[PATCH tip/core/rcu 0/7] Miscellaneous fixes for 4.10

[Paul E. McKenney]

Hello!

This series contains miscellaneous fixes to RCU:

1.	Tighten up __call_rcu's alignment check for the rcu_head structure
	now that no arch does two-byte alignment of pointers.

2.	Remove obsolete comment about when rcu_check_callbacks() was invoked.

3.	Remove obsolete comment about which function opportunistically
	notes grace periods beginnings and endings.

4.	Update the RCU_TRACE Kconfig option's help text to note that
	it enables event tracing in addition to debugfs, courtesy of
	Nikolay Borisov.

5.	Add event tracing for long read-side delays in rcutorture
	in order to better debug too-short grace periods.

6.	Make expedited grace periods recheck dyntick-idle state to avoid
	sending needless IPIs.

7.	Don't kick CPUs unless there is grace-period activity currently
	in progress.

							Thanx, Paul

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

 include/trace/events/rcu.h |    5 ++++-
 kernel/rcu/rcutorture.c    |   11 ++++++++++-
 kernel/rcu/tree.c          |   17 ++++++-----------
 kernel/rcu/tree.h          |    1 +
 kernel/rcu/tree_exp.h      |   12 +++++++++++-
 lib/Kconfig.debug          |    3 ++-
 6 files changed, 34 insertions(+), 15 deletions(-)