title: How to avoid grab when using posix named semphore?
body: <p>I was troubled when using a posix named semphore in multi-processed.
  After I used <strong><em>sem_wait()</em></strong> in process A, and process A is in semphore context. while process B grab cpu from process A before the sempore is released,  and process B will keep waiting for the sempohore.
  I wonder if there is a mechanism such as <strong><em>priority reversal</em></strong> that can avoid the situation I mentioned in linux os.</p>
  
  <p>Thanks in advance!</p>