Question

In this lab, you will implement the priority scheduling algorithm based on the nice value for xv6.

1. Write a user level program nice.c that will accepts two arguments: pid and priority which will change the nice value of the process with process id pid to priority, i.e. nice pid priority.

Answer 1

#include<bits/stdc++.h>

using namespace std;

  

struct Process

{

int pid; // Process ID

int bt; // CPU Burst time required

int priority; // Priority of this process

};

  

// Function to sort the Process acc. to priority

bool comparison(Process a, Process b)

{

return (a.priority > b.priority);

}

  

// Function to find the waiting time for all

// processes

void findWaitingTime(Process proc[], int n,

int wt[])

{

// waiting time for first process is 0

wt[0] = 0;

  

// calculating waiting time

for (int i = 1; i < n ; i++ )

wt[i] = proc[i-1].bt + wt[i-1] ;

}

  

// Function to calculate turn around time

void findTurnAroundTime( Process proc[], int n,

int wt[], int tat[])

{

// calculating turnaround time by adding

// bt[i] + wt[i]

for (int i = 0; i < n ; i++)

tat[i] = proc[i].bt + wt[i];

}