[PATCH v2 0/1] Fix lb_imbalance reporting in /proc/schedstat

[Swapnil Sapkal <swapnil.sapkal@amd.com>]

This patch adds new fields to /proc/schdstat. First version of
the patch is sent here [1]. This patch goes on top of the
commit d72cf62438d6 ("sched/balancing: Fix a couple of outdated function names in comments")
from tip/sched/core. This change is intended to be a part of v16 of
/proc/schedstat.

v1 --> v2 change:
  - Added links to previous schedstat documentation
  - Incorporated review comments by Shrikanth Hegde

Motivation:

In /proc/schedstat, lb_imbalance reports the sum of imbalances
discovered in sched domains with each call to sched_balance_rq(), which is
not very useful because lb_imbalance does not mention whether the imbalance
is due to load, utilization, nr_tasks or misfit_tasks. Remove this field
from /proc/schedstat.

Currently there is no field in /proc/schedstat to report different types
of imbalances. Introduce new fields in /proc/schedstat to report the
total imbalances in load, utilization, nr_tasks or misfit_tasks.

[1] https://lore.kernel.org/lkml/66f1e42c-9035-4f9b-8c77-976ab50638bd@amd.com/

Swapnil Sapkal (1):
  sched: Report the different kinds of imbalances in /proc/schedstat

 Documentation/scheduler/sched-stats.rst | 119 ++++++++++++++----------
 include/linux/sched/topology.h          |   5 +-
 kernel/sched/fair.c                     |  21 ++++-
 kernel/sched/stats.c                    |   7 +-
 4 files changed, 98 insertions(+), 54 deletions(-)

-- 
2.34.1