I don&#x27;t mind the &quot;heaviness&quot; of Linux on the RPi but I cannot rely on its user-space interrupts for GPIO use from userland.  Instead, I have to write kernel software or give up on guarantees.  So far it hasn&#x27;t been much of a problem, but if I wanted to do more tightly timed things, I&#x27;d need to use a real-time OS.<p>Meanwhile, it&#x27;s nice having the support of lots of Linux software so it&#x27;s hard to justify switching to a non-real-time OS with much less support.<p>I&#x27;ve noticed, browsing the RPi forums, that people are disappointed that they can&#x27;t get real-time behavior from Raspbian.