Quiz 2 - Memory Management in Operating System
(Answers are in bold blue)
1.
Which of the following types of binding takes place during runtime?
a.
Symbolic names to virtual addresses
b. Virtual to
physical addresses
c.
Both (a) and (b)
2.
Suppose the paging hardware with TLB has a 90 percent hit ratio. Page numbers
found in the TLB have a total access time of 100 nanoseconds. Those which are
not found there have a total access time of 200 nanoseconds. What is the effective
access time?
a.
100 nanoseconds
b. 110
nanoseconds
c.
190 nanoseconds
d.
200 nanoseconds
3.
If the page table is broken up in to pages, with an outer page-table to select
the correct inner table, we are using
a.
paged swapping
b.
inverted page table
c. multi-level
paging
d.
none of the above
4.
The total space required for an inverted page table is proportional to the number
of
a.
pages in the virtual memory
b.
pages * holes
c.
pages + overlays
d. page frames in
the physical memory
e.
none of the above
5.
A system that uses a paging virtual memory system will suffer from
a.
external fragmentation
b. internal
fragmentation
6.
Least Recently Used (LRU) Page Replacement Algorithm bases its decisions to
evict a page on
a.
future references
b. past
references that are organized via a stack structure
c.
references that have clean bit
7.
Consider a reference string ACDB, where Page A was referenced first, then Page
C was referenced in the next cycle, then other actions occurred (e.g., reading,
writing, updating bits), then Page D was referenced, and Page B was referenced
last. Consider for the given reference string the resulting reference bit (R )
and modified bit (M) for each page as follows: RA= 0, RC=
0, RD= 1, RB= 1, and the modified bit MA= 1, MC=
0, MD= 1, MB= 0. Which page out of the given reference
string would be the most appropriate to evict?
a.
Page A
b. Page C
c.
Page D
d.
Page B
8.
Which page replacement suffers from Belady anomaly?
a.
Least Recently Used
b. FIFO
c.
Second Chance
9.
Once the system detects thrashing, what can the system do to eliminate this
problem?
a.
Increase the number of CPU-bound jobs
b. Decrease the
degree of multiprogramming
c.
Install faster CPU
d.
None of the above
10.
In the paging virtual memory management system, let us consider program B with
10 pages. Each page is 16=24 bytes, and the variable b in program B has
the logical address 162. What is the virtual address of b in the representation
of (p,d), where p is the page number and d is the page offset?
a.
(10,4)
b.
(10,2)
c.
(16,2)
d.
(11,2)
e. invalid
address
**************
*Thanks
to Klara Nahrstedt, University of Illinois