Wipro interview 1995

Wipro Infotech

FIRST INTERVIEW:

(First the interviewer asked me to name two favorite subjects - OS and Networks)

a) Describe the memory management policies in Unix. How is paging
implemented? How page faults are handled?
Seems to be a favorite question for these chaps ---- Maurice Bach.

b) Write a macro in C for swapping two nibbles in a byte.
-Use the shift operators and be careful while defining temporary
variables( if you do so) as you have to write a macro. Otherwise
it is pretty simple.

c) What is the CPU-scheduling policy in Unix? - Round robin scheduling
with multilevel queues.

d) Diffrence between short term, long term and medium term scheduler.
-First two should be peaceful. The last one is also known as
swapper. (See Taenenbaum and/or Peterson)

e) Name various page-replacement policies. Which can be implemented
both with and without pre-emption? - see Peterson.

f) Describe the Sliding window protocol. What is it's advantage
over stop-and-wait? - Saves bandwidth. (Taenenbaum please)


SECOND INTERVIEW
(Both personal and technical interleaved)

a) Tell us something about yourself.
b) Aren't you going for higher studies abroad? Why?
c) Rank and CGPA. MSites do not have ranks but still they wanted to
know my approx position in my batch.
- Shady question. It is your job to convince them that for
MS, grades do not hold any meaning.

d) What is re-entrant code? --- Non-self modifying code. Can be
shared by many processes simultaneously. Gave e.g. of text-editors
like 'vi'.
Counter Q: But then no code modifies itself. What does 'non-self
modifying' mean? ---- I don't know for sure.

e) Diff between compilers and interpreters. Some fundaes about
how to link code in different files.

f) What would your friends tell us about you if we ask them?
Standard question for everyone.