[PATCH RFC tip/core/rcu 0/3] v1 RCU priority boosting

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

Hello!

This patch set is the first version of RCU priority boosting, consisting
of the following:

1.	Add RCU priority inversion testing to rcutorture.
2.	Move TINY_RCU grace-period processing from softirq to kthread
	to allow boosting.
3.	Implement RCU priority boosting for TINY_RCU.

This patch has the following shortcomings, and thus is not yet ready for
inclusion:

o	It does not yet include some restructuring of TREE_RCU that
	is required to make boosting practical.

o	It does not yet include boosting for TREE_RCU.

o	Documentation has not yet been updated.  In the meantime, it is
	important to note that the "rcu_kthread" process must have its
	priority set to at least SCHED_FIFO:2, given that rcutorture
	uses SCHED_FIFO:1 to do the testing.  This priority can be set
	using the new RCU_BOOST_PRIO kernel configuration parameter
	or by using the "chrt" command, for example, "chrt -p 2 6".

o	A great deal more testing is required.

o	There are probably quite a few bugs remaining, even in the parts
	done thus far.

							Thanx, Paul

 b/include/linux/init_task.h |    9 +
 b/include/linux/rcupdate.h  |    1 
 b/include/linux/rcutiny.h   |    8 -
 b/include/linux/rcutree.h   |    1 
 b/include/linux/sched.h     |   11 +
 b/init/Kconfig              |   39 ++++++
 b/kernel/rcutiny.c          |   71 +++++++++--
 b/kernel/rcutiny_plugin.h   |   15 +-
 b/kernel/rcutorture.c       |  270 ++++++++++++++++++++++++++++++++++++++++++--
 kernel/rcutiny.c            |   66 ++++------
 kernel/rcutiny_plugin.h     |  206 ++++++++++++++++++++++++++++++++-
 11 files changed, 608 insertions(+), 89 deletions(-)