[GIT PULL rcu/next] Additional RCU commit for 3.15

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

Hello, Ingo,

And, if you are willing to take it, one late-breaking commit.  This one
was requested for 3.15 by Peter Zijlstra.  It is low risk because it adds
a new in-kernel API with minimal changes to the existing code.  Those
minimal changes are the addition of memory barriers and ACCESS_ONCE()
macro calls, neither of which should be able to break things.  This commit
has passed significant rcutorture testing, with these additional additions
to rcutorture slated for 3.16.  This commit has also been exposed to
-next testing.

This change is available in the git repository at:

  git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu.git rcu/next

for you to fetch changes up to 765a3f4fed708ae429ee095914a7897acb3a65bd:

  rcu: Provide grace-period piggybacking API (2014-03-20 17:12:25 -0700)

----------------------------------------------------------------
Paul E. McKenney (1):
      rcu: Provide grace-period piggybacking API

 include/linux/rcutiny.h | 10 ++++++++
 include/linux/rcutree.h |  2 ++
 kernel/rcu/tree.c       | 62 +++++++++++++++++++++++++++++++++++++++++++++----
 3 files changed, 70 insertions(+), 4 deletions(-)