Dynamic and Relocatable Partitions
Management of memory is hard and is very critical. You have to consider many things before you could decide what to do with the system you are working on. By doing so, you have to consider how much memory is available in the system and the optimization of memory during the job processing. Memory allocation has four types : the single-user system, fixed partitions, dynamic partitions and the relocatable dynamic partition. The process of a dynamic partition goes like this :
Dynamic Partitions
a. Job1 (100k) turnaround: 3
b. Job2 (10k) turnaround: 1
c. Job3 (35k) turnaround: 2 the memory size is 220k with allocated OS for 15k
d. Job4 (15k) turnaround: 1
e. Job5 (23k) turnaround: 2
f. Job6 (6k) turnaround: 1
g. Job7 (25k) turnaround: 1
h. Job8 (55k) turnaround: 2
i. Job9 (88k) turnaround: 3
j. Job10 (100k) turnaround: 3
In a dynamic partition, the main memory is partitioned. Jobs given memory requested when loaded. The method in allocating the job is first come, first serve. In this kind of memory management, the memory waste is comparatively small but the full memory utilization happens only on the first allocation of the jobs. And on the next allocation or at the second turnaround of the jobs, memory waste happens since the first jobs being allocated would be the basis of the second batch of jobs to be processed.
Snapshots of main memory as the jobs are submitted for processing and allocated space on the basis of the “first come, first serve”.
In this kind of memory management, the memory manager relocates programs and gathers all the empty blocks. It makes one block of memory large enough to accommodate some or all of the jobs waiting to get in. This kind of method is called compaction. Snapshots for the jobs as it apply relocatable dynamic partition:
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