[PATCH RFC 0/3] Fix cpuidle_idle_call() RCU usage

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

Hello!

This patch series is a second attempt to fix the idle-loop uses of RCU,
see https://lkml.org/lkml/2012/2/1/741 for v1.  Where the first series
attempted to drive rcu_idle_enter() and rcu_idle_exit() further down
into the Linux kernels multitude of idle loops, this patch instead
marks specific idle-loop operations containing RCU read-side critical
sections, as suggested by Nicolas Pitre and Steven Rostedt.  The possibility
of code shared between idle and non-idle also requires the ability to nest
rcu_idle_enter() calls.  The individual patches are as follows:

1.	Allow nesting of rcu_idle_enter() and rcu_idle_exit().
2.	Add an RCU_NONIDLE() macro to enclose idle-loop code that
	contains RCU read-side critical sections.
3.	Use RCU_NONIDLE() to protect cpuidle_idle_call()'s tracepoints.

This patchset has the distinct advantage of avoiding touching any
architecture-specific code.  ;-)

							Thanx, Paul

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

 b/drivers/cpuidle/cpuidle.c |   12 ++++++++----
 b/include/linux/rcupdate.h  |   27 +++++++++++++++++++++++++++
 b/kernel/rcu.h              |   18 +++++++++++++++++-
 b/kernel/rcutiny.c          |   16 ++++++++++++----
 b/kernel/rcutree.c          |   19 +++++++++++++------
 kernel/rcutiny.c            |    2 ++
 kernel/rcutree.c            |    2 ++
 7 files changed, 81 insertions(+), 15 deletions(-)