What Compact Technology Can Do in Variable Partition Storage Management

What can compact technology do in variable partition storage management?

Compact technology in variable partition storage management can concentrate free areas.

Related introduction:

Variable partition storage management does not divide the user area in the memory into a number of fixed partitions in advance, but when the job requires loading into the memory, it is based on the size and size of the user job. The memory space usage at that time determines whether a partition is allocated for the job. Therefore, the size of the partitions is not fixed in advance, but is divided according to the job requirements; the number and location of the partitions are not determined in advance. It effectively overcomes the problem of waste caused by the remaining vacant memory inside the partition in the fixed partition method.

Merge of free areas

Four relationships between the front and back adjacent partitions

The front and back adjacent partitions of the released partition are all allocated areas, and there is no problem of merging .

The front adjacent partition of the released partition is the free area, and the rear adjacent partition is the allocated area. The free area should be merged with the previous adjacent free area to form a new free area.

The front adjacent partition of the release area is the allocated area, and the rear adjacent partition is the free area. Therefore, the released partition should be merged with the adjacent free area to form a new free area.

The adjacent partitions before and after the release area are free areas. Therefore, the release area should be merged with the two adjacent free areas before and after to form a new free area.

Timing of merging free partitions

First, when a job is scheduled, if the size of each free area in the system is smaller than its needs, but the total storage capacity of the free area is greater than its storage request , so the free areas are merged to obtain a large free area to meet the needs of the job.

First, as long as the occupied storage area is returned after a job is run, the system will merge the free areas.

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