Operating Systems (OS) interview quiz questions with answers
Operating Systems Questions TRUE/FALSE with Answers – 11
1. In disk scheduling, the SSTF (shortest seek time first) algorithm can lead to starvation.
(a) TRUE (b)
FALSE
Answer: TRUE.
This
algorithm selects the request with minimum seek time from the current head
position. That means the closest request will be serviced first. If new
request arrives at the nearest head position continuously, then those
requests which are far away will never serviced and they has to stay in a
waiting state. Thus lead to starvation.
Disadvantages of SSTF
--
It may cause starvation for some requests.
--
Switching direction on the frequent basis slows the working of algorithm.
--
It is not an optimal algorithm
|
2. The more cache memory the machine has, better the performance it provides.
(a) TRUE (b)
FALSE
Answer: TRUE.
Cache
is a small memory which is a part of CPU and physically close to the CPU than
Random Access Memory. It holds frequently used instructions or data which the
processor may require next. Since cache is on the same chip as the processor
and it can hold data for execution by the CPU, more cache memory leads to
better performance.
In modern computers, cache size may vary from 1 – 2 MB (in L1 cache), 256 KB – 8 MB (in L2 cache), 4 – 40 MB (in L3 cache) |
3. In OS memory management, page sizes are always power of 2.
(a) TRUE (b)
FALSE
Answer: TRUE.
Paging
is executed by breaking up an address into a page and offset number. It is
most competent to break the address into X page bits and Y offset bits rather
than perform arithmetic on the address to compute the page number and offset.
For the reason that each bit position represents a power of 2 splitting an
address between bits results in a page size that is a power of 2.
|
4. Switching among threads in the same process is more efficient than switching among processes.
(a) TRUE (b)
FALSE
Answer: TRUE.
During
the thread switch, the virtual memory space remains the same. During the
process switch, it is not, which makes it expensive.
--
Process
switching is context switching from one process to a different
process. It involves switching out all of the process abstractions and
resources in favor of those belonging to a new process. Most notably and
expensively, this means switching the memory address space.
--
Thread
switching is context switching from one thread to another in the same process. Thread
switching is cheaper, as it involves switching out only the abstraction
unique to threads: The processor state. The cost of thread-to-thread
switching is about the same as the cost of entering and exiting the kernel.
On systems such as Linux, that is very cheap.
|
5. Using mutual exclusion ensures that a system avoids deadlock.
(a)
TRUE (b) FALSE
Answer: FALSE.
Mutual exclusion is one of the four conditions that cause deadlocks. |
**********************
No comments:
Post a Comment