title: Local memory and registers scale linearly with work group size - how to choose optimal size?
body: <p>My kernel's local memory and register usage scale linearly with work group size. Besides trial and error, are there guidelines for choosing the optimal work group size? I am targeting AMD hardware, where the maximum work group size is 256; should I try to maximize the number of work items in group, or does this risk reducing occupancy and creating register spilling?  </p>