Modern Operating Systems by Herbert Bos ...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
Showing 209 out of 1137
Modern Operating Systems by Herbert...
Modern_Operating_Systems_by_Herbert_Bos_and_Andrew_S._Tanenbaum_4th_Ed.pdf-M ODERN O PERATING S YSTEMS
##### Page 209
178
CHAP. 2
(a) Round robin.
(b) Priority scheduling.
(c) First-come, first-served (run in order 10, 6, 2, 4, 8).
(d) Shortest job first.
For (a), assume that the system is multiprogrammed, and that each job gets its fair
share of the CPU.
For (b) through (d), assume that only one job at a time runs, until it
finishes. All jobs are completely CPU bound.
46.
A process running on CTSS needs 30 quanta to complete. How many times must it be
swapped in, including the very first time (before it has run at all)?
47.
Consider a real-time system with two voice calls of periodicity 5 msec each with CPU
time per call of 1 msec, and one video stream of periodicity 33 ms with CPU time per
call of 11 msec. Is this system schedulable?
48.
For the above problem, can another video stream be added and have the system still be
schedulable?
49.
The aging algorithm with
a
= 1/2 is being used to predict run times. The previous four
runs, from oldest to most recent, are 40, 20, 40, and 15 msec.
What is the prediction of
the next time?
50.
A soft real-time system has four periodic events with periods of 50, 100, 200, and 250
msec each. Suppose that the four events require 35, 20, 10, and
x
msec of CPU time,
respectively. What is the largest value of
x
for which the system is schedulable?
51.
In the dining philosophers problem, let the following protocol be used: An even-num-
bered philosopher always picks up his left fork before picking up his right fork; an
odd-numbered philosopher always picks up his right fork before picking up his left
fork. Will this protocol guarantee deadlock-free operation?
52.
A real-time system needs to handle two voice calls that each run every 6 msec and con-
sume 1 msec of CPU time per burst, plus one video at 25 frames/sec, with each frame
requiring 20 msec of CPU time. Is this system schedulable?
53.
Consider a system in which it is desired to separate policy and mechanism for the
scheduling of kernel threads. Propose a means of achieving this goal.
54.
In the solution to the dining philosophers problem (Fig. 2-47), why is the state variable
set to
HUNGRY
in the procedure
take
forks
?
55.
Consider the procedure
put
forks
in Fig. 2-47. Suppose that the variable
state
[
i
] was
set to
THINKING after
the two calls to
test
, rather than
before
.
How would this change
affect the solution?
56.
The readers and writers problem can be formulated in several ways with regard to
which category of processes can be started when. Carefully describe three different
variations of the problem, each one favoring (or not favoring) some category of proc-
esses. For each variation, specify what happens when a reader or a writer becomes
ready to access the database, and what happens when a process is finished.
57.
Write a shell script that produces a file of sequential numbers by reading the last num-
ber in the file, adding 1 to it, and then appending it to the file. Run one instance of the

Browse thousands of Study Materials & Solutions from your Favorite Schools
Concordia University
Concordia_University
School:
Operating_Systems
Course:
Great resource for chem class. Had all the past labs and assignments
Leland P.
Santa Clara University
Introducing Study Plan
Using AI Tools to Help you understand and remember your course concepts better and faster than any other resource.
Find the best videos to learn every concept in that course from Youtube and Tiktok without searching.
Save All Relavent Videos & Materials and access anytime and anywhere
Prepare Smart and Guarantee better grades