Hi,
Paul E. McKenney paulmck@linux.vnet.ibm.com proposed some changes which will reduce the amount of "kfree only" rcu-callback functions. The batman-adv compatibility layer has to add a similar functionality to support older kernels.
I wanted to propose a solution which should be discussed before the kfree_rcu functionality enters Linus' kernel and our master branch.
The amount of kfree_rcu_* function was reduced to support only a maximum offset of 256 to any 'struct rcu_head' inside a struct. This should be enough for the current version and supported architectures. Offsets of 4096 are supported by Paul E. McKenney's implementation, but our workaround would increase the size of the final module too much (personal opinion).
~~~ These patches should *NOT* enter the batman-adv repo right now ~~~~~
Kind regards, Sven