CITS2002 Systems Programming  
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Initial Memory Allocation Using Partitioning, continued

Equal sized partitions introduce two problems:

  1. a process's requirements may exceed the partition size, and

  2. a small process still occupies a full partition. Such wastage of memory is termed internal memory fragmentation.

The initial choice of partition - the placement algorithm - is, of course, trivial with equal-sized partitions.

 

Unequal sized partitions offer obvious advantages with respect to these problems, but they complicate the placement algorithm. Either:

  1. a process is placed in the largest (large-enough) partition, to minimise internal memory fragmentation, or

  2. a process is placed in the smallest (large-enough) available partition.

The initial placement algorithm is again simple, but also introduces excessive internal memory fragmentation.

Example of Fixed Partitioning of a 64-Mbyte Memory

 

CITS2002 Systems Programming, Lecture 13, p5, 11th September 2023.