title: PC and CPU registers when context switching happens?
body: <p>According to this question: <a href="https://stackoverflow.com/questions/9876323/storing-and-retrieving-process-control-block">Storing and retrieving process control block</a></p>
  
  <p>PCB contains a lot of information and it is managed by the kernel (to avoid user access).</p>
  
  <p>But I have question about PC and CPU registers. Is Kernel save these values every time an instruction is executed or only in context switching process?</p>
  
  <p>Are PCBs linked list?</p>