[PATCH tip/core/rcu 0/12] RCU Kconfig fixes for v4.2

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

Hello!

This patch series reduces the number of questions that RCU asks Kconfig
users.  After this series is applied, removing the RCU-related definitions
from .config and running "make oldconfig" results in only the following:

RCU Implementation
> 1. Tree-based hierarchical RCU (TREE_RCU) (NEW)
choice[1]: 1
Make expert-level adjustments to RCU configuration (RCU_EXPERT) [N/y/?] (NEW)

Those expert users wishing to tune RCU answer Y to this question.

The patches in this series are as follows:

1.	Drive TASKS_RCU directly from Kconfig, for example, by having
	RCU_TORTURE_TESTS select it.

2.	Remove CONFIG_TASKS_RCU=y from the three TASKS_RCU test
	scenarios, since this is set by virtue of having rcutorture
	configured.

3.	Drive RCU_USER_QS directly from Kconfig, relying on the fact
	that NO_HZ_FULL selects it.

4.	Convert CONFIG_RCU_FANOUT_EXACT to a boot parameter, where it
	is used by rcutorture.

5.	Update rcutorture test scenarios to use the boot parameter
	created in #4 instead of the Kconfig parameter.

6.	Create a boot parameter to do a diagnostic dump of the shape
	of the rcu_node combining tree, which is useful for verifying
	that intended changes to that tree actually happened.

7.	Create an RCU_EXPERT Kconfig parameter and hide the
	RCU_FAST_NO_HZ, RCU_BOOST, CONTEXT_TRACKING_FORCE, and
	RCU_NOCB_CPU boolean parameters behind it.

8.	Make rcutorture test scenarios force RCU_EXPERT, but have
	SRCU-P, TASKS03, and TREE09 retain !RCU_EXPERT in order to
	test the vanilla configuration.

9.	Remove the dependency of RCU_FANOUT_LEAF on RCU_FANOUT.

10.	Change RCU to allow it to tolerate an undefined RCU_FANOUT,
	and then hide RCU_FANOUT behind RCU_EXPERT.

11.	Change RCU to allow it to tolerate an undefined RCU_FANOUT_LEAF,
	and then hide RCU_FANOUT_LEAF behind RCU_EXPERT.

12.	Change RCU to allow it to tolerate an undefined RCU_KTHREAD_PRIO,
	and then hide RCU_KTHREAD_PRIO behind RCU_EXPERT.

							Thanx, Paul

------------------------------------------------------------------------

 b/Documentation/kernel-parameters.txt                          |   11 +
 b/init/Kconfig                                                 |   62 ++++------
 b/kernel/rcu/tree.c                                            |   50 ++++++--
 b/kernel/rcu/tree.h                                            |   29 ++++
 b/kernel/rcu/tree_plugin.h                                     |   14 +-
 b/lib/Kconfig.debug                                            |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/SRCU-N        |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS01       |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS02       |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TASKS03       |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE01        |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE02        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE02-T      |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE03        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE04        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE05        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE06.boot   |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE07        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08        |    2 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T      |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08-T.boot |    1 
 b/tools/testing/selftests/rcutorture/configs/rcu/TREE08.boot   |    1 
 23 files changed, 127 insertions(+), 65 deletions(-)