Advantages and Disadvantages

Advantages :

Allocating memory is easy and cheap

Any free page is ok, OS can take first one out of list it keeps

Eliminates external fragmentation

Data (page frames) can be scattered all over PM

Pages are mapped appropriately anyway

Allows demand paging and prepaging

More efficient swapping

No need for considerations about fragmentation

Just swap out page least likely to be used

Disadvantages :

Longer memory access times (page table lookup)

Can be improved using TLB

Guarded page tables

Inverted page tables

Memory requirements (one entry per VM page)

Improve using Multilevel page tables and variable page sizes (super-pages)

Guarded page tables

Page Table Length Register (PTLR) to limit virtual memory size

Internal fragmentation