Merge branches 'barrier.2012.04.26a', 'fixes.2012.04.26a', 'inline.2012.04.25a' and 'srcu.2012.04.30a' into dev3.5-2012.04.30a
These branches are as follows:
barrier.2012.04.26a: Make rcu_barrier() less disruptive to the rest of
the system by avoiding interrupting CPUs having no callbacks.
Due to dependencies among commits, this branch also contains
fixes and improvements to the new version of RCU_FAST_NO_HZ.
fixes.2012.04.26a: Miscellaneous fixes.
inline.2012.04.25a: Make preemptible RCU's __rcu_read_lock() be
inlinable.
srcu.2012.04.30a: Direct algorithmic SRCU implementation, including
call_srcu() and srcu_barrier(). Due to conflicts among
commits, all changes to rcutorture are on this branch.
