CPRE 308 EXAM 2 study || with Error-free Answers.
Where are page tables stored? correct answers physical memory
Page-table base register (PTBR) correct answers points to the page table
Page-table length register (PTLR) correct answers indicates size of the page table
What is a page table? correct answers An internal data structure that is used to translate virtual
addresses into corresponding physical addresses.
What is used as the index for the page table? correct answers VPN
This value stays the same in VPN and PFN correct answers Offset
Valid bit correct answers indicates whether the particular translation is valid
protection bits correct answers indicating whether the page could be read from, written to, or
executed from
Present bit correct answers indicates whether this page is in physical memory or on
disk(swapped out)
Dirty bit correct answers indicating whether the page has been modified since it was brought into
memory
reference bit correct answers indicating that a page has been accessed.
Shared Pages correct answers One page in the physical memory is mapped to the address spaces
of multiple processes.
, Page fault correct answers requested page is not in memory
Translation Lookaside Buffer (TLB) correct answers a hardware cache of popular virtual-to-
physical address translations.
How does a TLB work? correct answers check if page number is in associative register. If it is
get corresponding PFN next to it. Otherwise use page table to get PFN
TLB hit correct answers one memory access. (found it in TLB)
TLB miss correct answers 2 memory accesses ( looked up on TLB didn't find, found on page-
table)
temporal locality correct answers An instruction or data item that has been recently accessed will
likely be re-accessed soon in the future.
Spatial Locality correct answers if a program accesses memory at address x, it will likely soon
access memory near x
multi-level page table correct answers Chop up the page table into page-sized units. If an entire
page of page-table entries is invalid, don't allocate that page of the page table at all.
page directory correct answers to track whether a page of the page table is valid. a number of
page directory entries. NOTE: THIS IS A STRUCT. Basically, hold all page tables kinda like a
lookup.
page directory index correct answers Used to identify a page directory entry (PDE) in the page
directory. (First part of page number in VPN)
Where are page tables stored? correct answers physical memory
Page-table base register (PTBR) correct answers points to the page table
Page-table length register (PTLR) correct answers indicates size of the page table
What is a page table? correct answers An internal data structure that is used to translate virtual
addresses into corresponding physical addresses.
What is used as the index for the page table? correct answers VPN
This value stays the same in VPN and PFN correct answers Offset
Valid bit correct answers indicates whether the particular translation is valid
protection bits correct answers indicating whether the page could be read from, written to, or
executed from
Present bit correct answers indicates whether this page is in physical memory or on
disk(swapped out)
Dirty bit correct answers indicating whether the page has been modified since it was brought into
memory
reference bit correct answers indicating that a page has been accessed.
Shared Pages correct answers One page in the physical memory is mapped to the address spaces
of multiple processes.
, Page fault correct answers requested page is not in memory
Translation Lookaside Buffer (TLB) correct answers a hardware cache of popular virtual-to-
physical address translations.
How does a TLB work? correct answers check if page number is in associative register. If it is
get corresponding PFN next to it. Otherwise use page table to get PFN
TLB hit correct answers one memory access. (found it in TLB)
TLB miss correct answers 2 memory accesses ( looked up on TLB didn't find, found on page-
table)
temporal locality correct answers An instruction or data item that has been recently accessed will
likely be re-accessed soon in the future.
Spatial Locality correct answers if a program accesses memory at address x, it will likely soon
access memory near x
multi-level page table correct answers Chop up the page table into page-sized units. If an entire
page of page-table entries is invalid, don't allocate that page of the page table at all.
page directory correct answers to track whether a page of the page table is valid. a number of
page directory entries. NOTE: THIS IS A STRUCT. Basically, hold all page tables kinda like a
lookup.
page directory index correct answers Used to identify a page directory entry (PDE) in the page
directory. (First part of page number in VPN)
