HASHED PAGE TABLE

• Hashed page table handles the  address spaces > 32 bits.
• The virtual page number is used as  hash value into a page table.
• Linked List is used in the Hash table.
• This page table contains a chain of elements hashing to the same location.
• Each element in the hash table contains following fields

1.     Virtual page number
2.     Mapped page frame value
3.     Pointer to the next element in the linked list

• Virtual page number is taken from virtual address
• Virtual page number is hashed into the hash table.
• Virtual page number is compared with the first element of linked list.
• If both the value matches,that value(page frame) is used for calculating physical address.
• If both values does not match,the entire linked list is searched for a matching.
• Virtual page numbers are compared in this chain searching for a match
• If a match is found, the corresponding physical frame is extracted

 logical address(p,d)---->hash function---->hash table(p,r)----->physical address(r,d)---->physical memory