[GIT PULL] timers/nohz updates for 3.12

[Frederic Weisbecker <fweisbec@gmail.com>]

Ingo,

Please pull the timers/nohz branch that can be found at:

git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks.git
	timers/nohz

It mostly contains fixes and full dynticks off-case optimizations. I believe that
distros want to enable this feature so it seems important to optimize the case
where the "nohz_full=" parameter is empty. ie: I'm trying to remove any performance
regression that comes with NO_HZ_FULL=y when the feature is not used.

This patchset improves the current situation a lot (off-case appears to be around 11% faster
with hackbench, although I guess it may vary depending on the configuration but it should be
significantly faster in any case) now there is still some work to do: I can still observe a
remaining loss of 1.6% throughput seen with hackbench compared to CONFIG_NO_HZ_FULL=n

Thanks,
	Frederic
---

Frederic Weisbecker (23):
      sched: Consolidate open coded preemptible() checks
      context_tracing: Fix guest accounting with native vtime
      vtime: Update a few comments
      context_tracking: Fix runtime CPU off-case
      nohz: Only enable context tracking on full dynticks CPUs
      context_tracking: Remove full dynticks' hacky dependency on wide context tracking
      context_tracking: Ground setup for static key use
      context_tracking: Optimize main APIs off case with static key
      context_tracking: Optimize guest APIs off case with static key
      context_tracking: Optimize context switch off case with static keys
      context_tracking: User/kernel broundary cross trace events
      vtime: Remove a few unneeded generic vtime state checks
      vtime: Fix racy cputime delta update
      context_tracking: Split low level state headers
      hardirq: Split preempt count mask definitions
      m68k: hardirq_count() only need preempt_mask.h
      vtime: Describe overriden functions in dedicated arch headers
      vtime: Optimize full dynticks accounting off case with static keys
      vtime: Always scale generic vtime accounting results
      vtime: Always debug check snapshot source _before_ updating it
      nohz: Rename a few state variables
      nohz: Optimize full dynticks state checks with static keys
      nohz: Optimize full dynticks's sched hooks with static keys


 arch/ia64/include/asm/Kbuild            |    1 +
 arch/m68k/include/asm/irqflags.h        |    2 +-
 arch/powerpc/include/asm/Kbuild         |    1 +
 arch/s390/include/asm/cputime.h         |    3 -
 arch/s390/include/asm/vtime.h           |    7 ++
 arch/s390/kernel/vtime.c                |    1 +
 include/linux/context_tracking.h        |  120 +++++++++++++++--------------
 include/linux/context_tracking_state.h  |   39 +++++++++
 include/linux/hardirq.h                 |  117 +----------------------------
 include/linux/preempt_mask.h            |  122 +++++++++++++++++++++++++++++
 include/linux/tick.h                    |   45 +++++++++--
 include/linux/vtime.h                   |   74 ++++++++++++++++--
 include/trace/events/context_tracking.h |   58 ++++++++++++++
 init/Kconfig                            |   28 +++++--
 kernel/context_tracking.c               |  128 ++++++++++++++++++-------------
 kernel/sched/core.c                     |    4 +-
 kernel/sched/cputime.c                  |   53 ++++---------
 kernel/time/Kconfig                     |    1 -
 kernel/time/tick-sched.c                |   56 ++++++--------
 19 files changed, 534 insertions(+), 326 deletions(-)