 4 contains a disk input/output instruction (I10) corresponding to the respective register.
Stores the priority of the job that issued the command.

As a result of the above investigation, if the disk targeted by the I10 instruction is G, the priority of the job that has already issued the I10 instruction to the disk, that is, the priority storage register corresponding to the G disk is The corresponding priority storage register value and the job priority 2 are compared. Then, if priority 2 is greater than the value of the priority register, l
0CI transfers the input/output operation instruction part 32 of the input/output instruction that is currently being executed or the contents of the input/output operation register 7 stored therein to the save register 8, and then transfers the input/output operation instruction part 32 of the I10 instruction that has just arrived. The data is stored in the input/output operation register 7, and a stop instruction signal 14 is sent to the disk controller (DKC) 9 to stop the input/output operation of the disk indicated by the disk number register 6.

When the input/output operation of the disk is canceled, the cancellation acceptance signal 1 is generated.
0 is sent from the DKC 9 to the l0CI, and after waiting for the cancellation acceptance signal, the contents of the input/output operation register 7 are transmitted to the DKC 9 as the input/output operation signal 13. When the input/output operation to the disk according to the instructions of the input/output operation signal 13 and the disk number signal 12 is completed, the input/output completion signal 11 is sent to the 10CI. When the input/output end signal is received, the l0CI returns the contents of the save register 8 to the input/output operation register 7, and re-executes the I10 instruction whose operation was stopped.

Note that if the priority of the job that issued the newly arrived I10 instruction is not greater than that of the job that issued the already executed I10 instruction, the new I10 instruction will terminate the currently executing I10 instruction. The input/output end signal 11 shown is l0
They will have to wait in the IOC until they arrive at the CI.

The flow of the above processing will be briefly explained with reference to Fig. 2.
When the I10 instruction (Ia) for disk n arrives,
If disk n is toji, it is I10 that has just arrived.
Compare the priority Pa of the job that issued the command with the priority Pe of the job that issued the I10 command being executed, and if Pa is P
If larger than e, the currently executing I10 instruction (Ie)
After saving Ilo and canceling Ilo, Ia is executed. Then, after taking out the saved Ie, I
Re-execute e and wait for the next 110 instruction. If disk n is not busy, wait for the next I10 instruction after executing Ia.

(Effects of the Invention) As explained above, the present invention provides an advantageous method when an input/output command of a high-priority job cannot be executed due to the input/output of a job with a lower priority than the low-priority job. By stopping the input/output of the higher-priority job and executing the input/output command of the higher-priority job, the turnaround time (TAT) of the higher-priority job can be reduced compared to conventional control methods. There is an effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the configuration of an input/output control system according to the present invention, and FIG. 2 is a diagram showing a processing flow regarding handling of I10 instructions for the same disk in the embodiment shown in FIG. 1... Input/output control unit, 2... Job priority, 3...
・I/O command, 31...Disk number section, 32...
Input/output operation instruction unit, 4...Priority storage register group, 5
... Busy register group, 6... Disk number register, 7... Input/output operation register, 8... Save register, 9... Disk control unit (DKC), 10...
Cancellation acceptance signal, 11... Input/output end signal, 12...
Disk number signal, 13...I/O operation signal, 14.
...Abort instruction signal, 15...Disk group.

Claims (1)

[Claims] It is equipped with a means for stopping the input/output operation of a peripheral device midway, and a register for storing the processing priority of the job that issued the input/output command, and is equipped with a means for stopping the input/output operation of a peripheral device midway through, and a register that stores the processing priority of the job that issued the input/output command. If the priority stored in the storage register is compared with the priority of the job that issued the new input/output request, and if the priority of the job that issued the new input/output request is higher, For example, the currently executing input/output is immediately stopped, the new input/output instruction is executed, and the interrupted input/output instruction is re-executed after the high priority input/output instruction is completed. An input/output control method.