[PATCH tip/core/rcu 0/4] RCU CPU stall warning updates for v4.15

[Paul E. McKenney]

Hello!

This series updates RCU CPU stall warnings, and also, due to conflicts,
pulls along a long-standing patch that allows cond_resched() to do the
work that cond_resched_rcu_qs() does.

1.	Make cond_resched() provide RCU quiescent state.  This has been
	heavily optimized over its lifetime, which is almost one year.
	It should be close enough.  Yes, some benchmarks show that it
	results in higher context-switch rates, but then again, the
	problem being solved is in fact too few context switches.  ;-)

2.	Make RCU CPU stall warnings check for irq-disabled CPUs.

3.	Turn off tracing before dumping traces.

4.	Suppress RCU CPU stall warnings while dumping RCU-related traces.

							Thanx, Paul

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

 include/linux/sched.h    |    3 -
 kernel/rcu/rcu.h         |   21 +++++++
 kernel/rcu/tree.c        |  129 +++++++++++++++++++++++++++++++++++------------
 kernel/rcu/tree.h        |    5 +
 kernel/rcu/tree_plugin.h |    7 ++
 kernel/rcu/update.c      |    1 
 kernel/sched/core.c      |    1 
 7 files changed, 132 insertions(+), 35 deletions(-)