Why Operating System?

• Backbone of computer system

• Manages the computer’s memory and processes, as well as all of its software and hardware.

Introduction

• Docker

• xv6

What is Docker?

• The modern platform for high velocity innovation
• Docker has products that use operating system level virtualization to develop and deliver software in packages called containers
• Docker can run on any computer, on any infrastructure and in any cloud

What is xv6?

• A Unix-like operating system developed in MIT.

• xv6 is modern reimplementation of Sixth Edition Unix in ANSI C.

What helped us

• emacs editor (amidst the editor war between vi and emacs!)

• homebrew (it simplifies installation of software in macOS)

• Mercurial repository of the lab where we saved everything using ssh

Why Docker?

Features of Docker:

• Easy and Faster Configuration

• Increases productivity

• Application Isolation

• Services

• Security Management

Why xv6?

• It gives a good insight into Command Line Interface of Unix OS

• xv6 is modern reimplementation of Sixth Edition Unix in ANSI C

Scheduling processes by their priorities

• Added getpriority() and setpriority() and get_highest_priority() functions in proc.c file of xv6

• Added a test function testpriority() in usertests.c file of xv6 to implement our algorithm

The function

int get_highest_priority_proc(void)
{
  int highest_priority;
  int pid = 0;
  int hpid = -1;
  int rpid = 0;

  highest_priority=100;
  struct proc *p;
  for(p = ptable.proc; p < &ptable.proc[NPROC]; p++, pid++){
    if(p->state != RUNNABLE) {
      continue;
    }
    rpid = pid;
    if (highest_priority > p->priority) {
       highest_priority=p->priority;
       hpid = pid;
    }
  }
  return hpid > 0?hpid:rpid;
}

Docker Limitation

Mutliple images present in repository due to form command.

If repository breaks, Docker poses problem

What can be done?

We can keep track of images of Docker

Conclusion

• Docker environment poses some problems, some of which are difficult to comprehend

• Storage is difficult too

• Yet, it gives a good insight of the underlying important concepts of operating system beacuse it is well documented, fast and uses less resources