cpu_stop: implement and use cpu_stop, take#2

Hello,

This is the second take of cpu_stop.  There have been only two minor
changes from the last take[L].

* work_buf initialization in stop_one_cpu_nowait() simplified.

* Comment to clarify active_balance_work synchronization added.

Peter, if you ack the series, I'll add refresh the patches w/ your ACK
and request pull into sched/core to Ingo.

This patchset contains the following four patches.

 0001-cpu_stop-implement-stop_cpu-s.patch
 0002-stop_machine-reimplement-using-cpu_stop.patch
 0003-scheduler-replace-migration_thread-with-cpu_stop.patch
 0004-scheduler-kill-paranoia-check-in-synchronize_sched_e.patch

The patches are against the current linux-2.6-tip/sched/core
(99bd5e2f245d8cd17d040c82d40becdb3efd9b69) and are available in the
following git tree.

  git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git cpu_stop

diffstat follows.

 Documentation/RCU/torture.txt |   10 
 arch/s390/kernel/time.c       |    1 
 drivers/xen/manage.c          |   14 -
 include/linux/rcutiny.h       |    2 
 include/linux/rcutree.h       |    1 
 include/linux/stop_machine.h  |   59 ++--
 kernel/cpu.c                  |    8 
 kernel/module.c               |   14 -
 kernel/rcutorture.c           |    2 
 kernel/sched.c                |  271 +++------------------
 kernel/sched_fair.c           |   48 ++-
 kernel/stop_machine.c         |  530 ++++++++++++++++++++++++++++++++----------
 12 files changed, 525 insertions(+), 435 deletions(-)

Thanks.

--
tejun

[L] http://thread.gmane.org/gmane.linux.kernel/976691