MAIN MEMORY

MAIN MEMORY

1. CONTIGUOUS MEMORY ALLOCATION

   • Memory Protection
     • A phenomenon by which we control memory access rights on a computer.
     • The main aim of it is to prevent a process from accessing memory that has not been allocated to it.
   • Memory Allocation
     • - to assign each process to their own partition
     • -3 approaches :
       • i. First fit - The first hole that is big enough is allocated to program.
       • ii. Best fit - The smallest hole that is big enough is allocated to program.
       • iii. Worst fit - The largest hole that is big enough is allocated to program.
   • Fragmentation

2. SWAPPING

   • The process of bringing in each process in main memory, running it for a while and then putting back to the disk(backing store)

3. PAGING

   • A memory scheme that allows processes physical memory to be discontinued
   • Eliminates problems with fragmentation by allocating memory in equal sized blocks known as pages

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