title: Doubly linked list of process control block in Operating Systems
body: <p>What is the reasoning behind maintaining doubly linked lists of PCB's(process control blocks) in an OS for scheduling. I have seen this mentioned multiple times for Real time operating systems.</p>
  
  <p>I would ideally go for a circular singly linked list , so that you could do a round robin and reach back to 1st task after looking to all. You could also sort it by priority...</p>
  
  <p>But, why a doubly linked list?</p>