The OS is a program that uses various data structures. Like
all programs in execution, you can determine the
performance and other behavior of the OS by inspecting its
state - the values stored in its data structures. In this
part of the assignment, we study some aspects of the
organization and behavior of a Linux system by observing
values of kernel data structures exposed through the /proc
virtual file system.
The /proc virtual file system:
Linux uses the /proc file system to collect information
from kernel data structures. The /proc implementation
provided with Linux can read many different kernel data
structures. If you cd to /proc on a Linux machine, you will
see a number of files and directories at that location.
Files in this directory subtree each corresponds to some
kernel data structure. The subdirectories with numeric
names contain virtual files with information about the
process whose process ID is the same as the directory name.
Files in /proc can be read like ordinary ASCII files. You
can open each file and read it using library routines such
as fgets() or fscanf(). The proc (5) manual page explains
the virtual files and their content available through
the /proc file system.
Requirements in detail:
In this part, you are asked to write a program to report
the behavior of the Linux kernel. Your program should run
in two different versions. The default version should print
the following values on stdout:
Processor type
Kernel version
The amount of memory configured into this computer
Amount of time since the system was last booted
A second version of the program should run continuously and
print lists of the following dynamic values (each value in
the lists is the average over a specified interval):
The percentage of time the processor(s) spend in
user mode, system mode, and the percentage of time the
processor(s) are idle
The amount and percentage of available (or free)
memory
The rate (number of sectors per second) of disk
read/write in the system
The rate (number per second) of context switches in
the kernel
The rate (number per second) of process creations
in the system
If your program (compiled executable) is called proc_parse,
running it without any parameter should print out
information required for the first version. Running it with
two parameters "proc_parse <read_rate> <printout_rate>"
should print out information required for the second
version. read_rate represents the time interval between two
consecutive reads on the /proc file system. printout_rate
indicates the time interval over which the average values
should be calculated. Both read_rate and printout_rate are
in seconds. For instance, proc_parse 2 60 should read
kernel data structures once every two seconds. It should
then print out averaged kernel statistics once a minute
(average of 30 samples). The second version of your program
doesn't need to terminate.
The purpose of this exercise is to benchmark file writing
and reading speed. This exercise is divided into two parts.
a). Write a file character by character such that the total
file size becomes approximately >10K. After writing close
the file handler, open a new stream and read the file
character by character. Record both times. Execute this
exercise at least 4 times
b). Create a buffer capable of storing 100 characters. Now
after generating the characters, first store them in the
buffer. Once the buffer is filled up, store all the
elements in the file. Repeat the process until the total
file size becomes approximately >10K.While reading read a
while line, store it in buffer and once buffer gets filled
up, display the whole buffer. Repeat the exercise at least
4 times with different size of buffer (50, 100, 150 ).
Records the times.
c). Do an analysis of the differences in times and submit
it in class.
can you explain in brief what is "r+" mode in a file... i
know that it si used to read and modify rhe existing
content.... but explalanation about the file pointer in "r+"
mode i wann to know???????????
Design a program which assigns values to the array
temperature. The program should then display the array with
appropriate column and row headings.
112
pgm to find number of words starting with capital letters
in a file(additional memory usage not allowed)(if a word
starting with capital also next letter in word is capital
cann't be counted twice)
what does keyword extern mean in a function declaration?
1
find out largest elemant of diagonalmatrix
108
What is a Genralised LInked List??
Please give a detailed explation of it..
85
why arithmetic operation cant be performed on a void pointer?
1
Write a program that accepts a string where multiple spaces
are given in between the words. Print the string ignoring
the multiple spaces.
Example:
Input: We Are Student
Output: "We Are Student"
271
How to delete a node from linked list w/o using collectons?
Did you received any Funny E-Mails from your Friends and like to share with rest of our friends? Yeah!! you can post that stuff 
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