Idle changes for 3.8

Hello!

This patch series contains changes to RCU's interaction with idle. The individual patches are as follows:

1. Remove a layer of indirection to rcu_user_hooks_switch().
(Courtesy of Frederic Weisbecker.)
2. Update RCU_FAST_NO_HZ help text to remove the warning about
running on large systems.
3. Add "rcu_expedited" boot and sysfs parameters that cause the
kernel to substitute expedited primitives for the normal grace period primitives. (Courtesy of Antti P Miettinen.)
4. Fix a precedence error in cpu_needs_another_gp() that
surprisingly had no effect -- but clarity is good.
5. Fix grammar issue in RCU_USER_QS help text. (Courtesy of
Paul Gortmaker.)

Thanx, Paul

 b/arch/um/drivers/mconsole_kern.c |    2 +-
 b/include/linux/rcupdate.h        |    2 ++
 b/include/linux/sched.h           |    8 --------
 b/init/Kconfig                    |   15 +++++++--------
 b/kernel/ksysfs.c                 |   18 ++++++++++++++++++
 b/kernel/rcu.h                    |    2 ++
 b/kernel/rcupdate.c               |    3 +++
 b/kernel/rcutiny_plugin.h         |    5 ++++-
 b/kernel/rcutree.c                |   12 +++++++++---
 b/kernel/rcutree_plugin.h         |    7 +++++--
 b/kernel/sched/core.c             |    2 +-
 b/kernel/srcu.c                   |    8 +++++++-
 init/Kconfig                      |    6 +++---
 kernel/rcutree.c                  |    2 +-
 14 files changed, 63 insertions(+), 29 deletions(-)