[PATCH tip/core/rcu 0/2] rcu: v2: more review feedback

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

This patchset applies the last of the review comments:

o	Whitespace fixes, updated comments, and code movement.

o	Improve an existing abstraction and introduce two additional
	abstractions for traversing the rcu_node tree.

Change since v1 (http://lkml.org/lkml/2009/9/27/17):

o	Update second patch's changelog

Issues remaining:

o	I can force hangs given sufficient rcutorture testing in
	conjunction with random CPU-hotplug operations.  I am working
	on a simpler interface between RCU and CPU hotplug that I
	believe will clear this up.

o	TREE_PREEMPT_RCU currently uses the TREE_RCU variant of
	synchronize_rcu_expedited, which is wrong.  I am working on
	an expedited variant for TREE_PREEMPT_RCU, but will fall
	back on synchronize_rcu() for the short term if it gives me
	much trouble.

o	The IPI hyperactivity from call_rcu() noted by Nick Piggin.
	I believe I have identified a clean design for a fix for this.

o	Make RCU less dependent on IPIs for forcing grace periods
	(but this might be best deferred to 2.6.33).

o	RCU priority boosting (2.6.33!).

o	TINY_PREEMPT_RCU (2.6.33!).

o	Squeeze another 400 bytes or so out of TINY_RCU (2.6.33!).


 b/include/linux/rcupdate.h |   14 +++++------
 b/kernel/rcutree.c         |   11 ++++-----
 b/kernel/rcutree.h         |   12 ++++++++++
 b/kernel/rcutree_plugin.h  |    5 ----
 kernel/rcutree.c           |   53 +++++++++++++++++++++++----------------------
 5 files changed, 52 insertions(+), 43 deletions(-)