title: do system calls execute inside a software interrupt handler in entirety?
body: <p>Do system calls execute in the context of a software interrupt handler in entirety?</p>
  
  <p>I mean, some system calls like read() could take a long time to return, against the policy that ISR should be very short in execution time. Are system calls offloaded to other threads? How does that work?</p>
  
  <p>[A reference to any kernel is fine]</p>