title: Forcing Renderscript to run on CPU or GPU (Atleast for performance tuning purposes)
body: <p>I have a few <strong>basic</strong> algorithms (DCT/IDCT and a few others) ported and working (as expected atleast functionally) on Nexus 10. Since these algorithms are first implementations, their execution time is currently running into secs, which is understandable. </p>
  
  <p>However, given the architecture of Renderscript, I see that these algorithms run either on CPU or GPU depending on other parallel application activities. For instance, in my application, there is a scrollview for images and any activity on this view, essentially pushes the renderscript execution to CPU. If there is no activity the algorithm runs on GPU. I see this live via ARM-DS5 Mali/A15 traces.</p>
  
  <p>This situation is presenting itself as debug/tuning nightmare, since the performance delta when the algorithm runs on CPU (dual core) versus GPU (Mali) is of the order of 2 secs, making it very difficult to gauge the performance improvements that I am doing on my algorithm code.</p>
  
  <p>is there a way to get around this problem? One possible solution is to atleast have a debug configurability option to choose the target type (ARM, GPU) for renderscript code?</p>