JPS58222350A - Multiplex processing system - Google Patents

Abstract

PURPOSE:To eliminate the system dead lock and to release the congestion, by providing a device permitting a buffer use request of a low priority only when the number of vacant buffers is a prescribed value or below. CONSTITUTION:A buffer managing device 4 is constituted of a buffer request discriminating circuit 41 and a counter 42. Further, the managing device 4 counts the number of vacant buffers B, and the use is inhibited to the buffer use request of a low priority from an external input device 2 when a value of the counter 42 reaches a prescribed value. When the internal processing is finished and the number of vacant buffers is a prescribed value or over, the low priority buffer use request is also received. Thus, even if an external job demmand exceeds remarkably the prepared buffer size, the job is executed successively from the internal processing having a buffer use request of a high priority. Then, the information processing system attains job processing without intermission.

Description

[Detailed description of the invention] The present invention relates to a multiprocessing method for an information processing system.

2. Description of the Related Art In an information processing system intended for multi-processing, a storage device including a plurality of buffers is required to store a plurality of jobs required of the information processing system and to continue storing the jobs even during internal processing. When each job is completely finished, the used buffer becomes available for use by a new job. Information processing system.

Jobs requested by the system include jobs that are generated by requests from outside the information processing system, and jobs that are generated by requests from jobs that are once taken into the information processing system and are currently being processed. FIG. 1 is a diagram showing a system configuration for explaining the above job. In FIG. 1, 1 is a processing device, 2 is an input device, and 3 is a storage device.

In the information processing system shown in Fig. 1, P, ~"I*"'
1 #J, ~Ja eJJx t Bl~8, etc. are models of multiple processing. That is, the buffers are the first to sixth buffers. J1 to J8 represent jobs requested to the information processing system from outside the information processing system. Jobs J1 to J3 are already in internal processing and exist in the storage device, and are marked Pl, P, , P3 on the processing device.J4 to J8 are jobs that have not yet entered internal processing. refers to Processing P1 to 1d
The job requested to the information processing system will be represented by JJi. In FIG. It's pishi.

In such a system, the memory size of the buffer is generally limited, so as the demands for jobs from outside the information processing system increase, the buffer is used one after another and becomes full. Once the buffer is full, there will be no buffer available for a job that is requested by a job that has been imported and is currently being processed. In this case, the system simply waits for the buffer to become free, and internal processing cannot proceed, resulting in a system dead state.

FIG. 2 is a diagram illustrating a state in which a system deadlock occurs in the system configuration shown in FIG. 1. In the state shown in FIG. 1, processing p, , p, is job JJ, .

Before generating the crane, job J4 # J8 is put into buffer plane A, l& to create process P4s '5, and further process P1. After PP is completed, the buffer surface A,
When B, becomes free, move B! to buffer l. to job J6
．． Once JT has been inserted, when Pl on the processing device tries to generate job JJi, there is no free space on the buffer surface, and when processing Pi, it is necessary to wait for the buffer surface to become free for job JJ1. You can't proceed with the process by just waiting.

Conventionally, in such a case, a maintenance person, -f, or operator must intervene to start up the system. If the situation cannot be resolved automatically, or even if the system is started up, maintenance personnel and reed rack operators are forced to stop jobs during the period during which the system starts up from a system deadlock state. For this reason, after the system was launched due to demand for information processing systems, the system was concentrated on 1'□1. .

7A is full, causing system deadlock again □
In order to prevent situations such as system crashes and system deadlocks as much as possible, it is necessary to prepare a sufficient buffer size in anticipation of the worst-case scenario required of an information processing system.

The conventional technology has the drawback of being less economical.

The purpose of the present invention is to configure an information processing system that performs multiple processing so that even when the buffer becomes full, the system does not fall into a system deadlock state, but only remains in a temporary state of computation. The purpose is to provide a multi-processing method.

As described above, in conventional information processing systems intended for multi-processing, a system deadlock condition occurs when a buffer becomes full. It is necessary to take measures to prevent this situation from occurring and to ensure that internal processing is carried out smoothly. but.

The buffer full situation only happens once, so
As already explained, it is uneconomical to prepare enough buffers to cover all situations in order to prevent the buffer from becoming full.

Therefore, we prepare buffers with an appropriate memory size for normal demand, prioritize buffer usage requests, and only issue buffer usage requests for lower priority buffers when the number of free buffers is below a certain value. The problems of the conventional method were solved by adding a device for permitting.

That is, in the multiprocessing method according to the present invention, the input device and
This multiprocessing system includes a storage device including a plurality of buffers for storing information for internal processing, and a processing device, in which a buffer management device is added. The buffer management device includes a counter and a buffer request determination circuit. The counter counts and displays the number of free buffers. In response to a low priority buffer use request, the buffer request determination circuit prohibits the use of the buffer when the counter value becomes smaller than a predetermined constant value. Therefore, the configuration is such that a low-priority buffer use request is accepted only when the number of free buffers is less than a certain value.

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

FIG. 3 is a block diagram of a multiprocessing system in which a buffer management device is added to the information processing system having the system configuration shown in FIG. In Figure 3, the buffer management system +t
4 is composed of a buffer request determination circuit 41 and a counter 42.

The buffer management device 4 counts the number of free buffers, and when the value of the counter 42 reaches a certain value, prohibits buffer capture for low-level buffer usage requests.
Ru. Low buffer usage requests refer to buffer usage requests for jobs that come from input devices external to the processing system.

In this embodiment, the initial value of the counter is 6, the value is decremented each time the buffer is used, and is incremented by 7L each time the buffer is returned to an empty state. Thereafter, when the internal processing is completed and the number of desired buffers exceeds a certain value, buffer usage requests are allowed and accepted even for low-level buffer usage requests.

This buffer management device 4 has Q ``'' 9h Even when the external job demand for the relevant information processing system is significantly larger than the prepared buffer size, the internal buffer management device 4 keeps high-level buffer usage requests. Since jobs are executed one after another from processing, it is possible to limit the demand for one design standard amount to a temporary congestion of the report processing system. Therefore, the information processing system can process jobs without interruption, and the congestion state can be more effectively relieved.

This example shows a case where the μ buffer has two priorities. That is, priority is given to buffer usage requests for jobs entering the information processing system through the input device m2 and buffer usage requests requested from jobs that have already been taken into the system and are being processed. Even if the system becomes complex and there are multiple buffer usage requests requested by the jobs being processed internally, it is possible to apply water droplets in the same way by prioritizing each job. It is.

As explained above, the present invention employs a buffer management device to smoothly maintain a congestion state without causing a system deadlock state even when the buffer is full. There is an effect that can be removed.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the execution of a job using the conventional multiprocessing method. Figure 2 is a diagram explaining the system deadlock state f that occurs in the multiprocessing method shown in Figure 1. 1 is a block diagram illustrating an embodiment of a multi-processing scheme according to the invention; FIG. 10 fists, processing device 2, input device 3, storage device 4, buffer management device 41φΦ, buffer request determination circuit 42, color, patent applicant NEC Corporation agent, patent attorney Inoro Miyako 7j Figure 3 2vA

Claims (1)

[Claims] In a multiprocessing system that includes an input device, a storage device including a plurality of buffers for storing information for internal processing, and a processing device, the buffer management device includes a counter and a buffer request determination circuit. The counter counts and displays the number of free buffers, and the buffer request determination circuit determines whether the value of the counter is a predetermined constant value or not for a buffer use request having a low priority. When the number of free buffers becomes smaller, the use of the buffer is prohibited, and a request to use the buffer having the lower priority is accepted only when the number of free buffers is less than the certain value. Multiprocessing method.