Hello! This series contains various fixes for NO_HZ and NO_HZ_FULL problems, including re-enabling the tick during long-term kernel-mode execution. 1. Add TICK_DEP_BIT_RCU (which allows RCU-specific tick re-enabling), courtesy of Frederic Weisbecker. 2. Export tick start/stop functions for rcutorture. 3. Force on tick when invoking lots of callbacks. 4. Force on tick for rcutorture readers and callback flooders. 5. Provide RCU quiescent state in multi_cpu_stop(). 6. Make CPU-hotplug removal operations enable tick. 7. Use {READ,WRITE)_ONCE() for multi_cpu_stop() ->state. 8. Force tick on for nohz_full CPUs not reaching quiescent states. 9. Force nohz_full tick on upon irq enter instead of exit. 10. Reset CPU hints when reporting a quiescent state, courtesy of Joel Fernandes. 11. Confine ->core_needs_qs accesses to the corresponding CPU. 12. Make kernel-mode nohz_full CPUs invoke the RCU core processing. Thanx, Paul ------------------------------------------------------------------------ include/linux/rcutree.h | 1 include/linux/tick.h | 7 ++ include/trace/events/timer.h | 3 - kernel/rcu/rcutorture.c | 20 +++++--- kernel/rcu/tree.c | 105 ++++++++++++++++++++++++++++++------------- kernel/rcu/tree.h | 1 kernel/stop_machine.c | 7 +- kernel/time/tick-sched.c | 11 ++++ 8 files changed, 114 insertions(+), 41 deletions(-)