Hi folks,
Here is this year's series of misfit changes. On the menu:
o Patch 1 is an independent active balance cleanup
o Patch 2 adds some more sched_asym_cpucapacity static branches
o Patch 3 introduces yet another margin for capacity to capacity
comparisons
o Patches 4-6 build on top of patch 3 and change capacity comparisons
throughout misfit load balancing
o Patches 7-8 fix some extra misfit issues I've been seeing on "real"
workloads.
IMO the somewhat controversial bit is patch 3, because it attempts to solve
margin issues by... Adding another margin. This does solve issues on
existing platforms (e.g. Pixel4), but we'll be back to square one the day
some "clever" folks spin a platform with two different CPU capacities less than
5% apart.
This is based on top of today's tip/sched/core at:
65bcf072e20e ("sched: Use task_current() instead of 'rq->curr == p'")
Cheers,
Valentin
Valentin Schneider (8):
sched/fair: Clean up active balance nr_balance_failed trickery
sched/fair: Add more sched_asym_cpucapacity static branch checks
sched/fair: Tweak misfit-related capacity checks
sched/fair: Use dst_cpu's capacity rather than group {min, max}
capacity
sched/fair: Make check_misfit_status() only compare dynamic capacities
sched/fair: Filter out locally-unsolvable misfit imbalances
sched/fair: Attempt misfit active balance when migration_type !=
migrate_misfit
sched/fair: Relax task_hot() for misfit tasks
kernel/sched/fair.c | 138 ++++++++++++++++++++++++++-----------------
kernel/sched/sched.h | 6 ++
2 files changed, 89 insertions(+), 55 deletions(-)
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2.27.0
