20 Nov
2012
20 Nov
'12
6:19 a.m.
On Tue, Nov 6, 2012 at 9:31 PM, Thomas Hellstrom thellstrom@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.