title: Using pthread_yield to return control over the CPU back to Kernel
body: <p>Consider the following scenario:
  in a POSIX system, some thread from a user program is running and timer_interrupt has been disabled. </p>
  
  <p>to my understanding, unless it terminates - the currently running thread won't willingly give away control over the CPU. 
  My question is as follows: will calling <strong>pthread_yield()</strong> from within the thread give the kernel control over the CPU? </p>
  
  <p>any kind of help with this question would be greatly appreciated.</p>