[PATCH 0/4] Optimize sched avg computation and implement flat util hierarchy

[Yuyang Du <yuyang.du@intel.com>]

This patch series takes an effort to implement a flat util hierarchy, in order to
reflect group task's migration immediately.

Simply doing so may increase overhead in computing sched averages, or lose
accuracy if only updating util of root cfs_rq.

So, to not add overhead or to even reduce it, we must optimize __update_load_avg()
greatly. Hopefully, these patches can achieve it.

---

Yuyang Du (4):
  sched/fair: Optimize sum computation with a lookup table
  sched/fair: Drop out incomplete current period when sched averages
    accrue
  sched/fair: Modify accumulated sums for load/util averages
  sched/fair: Implement flat hierarchical structure for util_avg

 include/linux/sched.h |   2 +-
 kernel/sched/debug.c  |  11 +-
 kernel/sched/fair.c   | 313 ++++++++++++++++++++++++--------------------------
 kernel/sched/sched.h  |   5 +-
 4 files changed, 163 insertions(+), 168 deletions(-)

-- 
2.1.4