[PATCH v2 0/4] sched/fair: Task placement biasing using uclamp

[Valentin Schneider <valentin.schneider@arm.com>]

Hi,

While uclamp restrictions currently only impacts schedutil's frequency
selection, it would make sense to also let it impact CPU selection in
asymmetric topologies. This would let us steer specific tasks towards
certain CPU capacities regardless of their actual utilization - I give a
few examples in patch 3.

The first two patches are just cleanups/renames, the meat of the thing is
in patches 3 and 4.

Note that this is in the same spirit as what Patrick had proposed for EAS
on Android [1]

[1]: https://android.googlesource.com/kernel/common/+/b61876ed122f816660fe49e0de1b7ee4891deaa2%5E%21

Revisions
=========

Changed in v2:

- Collect Reviewed-by

- Make uclamp_task_util() unconditionally use util_est (Quentin)
- Because of the above, move uclamp_task_util() to fair.c

- Split v1's 3/3 into
  - task_fits_capacity() tweak (v2's 3/4)
  - find_energy_efficient_cpu() tweak (v2's 4/4).

Cheers,
Valentin

Valentin Schneider (4):
  sched/uclamp: Make uclamp_util_*() helpers use and return UL values
  sched/uclamp: Rename uclamp_util_*() into uclamp_rq_util_*()
  sched/fair: Make task_fits_capacity() consider uclamp restrictions
  sched/fair: Make feec() consider uclamp restrictions

 kernel/sched/cpufreq_schedutil.c |  2 +-
 kernel/sched/fair.c              | 30 +++++++++++++++++++++++++++---
 kernel/sched/sched.h             | 22 +++++++++++-----------
 3 files changed, 39 insertions(+), 15 deletions(-)

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2.24.0