[PATCH 3/4] drm/ttm, drm/vmwgfx: Use RCU locking for object lookups v3

[Dave Airlie]

On Tue, Nov 6, 2012 at 9:31 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
> The mostly used lookup+get put+potential_destroy path of TTM objects
> is converted to use RCU locks. This will substantially decrease the amount
> of locked bus cycles during normal operation.
> Since we use kfree_rcu to free the objects, no rcu synchronization is needed
> at module unload time.

As this is the first use of RCU in a drm driver from what I can see,
let me remind that the
RCU patent agreement AFAIK only covers GPL works.

So non-GPL or other OSes porting this code should take not of this.

Dave.