nohz_full: Offload task_tick to remote housekeeping cpus for nohz_full cpus

This patchset is for offloading task_tick() to a remote housekeeping cpu. The larger aim is to stop ticks on nohz_full cpus. For this, extra work must be done by housekeeping cpus. So, task_tick is called from a delayed workqueue for nohz_full cpus and the work is requeued every second for those nohz_full cpus whose ticks are stopped while they are busy. In the rest of the cases it will lead to redundant accounting. To facilitate this, a new function tick_nohz_remote_tick_stopped is added to indicate whether ticks are stopped on a remote cpu.
Tick related code in core.c is moved to tick.c

Vatika Harlalka (2):
nohz_full: Move tick related code to tick.c
nohz_full: Offload task_tick to remote housekeeping cpu

 include/linux/tick.h     |  2 ++
 kernel/sched/Makefile    |  2 +-
 kernel/sched/core.c      | 27 ---------------
 kernel/sched/tick.c      | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
 kernel/time/tick-sched.c |  5 +++
 5 files changed, 93 insertions(+), 28 deletions(-)
 create mode 100644 kernel/sched/tick.c

2.4.2