title: How to figure out pipe buffer is full?
body: <p>I wonder there is a linux utility to report pipe buffer usage or not. </p>
  
  <p>When I use subprocess module of python, sometime the subprocess is blocked because OS pipe buffer becomes full. When it happens, I usually spend significant amount to time to reason the buffer is full by guessing. So, I want to know there is much easier way to find out OS pipe buffer is full. </p>
  
  <p>Thanks</p>