Merge branches 'rcu/torture', 'rcu/fixes', 'rcu/docs', 'rcu/refscale', 'rcu/tasks...

rcu/torture: RCU torture, locktorture and generic torture infrastructure
rcu/fixes: Generic and misc fixes
rcu/docs: RCU documentation updates
rcu/refscale: RCU reference scalability test updates
rcu/tasks: RCU tasks updates
rcu/stall: Stall detection updates

diff --cc Documentation/RCU/Design/Memory-Ordering/TreeRCU-gp.svg
Simple merge

diff --cc Documentation/admin-guide/kernel-parameters.txt
Simple merge

diff --cc kernel/rcu/rcu.h
Simple merge

diff --cc kernel/rcu/rcutorture.c
Simple merge

diff --cc kernel/rcu/tasks.h
Simple merge

diff --cc kernel/rcu/tree.c
Simple merge