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Subject[PATCH 0/6 v5] sched: reflect sched_entity move into task_group's load
Ensure that the move of a sched_entity will be reflected in load and
utilization of the task_group hierarchy.

When a sched_entity moves between groups or CPUs, load and utilization
of cfs_rq don't reflect the changes immediately but converge to new values.
As a result, the metrics are no more aligned with the new balance of the
load in the system and next decisions will have a biased view.

This patchset synchronizes load/utilization of sched_entity with its child
cfs_rq (se->my-q) only when tasks move to/from child cfs_rq:
-move between task group
-migration between CPUs
Otherwise, PELT is updated as usual.

This version doesn't include any changes related to discussion that have
started during the review of the previous version about:
- encapsulate the sequence for changing the propoerty of a task
- remove a cfs_rq from list during update_blocked_averages
These topics don't gain anything from being added in this patchset as they
are fairly independent and deserve a separate patch.

Changes since v4:
- minor typo and commit message changes
- move call to cfs_rq_clock_task(cfs_rq) in post_init_entity_util_avg

Changes since v3:
- Replaced the 2 arguments of update_load_avg by 1 flags argument
- Propagated move in runnable_load_avg when sched_entity is already on_rq
- Ensure that intermediate value will not reach memory when updating load and
- Optimize the the calculation of load_avg of the sched_entity
- Fixed some typo

Changes since v2:
- Propagate both utilization and load
- Synced sched_entity and se->my_q instead of adding the delta

Changes since v1:
- This patch needs the patch that fixes issue with rq->leaf_cfs_rq_list
"sched: fix hierarchical order in rq->leaf_cfs_rq_list" in order to work
correctly. I haven't sent them as a single patchset because the fix is
independent of this one
- Merge some functions that are always used together
- During update of blocked load, ensure that the sched_entity is synced
with the cfs_rq applying changes
- Fix an issue when task changes its cpu affinity

Vincent Guittot (6):
sched: factorize attach entity
sched: fix hierarchical order in rq->leaf_cfs_rq_list
sched: factorize PELT update
sched: propagate load during synchronous attach/detach
sched: propagate asynchrous detach
sched: fix task group initialization

kernel/sched/core.c | 1 +
kernel/sched/fair.c | 359 +++++++++++++++++++++++++++++++++++++++++----------
kernel/sched/sched.h | 2 +
3 files changed, 292 insertions(+), 70 deletions(-)


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