[GIT PULL timers] Timer-wheel bandaids^Wcommits

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

Hello, Ingo,

This pull request contains latency bandaids^Woptimizations to the
timer-wheel code that are useful in conjunction with NO_HZ_FULL Kconfig
option.  These optimizations reduce the jiffy-by-jiffy looping in cases
where there is either zero or one timers in the timer wheel, which is
a common case for NO_HZ_FULL "worker" CPUs that run almost entirely
in usermode for a single task.

Each of these commits has at least two Reviewed-by, one Acked-by, and
one Tested-by tag, so they are ready for more extensive testing in -tip.

							Thanx, Paul

The following changes since commit 00e2bcd6d35f59fce7fa0e76e24d08f74c6a8506:

  clocksource: Timer-sun5i: Switch to sched_clock_register() (2014-01-19 13:23:23 +0100)

are available in the git repository at:

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

for you to fetch changes up to 6f089d0be7fef9705b3a7755b05d1092e772b910:

  timers: Make internal_add_timer() update ->next_timer if ->active_timers == 0 (2014-01-29 15:25:16 -0800)

----------------------------------------------------------------
Oleg Nesterov (1):
      timers: Make internal_add_timer() update ->next_timer if ->active_timers == 0

Paul E. McKenney (4):
      timers: Track total number of timers in list
      timers: Reduce __run_timers() latency for empty list
      timers: Reduce future __run_timers() latency for newly emptied list
      timers: Reduce future __run_timers() latency for first add to empty list

 kernel/timer.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)