JPH08263308A - Memory allocation management system - Google Patents

Abstract

PURPOSE: To prevent the processing delay of a process having high priority of execution by allocating the memory resource requests given from a process under execution with addition of the execution priority of the resources. CONSTITUTION: In a multiprocessor system where many processes of different levels of execution priority are processed in time division, a memory is allocated to the additional requests given to the memory resources from a process under execution. Then a memory allocation management system of such a constitution includes a limit decision table 1 which holds the limit value of every execution priority, a decision table production means 2 which sets the allocation limit value to a user prescribed value file 6 and expands it to the table 1, a decision table retrieval means 3 which retrieves the table 1 based on the execution priority of the process under execution when an allocation request is given from the process, and an allocation decision means 4 which monitors the using state of an additional allocation memory resource area 5 and compares the retrieved allocation limit value with the present memory remaining capacity to decide the possibility of its allocation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory allocation management system, and more particularly to a computer system in which a plurality of processors having different execution priorities are executed in a time-sharing manner in a memory system, and a memory is responsive to a request from a process being executed. The present invention relates to a memory allocation management method when additionally allocating resources.

[0002]

2. Description of the Related Art In a recent multiprocessor type computer system, the number of processes (user processes) to be executed in a time-sharing manner is very large.
Due to the necessity of effectively using memory resources, each process is controlled by the procedure shown in FIG. 3 by the OS that manages the entire system.

First, a process to be executed next is selected from processes waiting for execution by referring to the execution priority (step S1), and basic memory resources necessary for execution are allocated (step S2). ). Here, if the selected process is a process whose execution has been interrupted, after the memory state at the time of the previous execution interrupt is restored (step S3), control is passed to the selected process 8 and execution is started. (Step S4).

When a request for allocating an additional memory resource is issued from the running process 8 (step S5), the additional memory resource management section 7 judges the usage status of the memory resource area for additional allocation, and allocates or waits for allocation. Then, it is determined whether to suspend the execution (step S6). When interrupting the execution, control is returned from the executing process 8 to stop the execution (step S7), and the memory state at the time of interrupting the execution is saved and saved in an auxiliary storage such as a disk (step S8). The memory resource including the additional allocation for the next process is released (step S9), the process 8 is connected to the execution queue according to its execution priority, and the control is terminated (step S10). When the suspended process is selected again, necessary memory resources including the additional allocation are allocated in step S2.

On the other hand, when the additional allocation is executed and the process 8 ends normally, all the memories in use are released and the control ends (step S11). If the execution waits due to factors such as input / output during execution (step S12), or if the unit time of the time division processing has timed up and processing has not ended (step S13), the process proceeds to step S7 and the process 8 is executed. Execution is suspended. In addition,
The additional memory resource management unit 7 includes a function (step S14) of processing a release request of the additionally allocated memory resource issued from the process 8 being executed.

As a memory allocation management method performed by the additional memory resource management unit 7 described above, a method of allocating memory on a first-come-first-served basis has been generally used so far as long as there is a free area in the memory resource area for additional allocation. That is, the execution priority is referenced only when a process is selected, and has no meaning after the start of process execution. Therefore, when two processes with different execution priorities request memory resource allocation at the same time during process execution, if the process with the lower execution priority is accepted first, the process with the higher execution priority will be accepted. Will be turned around later,
If the area is near saturation, there is a disadvantage that a process with a high execution priority waits for memory resource allocation and execution is interrupted.

As an example in which the degree of urgency is taken into consideration when allocating a limited memory area to a plurality of processing purposes of the same type, there is a proposal concerning a communication buffer control system in Japanese Patent Laid-Open No. 2-211743. This method divides the communication buffer area into a shared area and an emergency area, allocates the shared area buffer on a first-come-first-served basis when the shared area is available, and only when the shared area is saturated, it is limited to emergency communication. Allocating a buffer in the emergency area.

[0008]

As described above, in the conventional memory allocation management method that processes memory resource requests from running processes on a first-come-first-served basis, the execution priority has no meaning after the process execution is started. There is a drawback that a process with a high execution priority is sent to a later stage and waits for memory resource allocation, and execution is interrupted. On the other hand, in order to solve this, a method of dividing the memory resource area into a plurality of fixed areas in advance like the method described in Japanese Patent Laid-Open No. 2-211743 is different from the case of the communication buffer in that the execution priority Under the condition that the amount of memory required for many divisions is not fixed, there is a problem that not only the control becomes complicated but also a useless area occurs in the memory resource.

In view of the above points, an object of the present invention is to execute a priority process corresponding to an execution priority without dividing a memory resource, and to minimize the execution delay of a process having a high execution priority so that the process can be executed smoothly. It is to provide a memory allocation management method capable of providing a different process execution environment.

[0010]

A memory allocation management system according to a first aspect of the present invention is a computer system in which a large number of processes having different execution priorities are time-shared by a plurality of processors.
In the memory allocation management method when allocating additional memory resources in response to a request from a running process,
An allocation limit judgment table that holds the allocation limit value for each execution priority, a judgment table creating unit that sets the allocation limit value for each execution priority and stores it in the allocation limit judgment table, and a memory resource from the process being executed. Determination table search means for searching the allocation limit determination table with the execution priority of the process when the allocation request is issued, the allocation limit value retrieved by the determination table search means, and the current additional allocation memory resource area And an allocation determining means for determining whether or not the request process can be allocated based on the usage status of the.

According to a second aspect of the memory allocation management method of the present invention, in the memory allocation management method of the first aspect, the allocation limit value stored in the allocation limit determination table is the memory resource area for additional allocation after execution of allocation. It is a value indicating the remaining amount of memory as a percentage, and the allocation determination means calculates and compares the percentage of the remaining amount of memory after allocation from the usage status of the memory resource area for additional allocation.

A memory allocation management method according to a third aspect is the memory allocation management method according to the first aspect, wherein the allocation limit value stored in the allocation limit determination table is the memory resource area for additional allocation before allocation execution. It is characterized by the percentage of remaining memory.

According to a fourth aspect of the memory allocation management system of the present invention, in the memory allocation management system of the first aspect, the allocation limit value stored in the allocation limit determination table indicates the remaining memory capacity of the additional allocation memory resource area. It is characterized by being a real number.

[0014]

Embodiments of the present invention will now be described with reference to the drawings.

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

The memory allocation management system of this embodiment is a computer system in which multiple processes having different execution priorities are executed by a plurality of processors in a time-sharing manner, and additional memory resources are allocated in response to a request from a process being executed. As shown in FIG. 1, an allocation limit determination table 1 for holding the allocation limit value for each execution priority, and an allocation limit value for each execution priority are set. A judgment table creating means 2 for storing in the judgment table 1, a judgment table searching means 3 for searching the allocation limit judgment table 1 with the execution priority of the process in response to a memory resource allocation request from a process being executed, and a judgment table search Based on the allocation limit value retrieved by the means 3 and the usage status of the additional allocation memory resource area 5, And a allocation determining means 4 for determining whether the memory allocation possible for Seth.

FIG. 2 is an explanatory diagram showing a configuration example of the allocation limit determination table 1. Allocation limit judgment table 1
As shown in FIG. 2, an allocation limit value, which is a criterion for determining whether or not to execute the allocation of the additional memory resource in correspondence with the execution priority, is stored in the table. In FIG. 2, the remaining memory capacity which is the criterion for 10 levels of execution priority from “1” to “10” is displayed as an integer representing the percentage of the total capacity of the additional allocation memory resource area 5. ing. Note that the numerical values in the case of FIG. 2 indicate the remaining memory capacity after allocating the memory requested for addition, and 0% in the case of the execution priority “10”, which has the highest priority, has a sufficient memory resource. As long as it shows that allocation is done.

The judgment table creating means 2 sets the allocation limit values stored in the allocation limit judgment table 1 in the user specified value file 6 in advance, and at the start of system operation, the set allocation limit values are set in the user specified value file. 6 is expanded to the allocation limit determination table 1. The allocation limit value of the user specified value file 6 is mainly set by the operation administrator from the statistic of the number of processes for each execution priority existing in the system.

When receiving the additional memory allocation request from the process being executed, the judgment table search means 3 acquires the execution priority of the requesting process and searches the allocation limit judgment table 1 to correspond to the execution priority. The allocation limit value is acquired and passed to the allocation determination means 4.

The allocation determining means 4 monitors the usage state of the additional allocation memory resource area 5, and when a memory request is received, the remaining memory value after allocation is determined from the current usage status of the additional allocation memory resource area 5. (%) Is calculated,
The allocation limit value (%) acquired from the determination table search means 3 is compared, and if the remaining memory value after the allocation is greater than or equal to the allocation limit value, memory allocation is executed and the allocation limit value is smaller than the allocation limit value. For example, the allocation is not performed and the execution of the process is suspended by waiting for the memory allocation.

For example, when the numerical values shown in FIG. 2 are set in the allocation limit judgment table 1, it is assumed that a process executing with the execution priority "4" issues a request for allocation of additional memory resources. At this time, first, the determination table search means 3 searches the allocation limit determination table 1,
The remaining memory capacity "12%" corresponding to the execution priority "4" is acquired as the allocation limit value. The allocation determination means 4 is
The use state of the additional allocation memory resource area 5 is monitored, and if the unused remaining memory capacity that can be allocated at that time is 20% and is larger than 12% of the remaining memory capacity acquired by the determination table search means 3, Based on this, the remaining memory capacity (X
%) Is calculated, and this is compared with 12% of the allocation limit value acquired by the determination table search means 3, and if X ≧ 12, it is determined that allocation is possible, and memory resources are allocated to the requesting process. On the other hand, when X <12 and the current remaining memory capacity at the time of request is, for example, 10% and less than 12%, it is determined that the allocation is impossible and the execution of the process is interrupted.

According to this method, since the allocation of the additional memory resource can be limited for each execution priority, it is possible to finely control the allocation of the memory resource, and the process with the high execution priority suspends the execution while waiting for the allocation of the additional memory resource. It is possible to avoid being done. Moreover, since the additional allocation memory resource area 5 can be used without being divided, the entire area can be effectively used without generating a wasteful unused area.

In the above-described embodiment, the allocation limit determination table displays the remaining memory amount after the allocation of the requested memory resource in%. However, the remaining memory amount at the time of the allocation request is displayed in%, and The allocation may be performed when the remaining memory capacity at that time is larger than this and the requested amount can be allocated. Further, the same effect can be obtained even if the configuration is such that the actual remaining memory amount is defined instead of%.

[0024]

As described above, according to the memory allocation management method of the present invention, when a request for allocation of additional memory resources is issued from an executing process, the allocation limit value determined from the execution priority of the requesting process and the current request time Since the memory remaining amount is compared and the process of allocating the memory resource or the process of suspending the execution is selectively performed, it is effective in reducing the state in which the process having a high execution priority is delayed in the process of waiting for the memory resource allocation.

[Brief description of drawings]

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

FIG. 2 is an explanatory diagram showing a configuration of an allocation limit determination table according to the present embodiment.

FIG. 3 is a flowchart showing an entire procedure regarding an additional memory allocation request from a running process.

[Explanation of symbols]

 1 Allocation Limit Judgment Table 2 Judgment Table Creation Means 3 Judgment Table Search Means 4 Allocation Judgment Means 5 Additional Allocation Memory Resource Area 6 User Specified Value File 7 Additional Memory Resource Management Unit 8 Process

Claims (4)

[Claims] 1. A computer system in which a large number of processes having different execution priorities are executed by a plurality of processors in a time-sharing manner,
In the memory allocation management method when allocating additional memory resources in response to a request from a running process,
An allocation limit judgment table that holds the allocation limit value for each execution priority, a judgment table creating unit that sets the allocation limit value for each execution priority and stores it in the allocation limit judgment table, and a memory resource from the process being executed. Determination table search means for searching the allocation limit determination table with the execution priority of the process when the allocation request is issued, the allocation limit value retrieved by the determination table search means, and the current additional allocation memory resource area A memory allocation management method, comprising: an allocation judgment means for judging whether or not allocation is possible to a requested process based on the usage status of the memory. 2. The allocation limit value stored in the allocation limit determination table is a value indicating the remaining memory capacity of the memory resource area for additional allocation after execution of allocation as a percentage, and the allocation determination means is the addition The percentage of the remaining memory capacity after allocation is calculated from the usage status of the allocation memory resource area and compared.
Memory allocation management method described. 3. The memory allocation according to claim 1, wherein the allocation limit value stored in the allocation limit determination table is a percentage of the remaining memory capacity of the additional allocation memory resource area before the allocation is executed. Management method. 4. The memory allocation management method according to claim 1, wherein the allocation limit value stored in the allocation limit determination table is a real value representing the remaining memory capacity of the additional allocation memory resource area. .