* Paul E. McKenney | 2014-12-03 13:19:11 [-0800]:

quoted

Is that not actually a bug indepedent of RT ? 
without the rcu_read_lock/unlock who says that the 
rcu_dereference is still valid at this point ? 
I though that if bh are already disabled you still
need the read_lock. disabled bh would allow to "downgrad" 
the rcu_read_lock_bh to rcu_read_lock but you still need it.

In vanilla kernels, anything that disables BH acts as rcu_read_lock_bh().
So yes, you can have cases where rcu_read_lock_bh() is needed only in
the -rt kernel.

But it won't hurt mainline using rcu_read_lock_bh() around
rcu_dereference_bh() right?
I am not going to apply this because that code is gone shortly after
v3.14 was released. The fm10k however does the same thing so atleast RCU
knows when to scream :)

						Thanx, Paul

Sebastian