Comparing capacity extrema of local and source sched_group's doesn't make much sense when at the day of the day the imbalance will be pulled by a known env->dst_cpu, whose capacity can be anywhere within the local group's capacity extrema.
Replace group_smaller_{min, max}_cpu_capacity() with comparisons of the source group's min/max capacity and the destination CPU's capacity. Signed-off-by: Valentin Schneider <valentin.schnei...@arm.com> --- kernel/sched/fair.c | 31 +++---------------------------- 1 file changed, 3 insertions(+), 28 deletions(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 58ce0b22fcb0..0959a770ecc0 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -8352,26 +8352,6 @@ group_is_overloaded(unsigned int imbalance_pct, struct sg_lb_stats *sgs) return false; } -/* - * group_smaller_min_cpu_capacity: Returns true if sched_group sg has smaller - * per-CPU capacity than sched_group ref. - */ -static inline bool -group_smaller_min_cpu_capacity(struct sched_group *sg, struct sched_group *ref) -{ - return capacity_greater(ref->sgc->min_capacity, sg->sgc->min_capacity); -} - -/* - * group_smaller_max_cpu_capacity: Returns true if sched_group sg has smaller - * per-CPU capacity_orig than sched_group ref. - */ -static inline bool -group_smaller_max_cpu_capacity(struct sched_group *sg, struct sched_group *ref) -{ - return capacity_greater(ref->sgc->max_capacity, sg->sgc->max_capacity); -} - static inline enum group_type group_classify(unsigned int imbalance_pct, struct sched_group *group, @@ -8523,15 +8503,10 @@ static bool update_sd_pick_busiest(struct lb_env *env, if (!sgs->sum_h_nr_running) return false; - /* - * Don't try to pull misfit tasks we can't help. - * We can use max_capacity here as reduction in capacity on some - * CPUs in the group should either be possible to resolve - * internally or be covered by avg_load imbalance (eventually). - */ + /* Don't try to pull misfit tasks we can't help */ if (static_branch_unlikely(&sched_asym_cpucapacity) && sgs->group_type == group_misfit_task && - (!group_smaller_max_cpu_capacity(sg, sds->local) || + (!capacity_greater(capacity_of(env->dst_cpu), sg->sgc->max_capacity) || sds->local_stat.group_type != group_has_spare)) return false; @@ -8615,7 +8590,7 @@ static bool update_sd_pick_busiest(struct lb_env *env, */ if (sd_has_asym_cpucapacity(env->sd) && (sgs->group_type <= group_fully_busy) && - (group_smaller_min_cpu_capacity(sds->local, sg))) + (capacity_greater(sg->sgc->min_capacity, capacity_of(env->dst_cpu)))) return false; return true; -- 2.27.0