Presentation gate Advanced Microprocessors and Microcontrollers

Memory Management

,Goals of Memory Management

 Allocate available memory efficiently to
multiple processes
 Main functions
 Allocate memory to processes when needed
 Keep track of what memory is used and what is
free
 Protect one process’s memory from another

,Memory Allocation
 Contiguous Allocation
 Each process allocated a single contiguous chunk
of memory
 Non-contiguous Allocation
 Parts of a process can be allocated non-
contiguous chunks of memory

In this part, we assume that the entire process
needs to be in memory for it to run

, Contiguous Allocation
 Fixed Partition Scheme
 Memory broken up into fixed size partitions
 But the size of two partitions may be different
 Each partition can have exactly one process
 When a process arrives, allocate it a free partition
 Can apply different policy to choose a partition
 Easy to manage
 Problems:
 Maximum size of process bound by max. partition size
 Large internal fragmentation possible