title: All CUDA devices are used for display: Can not debug my CUDA-code from within desktop environment
body: <p>since last week I got a big problem with my CUDA-development setup. I have an integrated GPU which I attached my monitors too and an extra NVIDIA Card for running my CUDA kernels on. 
  However, i can not debug my code anymore, because it says:</p>
  
  <pre><code>fatal:  All CUDA devices are used for display and cannot be used while debugging. (error code = CUDBG_ERROR_ALL_DEVICES_WATCHDOGGED(0x18)
  </code></pre>
  
  <p>Somehow it seems that my X-Server is blocking my NVIDIA GPU because if I switch to another virtual console (CTRL+ALT+F1) I am able to run my code using cuda-gdb. No monitor cable is plugged into the NVIDIA-card...</p>
  
  <p>"lsof /dev/nvidia*" does not give any output. I am using Xubuntu 14.04.</p>
  
  <p>Does anyone have an idea how to solve this problem?</p>