CS570 EXAM 2 WITH CORRECT
ANSWERS 2025
Addresses ( Correct answers ) • Logical
-Reference to a memory location independent of the current
assignment of data to memory
- Translation must be made to the physical address
• Relative
- Address expressed as a location relative to some known point
• Physical
- The absolute address or actual location in main memory
Paging ( Correct answers ) • Partition memory into small equal fixed-size
blocks and divide each process into the same size blocks
• The blocks of a process are called pages and the blocks of memory are
called frames
• Operating system maintains a page table for each process
- Contains the frame location for each page in the process
-Memory address consist of a page number and offset
within the page internal to program
Present Bit & Modify Bit in Page Table ( Correct answers ) •
A bit is needed to indicate
whether the page is in main memory or not
• Another bit, modify bit, is needed to indicate if the page has
been altered since it was
last loaded into main memory
• If no change has been made, the page does not have to be
written to the disk when it
needs to be swapped out
TLB (Translation Lookaside Buffer) ( Correct answers ) a high-speed cache
set up for page table entries
• Contains page table entries that have been most recently used
• Functions same way as a memory cache
• Given a virtual address, processor examines the TLB
• If page table entry is present (a hit), the frame number is retrieved and
the real
address is formed
• If page table entry is not found in the TLB (a miss), the page number is
used to index
GRADED
A+
the process page table
• First checks if page is already in main memory
- if not in main memory a page fault is issued
, • The TLB is updated to include the new page entry
Will determine whether the frame number will create a hit, miss, or page
fault
Page Size ( Correct answers ) • Large pages can be used for program
instructions
• Small pages can be used for threads
Segmentation ( Correct answers ) • Addressing consist of two
parts - a segment number and an offset
segmentation is similar to dynamic partitioning
•A bit is needed to determine if segment is already in main
memory
•Another bit is needed to determine if the segment has been
modified since it was
loaded in main
memory external to
program
Combined Paging
and Segmentation
( Correct answers )
• Paging is
transparent to the
programmer
•Paging eliminates
external
fragmentation
•Segmentation is
visible to the
programmer
•Segmentation
allows for growing
data structures,
modularity, and
support for sharing
and protection
•Each segment is
broken into fixed-
size pages
CHECK RUN TIME
PERFORMANCE
Fetch Policy ( Correct answers ) - Determines when a page should
be brought into memory
GRADED
-A+Demand paging only brings pages into main memory when a reference
is made to a location on the page
•Many page faults when process first started - Prepaging brings in more
pages than needed
•More efficient to bring in pages that reside contiguously on the disk
ANSWERS 2025
Addresses ( Correct answers ) • Logical
-Reference to a memory location independent of the current
assignment of data to memory
- Translation must be made to the physical address
• Relative
- Address expressed as a location relative to some known point
• Physical
- The absolute address or actual location in main memory
Paging ( Correct answers ) • Partition memory into small equal fixed-size
blocks and divide each process into the same size blocks
• The blocks of a process are called pages and the blocks of memory are
called frames
• Operating system maintains a page table for each process
- Contains the frame location for each page in the process
-Memory address consist of a page number and offset
within the page internal to program
Present Bit & Modify Bit in Page Table ( Correct answers ) •
A bit is needed to indicate
whether the page is in main memory or not
• Another bit, modify bit, is needed to indicate if the page has
been altered since it was
last loaded into main memory
• If no change has been made, the page does not have to be
written to the disk when it
needs to be swapped out
TLB (Translation Lookaside Buffer) ( Correct answers ) a high-speed cache
set up for page table entries
• Contains page table entries that have been most recently used
• Functions same way as a memory cache
• Given a virtual address, processor examines the TLB
• If page table entry is present (a hit), the frame number is retrieved and
the real
address is formed
• If page table entry is not found in the TLB (a miss), the page number is
used to index
GRADED
A+
the process page table
• First checks if page is already in main memory
- if not in main memory a page fault is issued
, • The TLB is updated to include the new page entry
Will determine whether the frame number will create a hit, miss, or page
fault
Page Size ( Correct answers ) • Large pages can be used for program
instructions
• Small pages can be used for threads
Segmentation ( Correct answers ) • Addressing consist of two
parts - a segment number and an offset
segmentation is similar to dynamic partitioning
•A bit is needed to determine if segment is already in main
memory
•Another bit is needed to determine if the segment has been
modified since it was
loaded in main
memory external to
program
Combined Paging
and Segmentation
( Correct answers )
• Paging is
transparent to the
programmer
•Paging eliminates
external
fragmentation
•Segmentation is
visible to the
programmer
•Segmentation
allows for growing
data structures,
modularity, and
support for sharing
and protection
•Each segment is
broken into fixed-
size pages
CHECK RUN TIME
PERFORMANCE
Fetch Policy ( Correct answers ) - Determines when a page should
be brought into memory
GRADED
-A+Demand paging only brings pages into main memory when a reference
is made to a location on the page
•Many page faults when process first started - Prepaging brings in more
pages than needed
•More efficient to bring in pages that reside contiguously on the disk
