This is v5 of patch 2/2 which is adding code to prevent
the tick from being stopped when the single running task
has bandwidth limits. Discussions had led to the idea of
adding a bit to task_struct to help make this decision.

There was some complexity with doing it in the task which
is  avoided by using something in the cfs_rq. Looking 
into that lead me to the hierarchical_quota field in the 
cfs_bandwith struct. We spend a good deal of effort
updating (or trying to, see patch 1/2) that value for
the whole task_group tree when a quota is set/changed.

This new version first fixes that value to be meaningful
for cgroupv2 and then leverages it to make the decisions
about blocking the tick_stop. 

Phil Auld (2):
  sched, cgroup: Restore meaning to hierarchical_quota
  Sched/fair: Block nohz tick_stop when cfs bandwidth in use

 kernel/sched/core.c     | 23 ++++++++++++++---
 kernel/sched/fair.c     | 56 ++++++++++++++++++++++++++++++++++++++---
 kernel/sched/features.h |  2 ++
 kernel/sched/sched.h    |  3 ++-
 4 files changed, 76 insertions(+), 8 deletions(-)

-- 
2.31.1