drm-shim: Optimize handle allocation
What does this MR do and why?
drm-shim: Optimize handle allocation
I noticed that we were spending a *bunch* of time doing hashtable
lookups when trying to find a available "handle", making drm-shim
somewhat useless for draw-overhead profiling. Keeping track of the
last allocated handle to avoid re-searching for handles which are
probably still in use avoids that.
Signed-off-by: Rob Clark <robdclark@chromium.org>